IMPLANTABLE EXPANDABLE BONE SUPPORT DEVICE, KITS OF COMPONENTS, SET OF BLOCKS, AND METHODS FOR DEPLOYING EXPANDABLE IMPLANTABLE DEVICES - Patent application

Abstract

An implantable, expandable bone supporting device for a bone, such as a vertebra, includes a preformed bulk block for filling an intraosseous implant cavity in the bone. The preformed bulk block is movable to protrude in an expanded state of the device relative to an unexpanded configuration of the device. The block includes a load-bearing surface that supports a load acting on the bone, and a fixation interface that interfaces with a preformed fixator that holds the preformed block against the load in the expanded state of the bone supporting device and prevents the device from collapsing from the expanded state to the unexpanded state. The actuator interface is capable of engaging an actuator to actuate movement of the bulk block along a predetermined path. The device includes a guide that defines the predetermined path, along which the bulk block can move.

Description

[Technical field]

[0001] The present invention relates to an implantable, expandable bone support device for bones, such as vertebrae, in mammals or non-human animals. More specifically, the present invention relates to an implantable device that can be used in percutaneous osteoplasty, vertebroplasty, and occipital osteoplasty. The present invention further relates to a kit of parts, a set of blocks, and a method for deploying the device. [Background technology]

[0002] Trauma or other conditions, such as osteoporosis, can weaken areas of bone tissue, leading to fractures and bone collapse. Percutaneous osteoplasty is known in which bone cement is injected to stabilize the bone and transfer mechanical loads. Various types of bones may require such stabilization and support.

[0003] For example, vertebral compression fractures can cause severely disabling back pain. Many patients experience significant morbidity and reduced quality of life after severe pain, prolonged immobilization, kyphosis, pulmonary deterioration, depression, loss of independence, etc. The most common cause is thought to be osteoporosis, with more than 700,000 osteoporosis-related fractures diagnosed annually in the United States alone. Other causes include primary and metastatic malignancies, trauma, hemangiomas, and bone collapse. Pharmacological therapies such as exercise therapy and physical therapy may not be effective or sufficient to alleviate symptoms, so surgery may be necessary.

[0004] Vertebroplasty is an alternative surgical procedure that is widely used to treat symptoms of fractures that do not respond to medical treatment. Vertebroplasty is an image-guided, minimally invasive procedure in which bone cement is injected into vertebral fractures to reduce pain and improve fracture stability. Vertebroplasty is a similar procedure, but uses an expandable balloon to reduce the fracture and create a cavity, theoretically allowing for safer injection of cement into the fractured vertebral body.

[0005] These procedures are known to use vertebral stents, which are expanded within the cavity to prevent the vertebral bodies from collapsing until the bone cement has hardened. However, commonly known stents are expandable mesh wire tubular structures similar to those used in angioplasty stents, which by themselves cannot withstand the compressive loads imposed on the spinal column. Thus, bone cement is required for stabilization and support of the vertebrae.

[0006] US Patent No. 5,399,633 discloses an expandable implantable device that can be inserted into a vertebral body as an alternative expandable structure to a stent for cavity maintenance and / or repair. During surgery, the implant is placed in the cavity of the vertebral body to be repaired and expanded. The device includes top and bottom plates that can be moved apart to allow the stent to expand and provide a support surface against the bone. Mechanical resistance prevents the expandable implantable device from contracting once expanded. When the device is expanded, the plates thus bear against the bone and support the adjacent bone tissue against vertical loads acting on the vertebrae. Once the device is properly positioned, a filler material such as bone cement is injected into the vertebral cavity to fill the void and the surrounding bone structure.

[0007] A common drawback of the above known support implants and their placement methods is the need to use bone cement. The intraosseous distribution of the cement is difficult to control, and after injection, extraosseous bodies exist in the vertebrae that cannot be eliminated due to uncontrolled leakage of the substance. It should be noted that this drawback also applies to other types of osteoplasty where bone cement is injected, such as knee and hip joint. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] International Publication No. 2010 / 103344 Summary of the Invention

[0009] The present invention provides an apparatus, a kit of parts, a set of blocks and a method for arranging an apparatus as set forth in the accompanying claims. Particular embodiments of the invention are set out in the dependent claims. These and other aspects of the invention will become apparent from and be elucidated with reference to the embodiments described hereinafter.

