Medical subassembly and medical assembly comprising the same

Abstract

The present invention relates to a medical subassembly (1) for releasable and rotationally stable anchorage within a bone part if the medical subassembly (1) is in use. As a result of an internal construction of an elongated housing member (41) of the medical subassembly (1) and as a result of ways in which an elongated expansion member (2) and an elongated actuator member (33) are arrangeable with respect to each other and with respect to the elongated housing member (41), the medical subassembly (1) has an improved sustainability and an increased application range compared to known medical devices in the field. The invention also relates to a medical assembly (100) that is suitable for fixation of bone parts that are separated by a gap. The medical assembly (100) comprises the medical subassembly (1) according to the invention.

Description

[0001] MEDICAL SUBASSEMBLY AND MEDICAL ASSEMBLY COMPRISING THE SAME

[0002] FIELD OF THE INVENTION

[0003] The present invention relates to a medical subassembly for releasable and rotationally stable anchorage within a bone part if the medical subassembly is in use. The invention also relates to a medical assembly that is suitable for fixation of bone parts that are separated by a gap. The medical assembly comprising the medical subassembly according to the invention.

[0004] BACKGROUND OF THE INVENTION

[0005] Medical devices for fixation of bone parts that are separated by a gap, which can be a result of a bone fracture, are known in the art. Said medical devices may be used for treating any type of bone fractures, e.g. femoral neck fractures or intertrochanteric fractures. Femoral neck fractures may be treated with pinning or hip arthroplasty, depending on the age of the patient, which can be human or animal, and the presence and degree of displacement. Intertrochanteric fractures may be treated with a sliding hip screw or an intramedullary hip screw, depending on the stability and location of the fracture.

[0006] EP 1 937 172 A1 discloses a medical device that can be used for positioning bone parts or for connecting stabilizing means to bone parts on either side of a joint so as to immobilize the intermediate joint, which device is sufficiently rigid for transmitting loads being exerted on the bone parts as a result of certain postures and movements of the body of a patient, either human or animal, in a direction substantially transversely to the longitudinal axis of the device, without there being a risk of the medical device being driven out of the bone, and which can be inserted over a guide wire by simple surgery. In order to accomplish the above-mentioned object, the medical device according to EP 1 937 172 A1 is configured as a rigid outer tube, which is provided with at least two opposed recesses on the side that is positioned in the bone if the medical device is in use, wherein a second inner tube is accommodated in said rigid outer tube, which inner tube is provided with at least two strips extending in the longitudinal direction of the inner tube on the side that is positioned in the bone, whilst means are present for loading the inner tube in axial direction, in such a manner that a pressure force is exerted on the aforesaid strips, which causes said strips to bend outwards through the aforesaid recesses. In this way, the medical device according to EP 1 937 172 A1 is capable of transmitting loads, such as transverse forces and bending moments, in a direction transversely to the longitudinal axis of the device, whilst the medical device is nevertheless secured against movement in the direction of its longitudinal axis. In this way, the medical device according to EP 1 937 172 A1 is locked against being driven out of the bone part in question.

[0007] Disadvantages of the medical device according to EP 1 937 172 A1 are that this medical device has a limited sustainability and application range. As a result, there is a need for an improved medical device that pre-empts or at least reduces these disadvantages.

[0008] SUMMARY OF THE INVENTION

[0009] It is an object of the present invention to provide a medical subassembly for releasable and rotationally stable anchorage within a bone part if the medical subassembly is in use that at least has an improved sustainability and increased application range.

[0010] It is another object of the present invention to provide a medical assembly that is suitable for fixation of bone parts that are separated by a gap. The medical assembly comprising the medical subassembly according to the invention.

[0011] Aspects of the present invention are set out in the accompanying independent and dependent claims. Features from the dependent claims may be combined with features from the independent claims as appropriate and not merely as explicitly set out in the claims. Furthermore, all features may be replaced with other technically equivalent features.

[0012] At least one of the abovementioned objects is achieved by a medical subassembly for releasable and rotationally stable anchorage within a bone part if the medical subassembly is in use, the medical subassembly comprising:

[0013] - an elongated expansion member having a first centerline that is parallel to an axial direction of the elongated expansion member, the elongated expansion member comprising:

[0014] • a first tubular end portion that has a first inner surface, a first inner diameter, a first end, and a second end, the first end and the second end being arranged opposite to each other in the axial direction of the elongated expansion member;

[0015] • a second tubular end portion that has a second inner surface, a second inner diameter that is smaller than the first inner diameter of the first tubular end portion, a third end and a fourth end, the third end and the fourth end being arranged opposite to each other in the axial direction of the elongated expansion member; and

[0016] • a first intermediate portion that is arranged to interconnect the second end of the first tubular end portion and the third end of the second tubular end portion; wherein the first inner surface of the first tubular end portion is provided with a first threaded section that comprises threads that are configured to have a first orientation and / or the second inner surface of the second tubular end portion is provided with a second threaded section that comprises threads that are configured to have a second orientation that is reverse to the first orientation of the threads of the first threaded section of the first tubular end portion, and wherein the first intermediate portion comprises:

[0017] ■ a first bendable assembly comprising a first elongated element having a fifth end and a sixth end, the fifth end and the sixth end being arranged opposite to each other in the axial direction of the elongated expansion member, and a second elongated element having a seventh end and an eighth end, the seventh end and the eighth end being arranged opposite to each other in the axial direction of the elongated expansion member, the fifth end of the first elongated element and the first tubular end portion being associated at a first location at the second end of the first tubular end portion via a first bendable connection, the sixth end of the first elongated element and the seventh end of the second elongated element being associated via a second bendable connection, and the eighth end of the second elongated element and the second tubular end portion being associated at a second location at the third end of the second tubular end portion via a third bendable connection, the first bendable connection, the second bendable connection and the third bendable connection being configured and arranged to allow the first bendable assembly to be displaceable in a radial direction of the elongated expansion member, wherein at least one of the first bendable connection, the second bendable connection and the third bendable connection comprises a first axle;

[0018] ■ a second bendable assembly comprising a third elongated element having a ninth end and a tenth end, the ninth end and the tenth end being arranged opposite to each other in the axial direction of the elongated expansion member, and a fourth elongated element having an eleventh end and a twelfth end, the eleventh end and the twelfth end being arranged opposite to each other in the axial direction of the elongated expansion member, the ninth end of the third elongated element and the first tubular end portion being associated at a third location at the second end of the first tubular end portion via a fourth bendable connection, the tenth end of the third elongated element and the eleventh end of the fourth elongated element being associated via a fifth bendable connection, and the twelfth end of the fourth elongated element and the second tubular end portion being associated at a fourth location at the third end of the second tubular end portion via a sixth bendable connection, the fourth bendable connection, the fifth bendable connection and the sixth bendable connection being configured and arranged to allow the second bendable assembly to be displaceable in the radial direction of the elongated expansion member, wherein at least one of the fourth bendable connection, the fifth bendable connection and the sixth bendable connection comprises a second axle;

[0019] - an elongated actuator member having a second centerline that is parallel to an axial direction of the elongated actuator member, the elongated actuator member comprising:

[0020] • a first end portion that has a first outer surface, a first outer diameter, a thirteenth end and a fourteenth end, the thirteenth end and the fourteenth end being arranged opposite to each other in the axial direction of the elongated actuator member;

[0021] • a second end portion that has a first end part and a second end part, the first end part and the second end part being arranged opposite to each other in the axial direction of the elongated actuator member, wherein the first end part has a second outer surface and a second outer diameter that is smaller than the first outer diameter of the first end portion and that is adapted to the first inner diameter of the first tubular end portion of the elongated expansion member, and wherein the second end part has a third outer surface and a third outer diameter that is smaller than the second outer diameter of the first end part and that is adapted to the second inner diameter of the second tubular end portion of the elongated expansion member; and

[0022] • a second intermediate portion that is arranged to interconnect the fourteenth end of the first end portion and the first end part of the second end portion; wherein the second outer surface of the first end part is provided with a third threaded section that comprises threads that are configured to enable cooperation with the threads of the first threaded section that is provided to the first inner surface of the first tubular end portion, if the first end part is at least partially accommodated in the first tubular end portion of the elongated expansion member, wherein the first centerline of the elongated expansion member and the second centerline of the elongated actuator member are parallel and / or the third outer surface of the second end part is provided with a fourth threaded section that comprises threads that are configured to enable cooperation with the threads of the second threaded section that is provided to the second inner surface of the second tubular end portion, if the second end part is accommodated in the second tubular end portion of the elongated expansion member, wherein the first centerline of the elongated expansion member and the second centerline of the elongated actuator member are parallel; and

[0023] - an elongated housing member having a third centerline that is parallel to an axial direction of the elongated housing member, the elongated housing member comprising:

[0024] • a fourth outer surface and a third inner surface that is arranged to face away from the fourth outer surface as seen in the radial direction of the elongated housing member;

[0025] • a third tubular end portion having a fifteenth end and a sixteenth end, the fifteenth end and the sixteenth end being arranged opposite to each other in the axial direction of the elongated housing member;

[0026] • a fourth tubular end portion having a seventeenth end and an eighteenth end, the seventeenth end and the eighteenth end being arranged opposite to each other in the axial direction of the elongated housing member; and

[0027] • a tubular intermediate portion that is arranged to interconnect the sixteenth end of the third tubular end portion and the seventeenth end of the fourth tubular end portion; wherein the fourth tubular end portion is provided with:

[0028] ■ a first flange that is arranged at the fourth outer surface and configured to extend in an axial direction of the elongated housing member;

[0029] ■ a second flange that is arranged at the fourth outer surface and configured to extend in the axial direction of the elongated housing member, the first flange and the second flange being arranged to: o divide the fourth outer surface into a first section and a second section as seen in a circumferential direction of the elongated housing member; and o allow, if the medical subassembly is in use, establishment of a rotationally stable anchorage of the fourth tubular end portion with a bone part;

[0030] ■ a first elongated through hole that is provided at a fifth location in said first section, the first elongated through hole being configured to extend in the axial direction of the elongated housing member; and

[0031] ■ a second elongated through hole that is provided at a sixth location in said second section, the second elongated through hole being configured to extend in the axial direction of the elongated housing member; and wherein the third tubular end portion of the elongated housing member comprises:

[0032] ■ a first reception chamber that is accessible via an opening at the fifteenth end, the first reception chamber being configured to accommodate the first end portion of the elongated actuator member after insertion of the elongated actuator member and the elongated expansion member in the elongated housing member, wherein the second centerline of the elongated actuator member and the third centerline of the elongated housing member are parallel; and

[0033] ■ a second reception chamber that is arranged in communication with the first reception chamber, the second reception chamber being configured to allow, if the medical subassembly is in use:

[0034] • transferring of the first end portion of the elongated actuator member from the first reception chamber into the second reception chamber in response to a first displacement of the elongated actuator member in the axial direction of the elongated housing member away from the fifteenth end, wherein if the first end portion is accommodated in the second reception chamber, the second end portion of the elongated actuator member and the elongated expansion member are at least partially accommodated in the fourth tubular end portion of the elongated housing member; and

[0035] • transferring of the first end portion of the elongated actuator member from the second reception chamber into the first reception chamber in response to a second displacement of the elongated actuator member in the axial direction of the elongated housing member towards the fifteenth end to at least partially remove the second end portion of the elongated actuator member and the elongated expansion member from the fourth tubular end portion of the elongated housing member; and wherein if the first end portion of the elongated actuator member is accommodated in the second reception chamber: o the first intermediate portion of the elongated expansion member is transferable, if the medical subassembly is in use:

[0036] - from an inactive state to an activated state in response to rotation of the elongated actuator member in a first direction around the second centerline of the elongated actuator member, wherein if the first intermediate portion is in the activated state, the first bendable assembly is arranged partially extending outside of the fourth tubular end portion via the first elongated through hole, and the second bendable assembly is arranged partially extending outside of the fourth tubular end portion via the second elongated through hole, wherein the first bendable assembly and the second bendable assembly allow establishment of a rotationally stable anchorage of the elongated expansion member with a bone part; and

[0037] - from an activated state to an inactive state in response to rotation of the elongated actuator member in a second direction around the second centerline of the elongated actuator member, the second direction being opposite to said first direction, wherein if the first intermediate portion is in the inactive state, the first bendable assembly and the second bendable assembly are arranged to prevent establishment of said rotationally stable anchorage of the elongated expansion member.

