Assembly for releasably attaching a surgical device to a patient or tool - Patent application

Abstract

The assembly (10) includes a patient mount (14) securable to a pin (16) configured to engage a patient, the patient mount defining an operable top portion (18) carrying a first magnetic body (20), and a device mount (22) securable to the device (12), the device mount defining an operable bottom portion (24) carrying at least one complementary second magnetic body (26), the bottom portion defining a recess (28) dimensioned to receive a length of at least one of the pin and the patient mount and allow the device mount to rotate relative to the patient mount. When the recess is attached to at least one of the pin and the patient mount, the bottom portion is adjacent to and spaced from the top portion. When the first magnetic body is aligned with the second magnetic body, the mounts (14, 22) are drawn toward each other, inhibiting relative rotation.

Description

[Technical Field]

[0001] The present disclosure relates generally to assemblies for releasably attaching a surgical device to a patient or a surgical tool, and more particularly to such assemblies for attaching a surgical device to a bone pin or tool shaft. [Background technology]

[0002] During a surgical procedure, various devices may need to be releasably attached to the patient, such as attaching digital sensing devices to the patient to measure the patient's orientation and / or position, or a portion of the patient, such as a limb. Other devices that may be attached to the patient include active or passive trackers. Trackers may be configured to allow the patient's orientation and / or position to be monitored by optical imaging during surgery or by radiographic imaging before or during surgery. Such devices may require rigid attachment to the patient to inhibit relative movement. This is typically achieved by attaching the device to one or more bone pins having threaded ends that are fixed into the patient's bones.

[0003] Surgical procedures may also require releasably attaching various devices to surgical tools, such as attaching digital sensing devices to the tool to measure the tool's orientation and / or position. Such devices may measure orientation and / or position relative to the patient to help guide the surgical procedure, increasing accuracy and / or efficiency. These devices may require rigid attachment to the tool to inhibit relative movement. This is generally achieved by attaching the device to the tool using a clamp-type mechanism configured to grasp a portion of the tool, typically the tool shaft or handle.

[0004] Some surgical procedures may require transferring a device from attachment to a patient to attachment to a tool. Then, in some instances, the device may be transferred from the tool back to the patient. Such situations typically require a device mounting system that is easily manipulated by surgical staff and / or minimizes injury or discomfort to the patient.

[0005] Any discussion of documents, acts, materials, devices, articles or the like which has been included in this specification should not be construed as an admission that any or all of that matter was common general knowledge in the art to which the present disclosure pertains by virtue of its existence prior to the priority date of each of the appended claims. Summary of the Invention

[0006] According to some disclosed aspects, an assembly for releasably attaching a surgical device to a patient is provided. The assembly includes a patient mount fixably securable to a pin configured for threaded engagement with the patient, the patient mount defining an operable top portion carrying at least one first magnetic body, and a device mount fixably securable to the surgical device, the device mount defining an operable bottom portion carrying at least one complementary second magnetic body, the bottom portion defining a recess dimensioned to receive a defined length of at least one of the pin and the patient mount and to allow the device mount to rotate relative to the patient mount. One or more of the at least one first magnetic body and the at least one second magnetic body comprises a magnet. When the recess in the device mount is attached to at least one of the pin and the patient mount, the bottom of the device mount is positioned immediately adjacent to and spaced apart from the top of the patient mount, and when the at least one first magnetic body is aligned with the at least one second magnetic body, the magnets attract the mounts toward each other, preventing relative rotation of the mounts.

[0007] The patient mount may carry a pair of spaced apart first magnetic bodies, each with a magnet arranged to have a corresponding polarity, and the device mount may carry a pair of spaced apart second magnetic bodies, each with a magnet arranged to have a corresponding polarity and an opposite polarity to the first magnetic bodies.

[0008] The upper portion of the patient mount may carry a third magnetic body interposed between the pair of first magnetic bodies, and the third magnetic body may comprise a magnet arranged to have a polarity that does not correspond to the first magnetic bodies.

[0009] The patient mount may carry a pair of spaced apart first magnetic bodies, each of which comprises a permanent magnet, and the device mount may carry a pair of spaced apart second magnetic bodies, each of which comprises a magnetizable material that enables it to form a temporary magnet.

[0010] The patient mount may be configured to position the first pair of magnetic bodies so as to be evenly spaced radially from the pin, and the device mount may be configured to position the second pair of magnetic bodies at a complementary spacing to the first magnetic bodies to enable attachment of the device mount to at least one of the pin and the patient mount and alignment of the first magnetic bodies with the second magnetic bodies in one of two relative positions.

[0011] The patient mount may be securable along the pin such that the end of the pin is spaced from the upper side by more than a defined length to allow the device mount to be attached to the pin.

[0012] The patient mount may be permanently joined to the pin or may be integrally formed with the pin.

[0013] According to some disclosed aspects, an assembly for releasably attaching a surgical device to a patient is provided, the assembly including: a patient mount including a pin configured for threaded engagement with the patient, the patient mount defining an operable top portion carrying at least one first magnetic body; and a device mount fixably securable to the surgical device, the device mount defining an operable bottom portion carrying at least one complementary second magnetic body, the bottom portion defining a recess dimensioned to receive the patient mount and allow the device mount to rotate relative to the patient mount. One or more of the at least one first magnetic body and the at least one second magnetic body comprise a magnet. When the recess of the device mount is attached to the patient mount, the bottom portion of the device mount is positioned immediately adjacent to but spaced from the top portion of the patient mount, and when the at least one first magnetic body is aligned with the at least one second magnetic body, the one or more magnets attract the mounts toward each other, allowing relative rotation of the mounts to be inhibited.

[0014] According to further disclosed aspects, there is provided a surgical device assembly including a surgical navigation device operable to determine orientation and an assembly as described in any of the preceding paragraphs, wherein a device mount forms a base portion of the surgical navigation device.

[0015] The surgical navigation device may include one or more sensors operable to detect magnetic fields, and the surgical navigation device may be configured to determine when the device is attached to the patient mount in response to the one or more sensors detecting the magnetic fields of one or more of the magnetic materials.

[0016] The surgical navigation device may be configured to determine the orientation of the device relative to the patient mount in response to one or more sensors that detect the magnetic field of one or more of the magnetic materials.

[0017] According to other disclosed aspects, there is provided an assembly for releasably attaching a surgical device to a surgical tool having a shaft, the assembly including: a tool mount having one side defining a receiving portion for receiving a portion of the shaft and an opposite side defining an engagement portion, the receiving portion associated with a retention mechanism including a strap securable across the receiving portion, the retention mechanism operable to adjust an effective length of the strap to capture the shaft between the strap and the receiving portion; and a device mount fixably securable to the surgical device, the device mount configured to releasably engage the engagement portion to enable attachment of the surgical device to the surgical tool.

[0018] The receiving portion may include at least one pair of abutment surfaces, the or each pair of surfaces being arranged to diverge away from one another to allow reception of a portion of the shaft between the surfaces.

[0019] The receiving portion includes a pair of abutment surfaces, each of which may be planar.

[0020] The tool mount can define an aperture dimensioned to receive the strap, and the retention mechanism can be configured to hold the strap in place when positioned to extend through the aperture.

[0021] The retention mechanism may include teeth disposed within the aperture, and the strap may be configured to engage the teeth.

[0022] The aperture may define a channel that receives the tooth, and the strap may define a protrusion shaped to slidingly engage the tooth when the strap is slid into the channel.