[0010] Further details, aspects and embodiments of the present invention are now described, by way of example only, with reference to the drawings, in which like reference numbers are used to identify like or functionally similar elements, and in which elements are illustrated for simplicity and clarity, and have not necessarily been drawn to scale. [Brief description of the drawings]

[0011] [Figure 1] 1A and 1B are cross-sectional views of a portion of a spinal column in which one example of an expandable implantable device is provided. [Diagram 2] FIG. 1A is a schematic diagram illustrating a side view of a first example of an expandable implantable device. [Diagram 3] FIG. 1A is a schematic diagram illustrating a side view of a first example of an expandable implantable device. [Figure 4] FIG. 1A is a schematic diagram illustrating a side view of a first example of an expandable implantable device. [Diagram 5] FIG. 2 is an exploded perspective view of a portion of a schematic diagram of a second embodiment of an expandable implantable device. [Figure 6] FIG. 2 is an exploded perspective view of a portion of a schematic diagram of a second embodiment of an expandable implantable device. [Figure 7] FIG. 2 is a schematic diagram of a second embodiment of an expandable implantable device, showing the expandable implantable device in an expanded state. [Figure 8] FIG. 2 is a schematic diagram of a second embodiment of an expandable implantable device, showing a side view of a sealed bulk block. [Figure 9] FIG. 13 is a side view of a third embodiment of an expandable implantable device. [Figure 10]FIG. 1 is a front view of a vertebra with an access and a trocar inserted therein. [Figure 11] FIG. 1 is a side view of a vertebra with a trocar inserted therein. [Figure 12] FIG. 13 is a side view of a vertebral body with a pin inserted. [Figure 13] FIG. 1 is a side view of a vertebra with a penetration. [Figure 14] FIG. 13 is a lateral view of a vertebral body with a drill and tube guide inserted. [Figure 15] FIG. 13 is a side view of a vertebral body with a canal guide inserted. [Figure 16] FIG. 13 is a side view of a vertebral body with a tube guide inserted and associated with the vertebral body. [Figure 17] FIG. 2 is a side view of a vertebral body with a drill inserted. [Figure 18] FIG. 18 shows the vertebral body of FIG. 17 with the drill removed. [Figure 19] FIG. 2 is a side view of a vertebral body with a gauge inserted. [Figure 20] FIG. 20 shows the vertebral body of FIG. 19 with the device gauge removed. [Figure 21] FIG. 2 is a side view of a vertebral body with an implantation device and holder inserted. [Figure 22] FIG. 2 shows a vertebral body with an implant device inserted. [Diagram 23] FIG. 11 illustrates the vertebral body of FIG. 10 with additional access through it including a trocar therethrough and original access including a cannula plug. [Figure 24] FIG. 1 illustrates a set of cores that may be used in an embodiment of an expandable implantable device. [Diagram 25] 1A and 1B are perspective and exploded views of an example of a bulk block suitable for an expandable implantable device. [Figure 26] FIG. 26 is a side view of a device body in an unexpanded state formed from the example blocks of FIG. 25. [Figure 27] FIG. 26 is an exploded view of the frame and molded fixture block assembly of the embodiment of FIG. 25. [Figure 28]FIG. 28 is an exploded view of the example assembly and actuator of FIG. 27. [Figure 29] FIG. 28 shows an example of an expandable implantable device assembled with the components of FIG. 27 in an unexpanded state. [Diagram 30] FIG. 30 shows the example of FIG. 29 in an expanded state. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] The description will not be more detailed than is deemed necessary for an understanding and appreciation of the basic concepts of the invention, and will not obscure or detract from the teachings of the invention. Referring to Figure 1, an example of an implantable, expandable bone support device 1 is implanted in a mammalian bone, in this example a human vertebra 102. The expandable, implantable device 1 can be sized, for example, for percutaneous placement in the vertebra 102.