[0038] The medical subassembly according to the invention has an improved sustainability because it is reconfigurable as a result of the way in which the first reception chamber and the second reception chamber of the third tubular end portion of the elongated housing member allow the elongated expansion member and the elongated actuator member to be arranged with respect to the elongated housing member in the inactive state and the activated state of the first intermediate portion of the elongated expansion member of the medical subassembly. For example, it is possible to exchange the elongated expansion member and the elongated actuator member if the medical subassembly is in use, i.e. the elongated expansion member and the elongated actuator member can be removed from the elongated housing member after displacing the elongated actuator member that is operatively associated with the elongated expansion member from the second reception chamber to the first reception chamber while the fourth tubular end portion of the elongated housing member remains anchored within a bone part. In this way, it is possible to replace an elongated expansion member and / or an elongated actuator member by another elongated expansion member and / or elongated actuator member having at least one technical specification that is different from the technical specifications of the removed elongated expansion member and / or elongated actuator member. As a result of the exchangeability of the elongated expansion member and / or the elongated actuator member, it is not required to remove the entire medical subassembly according to the invention. As a result, surgical waste and therefore costs can be reduced, which adds to the sustainability of the medical subassembly according to the invention.

[0039] As the elongated expansion member, the elongated actuator member and the elongated housing member can easily be separated from each other, the medical subassembly according to the invention also offers good resterilization options, which adds to the sustainability of the medical subassembly according to the invention. It is noted that the medical subassembly according to the invention can comprise any material that can impart the mechanical strength required and is suitable for resterilization. Preferably, the material is autoclavable.

[0040] An advantage of the above-described reconfigurability of the medical subassembly according to the invention is that a user of the medical subassembly, which typically will be a medical professional, is provided with an improved user experience as the user can make in situ, i.e. during surgery, changes to the medical subassembly depending on the specific requirements dictated by a condition of the bone parts to be fixated. Such condition can, for example, be the hardness of the bone part in which the medical subassembly is to be anchored.

[0041] Another advantage of the reconfigurability of the medical subassembly according to the invention is that, for example, it is possible to provide the elongated housing member in a first sterile package and the elongated expansion member and the elongated actuator member in a second sterile package. The elongated expansion member and the elongated actuator member can be in an operatively assembled state, i.e. in a state in which the elongated expansion member and the elongated actuator member are ready for insertion into the elongated housing member upon removal from the second sterile package. In this way, it is possible for a user to first take the elongated housing member out of the first sterile package and insert the elongated housing member, for example over a guide wire, into the bone part before deciding about opening the second sterile package. If it turns out that, for example, another elongated expansion member and / or elongated actuator member is required than the elongated expansion member comprised in the second sterile package, the user can choose a different elongated expansion member and / or elongated actuator member comprised in a third sterile package. In this way, spillage of sterile parts of the medical subassembly can be reduced. This adds to the sustainability of the medical subassembly according to the invention and to the reduction of surgical waste and costs.

[0042] For the sake of completeness it is noted that it is also possible to provide the elongated expansion member, the elongated actuator member and the elongated housing member in separate sterile packages. Alternatively, it is possible to provide the entire medical subassembly in a single sterile package.

[0043] The sustainability and application range of the medical subassembly according to the invention are also improved because at least one of the first bendable connection, the second bendable connection and the third bendable connection of the elongated expansion member comprises a first axle, and at least one of the fourth bendable connection, the fifth bendable connection and the sixth bendable connection of the elongated expansion member comprises a second axle.

[0044] If the second bendable connection, which associates the sixth end of the first elongated element and the seventh end of the second elongated element with each other, comprises the first axle, the first elongated element and the second elongated element of the first bendable assembly of the elongated expansion member constitute a first impaction anchor that has an improved strength because of the first axle. In addition, the first elongated element and the second elongated element can provide a sharp point if the medical assembly is in the activated state. The sharp point and the improved strength provide the medical subassembly according to the invention with an increased application range because it is possible to establish reliable anchorage in a hard bone part. The same holds for the fifth bendable connection, which associates the tenth end of the third elongated element of the second bendable assembly of the elongated expansion member and the eleventh end of the fourth elongated element of the second bendable assembly of the elongated expansion member with each other, if the fifth bendable connection comprises the second axle. The combination of the static first flange, the static second flange of the fourth tubular end portion of the elongated housing member and the first impaction anchor and the second impaction anchor provided by respectively the first bendable assembly and the second bendable assembly of the elongated expansion member allows a reliable non-rotational anchorage of the medical subassembly in a bone part, even if the bone part is very hard. Consequently, the medical subassembly according to the invention has an increased application range, i.e. allowing reliable non-rotational anchorage in bone parts having a hardness ranging between soft and very hard.

[0045] It is noted that if the second bendable connection comprises the first axle and the fifth bendable connection comprises the second axle, the first bendable connection, the third bendable connection, the fourth bendable connection and the sixth bendable connection can be configured for example as weakened wall parts of the elongated expansion member that can fold or hinge upon exertion of a mechanical force on the elongated expansion member thereby reducing a distance in an axial direction of the elongated expansion member between the first tubular end portion and the second tubular end portion of the elongated expansion member. In particular, the fifth end of the first elongated element of the first bendable assembly of the elongated expansion member can be integral with the second end of the first tubular end portion of the elongated expansion member, wherein the first bendable connection is configured and arranged as a weakened wall part of the elongated expansion member that connects the fifth end of the first elongated element and the second end of the first tubular end portion with each other. The eighth end of the second elongated element of the first bendable assembly of the elongated expansion member can be integral with the third end of the second tubular end portion of the elongated expansion member, wherein the third bendable connection is configured and arranged as a weakened wall part of the elongated expansion member that connects the eighth end of the second elongated element and the third end of the second tubular end portion with each other. The ninth end of the third elongated element of the second bendable assembly of the elongated expansion member can be integral with the second end of the first tubular end portion of the elongated expansion member, wherein the fourth bendable connection is configured and arranged as a weakened wall part of the elongated expansion member that connects the ninth end of the third elongated element and the second end of the first tubular end portion with each other. The twelfth end of the fourth elongated element of the second bendable assembly of the elongated expansion member can be integral with the third end of the second tubular end portion of the elongated expansion member, wherein the sixth bendable connection is configured and arranged as a weakened wall part of the elongated expansion member that connects the twelfth end of the fourth elongated element and the third end of the second tubular end portion with each other. For illustrative purposes only, it is noted that it is possible that the first bendable connection and the second bendable connection of the first bendable assembly of the elongated expansion member comprise respective axles and the third bendable connection is configured as a weakened wall part, and that the fourth bendable connection and the fifth bendable connection of the second bendable assembly of the elongated expansion member comprise respective axles and the sixth bendable connection is configured as a weakened wall part. The person skilled in the art will appreciate that any one of the first bendable connection, the second bendable connection, the third bendable connection, the fourth bendable connection, the fifth bendable connection and the sixth bendable connection of the elongated expansion member can comprise a first axle, a second axle, a third axle, a fourth axle, a fifth axle and a sixth axle, respectively depending on the specific technical specifications required for the elongated expansion member that are dictated by a condition of the bone parts to be fixated. Such condition can, for example, be the hardness of the bone parts in which the medical subassembly is to be anchored.

[0046] It is noted that the first axle, the second axle, the third axle, the fourth axle, the fifth axle and the sixth axle can have a diameter in a range between 0.2mm and 2.0mm.

[0047] It is noted that the above-mentioned distance in the axial direction of the elongated expansion member between the first tubular end portion and the second tubular end portion of the elongated expansion member can be reduced by displacement of the first tubular end portion towards the second tubular end portion in response to rotation of the elongated actuator member in a first direction around a second centerline of the elongated actuator member. In this way, the first intermediate portion of the elongated expansion member of medical subassembly is transferable from the inactive state to the activated state, i.e. from a state in which the first bendable assembly and the second bendable assembly of the first intermediate portion of the elongated expansion member prevent establishment of a rotationally stable anchorage of the elongated expansion member with the bone part to a state in which the first bendable assembly and the second bendable assembly allow establishment of a rotationally stable anchorage of the elongated expansion member with the bone part.

[0048] In addition, it is noted that the above-mentioned distance in the axial direction of the elongated expansion member between the first tubular end portion and the second tubular end portion of the elongated expansion member can be increased by displacement of the first tubular end portion away from the second tubular end portion in response to rotation of the elongated actuator member in a second direction around the second centerline of the elongated actuator member, wherein the second direction is opposite to the first direction. In this way, the first intermediate portion of the elongated expansion member of the medical subassembly is transferable from the activated state to the inactive state.

[0049] The person skilled in the art will appreciate that above-described displacement of the first tubular end portion towards or away from the second tubular end portion to respectively reduce or increase the distance between them is of an exemplary nature only as it is also possible to configure the medical subassembly according to the invention to displace the second tubular end portion towards or away from the first tubular end portion. Alternatively it is possible to simultaneously displace the first tubular end portion and the second tubular end portion towards each other or away from each other.

[0050] In order to displace the first tubular end portion of the elongated expansion member towards or way from the second tubular end portion of the elongated expansion member, the first inner surface of the first tubular end portion is provided with a first threaded section that comprises threads that are configured to have a first orientation, and the second outer surface of the first end part of the second end portion of the elongated actuator member is provided with a third threaded section that comprises threads that are configured to enable cooperation with the threads of the first threaded section that is provided to the first inner surface of the first tubular end portion of the elongated expansion member if the first end part of the elongated actuator member is at least partially accommodated in the first tubular end portion of the elongated expansion member, wherein the first centerline of the elongated expansion member and the second centerline of the elongated actuator member are parallel.

[0051] In order to displace the second tubular end portion of the elongated expansion member towards or way from the first tubular end portion of the elongated expansion member, the second inner surface of the second tubular end portion is provided with a second threaded section that comprises threads that are configured to have a second orientation that is reverse to the first orientation of the threads of the above-described first threaded section of the first tubular end portion, and the third outer surface of the second end part of the second end portion of the elongated actuator member is provided with a fourth threaded section that comprises threads that are configured to enable cooperation with the threads of the second threaded section that is provided to the second inner surface of the second tubular end portion of the elongated expansion member if the second end part of the elongated actuator member is accommodated in the second tubular end portion of the elongated expansion member, wherein the first centerline of the elongated expansion member and the second centerline of the elongated actuator member are parallel.

[0052] The person skilled in the art will appreciate that in order to simultaneously displace the first tubular end portion and the second tubular end portion of the elongated expansion member towards each other or away from each other, the first tubular end portion is provided with the above-described first threaded section, the second tubular end portion is provided with the above-described second threaded section, the first end part of the second end portion of the elongated actuator member is provided with the above-described third threaded section, and the second end part of the second end portion of the elongated actuator member is provided with the above-mentioned fourth threaded section.

[0053] In an embodiment of the medical subassembly according to the invention, the first end portion of the elongated actuator member has a first cross-section as seen perpendicular to the second centerline of the elongated actuator member, and the third tubular end portion of the elongated housing member at the first reception chamber has a second cross-section as seen perpendicular to the third centerline of the elongated housing member, wherein the first cross-section has a first non-circular outer circumference and the second cross-section has a first non-circular inner circumference that is adapted to the first non-circular outer circumference thereby preventing rotation of the elongated actuator member and the elongated housing member relative to each other around the second centerline if, in use of the medical subassembly, the first end portion of the elongated actuator member is accommodated in the first reception chamber. In this way, the first bendable assembly and the second bendable assembly of the elongated expansion member can be aligned with the first elongated through hole and the second elongated through hole, respectively, which are provided in the fourth tubular end portion of the elongated housing member. Upon displacement of the first end portion of the elongated actuator member from the first reception chamber to the second reception chamber of the third tubular end portion of the elongated housing member, the first bendable assembly of the elongated expansion member remains aligned with the first elongated through hole and is positioned opposite the first elongated through hole as seen in a radial direction of the elongated housing member. Similarly, the second bendable assembly of the elongated expansion member remains aligned with the second elongated through hole and is positioned opposite the second elongated through hole as seen in a radial direction of the elongated housing member. If the first end portion of the elongated actuator member is in the second reception chamber, the first bendable assembly and the second bendable assembly are arranged to allow the first intermediate portion of the elongated expansion member of the medical subassembly to be transferable between the inactive state and the activated state as a result of changing the above-mentioned distance between the first tubular end portion and the second tubular end portion of the elongated expansion member in the axial direction of the elongated expansion member.