[0023] The retention mechanism may include a depressible tab associated with the aperture, the tab being biased toward one side of the aperture to capture the strap and inhibit the strap from being pulled through the aperture in at least one direction.

[0024] The retention mechanism may include a pivotable member associated with the aperture, which, when pivoted to a locked position, captures the strap and inhibits the strap from being pulled through the aperture in at least one direction.

[0025] The pivotable member may be arranged such that pivoting the pivotable member towards the engagement portion moves the pivotable member from the locked position.

[0026] The retention mechanism may include a hook and loop fastener secured to the receiving portion and carried by the strap, the strap being positionable such that the hook and loop fastener engages to hold the strap in place.

[0027] The strap may define a free end arranged to be manually grasped and pulled away from the receiving portion to adjust the effective length.

[0028] The strap may define a free end that may define a shaped ring structure to aid in gripping.

[0029] The strap may define a fixed end releasably secured to the receiving portion.

[0030] The tool mount and the device mount may each define a portion of a bayonet coupling such that the portions are axially engaged and rotated relative to one another to engage the mounts together.

[0031] The engaging portion has an operable top portion defining a protrusion, the top portion carrying at least one first magnetic body, and the device mount may define an operable bottom portion carrying at least one complementary second magnetic body and defining a recess dimensioned to receive at least a portion of the protrusion, wherein one or more of the at least one first magnetic body and the at least one second magnetic body comprise magnets such that when the device mount is attached to the protrusion and the at least one first magnetic body is aligned with the at least one second magnetic body, the one or more magnets can attract the mounts toward each other.

[0032] The protrusions and recesses are shaped to allow rotation of the tool mount relative to the device mount, such that alignment of the at least one first magnetic body with the at least one second magnetic body can inhibit relative rotation.

[0033] The tool mount may carry a pair of first magnetic bodies, each of which comprises a magnet arranged to have corresponding polarities to one another, and the device mount may carry a pair of second magnetic bodies, each of which comprises a magnet arranged to have corresponding polarities to one another and opposite polarities to the first magnetic bodies.

[0034] The tool mount may carry a pair of first magnetic bodies, each of the first magnetic bodies comprising a magnet arranged with corresponding polarity, and the device mount carries a pair of second magnetic bodies, each of the second magnetic bodies formed from a ferrous metal.

[0035] According to further disclosed aspects, there is provided a surgical device assembly including a surgical navigation device operable to determine orientation and an assembly as described in any of the preceding paragraphs, wherein a device mount forms a base portion of the surgical navigation device.

[0036] The surgical navigation device may include one or more sensors operable to detect a magnetic field and positioned to detect the polarity of the at least one second magnetic body, and the surgical navigation device may be configured to determine when the device is attached to the tool mount in response to the one or more sensors detecting the magnetic field of the at least one second magnetic body.

[0037] In another disclosed aspect, a kit for releasably attaching a surgical device to a patient or a surgical tool having a shaft, the kit including a patient mount fixably securable to a pin configured to threadably engage the patient, the patient mount defining an operable upper portion that carries at least one first magnetic material; and a tool mount having one side defining a receiving portion for receiving a portion of the shaft of the surgical tool and an opposite side defining an engagement portion, the receiving portion associated with a retention mechanism including a strap securable across the receiving portion. The kit includes a tool mount, the retaining mechanism operable to adjust the effective length of the strap to capture the shaft between the strap and the receiving portion, the engagement portion having an operable top portion defining a protrusion, the top portion carrying at least one second magnetic material, and a device mount fixably securable to a surgical device, the device mount defining an operable bottom portion carrying at least one third magnetic material, the bottom portion configured to receive a portion of at least one of the pin and the patient mount, the bottom portion further configured to at least partially receive the protrusion. At least two of the first, second, and third magnetic materials comprise magnets. When the device mount is attached to at least one of the pin and the patient mount or to the protrusion and the at least one third magnetic material is aligned with the at least one first magnetic material or the at least one second magnetic material, the magnets attract the mounts toward each other, enabling the surgical device to be held to the patient or surgical tool.

[0038] In a further disclosed aspect, a surgical device assembly is provided that includes a surgical navigation device operable to determine orientation and an assembly as described in the preceding paragraph, wherein a device mount forms a base portion of the surgical navigation device.

[0039] Throughout this specification, the word "comprise" or variations thereof (e.g., "comprises" or "comprising") will be understood to mean the inclusion of a stated element, integer, or step, or group of elements, integers, or steps, but not the exclusion of any other element, integer, or step, or group of elements, integers, or steps.

[0040] It will be understood that embodiments may include the steps, features, and / or integers disclosed herein or indicated individually or collectively in the specification of this application, and any and all combinations of two or more of such steps or features.

[0041] Embodiments will now be described, by way of example only, with reference to the accompanying drawings, in which: [Brief explanation of the drawings]

[0042] [Figure 1] FIG. 1 is a front view of an assembly for releasably attaching a surgical device to a patient. [Figure 2] FIG. 2 is a perspective exploded view of the assembly shown in FIG. 1. [Figure 3] FIG. 2 is a detailed cross-sectional front view of the assembly shown in the previous figure. [Figure 4A] FIG. 2 is a schematic top view of the assembly shown in the previous figure. [Figure 4B] FIG. 2 is a schematic top view of the assembly shown in the previous figure. [Figure 4C] FIG. 2 is a schematic top view of the assembly shown in the previous figure. [Figure 5]1 is a perspective view of a first embodiment of an assembly for releasably attaching a surgical device to a surgical tool having a shaft. FIG. [Figure 6] 1 is a perspective view of a first embodiment of an assembly for releasably attaching a surgical device to a surgical tool having a shaft. FIG. [Figure 7] 10 is a perspective view of a second embodiment of an assembly for releasably attaching a surgical device to a surgical tool having a shaft. FIG. [Figure 8] 10 is a cross-sectional view of a second embodiment of an assembly for releasably attaching a surgical device to a surgical tool having a shaft. [Figure 9] FIG. 1 is a detailed cross-sectional front view of a kit for releasably attaching a surgical device to a patient or a surgical tool. [Figure 10] FIG. 1 is a detailed cross-sectional front view of a kit for releasably attaching a surgical device to a patient or a surgical tool. [Figure 11] FIG. 1 is a detailed cross-sectional front view of a kit for releasably attaching a surgical device to a patient or a surgical tool. [Figure 12] FIG. 10 is a perspective view of a third embodiment of an assembly for releasably attaching a surgical device to a surgical tool having a shaft. [Figure 13] 10 is a cross-sectional view of a third embodiment of an assembly for releasably attaching a surgical device to a surgical tool having a shaft. [Figure 14] 10 is a cross-sectional view of a third embodiment of an assembly for releasably attaching a surgical device to a surgical tool having a shaft. [Figure 15] FIG. 10 is a perspective view of a third embodiment of an assembly for releasably attaching a surgical device to a surgical tool having a shaft. [Figure 16] 10 is a cross-sectional view of a third embodiment of an assembly for releasably attaching a surgical device to a surgical tool having a shaft. DETAILED DESCRIPTION OF THE INVENTION

[0043] In the drawings, reference numeral 10 generally refers to an assembly 10 for releasably attaching a surgical device 12 to a patient (not shown). The assembly 10 includes a patient mount 14 fixably securable to a pin 16 configured for threaded engagement with the patient, the patient mount 14 defining an operable upper portion 18 carrying at least one first magnetic body 20, and a device mount 22 fixably securable to the device 12, the device mount 22 defining an operable lower portion 24 carrying at least one complementary second magnetic body 26, the bottom portion 24 defining a recess 28 dimensioned to receive a defined length of at least one of the pin 16 and the patient mount 14 and to allow the device mount 22 to rotate relative to the patient mount 14. One or more of the at least one first magnetic body 20 and the at least one second magnetic body 26 comprise a magnet. When the recess 28 of the device mount 22 is attached to the pin 16 and at least one of the patient mount 14, the bottom 24 of the device mount 22 is immediately adjacent to and spaced from the top 18 of the patient mount 14. When the at least one first magnetic body 20 is aligned with the at least one second magnetic body 26, the magnets can attract the mounts 14, 22 toward each other, inhibiting relative rotation of the mounts 14, 22 relative to each other.