[0013] The typical dimensions of the device 1 (which may be other sizes depending on the cavity in which the device is placed) may be between 5 mm and 50 mm in length. For example, the length may be 8 mm or more, such as 15 mm or more. The length may be less than 40 mm, such as less than 30 mm. A suitable range of lengths is between 8 mm and 38 mm. The typical maximum unexpanded diameter may be, for example, less than 8 mm, such as less than 5 mm, such as less than 4 mm. Preferably, but not necessarily, the diameter is 1 mm or more, such as 1.5 mm or more, such as 2.25 mm or more, such as 3 mm or more. The typical maximum expansion of the device is, for example, 1.5 to 3 times the unexpanded diameter. Other maximum expansions are possible as well, and it is currently preferred that the maximum expansion is less than 5 times the unexpanded diameter to ensure a mechanically stable and reliable expansion.

[0014] Bones become fragile due to a patient's condition, such as osteoporosis or cancer, and collapse under an external load applied to the bone, which in this example is a compressive load exerted by the spine on the vertebral endplates, as shown by the vertical arrow in FIG. 1B. Alternatively, bones may fracture due to an external cause, such as trauma. The device may be used, for example, to treat fragile bones and restore bone tissue, or to prevent bone collapse, such as due to osteoporosis or cancer, and to heal fractures caused by trauma or other causes.

[0015] The device can be placed in an intraosseous cavity 106 in the vertebral body 102 in an area of ​​weakened bone to stabilize and support the bone. The cavity 106 is surgically created through a relatively small access passage, the diameter of which corresponds to the diameter of the device 1 in its unexpanded state. The device 1 is inserted through this passage into the prepared intraosseous cavity 106.

[0016] 1A shows the implantable device 1 immediately after placement in a vertebral body 102. In this example, the passageway is a narrow diameter passageway formed percutaneously, forming an intraosseous cavity 106 therethrough.

[0017] In this embodiment, the intraosseous cavity 106 is pre-prepared to be located close to the bone surface on which the external load acts, in this embodiment the vertebral endplate 109. For example, 5 mm or less, such as 4 mm or less, such as 3 mm or less of bone tissue may be present between the top support surface 30 or the load-bearing surface 30 of the device and the endplate 109. This allows the load-bearing surface of the device 1 to press against the vertebral endplate 109 during expansion, thereby deforming the elastic or plastic nature of this tissue, thereby reducing the risk of fracture or collapse when expanding the device 1 (e.g., to partially or completely restore the vertebral height). For example, 1 mm or more, such as 2 mm or more, such as 3 mm of tissue may be present between the top surface 30 and the vertebral endplate. This reduces the risk of the device 1 penetrating the tissue and becoming exposed during expansion or after surgery.

[0018] Further, as shown, the device 1 may be positioned near the anterior wall 111 of the vertebral body 102. For example, the device 1 may be positioned such that a space of 1 mm or more, such as 2 mm or more, such as 3 mm or more, is left between the device 1 and the anterior wall 111, e.g., with cancellous bone material. Preferably, the space is 8 mm or less, such as 6 mm or less, such as 5 mm or less. This avoids perforation of the anterior wall 111 by the device 1. The position of the device 1 may be determined prior to expansion, e.g., via image processing techniques known in the art, to ensure that the device is entirely within the vertebral body, e.g., not within the pedicle.

[0019] In Figure 1A, device 1 is shown still in an unexpanded state, positioned near an upper vertebral endplate 109. In Figure 1B, device 1 is in an expanded state. As shown, in the expanded state, the diameter of device 1 is significantly larger than in the unexpanded state, and accordingly device 1 can be placed into bone in a relatively minimally invasive procedure, e.g., percutaneously, as described in more detail below with reference to Figures 10-23.

[0020] In this application of the device, as seen in FIG. 1B, expanding device 1 not only stabilizes and supports device 1 from collapsing, but also lifts vertebra 102 to at least partially, and preferably completely, regain its height.