[0054] In an embodiment of the medical subassembly according to the invention, the first outer surface of the elongated actuator member in the first end portion of the elongated actuator member is provided with a first protrusion to establish the first noncircular outer circumference of the first cross-section, and the third inner surface of the elongated housing member in the first reception chamber of the third tubular end portion is provided with a first recess to establish the first non-circular inner circumference of the second cross-section, the first recess being adapted to the first protrusion. In this way, rotation of both the elongated actuator member and the elongated expansion member relative to the elongated housing member can be prevented if the first end portion of the elongated actuator member is arranged in the first reception chamber. If the first end portion of the elongated actuator member is in the second reception chamber of the third tubular end portion of the elongated housing member, rotation of the elongated actuator member and the elongated expansion member relative to the elongated housing member is allowed for transferring the first intermediate portion of the elongated expansion member of the medical subassembly from the inactive state to the activated state in which the first bendable assembly partially extends outside of the fourth tubular end portion of the elongated housing member via the first elongated through hole and the second bendable assembly partially extends outside of the fourth tubular end portion of the elongated housing member via the second elongated through hole.

[0055] In an embodiment of the medical subassembly according to the invention, the second tubular end portion of the elongated expansion member and the fourth tubular end portion of the elongated housing member are configured to provide a releasable coupling if the second tubular end portion and the fourth tubular end portion are associated with each other, the releasable coupling being configured to prevent, if the medical subassembly is in use, rotation of the elongated expansion member and the elongated housing member relative to each other around the first centerline of the elongated expansion member upon rotation of the elongated actuator member around the second centerline of the elongated actuator member for transferring the first intermediate portion of the elongated expansion member between the inactive state to the activated state. In this way, misalignment of the first bendable assembly of the elongated expansion member and the first elongated through hole of the fourth tubular end portion of the elongated housing member, and misalignment of the second bendable assembly of the elongated expansion member and the second elongated through hole of the fourth tubular end portion of the elongated housing member can be prevented. As a result, the first intermediate portion of the elongated expansion member is transferable between the inactive state and the activated state.

[0056] In an embodiment of the medical subassembly according to the invention, the fourth end of the second tubular end portion of the elongated expansion member is provided with a second recess, and the third inner surface of the elongated housing member in the fourth tubular end portion is provided with a second protrusion that is adapted to the second recess, wherein if the second tubular end portion is at least partially accommodated in the fourth tubular end portion, the second recess and the second protrusion enable establishment of the releasable coupling.

[0057] In an exemplary embodiment of the medical subassembly according to the invention, the fourth end of the second tubular end portion of the elongated expansion member can be provided with a third protrusion, and the third inner surface of the elongated housing member in the fourth tubular end portion can be provided with a third recess that is adapted to the third protrusion, wherein if the second tubular end portion is at least partially accommodated in the fourth tubular end portion, the third protrusion and the third recess enable establishment of the releasable coupling.

[0058] It is noted that in addition to the above-described releasable couplings, additional elements, e.g. a traverse pin and / or a wedge, can be applied to prevent rotation of the elongated expansion member and the elongated housing member relative to each other around the first centerline of the elongated expansion member upon rotation of the elongated actuator member around the second centerline of the elongated actuator member for transferring the first intermediate portion of the elongated expansion member between the inactive state to the activated state.

[0059] In an embodiment of the medical subassembly according to the invention, the third inner surface of the elongated housing member in the first reception chamber of the third tubular end portion of the elongated housing member is provided with a fifth threaded section that comprises threads that are configured to have a third orientation, and wherein the second outer surface of the elongated actuator member in the first end portion of the elongated actuator member is provided with a sixth threaded section that comprises threads that are configured to enable, if the medical subassembly is in use, cooperation with the threads of the fifth threaded section to allow at least one of:

[0060] - accommodation of the first end portion of the elongated actuator member in the first reception chamber of the third tubular end portion of the elongated housing member after insertion of the elongated actuator member in the elongated housing member via the opening in the seventeenth end of the third tubular end portion of the elongated housing member in response to rotation of the elongated actuator member in the first direction around the second centerline of the elongated actuator member;

[0061] - transferring of the first end portion of the elongated actuator member from the first reception chamber into the second reception chamber of the third tubular end portion of the elongated housing member in response to rotation of the elongated actuator member in the first direction around the second centerline of the elongated actuator member to achieve the first displacement of the elongated actuator member in the axial direction of the elongated housing member away from the seventeenth end;

[0062] - transferring of the first end portion of the elongated actuator member from the second reception chamber into the first reception chamber in response to rotation of the elongated actuator member in the second direction around the second centerline of the elongated actuator member to achieve the second displacement of the elongated actuator member in the axial direction of the elongated housing member towards the seventeenth end; and

[0063] - removal of the first end portion of the elongated actuator member from the first reception chamber via the opening in the seventeenth end of the third tubular end portion in response to rotation of the elongated actuator member in the second direction around the second centerline of the elongated actuator member.

[0064] It is noted that the fifth threaded section that is provided to the third inner surface of the elongated housing member in the first reception chamber of the third tubular end portion of the elongated housing member can be configured in such a way, e.g. by choosing the pitch and / or the number of threads, to guarantee alignment of the first bendable assembly and the second bendable assembly of the elongated expansion member with the first elongated through hole and the second elongated through hole, respectively, which are provided in the fourth tubular end portion of the elongated housing member, if the first end portion of the elongated actuator member is accommodated in the first reception chamber of the third tubular end portion of the elongated housing member. Upon displacement of the first end portion of the elongated actuator member from the first reception chamber to the second reception chamber of the third tubular end portion of the elongated housing member, the first bendable assembly of the elongated expansion member remains aligned with the first elongated through hole and is positioned opposite the first elongated through hole as seen in a radial direction of the elongated housing member. Similarly, the second bendable assembly of the elongated expansion member remains aligned with the second elongated through hole and is positioned opposite the second elongated through hole as seen in a radial direction of the elongated housing member. If the first end portion of the elongated actuator member is in the second reception chamber of the third tubular end portion of the elongated housing member, the first bendable assembly and the second bendable assembly are arranged to allow the first intermediate portion of the elongated expansion member of the medical subassembly to be transferable between the inactive state and the activated state as a result of changing the above-mentioned distance between the first tubular end portion and the second tubular end portion of the elongated expansion member in the axial direction of the elongated expansion member.

[0065] In an exemplary embodiment of the medical subassembly according to the invention, the first tubular end portion of the elongated expansion member has a length as seen in the axial direction of the elongated expansion member that allows a part of the first tubular end portion to be accommodated in the third tubular end portion of the elongated housing member if the second tubular end portion is at least partially accommodated in the fourth tubular end portion of the elongated housing member. The part of the first tubular end portion of the elongated expansion member that in use of the medical subassembly is accommodated in the third tubular end portion of the elongated housing member has a third cross-section as seen perpendicular to the first centerline of the elongated expansion member, and the third tubular end portion of the elongated housing member at the second reception chamber has a fourth cross-section as seen perpendicular to the third centerline of the elongated housing member, wherein the third cross-section has a second non-circular outer circumference and the fourth cross-section has a second non-circular inner circumference that is adapted to the second non-circular outer circumference to prevent rotation of the elongated expansion member and the elongated housing member relative to each other around the first centerline of the elongated expansion member if in use of the medical subassembly said part of the first tubular end portion is accommodated in the second reception chamber of the third tubular end portion of the elongated housing member. In accordance with this exemplary embodiment of the medical subassembly, the first tubular end portion of the elongated expansion member incorporates structural functionality that is provided to the first end portion of the elongated actuator member of the above-mentioned embodiments of the medical subassembly according to the invention.

[0066] In another exemplary embodiment of the medical subassembly according to the invention, the first tubular end portion of the elongated expansion member has a fifth outer surface, wherein the fifth outer surface in said part of the first tubular end portion that in use of the medical subassembly is accommodated in the third tubular end portion of the elongated housing member is provided with a fourth protrusion to establish the second non-circular outer circumference of the third cross-section, and wherein the third inner surface of the elongated housing member in the second reception chamber of the third tubular end portion is provided with a fourth recess to establish the second non-circular inner circumference of the fourth cross-section, the fourth recess being adapted to the fourth protrusion. In this way, rotation of the elongated expansion member and the elongated housing member relative to each other can be prevented if the first tubular end portion of the elongated expansion member is arranged in the first reception chamber of the third tubular end portion of the elongated housing member. If the first tubular end portion of the elongated expansion member is in the second reception chamber of the third tubular end portion of the elongated housing member, rotation of the elongated expansion member and the elongated housing member relative to each other is allowed for transferring the first intermediate portion of the elongated expansion member of the medical subassembly from the inactive state to the activated state in which the first bendable assembly partially extends outside of the fourth tubular end portion of the elongated housing member via the first elongated through hole and the second bendable assembly partially extends outside of the fourth tubular end portion of the elongated housing member via the second elongated through hole.

[0067] In an embodiment of the medical subassembly according to the invention, the elongated expansion member, the elongated actuator member and the elongated housing member comprise surgical stainless steel. A suitable type of surgical stainless steel is for example 316L grade stainless steel because of its excellent mechanical properties and resistance to corrosion due to presence of high chromium content (16%), molybdenum (2%) and low carbon content (<0.03%). As stainless steel has less close contact with bone tissue compared to for example titanium, medical subassemblies comprising surgical stainless steel give rise to smaller osseointegration compared to medical subassemblies comprising titanium. This is advantageous for removal of the medical subassembly according to the present invention following healing of the fracture.

[0068] In an embodiment of the medical subassembly according to the invention, the third tubular end portion of the elongated housing member has a fifth cross-section as seen perpendicular to the third centerline of the elongated housing member, the fifth crosssection having a third non-circular outer circumference and / or the tubular intermediate portion of the elongated housing member has a sixth cross-section as seen perpendicular to the third centerline of the elongated housing member, the sixth crosssection having a fourth non-circular outer circumference. In this way, the rotational stability of the elongated housing member can be increased. The fifth cross-section and the sixth cross-section can have any suitable shape such as any suitable polygonal shape, e.g. triangular, square, pentagonal, hexagonal. The third non- circular outer circumference and the fourth non-circular outer circumference can have a same shape or a different shape. The third non-circular outer circumference and the fourth non-circular outer circumference can have a same size and a different size.

[0069] In an embodiment of the medical subassembly according to the invention, the fourth outer surface of the elongated housing member in at least one of the first section and the second section of the fourth tubular end portion of the elongated housing member is provided with a flattened area that is arranged parallel to the first flange and the second flange. In this way, at least one flattened area in addition to the first flange and the second flange can be provided for increasing the rotational stability of the fourth tubular end portion of the elongated housing member.

[0070] In an embodiment of the medical subassembly according to the invention, the fourth tubular end portion of the elongated housing member has a third inner diameter, the first elongated through hole has a first length as seen in the axial direction of the elongated housing member and the second elongated through hole has a second length as seen in the axial direction of the elongated housing member, wherein the first length and the second length are at least twice the third inner diameter of the fourth tubular end portion. In this way, sufficient space is provided for the first bendable assembly and the second bendable assembly of the first intermediate portion of the elongated expansion member to protrude outside of the fourth tubular end portion of the elongated housing member via the first elongated through hole and the second elongated through hole, respectively.