[0044] 1-3 illustrate an embodiment 100 of the assembly 10. In this embodiment 100, the pin 16 is a custom bone pin 102 configured for the assembly 100. The bone pin 102 defines opposite ends 104, 106, with one end 104 having threads 108 for threaded engagement with the patient's bone. A shoulder 110 is defined along the pin 102 proximate and spaced from the other end 106. While the shoulder 110 is an exemplary structure suitable for supporting the patient mount 14, it will be understood that in other embodiments, the structure can alternatively include any of a recess, indentation, rib, spline, knurled portion, or the like.

[0045] In this embodiment 100, the patient mount 14 includes a body 29 configured to attach to the pin 102 at a shoulder 110. The body 29 slides along the pin 102, abuts the shoulder 110, and is then securely fastened to the pin 102 to constrain relative axial and rotational movement by a portion of the body 29 that elastically deforms to clip onto the shoulder 110, and / or by adhesive bonding and / or by operating fasteners such as grub screws, assembly of the body 29 to the pin 102 typically performed during factory production. In some embodiments, the body 29 is configured to be press-fit onto the pin 102.

[0046] In other embodiments (not shown), the body 29 is overmolded onto the pin 102, effectively forming the patient mount 14 integrally with the pin 102. In yet other embodiments (not shown), the body 29 is integrally formed with the pin 102, such as by defining a radially extending flange of the pin 102. In further embodiments (not shown) of the assembly 10, the pin 16 is a conventional bone pin, which typically does not define a shoulder 110, and the patient mount 14 may be manually assembled on-site by surgical staff who secure the mount 14 to the pin 16. This may involve the body 29 comprising two portions configured to fit around the pin 102 and be secured together with a clip mechanism and / or fasteners, or the like, and / or may involve adhering the patient mount 14 to the pin 16 with an adhesive.

[0047] 3 , the body 29 of the patient mount 14 is secured along the pin 102 such that the pin 102 extends through the patient mount 14 and positions the end 106 of the pin 102 away from the top 18 of the mount 14. The spacing between the shoulder 110 and the end 106 positions the patient mount 14 a defined distance along the pin 102 away from the end 106 such that a defined portion of the pin 102 protrudes from the mount 14. The protruding portion of the pin 102 forms a mounting shaft configured to carry the device mount 22.

[0048] In other embodiments (not shown), the patient mount 14 is configured to secure over and receive the end 106 of the pin 102 so that the pin 102 does not protrude through the mount 14, and the mount 14 defines or carries an alternative mounting axis for the device mount 22. This configuration of the patient mount 14 may be useful when it is beneficial for the device mount 22 to be positioned on a mounting axis having a larger diameter than the diameter defined by the pin 102 and / or when a bearing surface between the device mount 22 and the patient mount 14 is required, for example, to reduce rotational friction. In such situations, the mounting axis of the patient mount 14 may be formed from a self-lubricating material, such as nylon, or may carry a thrust bearing mechanism.

[0049] In a further embodiment (not shown), the patient mount 14 is configured to receive the pin 102 therethrough and to define a sleeve portion that extends somewhat along the pin 102 from the upper portion 18 toward the protruding end 106 of the pin 102. In such an embodiment, the pin 102 and mount 14 together form a mounting axis for carrying the device mount 22. In this configuration, the device mount 22 may receive a portion of the patient mount 14 and the pin 102 that is attached to both components.

[0050] In yet another embodiment (not shown), the patient mount 14 is configured to securely receive and secure the pin 102 over the end 106 thereof such that the pin 102 does not protrude through the mount 14, and the mount 14 defines a recess or aperture, such as in a tubular sleeve structure. In such an embodiment, the device mount 22 defines or carries a mounting shaft that protrudes from the bottom 28 and is dimensioned to fit within the sleeve structure, allowing the bottom 24 to be positioned immediately adjacent to and spaced apart from the top 18 of the patient mount 14.

[0051] In the illustrated embodiment 100, the device mount 22 is secured across a base portion of the device 12. If the device 12 is configured as a surgical navigation device, including one or more sensors or the like operable to enable the orientation of the device 12 to be determined, the device mount 22 may be releasably or permanently secured to the device 12 and form the base of the housing for the device 12. Alternatively, the device 12 may be configured as a tracker configured for optical image tracking of the device 12, or configured for radiographic image tracking of the device 12, and the device mount 22 may be releasably or permanently secured to the tracker or formed integrally with the tracker. It will be understood that the device 12 described above is exemplary and that the device mount 22 can be configured to be secured to a wide variety of other surgical devices.

[0052] 3, the device mount 22 is configured such that the recess 28 receives a defined length of the pin 102 such that the end 106 of the pin 102 presses against an end wall of the recess 28. In this embodiment 100, the end wall 32 covers the entire recess 28. It will be appreciated that the end wall can alternatively be defined by a shoulder or step within the recess 28.

[0053] Mounting the pin 102 in the recess 28 constrains axial movement of the device mount 22 relative to the pin 102, but allows the device mount 22 to rotate freely about the axis of the pin 102. When the pin 102 is received in the recess 28 so that it contacts the end wall 32, this positions the bottom 24 of the device mount 22 immediately adjacent to, and spaced apart from, the top 18 of the patient mount 14. As shown in FIG. 3 , this defines a gap between the mount 14 and the mount 22. The mounts 14, 22 are typically constructed small, with the gap being in the region of 1 mm or less, so that during use the mounts 14, 22 are in close proximity but do not touch. This allows the magnetic materials 20, 26 to attract each other firmly enough to inhibit relative rotation of the mounts 14, 22 while minimizing rotational friction between the device mount 22 and the pin 102, allowing a user to manually rotate the device mount 22 relative to the patient mount 12 and separate the mounts 14, 22 without the pin 102 becoming dislodged from the patient.

[0054] In the illustrated embodiment, the recess 28 is sized to have a clearance between the pin 102 and the sidewall of the recess 28 such that only the end wall 32 contacts the pin 102. In other embodiments, the recess 28 is sized to slidingly engage the pin 102. In further embodiments, the recess 28 is sized to frictionally engage the pin 102.

[0055] In this embodiment 100, the pair of first magnetic bodies 20 is carried by the patient mount 14, and the pair of second magnetic bodies 26 is carried by the device mount 22. The bodies 20, 26 are each spaced apart by their respective mounts 14, 22 in a complementary annular arrangement so as to be evenly spaced and radially spaced apart about the pin 102 or recess 28. In this embodiment 100, each of the magnetic bodies 20, 26 comprises a permanent magnet. In other embodiments, only one of the first magnetic body 20 and the second magnetic body 26 comprises a permanent magnet, with the other magnetic body 20, 26 being at least partially formed from a magnetizable material, such as one comprising ferrous metal or ferrite. A magnetic field can be induced in such a material, allowing the bodies 20, 26 to act as temporary magnets.