[0021] The device 1 is brought from a non-expanded state to an expanded state by an actuator device, not shown, that engages with the actuator interface 10 of the device. In this regard, the actuator may be any actuator that moves one or more of the bulk blocks 3, 4 when engaged at the interface 10, a variety of actuators being known in the art. The actuator may be, for example, a manual, hydraulic, pneumatic, electro-magnetic or mechanically driven actuator, for example, using a suitable mechanical transducer to drive the movement. In general, the actuator may be a medically acceptable actuator, i.e., a sterile actuator and a biocompatible actuator. The actuator may be, for example, a linear spreader, a scissor jack, or a linear actuator that can move the bulk blocks away from each other and possibly back, such as a rotary pair of linear actuators, a hydraulic or pneumatic actuator. For example, the device may use a classic wedge actuator, a parallel bar and link actuator, a screw jack, a cam system, a balloon and bellows system, a longitudinal deformation / compression system, or a stacking system, etc.

[0022] The expanded state is the final state in which the device 1 will typically survive surgery, without device failure, and in which the device 1 is stable and supports the bone. In the transition between the unexpanded and expanded states, the device passes through intermediate states, in which the device 1 is partially expanded, but not to the extent necessary to provide the stabilization and support deemed necessary by the operating surgeon. In this regard, in the expanded state, the device 1 does not need to be expanded to its maximum expansion, and depending on the condition of the bone, the support required, and the loading conditions, the surgeon can choose to expand the device 1 to a maximum or lesser extent. Once expanded, the state of the device 1 can be finalized by fixing the parts of the device 1 that were moved to expand the device 1, such as fixing the positions of the bulk blocks 3, 4 in the example.

[0023] As can be seen more clearly from Figures 2-4, the illustrated device 1 comprises one or more preformed bulk blocks 3, 4 which fill an intraosseous implant cavity 106 in the expanded state of the device. Because the cavity 106 is filled with the preformed bulk blocks 3, 4, injection of bone cement, for example, is not required. However, it will be apparent that a bone cement may be used to fill the cavity and provide a stable fixation of the device 1 to the walls of the cavity 106, and may be applied for purposes other than fracture reduction.

[0024] In this regard, depending on the specific embodiment, the preformed blocks 3, 4 and, if present, 5, in the expanded state, can fill the total volume of the implantable expandable bone support device in a proportion selected from the group consisting of at least 30%, at least 50%, at least 70%, at least 80%, at least 90%, at least 95%, at least 98%. In this regard, the total volume is defined by the outer contour of the device 1 in the expanded state. As shown, in this embodiment, the movement of the bulk blocks 3, 4 expands, i.e., the difference in volume between the non-expanded state and the expanded state is filled with the bulk blocks, so that the preformed bulk blocks 3, 4 completely fill the volume that is added to the total volume. In the illustrated example. For example, the total volume is increased by about three times with the movement of the blocks, and about 2 / 3 of the total volume is filled with the bulk blocks 3, 4, as most clearly shown in FIG. 7B. In this example, the bulk blocks completely fill the additional volume, but other shapes may also be used that may result in a lower filling grade.

[0025] Preferably, the blocks completely fill the total volume, but in some cases the filling may be less than 100% of the volume. When the device 1 is maximally expanded, for example less than 80%, for example less than 70%, for example 2 / 3 of the total volume may be filled by the bulk blocks. In the case of a type of fixation different from the fixation blocks 5 described below with reference to Figs. 2-4, for example, a portion of this volume, the block gaps 11, may not be filled and the blocks 3, 4 may be shaped such that a portion of the total volume is not filled, for example when axial grooves are provided on the bone sides 30, 40. In the example of Figs. 25-30, for example, the block gaps 11 created by the expansion are not filled, except for the two fixation blocks 5 that keep the bulk blocks 3, 4 separated. Thus, the total volume filled is less than 100% in the expanded state, and in the example of Figs. 25-30, even at maximum expansion, only about 2 / 3 of the total volume is filled by the bulk blocks.