[0071] In an embodiment of the medical subassembly according to the invention, the first end portion of the elongated actuator member at the thirteenth end is provided with a fifth recess, wherein the first end portion at the fifth recess has a seventh crosssection as seen perpendicular to the second centerline of the elongated actuator member, the seventh cross-section having a third non-circular inner circumference as a result of the fifth recess. The third non-circular inner circumference of the seventh cross-section can have any suitable shape such as any suitable polygonal shape, e.g. triangular, square, pentagonal, hexagonal. In this way, the fifth recess can receive any suitable tool, e.g. a screw driver or a canning-in tool, for rotating the elongated actuator member relative to the elongated housing member. The fifth recess can be configured to have any suitable length in the axial direction of the elongated actuator member. Hence, the fifth recess can for example be configured and arranged as an elongated receiving space.

[0072] According to another aspect of the present invention, a medical assembly suitable for fixation of bone parts that are separated by a gap is provided, the medical assembly comprising a medical subassembly according to the invention. It is noted that the gap can be a result of a bone fracture dividing a bone in separated bone parts. As a result of comprising the medical subassembly according to the invention, the medical assembly has an improved sustainability and increased application range for the reasons mentioned above.

[0073] In an embodiment of the medical assembly according to the invention comprises: a plate that in use of the medical assembly is associated with a first bone part that is separated from a second bone part by a gap; and an elongated tubular member that is associated with the plate and arranged at a non-zero angle relative to the plate, the elongated tubular member being configured to:

[0074] • accommodate the medical subassembly; and

[0075] • allow, if the medical assembly is in use, sliding movement of the medical subassembly and the plate relative to each other. The above-defined embodiment of the medical assembly according to the invention can advantageously be used, for example, for healing fractures of the femur. In the context of this exemplary application, the part of the elongated housing member, i.e. the third tubular end portion and the tubular intermediate portion of the elongated housing member, which in use of the medical assembly is not anchored in the second bone part, i.e. the femur head, that is separated from the first bone part, i.e. the femur, by a fracture, is slidingly accommodated in the elongated tubular member. The elongated tubular member is associated at the non-zero angle with the plate that, in use of the medical assembly, is fixed to the first bone part, i.e. the femur. In this way, the medical assembly, if in use, can absorb forces that are directed transverse to the axial direction of the elongated housing member of the medical subassembly and transmit the forces to the plate, whilst the elongated housing member of the medical subassembly that is rotationally stable anchored inside the second bone part, i.e. the femur head, is allowed to slide relative to the plate in an axial direction of the elongated tubular member towards the first bone part, i.e. the femur, as a result of which the first bone part and the second bone part are firmly pressed together, which is beneficial for the healing process.

[0076] In accordance with an exemplary embodiment of the medical assembly according to the invention, the medical assembly can be used for immobilizing two bones that are connected by one or more joints, in particular vertebrae. A first the medical subassembly of the exemplary embodiment of the medical assembly according to the invention is rotationally stable anchored inside a first pedicle of a first vertebrae, and a second medical subassembly of the exemplary embodiment of the medical assembly according to the invention is rotationally stable anchored inside a second pedicle of a second vertebrae. The first medical subassembly and the second medical subassembly are arranged at a distance from each other as seen in the radial direction of the elongated housing members of the respective first medical subassembly and the second medical subassembly. The third tubular end portion of the elongated housing member of the first medical subassembly and the third tubular end portion of the elongated housing member of the second medical subassembly are interconnected by a stabilizing element that is configured and arranged to restrict movement of an intervertebral disc that is located between the first vertebrae and the second vertebrae.

[0077] In an embodiment of the medical assembly according to the invention, the plate is provided with at least two through holes that are configured and arranged to allow, if the medical assembly is in use, establishment of a rotationally stable and releasable connection of the plate with the first bone part, e.g. the femur.

[0078] In an embodiment of the medical assembly according to the invention, at least one of the plate and the elongated tubular member comprises surgical stainless steel. As mentioned above, a suitable type of surgical stainless steel is for example 316L grade stainless steel because of its excellent mechanical properties and resistance to corrosion due to presence of high chromium content (16%), molybdenum (2%) and low carbon content (<0.03%). As stainless steel has less close contact with bone tissue compared to for example titanium, medical assemblies comprising surgical stainless steel give rise to smaller osseointegration compared to medical assemblies comprising titanium. This is advantageous for removal of the medical assembly according to the present invention following healing of the fracture.

[0079] BRIEF DESCRIPTION OF THE DRAWINGS

[0080] Further features and advantages of the invention will become apparent from the description of exemplary and non-limiting embodiments of a medical subassembly according to the present invention and a medical assembly comprising the medical subassembly according to the invention.

[0081] The person skilled in the art will appreciate that the described embodiments of the medical subassembly and the medical assembly according to the present invention are exemplary in nature only and not to be construed as limiting the scope of protection in any way. The person skilled in the art will realize that alternatives and equivalent embodiments of the medical subassembly and the medical assembly can be conceived and reduced to practice without departing from the scope of protection of the present invention.

[0082] Reference will be made to the figures on the accompanying drawing sheets. The figures are schematic in nature and therefore not necessarily drawn to scale. Furthermore, equal reference numerals denote equal or similar parts.

[0083] On the attached drawing sheets, figure 1A shows a schematic exploded view of a first exemplary, non-limiting embodiment of a medical subassembly according to the invention; figure 1 B shows a close-up of the schematic exploded view of the first exemplary, non-limiting embodiment of the medical subassembly according to the invention shown in figure 1A; figure 1C shows a schematic perspective view of an elongated actuator member of the medical subassembly in accordance with the first exemplary, non-limiting embodiment of the medical subassembly shown in figure 1A; figure 1D shows a schematic perspective cross-sectional view of the first exemplary, non-limiting embodiment of the medical subassembly shown in figure 1A; figure 2A shows a schematic perspective view of the elongated expansion member and the elongated actuator member of the medical subassembly in accordance with the first exemplary, non-limiting embodiment of the medical subassembly, wherein the first intermediate portion of the elongated expansion member is in an activated state; figure 2B shows a schematic perspective view of the elongated housing member of the medical subassembly in accordance with the first exemplary, non-limiting embodiment of the medical subassembly, focusing on the fourth tubular end portion of the elongated housing member; figure 2C shows a schematic perspective view of the elongated housing member of the medical subassembly in accordance with the first exemplary, non-limiting embodiment of the medical subassembly, focusing on the third tubular end portion of the elongated housing member; figure 3A shows a schematic perspective view of the first exemplary, non-limiting embodiment of the medical subassembly according to the invention, wherein the first intermediate portion of the elongated expansion member is in an inactive state; figure 3B shows a schematic perspective view of the first exemplary, non-limiting embodiment of the medical subassembly according to the invention, wherein the first intermediate portion of the elongated expansion member is in a transitional state between the inactive state shown in figure 3A and an activated state shown in figure 3C; figure 3C shows a schematic perspective view of the first exemplary, non-limiting embodiment of the medical subassembly according to the invention, wherein the first intermediate portion of the elongated expansion member is in an activated state; figure 4A shows a schematic combined view of the first exemplary, non-limiting embodiment of the medical subassembly according to the invention, wherein the elongated housing member has been partially cut away to provide a view on the arrangement of elongated actuator member and the elongated expansion member if the first intermediate portion of the elongated expansion member is in the inactive state; figure 4B shows a schematic combined view of the first exemplary, non-limiting embodiment of the medical subassembly according to the invention, wherein the elongated housing member has been partially cut away to provide a view on the arrangement of elongated actuator member and the elongated expansion member if the first intermediate portion of the elongated expansion member is in a transitional state between the inactive state and the activated state; figure 4C shows a schematic combined view of the first exemplary, non-limiting embodiment of the medical subassembly according to the invention, wherein the elongated housing member has been partially cut away to provide a view on the arrangement of elongated actuator member and the elongated expansion member if the first intermediate portion of the elongated expansion member is in the activated state; figure 5A shows a schematic perspective cross-sectional view of a second exemplary, non-limiting embodiment of the medical subassembly according to the invention; figure 5B shows a close-up of the schematic cross-sectional view of a part of the medical subassembly in accordance with the second exemplary, non-limiting embodiment of the medical subassembly shown in figure 5A; figure 6 shows a schematic partially exploded view of a first exemplary, non-limiting embodiment of a medical assembly according to the invention; and figure 7 shows a schematic view of an exemplary use situation in which a plate of the medical assembly in accordance with the first exemplary, non-limiting embodiment of the medical assembly is rotationally stable connected with a femur and the medical subassembly of the medical assembly in accordance with the first exemplary, nonlimiting embodiment of the medical assembly is rotationally stable anchored inside the femur head and slidingly accommodated in an elongated tubular member of the medical assembly in accordance with the first exemplary, non-limiting embodiment of the medical assembly.

[0084] DETAILED DESCRIPTION OF EMBODIMENTS

[0085] A first exemplary, non-limiting embodiment of a medical subassembly 1 according to the invention for releasable and rotationally stable anchorage within a bone part, if the medical subassembly is in use, is described with reference to figures 1A-1 D, 2A- 2C, 3A-3C and 4A-4C. Figure 1A shows that the medical subassembly 1 comprises an elongated expansion member 2 that has a first centerline 3 that is parallel to an axial direction of the elongated expansion member 2. The elongated expansion member 2 comprises a first tubular end portion 4, a second tubular end portion 7 and a first intermediate end portion 10.

[0086] The first tubular end portion has a first inner surface, a first inner diameter, a first end 5, and a second end 6. The first end 5 and the second end 6 are arranged opposite to each other in the axial direction of the elongated expansion member 2.

[0087] The second tubular end portion 7 has a second inner surface, a second inner diameter that is smaller than the first inner diameter of the first tubular end portion 4, a third end 8 and a fourth end 9. The third end 8 and the fourth end 9 being arranged opposite to each other in the axial direction of the elongated expansion member 2.

[0088] The first intermediate portion 10 is arranged to interconnect the second end 6 of the first tubular end portion 4 and the third end 8 of the second tubular end portion 7.

[0089] Figure 1 D shows that the first inner surface of the first tubular end portion 4 is provided with a first threaded section 71. The threads of the first threaded section 71 are configured to have a first orientation. Figure 1D also shows that the second inner surface of the second tubular end portion 7 is provided with a second threaded section 74. The threads of the second threaded section 74 are configured to have a second orientation that is reverse to the first orientation of the threads of the first threaded section 71 of the first tubular end portion 4.

[0090] As shown in figures 1A and 1 B, the first intermediate portion 10 of the elongated expansion member 2 comprises a first bendable assembly 11 that comprises a first elongated element 12 that has a fifth end 13 and a sixth end 14. The fifth end 13 and the sixth end 14 are arranged opposite to each other in the axial direction of the elongated expansion member 2. The first bendable assembly 11 also comprises a second elongated element 15 that has a seventh end 16 and an eighth end 17. The seventh end 16 and the eighth end 17 are arranged opposite to each other in the axial direction of the elongated expansion member 2. The fifth end 13 of the first elongated element 12 and the first tubular end portion 4 are associated at a first location at the second end 6 of the first tubular end portion 4 via a first bendable connection 18. The sixth end 14 of the first elongated element 12 and the seventh end 16 of the second elongated element 15 are associated via a second bendable connection 19. The eighth end 17 of the second elongated element 15 and the second tubular end portion 7 are associated at a second location at the third end 8 of the second tubular end portion 7 via a third bendable connection 20. The first bendable connection 18, the second bendable connection 19 and the third bendable connection 20 are configured and arranged to allow the first bendable assembly 11 to be displaceable in a radial direction of the elongated expansion member 2.