[0056] The first magnetic bodies 20 are arranged by the patient mount 14 to have corresponding polarities, and the second magnetic bodies 26 are arranged by the device mount 22 to have corresponding polarities and opposite polarities to the first magnetic bodies 20. As best shown in FIG. 3 , the patient mount 14 arranges the first bodies 20 parallel to each other and in the same orientation so that the magnetic vectors of the first bodies 20 are in the same direction, in this embodiment with the south pole of each first body 20 pointing toward the top 18 of the mount 14. The device mount 22 arranges the second bodies 26 parallel to each other and in the same orientation so that the magnetic vectors of the second bodies 26 are in the same direction, in this embodiment with the north pole of each second body 26 pointing toward the bottom 24 of the mount 22. Arranging the magnetic bodies 20, 26 in this manner means that when the device mount 22 is attached to the pin 102 adjacent to the patient mount 14 and the magnetic bodies 20, 26 are aligned, the magnetic fields of the bodies 20, 26 attract the bodies 20, 26 toward each other. The positioning of the bodies 20, 26 in equally spaced pairs about the pin 102 or recess 28, and the corresponding polarities of the bodies 20, 26 in each pair, means that the device mount 22 can be held relative to the patient mount 14 by magnetic forces to inhibit relative rotation in one of two relative positions spaced 180 degrees apart about the axis of the pin 102.

[0057] It will be understood that the mounts 14, 22 can be configured to carry more or fewer magnetic bodies 20, 26 than the pairs shown in the illustrated embodiment 100, which includes only a single first magnetic body 20 and a single second magnetic body 26, and / or the orientation of the magnetic bodies 20, 26 can be configured to affect the magnetic vector direction, which can alternatively affect the relative mounting position of the device mount 22 and the patient mount 14. It will also be understood that one mount 14, 22 may carry more magnetic bodies 20, 26 than the other mount 14, 20, and / or the bodies 20, 26 may be unevenly spaced about the pin 102 or recess 28.

[0058] For example, in some embodiments (not shown), each mount 14, 22 has each body 20, 26 of each pair of magnetic bodies 20, 26 arranged to have alternating polarities, e.g., north-south, meaning that the mounts 14, 22 attract each other only when the bodies 20, 26 are aligned in one relative position on the mounts 14, 22. Alternatively, in other embodiments (not shown), each mount 14, 22 carries a set of three first or second magnetic bodies 20, 26 arranged in an annular array to have partially corresponding polarities, i.e., north-north-south, meaning that the mounts 14, 22 attract each other only when the bodies 20, 26 are aligned in one relative position on the mounts 14, 22. In still other embodiments (not shown), each mount 14, 22 carries a set of three first or second magnetic bodies 20, 26 arranged in an annular array with corresponding polarities, e.g., north-north-north, meaning that the mounts 14, 22 attract each other when the bodies 20, 26 are aligned in any of the three relative positions of the mounts 14, 22. In further embodiments (not shown), each mount 14, 22 carries a set of four first or second magnetic bodies 20, 26 arranged in an annular array with corresponding polarities, e.g., north-north-north-north, meaning that the mounts 14, 22 attract each other when the bodies 20, 26 are aligned in any of the four relative positions of the mounts 14, 22.

[0059] In the illustrated embodiment 100, when the second magnetic body 26 is positioned proximate to the first magnetic body 20, this attracts the device mount 22 toward the patient mount 14, placing it closest to one of two defined relative positions of the mounts 14, 22, such as at 0° or 180° about the axis of the pin 102. In some embodiments, the patient mount 14 may carry one or more additional magnets (not shown) equally interposed between the first magnetic bodies 20 and positioned to have a polarity that does not correspond to the first magnetic body 20 and typically corresponds to the polarity of the second magnetic body 26. In such embodiments, rotating the device mount 22 a quarter turn from one of the two defined relative positions, such as 90° about the axis, aligns the second magnetic body 26 and the additional magnetic bodies, repelling the device mount 22 away from the patient mount 14, effectively lifting the device mount 22 before the mounts 14, 22 are again attracted together to the other of the two defined relative positions. This arrangement can constrain the mounts 14, 22 from being positioned relative to one another between two defined relative positions, thereby helping to orient the mounts 14, 22 toward one of the two positions.

[0060] Figure 4A illustrates device 12 bonded to device mount 22, attached to patient mount 14, and rotated into one of two relative mounting positions. Figure 4B illustrates device 12 and device mount 22 positioned in one of two mounting positions such that second magnetic body 26 is aligned with first magnetic body 20. In this position, the magnetic field created by bodies 20, 26 attracts bodies 20, 26 toward each other, holding mounts 14, 22 in their relative mounting positions.

[0061] In the illustrated embodiment 100, the patient mount 14 carries a third magnetic body 34 configured as a permanent magnet arranged to enable indexing of the relative positions of the patient mount 14 and the device mount 22. The third body 34 is positioned between the pair of first bodies 20, so that when viewed from above the upper portion 18, the patient mount 14 is asymmetric about the axis of the pin 102. The third body 34 is typically oriented so that its magnetic vector does not correspond to the magnetic vector of the first body 20. In this embodiment 100, the third body 34 is arranged to have a magnetic vector that is parallel and opposite to the magnetic vector of the first body 20. This can usefully repel the second magnetic body 26 of the device mount 22, encouraging rotation toward one of two defined mounting positions. In other embodiments (not shown), the third body 34 can be arranged so that its magnetic vector transverses the magnetic vector of the first body 20. In still other embodiments, third body 34 is positioned such that its magnetic vector corresponds to the magnetic vector of first body 20. In such embodiments, third body 34 is typically configured to have a weaker magnetic field than first body 20 to avoid second body 26 being attracted to and held by third body 34. In any of these embodiments, the placement of third body 34 spaced apart from first body 20 enables a sensor, operable to detect a magnetic field, and carried by device mount 22 or by device 12 itself, to determine the proximity of third body 34 and, consequently, the orientation of device 12 (carrying device mount 22) relative to patient mount 14.

[0062] 4C illustrates device 12 bonded to device mount 22 and mounted to patient mount 14 in one of two relative mounting positions such that first and second magnetic bodies 20, 26 are aligned (not shown in this view for simplicity). Device 12 contains two PCBs 36, only one of which carries a sensor configured to detect a magnetic field. In response to the sensor detecting the magnetic field of third magnetic body 24, device 12 can determine whether device 12 is mounted to patient mount 14 and can determine its orientation relative to patient mount 14.

[0063] In the drawings, reference numeral 50 generally refers to an assembly 50 for releasably attaching a surgical device 12 to a surgical tool having a shaft (not shown), such as an acetabular cup impactor. The assembly 50 includes a tool mount 52 having one side defining a receiving portion 54 for receiving a portion of the shaft and an opposite side defining an engagement portion 56, the receiving portion 54 associated with a retention mechanism 58 including a strap 60 securable across the receiving portion 54, the retention mechanism 58 operable to adjust the effective length of the strap 60 to capture the shaft between the strap 60 and the receiving portion 54, and a device mount 62 fixably securable to the surgical device 12, the device mount 62 configured to releasably engage the engagement portion 56 of the tool mount 52 to enable attachment of the surgical device 12 to the surgical tool.