[0026] The bulk blocks 3, 4 have load-bearing surfaces 30, 40 which, in the expanded state, support a load applied by the bone resulting from an external load acting on the bone, as shown by the arrows in Fig. 1B. The bulk blocks 30, 40 can move relative to each other in a direction that is not parallel to the load-bearing surfaces, in this example perpendicular to the load-bearing surfaces, as shown by the arrows in Fig. 3.

[0027] More specifically, when the device 1 is placed in the cavity 106 with the surfaces 30, 40 facing the bone, moving the blocks 3, 4 causes the load bearing surfaces 30, 40 to contact, and in this example, press against, the opposing walls of the cavity 106. They cannot move against each other under load (when fixed with preformed fixtures). That is, the device 1 supports the bone material that is between the load bearing surfaces 30, 40 and the outer side of the bone where the external load acts. Thus, the bone collapse can be prevented. In this example, the outer side of the bone is the vertebral endplate 109 that interfaces with the intervertebral disc 103 and where the spinal load acts. Thus, the device 1 supports the vertebrae to resist spinal loads and prevent the collapse of the vertebral body.

[0028] Additionally, the bulk blocks 3, 4 shield the cavity to reduce loading pressure on the material within the cavity, allowing bone to heal. More specifically, the shielding improves bone regrowth within the cavity. Furthermore, as the device 1 expands, it can push this bone material away from the cavity, thus lifting the vertebral body, also known as jacking it up, to restore its height (or restore the contours of other bones) when properly positioned.

[0029] As shown in Figures 1(A) and 1(B), after implantation of the unexpanded device 1, the bulk blocks 3, 4 move away from each other so that the blocks rest against the upper and lower parts of the intraosseous cavity. A suitable actuator, for example a screw-driven jack or spreader, can engage the actuator interface 10 of the device 1 to expand the device. The actuator may be removed from the actuator interface when the position of the blocks 3, 4 is fixed by suitable fixation and removed from the intraosseous cavity by entering and exiting the patient's body, for example as in the second example of Figures 5-8. Alternatively, the actuator may be left in the intraosseous cavity, as in the example of Figures 25-30. A threaded rod 18 now holds the fixation blocks 5 in place relative to each other, ensuring that the bulk blocks 3, 4 form a closed connection.

[0030] Once the device 1 is fixed, it can osseointegrate into the surrounding bone tissue, which can then re-enter the cavity 106. For this purpose, for example, the inner and / or outer surfaces of one or more of the blocks 3-5 can be provided with a growth-promoting coating or can be roughened by sandblasting. Furthermore, bone implant material can be provided within one or more of the bulk blocks 3, 4 or other parts of the device 1 in fluid communication with the cavity, which will prevent the bulk blocks 3, 4 from returning to their initial, unexpanded positions of the device 1.

[0031] With reference to Figures 2-4, the expandable implantable device 1 used in Figures 1A and 1B is shown in more detail in different states. Figure 2 shows the expandable implantable device 1 in an unexpanded state, and Figure 3 shows the expandable implantable device 1 in an expanded state. Figure 4 shows the expandable implantable device in an expanded and fixed state.

[0032] As shown in Figures 2-4, the device 1 further comprises a guide that defines a predetermined path along which the bulk blocks can move. In this embodiment, the guide is formed by at least one rod 21, in embodiment 4. The rod 21 extends in the direction of movement of the bulk blocks 3, 4 with a vertical arrow, as shown in Figure 3. Each rod 21 has a first rod end and a second rod end, the range of movement of the bulk blocks being defined by the distance between these ends. Although other guides are possible as well, the rod in this example is part of a frame 2 to which the bulk blocks 3, 4 are movably attached together. In this example, the bulk blocks are movably attached together to the frame 2 by a form-closure connection, and can slide along the rod, but are prevented from moving further by a lateral rod 22 of the frame. The lateral rod 22 is located for each bulk block on the bone side of the frame, i.e. on the same side of the frame 2 as the bulk block in question. Each lateral rod 22 connects corresponding ends of a number of spaced apart rods 21. As shown, and as can be seen more clearly in Figs. 5 and 6 for the second example, the shape of the frame 2 can be box-like.