[0091] Figures 1A and 1 B show that the first intermediate portion 10 of the elongated expansion member 2 also comprises a second bendable assembly 22 that comprises a third elongated element 23 that has a ninth end 24 and a tenth end 25. The ninth end 24 and the tenth end 25 are arranged opposite to each other in the axial direction of the elongated expansion member 2. The second bendable assembly 22 also comprises a fourth elongated element 26 that has an eleventh end 27 and a twelfth end 28. The eleventh end 27 and the twelfth end 28 are arranged opposite to each other in the axial direction of the elongated expansion member 2. The ninth end 24 of the third elongated element 23 and the first tubular end portion 4 are associated at a third location at the second end 6 of the first tubular end portion 4 via a fourth bendable connection 29. The tenth end 25 of the third elongated element 23 and the eleventh end 27 of the fourth elongated element 26 are associated via a fifth bendable connection 30. The twelfth end 28 of the fourth elongated element 26 and the second tubular end portion 7 are associated at a fourth location at the third end 8 of the second tubular end portion 7 via a sixth bendable connection 31. The fourth bendable connection 29, the fifth bendable connection 30 and the sixth bendable connection 31 are configured and arranged to allow the second bendable assembly 22 to be displaceable in the radial direction of the elongated expansion member 2.

[0092] In accordance with the first exemplary, non-limiting embodiment of the medical subassembly shown in figures 1A-1D, 2A-2C, 3A-3C and 4A-4C, the second bendable connection 19 comprises a first axle 21 and the fifth bendable connection 30 comprises a second axle 32. The first bendable connection 18, the third bendable connection 20, the fourth bendable connection 29 and the sixth bendable connection 31 are configured as weakened wall parts of the elongated expansion member 2 that can fold or hinge upon exertion of a mechanical force on the elongated expansion member 2 thereby reducing a distance in an axial direction of the elongated expansion member 2 between the first tubular end portion 4 and the second tubular end portion 7 of the elongated expansion member 2. In particular, the fifth end 13 of the first elongated element 12 of the first bendable assembly 11 is integral with the second end 6 of the first tubular end portion 4 of the elongated expansion member 2, wherein the first bendable connection 18 is configured and arranged as a weakened wall part of the elongated expansion member 2 that connects the fifth end 13 of the first elongated element 12 and the second end 6 of the first tubular end portion 4 with each other. The eighth end 17 of the second elongated element 15 of the first bendable assembly 11 is integral with the third end 8 of the second tubular end portion 7 of the elongated expansion member 2, wherein the third bendable connection 20 is configured and arranged as a weakened wall part of the elongated expansion member 2 that connects the eighth end 17 of the second elongated element 15 and the third end 8 of the second tubular end portion 7 with each other.

[0093] The ninth end 24 of the third elongated element 23 of the second bendable assembly 22 of the elongated expansion member 2 is integral with the second end 6 of the first tubular end portion 4 of the elongated expansion member 2, wherein the fourth bendable connection 29 is configured and arranged as a weakened wall part of the elongated expansion member 2 that connects the ninth end 24 of the third elongated element 23 and the second end 6 of the first tubular end portion 4 with each other. The twelfth end 28 of the fourth elongated element 26 of the second bendable assembly 22 of the elongated expansion member 2 is integral with the third end 8 of the second tubular end portion 7 of the elongated expansion member 2, wherein the sixth bendable connection 31 is configured and arranged as a weakened wall part of the elongated expansion member 2 that connects the twelfth end 28 of the fourth elongated element 26 and the third end 8 of the second tubular end portion 7 with each other.

[0094] The medical subassembly 1 further comprises an elongated actuator member 33 that has a second centerline 92 that is parallel to an axial direction of the elongated actuator member 33. Figure 1A shows that the elongated actuator member 33 comprises a first end portion 34, a second end portion 37 and a second intermediate portion 40.

[0095] The first end portion 34 has a first outer surface 64, a first outer diameter, a thirteenth end 35 and a fourteenth end 36. The thirteenth end 35 and the fourteenth end 36 are arranged opposite to each other in the axial direction of the elongated actuator member 33. The second end portion 37 has a first end part 38 and a second end part 39. The first end part 38 and the second end part 39 are arranged opposite to each other in the axial direction of the elongated actuator member 33. The first end part 38 has a second outer surface 90 and a second outer diameter that is smaller than the first outer diameter of the first end portion 34 and that is adapted to the first inner diameter of the first tubular end portion 4 of the elongated expansion member 2. The second end part 39 has a third outer surface 91 and a third outer diameter that is smaller than the second outer diameter of the first end part 38 and that is adapted to the second inner diameter of the second tubular end portion 7 of the elongated expansion member 2.

[0096] The second intermediate portion 40 is arranged to interconnect the fourteenth end 36 of the first end portion 34 and the first end part 38 of the second end portion 37. Figures 1 A, 1 D and 5B show that the second outer surface 90 of the first end part 38 is provided with a third threaded section 72. The threads of the third threaded section 72 are configured to enable cooperation with the threads of the first threaded section 71 that is provided to the first inner surface of the first tubular end portion 4 of the elongated expansion member 2, if the first end part 38 is at least partially accommodated in the first tubular end portion 4, wherein the first centerline 3 of the elongated expansion member 2 and the second centerline 92 of the elongated actuator member 33 are parallel. The third outer surface 91 of the second end part 39 is provided with a fourth threaded section 75 that comprises threads that are configured to enable cooperation with the threads of the second threaded section 74 that is provided to the second inner surface of the second tubular end portion 7 of the elongated expansion member 2, if the second end part 39 is accommodated in the second tubular end portion 7, wherein the first centerline 3 of the elongated expansion member 2 and the second centerline 92 of the elongated actuator member 33 are parallel.

[0097] Figure 1A shows that the medical subassembly 1 further comprises an elongated housing member 41 having a third centerline 93 that is parallel to an axial direction of the elongated housing member 41. The elongated housing member 41 comprises a fourth outer surface 42 and a third inner surface 43 that is arranged to face away from the fourth outer surface 42 as seen in the radial direction of the elongated housing member 41.

[0098] The elongated housing member 41 comprises a third tubular end portion 44, a fourth tubular end portion 47 and a tubular intermediate portion 50. The third tubular end portion 44 has a fifteenth end 45 and a sixteenth end 46. The fifteenth end 45 and the sixteenth end 46 are arranged opposite to each other in the axial direction of the elongated housing member 41. The fourth tubular end portion 47 has a seventeenth end 48 and an eighteenth end 49. The seventeenth end 48 and the eighteenth end 49 are arranged opposite to each other in the axial direction of the elongated housing member 41. The tubular intermediate portion 50 is arranged to interconnect the sixteenth end 46 of the third tubular end portion 44 and the seventeenth end 48 of the fourth tubular end portion 47.

[0099] Figures 1 A, 1 B and 2B show that the fourth tubular end portion 47 is provided with a first flange 54 and a second flange 55 that are arranged at the fourth outer surface 42 and are configured to extend in an axial direction of the elongated housing member 41. Figure 2B shows that the first flange 54 and the second flange 55 are arranged to divide the fourth outer surface 42 into a first section 56 and a second section 57 as seen in a circumferential direction of the elongated housing member 41 , and to allow, if the medical subassembly 1 is in use, establishment of a rotationally stable anchorage of the fourth tubular end portion 47 with a bone part.

[0100] The fourth tubular end portion 47 is provided with a first elongated through hole 58 that is provided at a fifth location in the first section 56. The first elongated through hole 58 is configured to extend in the axial direction of the elongated housing member 41. The fourth tubular end portion 47 is also provided with a second elongated through hole 59 that is provided at a sixth location in the second section 57. The second elongated through hole 59 is configured to extend in the axial direction of the elongated housing member 41.

[0101] Figure 1 A shows that the third tubular end portion 44 of the elongated housing member 41 comprises a first reception chamber 51 that is accessible via an opening 52 at the fifteenth end 45. The first reception chamber 51 is configured to accommodate the first end portion 34 of the elongated actuator member 33 after insertion of the elongated actuator member 33 and the elongated expansion member 2 in the elongated housing member 41 , wherein the second centerline 92 of the elongated actuator member 33 and the third centerline 93 of the elongated housing member 41 are parallel.

[0102] The third tubular end portion 44 of the elongated housing member 41 also comprises a second reception chamber 53 that is arranged in communication with the first reception chamber 51. The second reception chamber 53 is configured to allow, if the medical subassembly 1 is in use, transferring of the first end portion 34 of the elongated actuator member 33 from the first reception chamber 51 into the second reception chamber 53 in response to a first displacement of the elongated actuator member 33 in the axial direction of the elongated housing member 41 away from the fifteenth end 45. Figure 1D shows that if the first end portion 34 of the elongated actuator member 33 is accommodated in the second reception chamber 53, the second end portion 37 of the elongated actuator member 33 and the elongated expansion member 2 are accommodated in the fourth tubular end portion 47 of the elongated housing member 41.

[0103] The second reception chamber 53 is also configured to allow, if the medical subassembly 1 is in use, transferring of the first end portion 34 of the elongated actuator member 33 from the second reception chamber 53 into the first reception chamber 51 in response to a second displacement of the elongated actuator member 33 in the axial direction of the elongated housing member 41 towards the fifteenth end 45 to at least partially remove the second end portion 37 of the elongated actuator member 33 and the elongated expansion member 2 from the fourth tubular end portion 47 of the elongated housing member 41.

[0104] It is noted that if the first end portion 34 of the elongated actuator member 33 is accommodated in the second reception chamber 53, the first intermediate portion 10 of the elongated expansion member 2 is transferable, if the medical subassembly 1 is in use, between an inactive state and an activated state. This is illustrated in figures 3A-3C and figures 4A-4C.

[0105] Figure 3A shows a schematic perspective view of the first exemplary, non-limiting embodiment of the medical subassembly 1, wherein the first intermediate portion 10 of the elongated expansion member 2 is in the inactive state. Figure 4A shows a schematic combined view of the first exemplary, non-limiting embodiment of the medical subassembly 1 shown in figure 3A, wherein the elongated housing member 41 has been partially cut away to provide a view on the arrangement of elongated actuator member 33 and the elongated expansion member 2 if the first intermediate portion 10 of the elongated expansion member 2 is in the inactive state. Figures 3A and 4A show that in the inactive state, the first bendable assembly 11 and the second bendable assembly 22 are inside the fourth tubular end portion 47 of the elongated housing member 41 and extend substantially parallel to the axial direction of the elongated housing member 41. In the inactive state, the first bendable assembly 11 and the second bendable assembly 22 are arranged to prevent establishment of said rotationally stable anchorage of the elongated expansion member 2.

[0106] Transfer from the inactive state to the activated state can be accomplished by rotation of the elongated actuator member in a first direction around the second centerline 92 of the elongated actuator member 33. In this way, the first tubular end portion 4 of the elongated expansion member 2 and the second tubular end portion 7 of the elongated expansion member 2 are simultaneously movable towards each other as a result of the cooperation between the threads of the first threaded section 71 that is provided at the first inner surface of the first tubular end portion 4 of the elongated expansion member 2 and the threads of the third threaded section 72 that is provided at the second outer surface of the first end part 38 of the second end portion 37 of the elongated actuator member 33, and between the threads of the second threaded section 74 that is provided to the second inner surface of the second tubular end portion 7 of the elongated expansion member 2 and the threads of the fourth threaded section 75 that is provided to the third outer surface 91 of the second end part 39 of the second end portion 37 of the elongated actuator member 33.

[0107] Figure 3B shows a schematic perspective view of the first exemplary, non-limiting embodiment of the medical subassembly 1, wherein the first intermediate portion 10 of the elongated expansion member 2 is in a transitional state between the inactive state shown in figure 3A and the activated state shown in figure 3C. Figure 4B shows a schematic combined view of the first exemplary, non-limiting embodiment of the medical subassembly 1 shown in figure 3B, wherein the elongated housing member 41 has been partially cut away to provide a view on the arrangement of elongated actuator member 33 and the elongated expansion member 2 if the first intermediate portion 10 of the elongated expansion member 2 is in the transitional state between the inactive state and the activated state. Figures 3B and 4B show that in the transitional state the first bendable assembly 11 and the second bendable assembly 22 are arranged slightly slanted with respect to the axial direction of the elongated housing member 41.