[0064] Figures 5-8 and 12-16 illustrate embodiments of assembly 50. Figures 5 and 6 illustrate a first embodiment 200 of assembly 50. Figures 7 and 8 illustrate a second embodiment 300 of assembly 50. Figures 12-14 illustrate a third embodiment 500 of tool mount 52 of assembly 50. Figures 15 and 16 illustrate a fourth embodiment 600 of tool mount 52 of assembly 50. It will be understood that common reference numerals identify common features unless otherwise indicated.

[0065] Each of the illustrated embodiments of the tool mount 52 has a receiving portion 54 including a pair of abutment surfaces 55. The surfaces 55 are arranged to diverge from one another to allow for reception of a shaft therebetween. In the illustrated embodiment, the surfaces 55 are joined or abut one another to form a V-shaped structure for receiving the tool shaft and firmly supporting the tool mount 52 on the shaft. It will be understood that in other embodiments (not shown), the surfaces 55 may be separate and spaced apart from one another, such as defined by standoff pads positioned to abut against the tool. In still other embodiments (not shown), the angle of the abutment surfaces 55 relative to one another is adjustable, such as by each surface being defined by a body pivotally connected to a central chassis. In further embodiments (not shown), the receiving portion 54 includes only a single abutment surface 55 positioned to abut against the tool shaft. In such embodiments, the single abutment surface may be formed from or carry a substantially elastically deformable material to allow it to partially wrap around the tool shaft to enhance grip.

[0066] Each of the abutment surfaces 55 is shaped to be planar to allow it to accommodate a variety of different tool shaft diameters, such as the 8 mm, 9.5 mm, 15 mm, and 22 mm shaft diameters illustrated in Figure 14. It will be appreciated that in other embodiments, one or both of the abutment surfaces 55 may be at least partially curved. Typically, each surface 55 is formed from or carries a resiliently deformable material, such as an elastomer, to strengthen the surface 55 in gripping the tool shaft.

[0067] In the illustrated embodiment of tool mount 52, strap 60 is an elongated flexible member that is at least partially elastically deformable, such as to allow some stretching around the instrument shaft. Strap 60 may define structures to enhance grip on the shaft and / or be gripped by retention mechanism 58, such as undulations 65 shown in FIGS. 12-16 and discussed further below. In some embodiments, one or both sides of strap 60 define any of grooves, teeth, indentations, or hemispheres to affect gripping and / or being gripped. In some embodiments, strap 60 is configured as a ratchet strap engageable by a ratchet mechanism of retention mechanism 58.

[0068] In the illustrated embodiments 200, 300, 500, the engagement portion 56 of the tool mount 52 includes a protrusion in the form of a boss defining a cylindrical shaft 57 that is receivable by the device mount 62 to enable the mount 62 to engage with and be rotatable relative to the tool mount 52. In other embodiments (not shown), the boss defines a non-cylindrical shaft, such as a square or oval section shaft, to constrain relative rotation between the mounts 52, 62. In still other embodiments, the engagement portion 56 defines a thread or bayonet-type structure, such as the axially extending recess 602 shown in FIGS. 15 and 16 and discussed below, to enable the device mount 62 to be axially and rotatably locked to the tool mount 52. In an embodiment 600 in which the engagement portion 56 defines a recess 602, the device mount 62 (not shown in Figures 15 and 16) includes a connector portion, such as a post or other protrusion, that is dimensioned to slidably engage the recess to enable attachment of the device mount 62 to the tool mount 52.

[0069] Each illustrated embodiment of the tool mount 52 has one end 61 of the strap 60 fixedly secured toward one side of the receiving portion 54 and the other end 63 of the strap 60 positioned toward the other side of the receiving portion 54 to pass through an aperture 67 sized to receive the strap 60 and allow the strap 60 to form a closed loop. In some embodiments, the first end 61 of the strap 60 is configured to be releasably securable to the receiving portion 54, allowing the first end 61 to be released so that the strap 60 can be worn around a surgical tool. Generally, the first end 61 is permanently secured to the side of the receiving portion 54 to prevent removal of the strap 60, and wearing it on a tool involves operating the retention mechanism 58 to increase the effective length of the strap 60, thereby increasing the diameter of the loop to allow it to be worn around a tool shaft.

[0070] The retention mechanism 58 of each embodiment 200, 300, 500, 600 is configured to hold the strap 60 in place when positioned to extend through the aperture 67.

[0071] The first embodiment 200 has a retention mechanism 58 that includes a depressible tab 206 associated with the aperture 67 and biased toward one side of the aperture 67. The strap 60 is arranged to extend through the aperture 67 such that the strap 60 is captured by the tab 206, inhibiting the strap 60 from being pulled through the aperture 67 in at least one direction. This arrangement means that the tab 206 must be manually depressed to allow the effective length of the strap 60 to be increased, such as to remove the tool mount 52 from a tool.

[0072] The second embodiment 300 has a retention mechanism 58 including a pivotable lever 306 associated with and positioned to pivot across the aperture 67. The strap 60 is positioned to extend through the aperture 67, and the lever 306 is pivotable to capture the strap 60 and prevent the strap 60 from being pulled through the aperture 67 in at least one direction. This arrangement means that the lever 306 must be manually pivoted to allow the effective length of the strap 60 to be increased, such as to remove the tool mount 52 from the tool. Typically, the lever 306 is positioned such that pulling the second end 63 of the strap 60 away from the receiving portion 58 (upward as shown) causes the lever 306 to pivot and allow the strap 60 to be pulled through the aperture 67.

[0073] It will be appreciated that the retention mechanism 58 can be configured to include other features suitable for holding the strap 60 in place to secure the closed loop over the receiving portion 54. For example, in some embodiments (not shown), the retention mechanism 58 includes a hook and loop fastener that is fixed relative to the receiving portion 54 and carried by the strap 60. In such embodiments, the strap 60 can be positioned such that the hook and loop fastener engages and holds the strap in place. In other embodiments, the retention mechanism 58 includes a fastener or a buckle-type mechanism, such as a side-release buckle or a sliding magnetic buckle, that is fixed relative to the receiving portion 54 and positioned to receive and hold the strap 60.

[0074] The second end 63 of the strap 60 of the first embodiment 200 is joined to a side of the receiving portion 54. This arrangement secures the strap 60 at both ends 61, 63, preventing the strap 60 from being removed from the tool mount 52. It will be appreciated that the strap 60 of the second embodiment 300 may alternatively be configured in this manner.

[0075] The second end 63 of the strap 60 of the second embodiment 300 includes a ring pull structure 308, which may increase the ease with which a user can grip the strap 60. It will be appreciated that the strap 60 of the first embodiment 200 may alternatively be configured in this manner.

[0076] 8 , the engagement portion 56 of the illustrated embodiment 300 has an operable top portion 310 that defines a protrusion 57 and carries a pair of spaced-apart first magnetic bodies 312. The device mount 62 defines an operable bottom portion 314 that carries a pair of spaced-apart complementary second magnetic bodies 316 and defines a recess 318 that is sized to receive at least a portion of the protrusion 57. At least one of the first magnetic body 312 and the second magnetic body 316 comprises a magnet. When the device mount 62 is attached to the protrusion 57 and the first magnetic body 312 is aligned with the second magnetic body 316, the magnet can attract the mounts 52, 62 toward each other. It will be understood that the pair of first magnetic bodies 312 and the pair of second magnetic bodies 316 are exemplary, and that mounts 52, 62 may each carry more or fewer magnetic bodies 312, 316, including only a single magnetic body 312, 316.