[0108] Figure 3C shows a schematic perspective view of the first exemplary, non-limiting embodiment of the medical subassembly 1 according to the invention, wherein the first intermediate portion 10 of the elongated expansion member 2 is in an activated state. Figure 4C shows a schematic combined view of the first exemplary, non-limiting embodiment of the medical subassembly 1 shown in figure 4C, wherein the elongated housing member 41 has been partially cut away to provide a view on the arrangement of elongated actuator member 33 and the elongated expansion member 2 if the first intermediate portion 10 of the elongated expansion member is in the activated state. Figures 3C and 4C show that in the activated state the first bendable assembly 11 and the second bendable assembly 22 extend outside of the fourth tubular end portion 47 of the elongated housing member 41 via the first elongated through hole 58 and the second elongated through hole 59, respectively. In the activated state, the first bendable assembly 11 and the second bendable assembly 22 allow establishment of a rotationally stable anchorage of the elongated expansion member 2 with a bone part.

[0109] Transfer from the activated state to the inactive state can be accomplished by rotation of the elongated actuator member 33 in a second direction around the second centerline 92 of the elongated actuator member 33, wherein the second direction is opposite to said first direction. In this way, the first tubular end portion 4 of the elongated expansion member 2 and the second tubular end portion 7 of the elongated expansion member 2 are simultaneously movable away from each other as a result of the cooperation between the threads of the first threaded section 71 and the threads of the third threaded section 72, and between the threads of the second threaded section 74 and the threads of the fourth threaded section 75.

[0110] Figures 1D and 4A-4C show that the elongated actuator member 33 is snugly accommodated in the elongated expansion member 2, and that the assembly of the elongated expansion member 2 and the elongated actuator member 33 is snugly accommodated in the elongated housing member 41. In this way play between the elongated expansion member 2, the elongated actuator member 33 and the elongated housing member 41 can be minimized. In addition, contamination of the medical subassembly 1 by for example bone particles and / or tissue can be minimized.

[0111] Figures 1A, 1C and 2C show that the first end portion 34 of the elongated actuatior member 33 has a first cross-section as seen perpendicular to the second centerline 92 of the elongated actuator member 33, and that the third tubular end portion 44 of the elongated housing member 41 at the first reception chamber 51 has a second cross-section as seen perpendicular to the third centerline 93 of the elongated housing member 41. The first cross-section has a first non-circular outer circumference and the second cross-section has a first non-circular inner circumference that is adapted to the first non-circular outer circumference thereby preventing rotation of the elongated actuator member 33 and the elongated housing member 41 relative to each other around the second centerline 92 if, in use of the medical subassembly 1, the first end portion 34 of the elongated actuator member 33 is accommodated in the first reception chamber 51.

[0112] In this way, the first bendable assembly 11 and the second bendable assembly 22 of the elongated expansion member 2 can be aligned with the first elongated through hole 58 and the second elongated through hole 59, respectively, which are provided in the fourth tubular end portion 47 of the elongated housing member 41. Upon displacement of the first end portion 34 of the elongated actuator member 33 from the first reception chamber 51 to the second reception chamber 53 of the third tubular end portion 44 of the elongated housing member 41 , the first bendable assembly 11 of the elongated expansion member 2 remains aligned with the first elongated through hole 58 and is positioned opposite the first elongated through hole 58 as seen in a radial direction of the elongated housing member 41. Similarly, the second bendable assembly 22 of the elongated expansion member 2 remains aligned with the second elongated through hole 59 and is positioned opposite the second elongated through hole 59 as seen in a radial direction of the elongated housing member 41. If the first end portion 34 of the elongated actuator member 33 is in the second reception chamber 53, the first bendable assembly 11 and the second bendable assembly 22 are arranged to allow the first intermediate portion 10 of the elongated expansion member 2 to be transferable between the inactive state and the activated state as a result of moving the first tubular end portion 4 and the second tubular end portion 7 of the elongated expansion member 2 towards each other in the axial direction of the elongated expansion member 2.

[0113] In accordance with the first exemplary, non-limiting embodiment of the medical subassembly 1 shown in figures 1A, 1C and 2C, the first outer surface 64 of the elongated actuator member 33 in the first end portion 34 of the elongated actuator member 33 is provided with a first protrusion 65 to establish the first non-circular outer circumference of the first cross-section. The third inner surface 43 of the elongated housing member 41 in the first reception chamber 51 of the third tubular end portion 44 is provided with a first recess 66 to establish the first non-circular inner circumference of the second cross-section. The first recess 66 and the first protrusion 65 are adapted to each other. In this way, rotation of both the elongated actuator member 33 and the elongated expansion member 2 relative to the elongated housing member 41 can be prevented if the first end portion 34 of the elongated actuator member 33 is arranged in the first reception chamber 51. If the first end portion 34 of the elongated actuator member 33 is in the second reception chamber 53 of the third tubular end portion 44 of the elongated housing member 41, rotation of the elongated actuator member 33 and the elongated expansion member 2 relative to the elongated housing member 41 is allowed for transferring the first intermediate portion 10 of the elongated expansion member 2 from the inactive state to the activated state. In the activated state, the first bendable assembly 11 and the second bendable assembly 22 partially extend outside of the fourth tubular end portion 47 of the elongated housing member 41 via the first elongated through hole 58 and the second elongated through hole 59, respectively.'

[0114] Figures 1 B, 1 D and 4C show that the second tubular end portion 7 of the elongated expansion member 2 and the fourth tubular end portion 47 of the elongated housing member 41 are configured to provide a releasable coupling 63 if the second tubular end portion 7 and the fourth tubular end portion 47 are associated with each other. The releasable coupling 63 is configured to prevent, if the medical subassembly 1 is in use, rotation of the elongated expansion member 2 and the elongated housing member 41 relative to each other around the first centerline 3 of the elongated expansion member 2 upon rotation of the elongated actuator member 33 around the second centerline 92 of the elongated actuator member 33 for transferring the first intermediate portion 10 of the elongated expansion member 2 between the inactive state to the activated state. In this way, misalignment of the first bendable assembly 11 of the elongated expansion member 2 and the first elongated through hole 58 of the fourth tubular end portion 47 of the elongated housing member 41 , and misalignment of the second bendable assembly 22 of the elongated expansion member 2 and the second elongated through hole 59 of the fourth tubular end portion 47 of the elongated housing member 41 can be prevented.

[0115] The fourth end 9 of the second tubular end portion 7 of the elongated expansion member 2 is provided with a second recess 60, and the third inner surface 43 of the elongated housing member 41 in the fourth tubular end portion 47 is provided with a second protrusion 62 that is adapted to the second recess 60. If the second tubular end portion 7 is at least partially accommodated in the fourth tubular end portion 47, the second recess 60 and the second protrusion 62 enable establishment of the releasable coupling 63.

[0116] Figure 5A shows a schematic perspective cross-sectional view of a second exemplary, non-limiting embodiment of the medical subassembly 1 according to the invention. In accordance with the second exemplary, non-limiting embodiment of the medical subassembly 1, the third inner surface 43 of the elongated housing member 41 in the first reception chamber 51 of the third tubular end portion 44 of the elongated housing member 41 is provided with a fifth threaded section 68 that comprises threads that are configured to have a third orientation, and the second outer surface 64 of the elongated actuator member 33 in the first end portion 34 of the elongated actuator member 33 is provided with a sixth threaded section 69. The threads of the sixth threaded section 69 are configured to enable, if the medical subassembly 1 is in use, cooperation with the threads of the fifth threaded section 68 to allow accommodation of the first end portion 34 of the elongated actuator member 33 in the first reception chamber 51 of the third tubular end portion 44 of the elongated housing member 41 after insertion of the elongated actuator member 33 in the elongated housing member 41 via the opening 52 in the seventeenth end 45 of the third tubular end portion 44 of the elongated housing member 41 in response to rotation of the elongated actuator member 33 in the first direction around the second centerline 92 of the elongated actuator member 33.

[0117] Cooperation between the sixth threaded section 69 and the fifth threaded section 68, if the medical subassembly 1 is in use, also allows transferring of the first end portion 34 of the elongated actuator member 33 from the first reception chamber 51 into the second reception chamber 53 of the third tubular end portion 44 of the elongated housing member 41 in response to rotation of the elongated actuator member 33 in the first direction around the second centerline 92 of the elongated actuator member 33 to achieve the first displacement of the elongated actuator member 33 in the axial direction of the elongated housing member 41 away from the seventeenth end 45.

[0118] In addition, cooperation between the sixth threaded section 69 and the fifth threaded section 68, if the medical subassembly 1 is in use, allows transferring of the first end portion 34 of the elongated actuator member 33 from the second reception chamber 53 into the first reception chamber 51 in response to rotation of the elongated actuator member 33 in the second direction around the second centerline 92 of the elongated actuator member 33 to achieve the second displacement of the elongated actuator member 33 in the axial direction of the elongated housing member 41 towards the seventeenth end 45.

[0119] Furthermore, cooperation between the sixth threaded section 69 and the fifth threaded section 68, if the medical subassembly 1 is in use, allows removal of the first end portion 34 of the elongated actuator member 33 from the first reception chamber 51 via the opening 52 in the seventeenth end 45 of the third tubular end portion 44 in response to rotation of the elongated actuator member 33 in the second direction around the second centerline 92 of the elongated actuator member 33.

[0120] It is noted that the fifth threaded section 68 that is provided to the third inner surface of the elongated housing member 41 in the first reception chamber 51 of the third tubular end portion 44 of the elongated housing member can be configured in such a way, e.g. by choosing the pitch and / or the number of threads, to guarantee alignment of the first bendable assembly 11 and the second bendable assembly 22 of the elongated expansion member 2 with the first elongated through hole 58 and the second elongated through hole 59, respectively, which are provided in the fourth tubular end portion 47 of the elongated housing member, if the first end portion 34 of the elongated actuator member 33 is accommodated in the first reception chamber 51 of the third tubular end portion 44 of the elongated housing member 41. Upon displacement of the first end portion 34 of the elongated actuator member 33 from the first reception chamber 51 to the second reception chamber 53 of the third tubular end portion 44 of the elongated housing member 41 , the first bendable assembly 11 of the elongated expansion member 2 remains aligned with the first elongated through hole 58 and is positioned opposite the first elongated through hole 58 as seen in a radial direction of the elongated housing member 41.

[0121] Similarly, the second bendable assembly 22 of the elongated expansion member 2 remains aligned with the second elongated through hole 59 and is positioned opposite the second elongated through hole 59 as seen in a radial direction of the elongated housing member 41. If the first end portion 34 of the elongated actuator member 33 is in the second reception chamber 53 of the third tubular end portion 44 of the elongated housing member 41 , the first bendable assembly 11 and the second bendable assembly 22 are arranged to allow the first intermediate portion 10 of the elongated expansion member 2 to be transferable between the inactive state and the activated state as a result of moving the first tubular end portion 4 and the second tubular end portion 7 of the elongated expansion member 2 towards each other in the axial direction of the elongated expansion member 2.

[0122] Figures 1 D, 3A-3C and 5A show that the third tubular end portion 44 of the elongated housing member 41 has a fifth cross-section as seen perpendicular to the third centerline 93 of the elongated housing member 41. The fifth cross-section has a third non-circular outer circumference. The tubular intermediate portion 50 of the elongated housing member 41 has a sixth cross-section as seen perpendicular to the third centerline 93 of the elongated housing member 41. In accordance with the exemplary embodiments of the medical subassembly 1 shown in figures 1D, 3A-3C and 5A, the sixth cross-section has a fourth non-circular outer circumference that is the same as the third non-circular outer circumference of the fifth cross-section, i.e. the same shape and the same size. This is merely an example as the fifth crosssection and the sixth cross-section can have a different shape and the different shapes can be any suitable shapes such as any suitable polygonal shape, e.g. triangular, square, pentagonal, hexagonal. In addition, the third non-circular outer circumference and the fourth non-circular outer circumference can also have a different size.

[0123] Figures 1 D, 2B, 2C and 3A-3C show that the fourth outer surface 42 of the elongated housing member 41 in at least one of the first section 56 and the second section 57 of the fourth tubular end portion 47 of the elongated housing member 41 is provided with a flattened area 76 that is arranged parallel to the first flange 54 and the second flange 55. By providing the flattened area 76 in addition to the first flange 54 and the second flange 55, the rotational stability of the fourth tubular end portion 47 of the elongated housing member 41 can be increased.