[0077] In this embodiment 300, the protrusion 57 is configured to permit relative rotation between the mounts 52, 62. When the first and second magnetic bodies 312, 316 are aligned, the magnetic forces of the bodies 312, 316 are typically configured to inhibit relative rotation to position the bodies in one or more defined relative positions.

[0078] It will be understood that the first embodiment 200 can be configured in the same manner so that the mounts 52, 62 are held together by magnetic material. It will also be understood that, as described above with reference to assembly 10, the mounts 52, 62 of either embodiment 200, 330 can alternatively be configured with more or fewer magnetic materials 312, 316, and / or the bodies 312, 316 can alternatively be positioned in a different manner, such as by orienting magnetic vectors, to affect holding the mounts 52, 62 together in one or more relative positions.

[0079] In the illustrated embodiment, device mount 62 is secured across a base portion of device 12. If device 12 is configured as a surgical navigation device, including one or more sensors or the like operable to enable the orientation of device 12 to be determined, device mount 62 may be releasably or permanently secured to device 12 and form the base of a housing for device 12. Alternatively, device 12 may be configured as a tracker configured for optical image tracking of device 12, or configured for radiographic image tracking of device 12, and device mount 62 may be releasably or permanently secured to or integrally formed with the tracker. It will be understood that the device 12 described above is exemplary and that device mount 62 may be configured to be secured to a wide variety of other surgical devices.

[0080] 9-11 show a kit 400 for releasably attaching the surgical device 12 to a patient (not shown) or to a surgical tool (not shown) having a shaft. The kit 400 includes: a patient mount 402 fixably securable to a pin 404, the pin 404 configured to threadably engage a patient, the patient mount 402 defining an operable upper portion 406 carrying at least one first magnetic body 408, in this embodiment 400 a pair of spaced apart first magnetic bodies 408; a tool mount 410 having a receiving portion 412 for receiving a portion of a shaft and an opposing engagement portion 414, the receiving portion 412 associated with a retention mechanism 416 including a strap 418 securable across the receiving portion 412, the retention mechanism 416 operable to adjust the effective length of the strap 418 to capture the shaft between the strap 418 and the receiving portion 412, the engagement portion 414 having an operable upper portion 420 defining a protrusion 422, the upper portion 420 carrying at least one second magnetic body 423, in this embodiment 400 carrying a pair of second magnetic bodies 423 spaced apart from one another; and a device mount 424 that can be fixedly secured to the surgical device 12, the device mount 424 carrying at least one third magnetic body 428, in this embodiment 400, the device mount defining an operable bottom 426 that carries a pair of third magnetic bodies 428 spaced apart from one another, the bottom 426 configured to receive a portion of at least one of the pin 404 and the patient mount 402, and the bottom 426 further configured to at least partially receive the protrusion 422.

[0081] At least two of the first, second, and third magnetic bodies 408, 423, 428 comprise magnets. When the device mount 424 is attached to at least one of the pin 404 and the patient mount 402 or to the protrusion 422 and the third magnetic body 428 is aligned with the first magnetic body 408 or the third magnetic body 428 is aligned with the second magnetic body 423, the magnets attract the mounts 424, 402, 410 toward each other, allowing the surgical device 12 to be held to the patient or surgical tool.

[0082] In the illustrated embodiment 400, the patient mount 402 carries a pair of radially spaced first magnetic bodies 408 evenly spaced from the pin 404, each body 408 comprising a permanent magnet. The magnets are arranged to have opposite polarities, with one body 408 arranged with its north pole adjacent the top 406 and the other body 408 arranged with its south pole adjacent the top 406.

[0083] The tool mount 410 carries a pair of second magnetic bodies 423, each comprising a permanent magnet. The magnets are arranged with corresponding polarities, with one body 423 arranged with its north pole adjacent to the top 420 and the other body 423 arranged with its north pole adjacent to the top 420.

[0084] The device mount 424 carries a pair of third magnetic bodies 428, each comprising a magnetizable material such as ferrous metal or ferrite. A magnetic field can be induced in the third magnetic bodies 428, allowing them to act as temporary magnets. Each third body 428 is associated with a sensor (not shown) operable to determine magnetic poles, such as a Hall Effect sensor. The sensor can be attached to the device mount 424 or to the device 12.

[0085] 9 shows the device mount 424 attached to the patient mount 402 in a first orientation, such that the third magnetic body 428 is aligned with the first magnetic body 408. When positioned in this manner, the magnetic field of the first body 408 causes the third body 428 to adopt an opposite polarity, which allows the sensor to detect a first reading, which in this situation is south pole-north pole, to determine that the device mount 424 is positioned on the patient mount 402 in a first relative position.

[0086] 10 shows the device mount 424 attached to the patient mount 402 in a second orientation, such that the third magnetic body 428 is aligned with the first magnetic body 408. When positioned in this manner, the magnetic field of the first body 408 causes the third body 428 to adopt an opposite polarity, which allows the sensor to detect a second reading, which in this situation is south pole-north pole, to determine that the device mount 424 is positioned on the patient mount 402 in a second relative position.

[0087] 11 shows device mount 424 attached to tool mount 410 such that third magnetic body 428 is aligned with second magnetic body 423. When positioned in this manner, the magnetic field of second body 423 causes third body 428 to adopt the opposite polarity, allowing the sensor to detect a third reading, which in this situation is north-north, to determine that device mount 424 is positioned on tool mount 410.

[0088] It will be understood that the arrangement of the first magnetic body 408 and the second magnetic body 423 is exemplary, and that the bodies 408, 423 may alternatively be arranged to enable the sensor to determine the polarity and, consequently, to which of the mounts 402, 410 the device mount 424 is attached and in what relative position.

[0089] 12-14 illustrate a third embodiment 500 of tool mount 52. This embodiment 500 is mateable with device mount 62 shown in FIGS. 5, 7, and 8 and can carry magnetic member 312 (not shown in these figures) within recess 501. As discussed above, third embodiment 500 shares features with the previous embodiments, and common reference numbers indicate the common features.

[0090] The receiving portion 54 of this embodiment 500 includes abutment surfaces 55 adjacent to one another and separated by a gap 502. As shown in FIG. 14 , the surfaces 55 are arranged to diverge from one another to allow for the reception of a wide range of shaft diameters, with common surgical tool diameters being shown in the figures.

[0091] The strap 60 is positionable across the receiving portion 54 to be received in the aperture 67. In this embodiment 500, the aperture 67 is configured as an outwardly opening channel 504 on one side 506 of the mount 52. This configuration of the aperture 67 allows the strap 60 to slide in and out of the open side of the channel 504, which may enhance the ease of securing the strap 60 about an instrument shaft when positioned against the abutment surface 55 or of removing the strap 60 from the channel 504, thereby freeing the instrument shaft. A second aperture 508 is defined adjacent the channel 504 and is dimensioned to receive the strap 60 and allow the strap 60 to fold back upon itself. This may position the strap 60 to form a serpentine path to enhance secure attachment of the strap 60 across the receiving portion 54 and / or conveniently accommodate the free end 63 of the strap 60, for example, to inhibit the end 63 from getting caught on other objects during use.

[0092] The retention feature 58 in this embodiment 500 includes a plurality of teeth 510 disposed in the channel 504 and shaped to engage with the undulations 65 of the strap 60. The open-side configuration of the channel 504 means that the strap 60 can be slidingly engaged with the teeth 510 as it is slid into the channel 504. As best shown in FIGS. 13 and 14 , the teeth 510 and the undulations 65 may be complementarily shaped to provide a ratchet-type function, where the teeth 510 and the undulations 65 engage to restrict the strap 60 from advancing in one direction through the channel 504, thereby loosening the strap 60 from the shaft, while allowing the strap to advance in the opposite direction through the channel 504, thereby tightening the strap 60 around the shaft. It will be appreciated that in other embodiments (not shown), the teeth 510 may be replaced with a ratchet mechanism operable to engage the strap 60, such as including a biased, depressible tab configured to press the strap 60 against the sidewall of the channel 504.

[0093] 15 and 16 show a fourth embodiment 600 of the tool mount 52. This embodiment 600 shares features with the previously described embodiment 500, and common reference numbers indicate the common features. The embodiment 600 is configured to form a bayonet coupling with a complementary device mount 62 (not shown) to facilitate releasably engaging the device mount 62 with the tool mount 52.

[0094] The engagement portion 56 of this embodiment 600 includes a sleeve section 601 defining an axially extending recess 602. The recess 602 defines a slot 604 shaped to receive a complementarily shaped connector portion of the device mount 62. Displacing the connector portion through the slot 604 and inducing relative rotation of the device mount 62 and the tool mount 52 engages the mounts 62, 53 together. In this embodiment 600, the device mount 62 is configured with a male portion of a bayonet coupling and the tool mount 52 is configured with a female portion of a bayonet coupling, although it will be understood that this configuration can be reversed. Furthermore, it will be understood that each mount 52, 62 may alternatively be shaped and dimensioned to provide a portion of a bayonet coupling, and a wide variety of configurations are within the scope of this disclosure.

[0095] Use of the assembly 10 may involve securing the patient mount 14 to the pin 16, securing the device mount 22 to the device 12, engaging the pin 16 with the patient, positioning the device mount 22 over the pin 16 so that the pin 16 is received in the recess 28 with the bottom 24 of the device mount 22 immediately adjacent to but spaced from the top 18 of the patient mount 14, and aligning the first magnetic body 20 with the second magnetic body 26 so that the magnets attract the mounts 14, 22 toward each other and inhibit relative rotation of the mounts 14, 22.

[0096] Use may also involve repositioning the device mount 22 on the patient mount 14 by rotating the device 12 or device mount 22 with sufficient torque to overcome the magnetic attraction between the magnetic material 20 and the magnetic material 26, and then realigning the magnetic materials 20, 26 by rotating the device mount 22 approximately 180 degrees from its initial position relative to the patient mount 14 to allow the magnets to attract the mounts 14, 22 toward each other and inhibit relative rotation of the mounts 14, 22.

[0097] Use may also involve removing the device mount 22 from the patient mount 14 by rotating the device 12 or the device mount 22 with sufficient torque to overcome the magnetic attraction between the magnetic material 20 and the magnetic material 26, and then displacing the device mount 22 axially along the pin 16 and away from the patient mount 14 to withdraw the pin 16 from the recess 28.

[0098] Use of assembly 50 may involve centering tool mount 52 on the shaft of a tool, typically by manipulating retention mechanism 58 and adjusting the effective length of strap 60 to allow spacing between strap 60 and receiving portion 54 to allow passage of the shaft, and in some tools, the handle; securing tool mount 52 to the shaft, typically by adjusting the effective length of strap 60 to capture the shaft between strap 60 and receiving portion 54; securing device mount 62 to device 12; and engaging device mount 62 with engagement portion 56 of tool mount 52.

[0099] Assembly 10 releasably attaches device 12 to a single pin 16 that threadably engages the patient. This can be useful for minimizing patient discomfort and / or injury and / or increasing surgical efficiency by requiring only a single pin to securely attach device 12 to the patient. Assembly 10 can also advantageously allow the device to be easily removed from and repositioned relative to pin 16 while minimizing friction between mount 14 and mount 22 and / or between device mount 22 and pin 16, thereby reducing torque transmission to pin 16 that may disengage the pin from the patient.

[0100] Assembly 50 releasably attaches device 12 to the shaft of a tool. The arrangement of retractable strap 60 and receiving portion 54 may allow tool mount 52 to easily attach to a variety of shaft shapes and / or diameters. Additionally, tool mount 52 may provide a secure attachment mechanism that can be easily attached and detached from a tool, thereby increasing the efficiency of a surgical procedure.

[0101] The kit 400 releasably attaches the device 12 to a single pin 16 that threadably engages the patient, or releasably attaches the device 12 to the shaft of a tool, which can usefully increase the ease with which the device 12 can be transferred from being attached to the patient to being attached to the tool (or vice versa), thereby increasing the efficiency of the procedure.

[0102] Those skilled in the art will appreciate that numerous variations and / or modifications may be made to the above-described embodiments without departing from the broad general scope of the present disclosure, and the present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive.

Claims

1. 1. An assembly for releasably attaching a surgical device to a patient, said assembly comprising: a patient mount fixably securable to a pin, the pin configured to threadably engage the patient, the patient mount defining an operable upper portion carrying at least one first magnetic body; a device mount fixably securable to the surgical device, the device mount defining a movable bottom portion carrying at least one complementary second magnetic body, the bottom portion defining a recess dimensioned to receive a defined length of at least one of the pin and the patient mount and to allow the device mount to rotate relative to the patient mount; and one or more of the at least one first magnetic body and the at least one second magnetic body comprise magnets, such that when the recess of the device mount is attached to the pin and at least one of the patient mount, the bottom of the device mount is positioned immediately adjacent to and spaced apart from the top of the patient mount, and when the at least one first magnetic body is aligned with the at least one second magnetic body, the one or more magnets attract the mounts toward each other to inhibit relative rotation of the mounts.

2. 2. The assembly of claim 1, wherein the patient mount carries a pair of the first magnetic bodies spaced apart from one another, each of the first magnetic bodies comprising a magnet arranged to have a corresponding polarity, and the device mount carries a pair of the second magnetic bodies spaced apart from one another, each of the second magnetic bodies comprising a magnet arranged to have a corresponding polarity and an opposite polarity to the first magnetic bodies.

3. 3. The assembly of claim 2, wherein the upper portion of the patient mount carries a third magnetic body interposed between the pair of first magnetic bodies, the third magnetic body comprising a magnet arranged to have a polarity opposite to that of the first magnetic bodies.

4. 2. The assembly of claim 1, wherein the patient mount carries a pair of spaced apart first magnetic bodies, each of the first magnetic bodies comprising a permanent magnet, and the device mount carries a pair of spaced apart second magnetic bodies, each of the second magnetic bodies comprising a magnetizable material that enables it to form a temporary magnet.

5. 5. The assembly of claim 2, wherein the patient mount is configured to position the pair of first magnetic materials so as to be evenly spaced radially from the pin, and the device mount is configured to position the pair of second magnetic materials at a complementary spacing with the first magnetic materials to enable attachment of the device mount to at least one of the pin and the patient mount and alignment of the first magnetic materials with the second magnetic materials in one of two relative positions.

6. 10. An assembly according to any one of the preceding claims, wherein the patient mount is securable along the pin such that an end of the pin is spaced from above by more than the defined length to allow attachment of the device mount to the pin.