[0124] Figures 1 B, 1 D and 3C show that the fourth tubular end portion 47 of the elongated housing member 41 has a third inner diameter, the first elongated through hole 58 has a first length as seen in the axial direction of the elongated housing member 41 , and the second elongated through hole 59 has a second length as seen in the axial direction of the elongated housing member 41. The first length and the second length are at least twice the third inner diameter of the fourth tubular end portion 47. In this way, sufficient space is provided for the first bendable assembly 11 and the second bendable assembly 22 of the first intermediate portion 10 of the elongated expansion member 2 to protrude outside of the fourth tubular end portion 47 of the elongated housing member 41 via the first elongated through hole 58 and the second elongated through hole 59, respectively.

[0125] Figures 1 C, 1D and 5A show that the first end portion 34 of the elongated actuator member 33 at the thirteenth end 35 is provided with a fifth recess 77. The first end portion 34 at the fifth recess 77 has a seventh cross-section as seen perpendicular to the second centerline 92 of the elongated actuator member 33. The seventh crosssection has a third non-circular inner circumference as a result of the fifth recess 77. The third non-circular inner circumference of the seventh cross-section can have any suitable shape such as any suitable polygonal shape, e.g. triangular, square, pentagonal, hexagonal. In this way, the fifth recess 77 can receive any suitable tool, e.g. a screw driver or a canning-in tool, for rotating the elongated actuator member 33 relative to the elongated housing member 41. The fifth recess 77 can be configured to have any suitable length in the axial direction of the elongated actuator member.

[0126] Figure 6 shows a schematic partially exploded view of a first exemplary, nonlimiting embodiment of a medical assembly 100 according to the invention. The medical assembly 100 is suitable for fixation of bone parts that are separated by a gap. The medical assembly 100 comprises a medical subassembly 1 according to the invention. It is noted that the gap can be a result of a bone fracture dividing a bone in separated bone parts. As a result of comprising the medical subassembly 1 according to the invention, the medical assembly 100 also has an improved sustainability and increased application range.

[0127] The medical assembly 100 comprises a plate 101 that in use of the medical assembly 100 is associated with a first bone part that is separated from a second bone part by a gap. The plate 101 is provided with two through holes 103, 104 that are configured and arranged to allow, if the medical assembly 100 is in use, establishment of a rotationally stable and releasable connection of the plate 101 with the first bone part.

[0128] The medical assembly 100 also comprises an elongated tubular member 102 that is associated with the plate 101 and arranged at a non-zero angle relative to the plate 101. The elongated tubular member 102 is configured to accommodate the medical subassembly 1, and to allow, if the medical assembly 100 is in use, sliding movement of the medical subassembly 1 and the plate 101 relative to each other.

[0129] Figure 7 shows a schematic view of an exemplary use situation in which the plate 101 of the medical assembly 100 in accordance with the first exemplary, non-limiting embodiment of the medical assembly 100 shown in figure 6 is rotationally stable connected with the first bone part 121 , in this case a femur. The medical subassembly 1 of the medical assembly 100 is rotationally stable anchored inside the second bone part 122, in this case a femur head, that is separated from the femur by a fracture 120. The medical subassembly 1 is slidingly accommodated in the elongated tubular member 102 of the medical assembly 100. In this way, the medical assembly 100 can absorb forces that are directed transverse to the axial direction of the elongated housing member 41 of the medical subassembly 1 and transmit the forces to the plate 101 , whilst the elongated housing member 41 that is rotationally stable anchored inside the femur head, is allowed to slide relative to the plate 101 in an axial direction of the elongated tubular member 102 towards the femur. As a result, the femur and the femur head are firmly pressed together, which is beneficial for the healing process.

[0130] The present invention can be summarized in the following clauses, wherein clauses 1 to 15 correspond to the appended claims 1 to 15.

[0131] Clause 16. Use of a medical subassembly for releasable and rotationally stable anchorage within a bone part according to clause 1. Clause 17. Use of a medical assembly according to clause 13 for the stable fixation of neck fractures and stable intertrochanteric fractures of the femur.

[0132] Clause 18. A method for fixing bone parts that are separated by a gap, the method comprising:

[0133] - reducing a gap separating a first bone part and a second bone part;

[0134] - providing a channel that extends through the first bone part and into the second bone part across the gap;

[0135] - providing the medical assembly according to clause 13;

[0136] - inserting a medical subassembly of the medical assembly into the channel;

[0137] - anchoring a first flange and a second flange of a fourth tubular end portion of an elongated housing member of the medical subassembly in the second bone part;

[0138] - rotating an elongated actuator member of the medical subassembly in a first direction around a second centerline of the elongated actuator member to anchor a first bendable assembly and a second bendable assembly of the fourth tubular end portion in the second bone part; and

[0139] - attaching a plate of the medical assembly with the first bone part by fixing a first screw in the first bone part via a first through hole that is provided to the plate, and fixing a second screw in the first bone part via a second through hole that is provided to the plate.

[0140] The present invention can be summarized as relating to a medical subassembly 1 for releasable and rotationally stable anchorage within a bone part if the medical subassembly 1 is in use. As a result of an internal construction of an elongated housing member 41 of the medical subassembly 1 and as a result of ways in which an elongated expansion member 2 and an elongated actuator member 33 are arrangeable with respect to each other and with respect to the elongated housing member 41 , the medical subassembly 1 has an improved sustainability and an increased application range compared to known medical devices in the field. The invention also relates to a medical assembly 100 that is suitable for fixation of bone parts that are separated by a gap. The medical assembly 100 comprises the medical subassembly 1 according to the invention.

[0141] It will be clear to a person skilled in the art that the scope of the present invention is not limited to the examples discussed in the foregoing but that several amendments and modifications thereof are possible without deviating from the scope of the present invention as defined by the attached claims. In particular, combinations of specific features of various aspects of the invention may be made. An aspect of the invention may be further advantageously enhanced by adding a feature that was described in relation to another aspect of the invention. While the present invention has been illustrated and described in detail in the figures and the description, such illustration and description are to be considered illustrative or exemplary only, and not restrictive. The present invention is not limited to the disclosed embodiments. Variations to the disclosed embodiments can be understood and effected by a person skilled in the art in practicing the claimed invention, from a study of the figures, the description and the attached claims. In the claims, the word “comprising” does not exclude other steps or elements, and the indefinite article “a” or “an” does not exclude a plurality. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. Any reference numerals in the claims should not be construed as limiting the scope of the present invention.

Claims

CLAIMS1. A medical subassembly (1) for releasable and rotationally stable anchorage within a bone part if the medical subassembly (1) is in use, the medical subassembly (1) comprising:- an elongated expansion member (2) having a first centerline (3) that is parallel to an axial direction of the elongated expansion member (2), the elongated expansion member (2) comprising:• a first tubular end portion (4) that has a first inner surface, a first inner diameter, a first end (5), and a second end (6), the first end (5) and the second end (6) being arranged opposite to each other in the axial direction of the elongated expansion member (2);• a second tubular end portion (7) that has a second inner surface, a second inner diameter that is smaller than the first inner diameter of the first tubular end portion (4), a third end (8) and a fourth end (9), the third end (8) and the fourth end (9) being arranged opposite to each other in the axial direction of the elongated expansion member (2); and• a first intermediate portion (10) that is arranged to interconnect the second end (6) of the first tubular end portion (4) and the third end (8) of the second tubular end portion (7); wherein the first inner surface of the first tubular end portion (4) is provided with a first threaded section (71) that comprises threads that are configured to have a first orientation and / or the second inner surface of the second tubular end portion (7) is provided with a second threaded section (74) that comprises threads that are configured to have a second orientation that is reverse to the first orientation of the threads of the first threaded section (71) of the first tubular end portion (4), and wherein the first intermediate portion (10) comprises:■ a first bendable assembly (11) comprising a first elongated element (12) having a fifth end (13) and a sixth end (14), the fifth end (13) and the sixth end (14) being arranged opposite to each other in the axial direction of the elongated expansion member (2), and a second elongated element (15) having a seventh end (16) and an eighth end (17), the seventh end (16) and the eighth end (17) being arranged opposite to each other in the axial direction of the elongated expansion member (2), the fifth end (13) of the first elongated element (12) and the first tubular end portion (4) being associatedat a first location at the second end (6) of the first tubular end portion (4) via a first bendable connection (18), the sixth end (14) of the first elongated element (12) and the seventh end (16) of the second elongated element (15) being associated via a second bendable connection (19), and the eighth end (17) of the second elongated element (15) and the second tubular end portion (7) being associated at a second location at the third end (8) of the second tubular end portion (7) via a third bendable connection (20), the first bendable connection (18), the second bendable connection (19) and the third bendable connection (20) being configured and arranged to allow the first bendable assembly (11) to be displaceable in a radial direction of the elongated expansion member (2), wherein at least one of the first bendable connection (18), the second bendable connection (19) and the third bendable connection (20) comprises a first axle (21);■ a second bendable assembly (22) comprising a third elongated element (23) having a ninth end (24) and a tenth end (25), the ninth end (24) and the tenth end (25) being arranged opposite to each other in the axial direction of the elongated expansion member (2), and a fourth elongated element (26) having an eleventh end (27) and a twelfth end (28), the eleventh end (27) and the twelfth end (28) being arranged opposite to each other in the axial direction of the elongated expansion member (2), the ninth end (24) of the third elongated element (23) and the first tubular end portion (4) being associated at a third location at the second end (6) of the first tubular end portion (4) via a fourth bendable connection (29), the tenth end (25) of the third elongated element (23) and the eleventh end (27) of the fourth elongated element (26) being associated via a fifth bendable connection (30), and the twelfth end (28) of the fourth elongated element (26) and the second tubular end portion (7) being associated at a fourth location at the third end (8) of the second tubular end portion (7) via a sixth bendable connection (31), the fourth bendable connection (29), the fifth bendable connection (30) and the sixth bendable connection (31) being configured and arranged to allow the second bendable assembly (22) to be displaceable in the radial direction of the elongated expansion member (2), wherein at least one of the fourth bendable connection (29), the fifth bendable connection (30) and the sixth bendable connection (31) comprises a second axle (32);- an elongated actuator member (33) having a second centerline (92) that is parallel to an axial direction of the elongated actuator member (33), the elongated actuator member (33) comprising:• a first end portion (34) that has a first outer surface (64), a first outer diameter, a thirteenth end (35) and a fourteenth end (36), the thirteenth end (35) and the fourteenth end (36) being arranged opposite to each other in the axial direction of the elongated actuator member (33);• a second end portion (37) that has a first end part (38) and a second end part (39), the first end part (38) and the second end part (39) being arranged opposite to each other in the axial direction of the elongated actuator member (33), wherein the first end part (38) has a second outer surface (90) and a second outer diameter that is smaller than the first outer diameter of the first end portion (34) and that is adapted to the first inner diameter of the first tubular end portion (4) of the elongated expansion member (2), and wherein the second end part (39) has a third outer surface (91) and a third outer diameter that is smaller than the second outer diameter of the first end part (38) and that is adapted to the second inner diameter of the second tubular end portion (7) of the elongated expansion member (2); and• a second intermediate portion (40) that is arranged to interconnect the fourteenth end (36) of the first end portion (34) and the first end part (38) of the second end portion (37); wherein the second outer surface (90) of the first end part (38) is provided with a third threaded section (72) that comprises threads that are configured to enable cooperation with the threads of the first threaded section (71) that is provided to the first inner surface of the first tubular end portion (4), if the first end part (38) is at least partially accommodated in the first tubular end portion (4) of the elongated expansion member (2), wherein the first centerline (3) of the elongated expansion member (2) and the second centerline (92) of the elongated actuator member (33) are parallel and / or the third outer surface (91) of the second end part (39) is provided with a fourth threaded section (75) that comprises threads that are configured to enable cooperation with the threads of the second threaded section (74) that is provided to the second inner surface of the second tubular end portion (7), if the second end part (39) is accommodated in the second tubular end portion (7) of the elongated expansion member (2),wherein the first centerline (3) of the elongated expansion member (2) and the second centerline (92) of the elongated actuator member (33) are parallel; and - an elongated housing member (41) having a third centerline (93) that is parallel to an axial direction of the elongated housing member (41), the elongated housing member (41) comprising:• a fourth outer surface (42) and a third inner surface (43) that is arranged to face away from the fourth outer surface (42) as seen in the radial direction of the elongated housing member (41);• a third tubular end portion (44) having a fifteenth end (45) and a sixteenth end (46), the fifteenth end (45) and the sixteenth end (46) being arranged opposite to each other in the axial direction of the elongated housing member (41);• a fourth tubular end portion (47) having a seventeenth end (48) and an eighteenth end (49), the seventeenth end (48) and the eighteenth end (49) being arranged opposite to each other in the axial direction of the elongated housing member (41); and• a tubular intermediate portion (50) that is arranged to interconnect the sixteenth end (46) of the third tubular end portion (44) and the seventeenth end (48) of the fourth tubular end portion (47); wherein the fourth tubular end portion (47) is provided with:■ a first flange (54) that is arranged at the fourth outer surface (42) and configured to extend in an axial direction of the elongated housing member (41);■ a second flange (55) that is arranged at the fourth outer surface (42) and configured to extend in the axial direction of the elongated housing member (41), the first flange (54) and the second flange (55) being arranged to: o divide the fourth outer surface (42) into a first section (56) and a second section (57) as seen in a circumferential direction of the elongated housing member (41); and o allow, if the medical subassembly (1) is in use, establishment of a rotationally stable anchorage of the fourth tubular end portion (47) with a bone part;■ a first elongated through hole (58) that is provided at a fifth location in said first section (56), the first elongated through hole (58) being configured to extend in the axial direction of the elongated housing member (41); and■ a second elongated through hole (59) that is provided at a sixth location in said second section (57), the second elongated through hole (59) being configured to extend in the axial direction of the elongated housing member (41); and wherein the third tubular end portion (44) of the elongated housing member (41) comprises:■ a first reception chamber (51) that is accessible via an opening (52) at the fifteenth end (45), the first reception chamber (51) being configured to accommodate the first end portion (34) of the elongated actuator member (33) after insertion of the elongated actuator member (33) and the elongated expansion member (2) in the elongated housing member (41), wherein the second centerline (92) of the elongated actuator member (33) and the third centerline (93) of the elongated housing member (41) are parallel; and■ a second reception chamber (53) that is arranged in communication with the first reception chamber (51), the second reception chamber (53) being configured to allow, if the medical subassembly (1) is in use:• transferring of the first end portion (34) of the elongated actuator member (33) from the first reception chamber (51) into the second reception chamber (53) in response to a first displacement of the elongated actuator member (33) in the axial direction of the elongated housing member (41) away from the fifteenth end (45), wherein if the first end portion (34) is accommodated in the second reception chamber (53), the second end portion (37) of the elongated actuator member (33) and the elongated expansion member (2) are at least partially accommodated in the fourth tubular end portion (47) of the elongated housing member (41); and• transferring of the first end portion (34) of the elongated actuator member (33) from the second reception chamber (53) into the first reception chamber (51) in response to a second displacement of the elongated actuator member (33) in the axial direction of the elongated housing member (41) towards the fifteenth end (45) to at least partially remove the second end portion (37) of the elongated actuator member (33) and the elongated expansion member (2) from the fourth tubular end portion (47) of the elongated housing member (41); and wherein if the first end portion (34) of the elongated actuator member (33) is accommodated in the second reception chamber (53):o the first intermediate portion (10) of the elongated expansion member (2) is transferable, if the medical subassembly (1) is in use:- from an inactive state to an activated state in response to rotation of the elongated actuator member (33) in a first direction around the second centerline (92) of the elongated actuator member (33), wherein if the first intermediate portion (10) is in the activated state, the first bendable assembly (11) is arranged partially extending outside of the fourth tubular end portion (47) via the first elongated through hole (58), and the second bendable assembly (22) is arranged partially extending outside of the fourth tubular end portion (47) via the second elongated through hole (59), wherein the first bendable assembly (11) and the second bendable assembly (22) allow establishment of a rotationally stable anchorage of the elongated expansion member (2) with a bone part; and- from an activated state to an inactive state in response to rotation of the elongated actuator member (33) in a second direction around the second centerline (92) of the elongated actuator member (33), the second direction being opposite to said first direction, wherein if the first intermediate portion (10) is in the inactive state, the first bendable assembly (11) and the second bendable assembly (22) are arranged to prevent establishment of said rotationally stable anchorage of the elongated expansion member (2).