7. The assembly of claim 6 , including the pin, the patient mount being permanently joined to the pin.

8. The assembly of claim 6 , including the pin, the patient mount being integrally formed with the pin.

9. 1. An assembly for releasably attaching a surgical device to a patient, said assembly comprising: a patient mount including a pin configured to threadably engage the patient, the patient mount defining an operable upper portion that carries at least one first magnetic body; a device mount fixably securable to the surgical device, the device mount defining a movable bottom portion carrying at least one complementary second magnetic material, the bottom portion defining a recess dimensioned to receive the patient mount and allow the device mount to rotate relative to the patient mount; and one or more of the at least one first magnetic body and the at least one second magnetic body comprise magnets, such that when the recess of the device mount is attached to the patient mount, the bottom of the device mount is positioned immediately adjacent to but spaced apart from the top of the patient mount, and when the at least one first magnetic body is aligned with the at least one second magnetic body, the one or more magnets attract the mounts toward each other, preventing relative rotation between the mounts.

10. 1. A surgical device assembly comprising: a surgical navigation device operable to determine an orientation; 10. A surgical device assembly according to any one of the preceding claims, wherein the device mount forms a base portion of the surgical navigation device.

11. The surgical device assembly of claim 10, wherein the surgical navigation device includes one or more sensors operable to detect a magnetic field, and wherein the surgical navigation device is configured to determine when the device is attached to the patient mount in response to the one or more sensors detecting the magnetic field of one or more of the magnetic materials.

12. The surgical device assembly of claim 11, wherein the surgical navigation device is configured to determine an orientation of the device relative to the patient mount in response to the one or more sensors detecting the magnetic field of one or more of the magnetic materials.

13. 1. An assembly for releasably attaching a surgical device to a surgical tool having a shaft, said assembly comprising: a tool mount having one side defining a receiving portion for receiving a portion of the shaft and an opposite side defining an engagement portion, the receiving portion associated with a retention mechanism including a strap securable across the receiving portion, the retention mechanism operable to adjust an effective length of the strap to capture the shaft between the strap and the receiving portion; a device mount fixably securable to the surgical device, the device mount configured to releasably engage the engagement portion to enable attachment of the surgical device to the surgical tool.

14. 14. The assembly of claim 13, wherein the receiving portion includes at least one pair of abutment surfaces, the or each pair of surfaces being arranged to diverge away from one another to allow reception of the portion of the shaft therebetween.

15. The assembly of claim 14 , wherein the receiving portion includes a pair of the abutment surfaces, each of the surfaces being planar.

16. 16. The assembly of any one of claims 13 to 15, wherein the tool mount defines an aperture dimensioned to receive the strap, and the retention mechanism is configured to hold the strap in place when positioned to extend through the aperture.

17. The assembly of claim 16 , wherein the retention mechanism includes teeth disposed within the aperture, the strap configured to engage the teeth.

18. 18. The assembly of claim 17, wherein the aperture defines a channel that receives the tooth, and the strap defines a protrusion shaped to slidingly engage the tooth when the strap is slid into the channel.

19. 17. The assembly of claim 16, wherein the retention mechanism includes a depressible tab associated with the aperture such that the tab is biased toward one side of the aperture to capture the strap and inhibit the strap from being pulled through the aperture in at least one direction.

20. 17. The assembly of claim 16, wherein the retention mechanism includes a pivotable member associated with the aperture such that pivoting the pivotable member to a locked position captures the strap and inhibits the strap from being pulled through the aperture in at least one direction.

21. 21. The assembly of claim 20, wherein the pivotable member is positioned such that pivoting the pivotable member toward the engagement portion moves the pivotable member from the locked position.

22. 17. The assembly of claim 16, wherein the retention mechanism includes a hook and loop fastener secured to the receiving portion and carried by the strap, the strap being positionable such that the hook and loop fastener engages to hold the strap in place.

23. 23. The assembly of any one of claims 13 to 22, wherein the strap defines a free end arranged to be manually grasped and pulled away from the receiving portion to adjust the effective length.

24. 24. The assembly of claim 23, wherein the free end defines a ring structure shaped to aid in gripping.

25. An assembly according to any one of claims 13 to 24, wherein the strap defines a fixed end releasably secured to the receiving portion.

26. 26. An assembly according to any one of claims 13 to 25, wherein the tool mount and the device mount each define a portion of a bayonet coupling such that the portions are axially engaged and when rotated relative to one another the mounts engage together.

27. the engagement portion has an operable upper portion defining a protrusion, the upper portion carrying at least one first magnetic material; the device mount defining an operable bottom carrying at least one complementary second magnetic material and defining a recess dimensioned to receive at least a portion of the protrusion; 26. The assembly of any one of claims 13 to 25, wherein one or more of the at least one first magnetic body and the at least one second magnetic body comprise magnets, such that when the device mount is attached to the protrusion and the at least one first magnetic body is aligned with the at least one second magnetic body, the one or more magnets enable the mounts to attract each other.

28. 28. The assembly of claim 27, wherein the protrusions and recesses are shaped to allow rotation of the tool mount relative to the device mount, and alignment of the at least one first magnetic body with the at least one second magnetic body inhibits relative rotation.

29. 29. The assembly of claim 27 or 28, wherein the tool mount carries the pair of first magnetic bodies, each of the first magnetic bodies comprising a magnet arranged to have corresponding polarities, and the device mount carries the pair of second magnetic bodies, each of the second magnetic bodies comprising a magnet arranged to have corresponding polarities and a polarity opposite to that of the first magnetic bodies.

30. 29. The assembly of claim 27 or 28, wherein the tool mount carries the pair of first magnetic bodies, each of the first magnetic bodies comprising a magnet arranged with corresponding polarity, and the device mount carries the pair of second magnetic bodies, each of the second magnetic bodies formed from a ferrous metal.

31. 1. A surgical device assembly comprising: a surgical navigation device operable to determine an orientation; 30. The surgical device assembly of any one of claims 27 to 29, wherein the device mount forms a base portion of the surgical navigation device.

32. 32. The surgical device assembly of claim 31, wherein the surgical navigation device includes one or more sensors operable to detect a magnetic field and positioned to detect a polarity of the at least one second magnetic body, and wherein the surgical navigation device is configured to determine when the device is attached to the tool mount in response to the one or more sensors detecting the magnetic field of the at least one second magnetic body.

33. 1. A kit for releasably attaching a surgical device to a patient or to a surgical tool having a shaft, the kit comprising: a patient mount fixably securable to a pin, the pin configured to threadably engage the patient, the patient mount defining an operable upper portion carrying at least one first magnetic body; a tool mount having one side defining a receiving portion for receiving a portion of the shaft of the surgical tool and an opposite side defining an engagement portion, the receiving portion associated with a retention mechanism including a strap securable across the receiving portion, the retention mechanism operable to adjust an effective length of the strap to capture the shaft between the strap and the receiving portion, the engagement portion having an operable upper portion defining a protrusion, the upper portion carrying at least one second magnetic material; a device mount fixably securable to the surgical device, the device mount defining an operable bottom carrying at least one third magnetic body, the bottom configured to receive a portion of at least one of the pin and the patient mount, the bottom further configured to at least partially receive the protrusion; at least two of the first, second, and third magnetic bodies comprise magnets, such that when the device mount is attached to at least one of the pin and the patient mount, or to the protrusion, and the at least one third magnetic body is aligned with the at least one first magnetic body or the at least one second magnetic body, the magnets attract the mounts toward each other to hold the surgical device to the patient or the surgical tool.

34. 1. A surgical device assembly comprising: a surgical navigation device operable to determine an orientation; 34. The surgical device assembly of claim 33, wherein the device mount forms a base portion of the surgical navigation device.

Images