2. The medical subassembly (1) according to claim 1 , wherein the first end portion (34) of the elongated actuator member (33) has a first cross-section as seen perpendicular to the second centerline (92) of the elongated actuator member (33), and the third tubular end portion (44) of the elongated housing member (41) at the first reception chamber (51) has a second cross-section as seen perpendicular to the third centerline (93) of the elongated housing member (41), wherein the first cross-section has a first non-circular outer circumference and the second cross-section has a first non-circular inner circumference that is adapted to the first non-circular outer circumference thereby preventing rotation of the elongated actuator member (33) and the elongated housing member (41) relative to each other around the second centerline (92) if, in use of the medical subassembly (1), the first end portion (34) ofthe elongated actuator member (33) is accommodated in the first reception chamber (51).

3. The medical subassembly (1) according to claim 2, wherein the first outer surface (64) of the elongated actuator member (33) in the first end portion (34) of the elongated actuator member (33) is provided with a first protrusion (65) to establish the first non-circular outer circumference of the first cross-section, and the third inner surface (43) of the elongated housing member (41) in the first reception chamber (51) of the third tubular end portion (44) is provided with a first recess (66) to establish the first non-circular inner circumference of the second cross-section, the first recess (66) being adapted to the first protrusion (65).

4. The medical subassembly (1) according to any one of the claims 1 to 3, wherein the second tubular end portion (7) of the elongated expansion member (2) and the fourth tubular end portion (47) of the elongated housing member (41) are configured to provide a releasable coupling (63) if the second tubular end portion (7) and the fourth tubular end portion (47) are associated with each other, the releasable coupling (63) being configured to prevent, if the medical subassembly (1) is in use, rotation of the elongated expansion member (2) and the elongated housing member (41) relative to each other around the first centerline (3) of the elongated expansion member (2) upon rotation of the elongated actuator member (33) around the second centerline (92) of the elongated actuator member (33) for transferring the first intermediate portion (10) of the elongated expansion member (2) between the inactive state to the activated state.

5. The medical subassembly (1) according to claim 4, wherein the fourth end (9) of the second tubular end portion (7) of the elongated expansion member (2) is provided with a second recess (60), and the third inner surface (43) of the elongated housing member (41) in the fourth tubular end portion (47) is provided with a second protrusion (62) that is adapted to the second recess (60), wherein if the second tubular end portion (7) is at least partially accommodated in the fourth tubular end portion (47), the second recess (60) and the second protrusion (62) enable establishment of the releasable coupling (63).

6. The medical subassembly (1) according to claim 1 , wherein the third inner surface (43) of the elongated housing member (41) in the first reception chamber (51) of the third tubular end portion (44) of the elongated housing member (41) is provided with a fifth threaded section (68) that comprises threads that are configured to have a third orientation, and wherein the second outer surface (64) of the elongated actuator member (33) in the first end portion (34) of the elongated actuator member (33) is provided with a sixth threaded section (69) that comprises threads that are configured to enable, if the medical subassembly (1) is in use, cooperation with the threads of the fifth threaded section (68) to allow at least one of:- accommodation of the first end portion (34) of the elongated actuator member (33) in the first reception chamber (51) of the third tubular end portion (44) of the elongated housing member (41) after insertion of the elongated actuator member (33) in the elongated housing member (41) via the opening (52) in the seventeenth end (45) of the third tubular end portion (44) of the elongated housing member (41) in response to rotation of the elongated actuator member (33) in the first direction around the second centerline (92) of the elongated actuator member (33);- transferring of the first end portion (34) of the elongated actuator member (33) from the first reception chamber (51) into the second reception chamber (53) of the third tubular end portion (44) of the elongated housing member (41) in response to rotation of the elongated actuator member (33) in the first direction around the second centerline (92) of the elongated actuator member (33) to achieve the first displacement of the elongated actuator member (33) in the axial direction of the elongated housing member (41) away from the seventeenth end (45);- transferring of the first end portion (34) of the elongated actuator member (33) from the second reception chamber (53) into the first reception chamber (51) in response to rotation of the elongated actuator member (33) in the second direction around the second centerline (92) of the elongated actuator member (33) to achieve the second displacement of the elongated actuator member (33) in the axial direction of the elongated housing member (41) towards the seventeenth end (45); and- removal of the first end portion (34) of the elongated actuator member (33) from the first reception chamber (51) via the opening (52) in the seventeenth end (45) of the third tubular end portion (44) in response to rotation of the elongatedactuator member (33) in the second direction around the second centerline (92) of the elongated actuator member (33).

7. The medical subassembly (1) according to any one of the claims 1 to 6, wherein the elongated expansion member (2), the elongated actuator member (33) and the elongated housing member (41) comprise surgical stainless steel.

8. The medical subassembly (1) according to any one of the claims 1 to 7, wherein the third tubular end portion (44) of the elongated housing member (41) has a fifth cross-section as seen perpendicular to the third centerline (93) of the elongated housing member (41), the fifth cross-section having a third non-circular outer circumference and / or the tubular intermediate portion (50) of the elongated housing member (41) has a sixth cross-section as seen perpendicular to the third centerline (93) of the elongated housing member (41), the sixth cross-section having a fourth non-circular outer circumference.

9. The medical subassembly (1) according to any one of the claims 1 to 8, wherein the fourth outer surface (42) of the elongated housing member (41) in at least one of the first section (56) and the second section (57) of the fourth tubular end portion (47) of the elongated housing member (41) is provided with a flattened area (76) that is arranged parallel to the first flange (54) and the second flange (55).

10. The medical subassembly (1) according to any one of the claims 1 to 9, wherein the fourth tubular end portion (47) of the elongated housing member (41) has a third inner diameter, the first elongated through hole (58) has a first length as seen in the axial direction of the elongated housing member (41) and the second elongated through hole (59) has a second length as seen in the axial direction of the elongated housing member (41), wherein the first length and the second length are at least twice the third inner diameter of the fourth tubular end portion (47).

11. The medical subassembly (1) according to any one of the claims 1 to 10, wherein the first end portion (34) of the elongated actuator member (33) at the thirteenth end (35) is provided with a fifth recess (77), wherein the first end portion (34) at the fifth recess (77) has a seventh cross-section as seen perpendicular to the second centerline (92) of the elongated actuator member (33), the seventh cross-section having a third non-circular inner circumference as a result of the fifth recess (77).

12. A medical assembly (100) suitable for fixation of bone parts that are separated by a gap, the medical assembly (100) comprising a medical subassembly (1) according to any one of the claims 1 to 11.

13. The medical assembly (100) according to claim 12 comprises: a plate (101) that in use of the medical assembly (100) is associated with a first bone part that is separated from a second bone part by a gap; and an elongated tubular member (102) that is associated with the plate (101) and arranged at a non-zero angle relative to the plate (101), the elongated tubular member (102) being configured to:• accommodate the medical subassembly (1); and• allow, if the medical assembly (100) is in use, sliding movement of the medical subassembly (1) and the plate (101) relative to each other.

14. The medical assembly (100) according to claim 13, wherein the plate (101) is provided with at least two through holes (103, 104) that are configured and arranged to allow, if the medical assembly (100) is in use, establishment of a rotationally stable and releasable connection of the plate (101) with the first bone part.

15. The medical assembly (100) according to claim 13 or 14, wherein at least one of the plate (101) and the elongated tubular member (102) comprises surgical stainless steel.

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