[0033] Instead of a single frame to which all bulk blocks 3, 4 are attached, for example, several frames may be provided and other suitable connections may be provided which impose a maximum distance between the bulk blocks 3, 4 and define a limited range of movement of the bulk blocks. As shown in the example of Figs. 25-30, for example, each bulk block 3, 4 may be movably attached to an intermediate object of the rod 18. For example, each bulk block 3, 4 may be attached via a closed form connection, in this example via each ring-shaped member 62, 63.

[0034] In this regard, the term "form-closed" refers to the German word "form-clas", which is a connection between at least two connected elements that is formed by the interlocking shapes of the elements, and the connection cannot be released even in the absence of a connecting force. In other words, in the case of a form-closed connection, the shape of the connected elements is different from one another, so that the connection cannot be released without deforming the shapes.

[0035] Each of the bulk blocks 3, 4 has a fixation interface 13. The fixation interface 13 can be interfaced with a preformed fixator, which when interfaced holds the preformed bulk block against load in the expanded state of the bone support device and prevents the device 1 from moving back from the expanded state to the non-expanded state. In this example, the interface 13 is formed by the block gap sides 31, 41 of the blocks 3, 4. As shown, the block gap 11 is formed by the bulk blocks 3, 4 moving away from each other. The block gap 11 is in the direction of movement defined by the block gap sides 31, 41. Alternatively, for example, a scissor jack can be provided between the block gap sides 31, 41 in this embodiment as shown in Figures 3 and 4, but the fixation is implemented as a preformed fixation block 5, which is suitably shaped and of a certain size in the embodiment of Figures 25-30. The fixation is implemented as a plurality of fixation blocks 5. With reference to the example of Figures 3 and 4, the fixation block 5 can be slid into the block gap 11 after the device is placed in the cavity 106 to prevent the preformed blocks from moving against each other. As is clear from Figure 4, this block gap 11 is filled with the fixation block 5. The fixation block 5 can be selected from a set of fixation blocks of different sizes (such as in Figure 24), for example, depending on the size of the formed intraosseous cavity 106 or the dimensions of the block gap 11 observed during the operation. However, in the expanded state, the block gap 11 remains empty and is obviously not filled. For example, this is the case when the bulk blocks 3, 4 are fixed with a scissor jack placed in the block gap 11, which holds the position of the bulk blocks 3, 4.

[0036] Once the fixation block 5 is in place, the bulk blocks 3, 4 are prevented from returning to their initial position under load acting on the vertebrae. In this example, the bulk blocks 3, 4 are in the opposite direction towards the bone and are prevented from moving due to a form-closing connection with the frame 2. In the illustrated example, the shape of the fixation block 5 is substantially cuboidal, but for example, a wedge-shaped fixation block (as in the example of Figs. 25-30) could also be used, in which case the surfaces 31, 41 could be inclined to define a block gap 11 that is tapered towards the front end of the device, for example seen in the longitudinal or axial direction in which the device 1 is to be implanted. More generally, in the case of a wedge-shaped fixation block, i.e. block 5, the surfaces 31, 41 could be inclined so that the block gap 11 tapers in the same direction as the wedge is tapered, at least over the length that the wedge is moved into the block gap 11. For example, in the example of Figs. 25-30, if the wedge-shaped fixation block 5 can move into the gap space 11 from the axial end to a certain depth, the surfaces 31, 41 are at the inclined ends such that there is a similarly tapered gap over that depth. In this example, at the axial end, in other words, the gap space is formed as a wedge-shaped notch between the protruding ends 35, 45 of the bulk block. In that case, for example, a wedge can act as an actuator and, by inserting into the block gap 11, widen the block gap 11 and move the blocks 3, 4 towards the bone tissue defining the cavity 106.

[0037] As shown in Figures 2-4, the preformed bulk blocks 3, 4 can be moved along a predefined path as shown in Figures 3 and 4 to project out of the device in an expanded state relative to the unexpanded shape of the device as shown in Figure 2. In the example of Figures 2-4, the device has two bulk blocks in this regard, but similarly, the device 1 may only comprise one or more bulk blocks that can be moved away from an initial position (and from each other in the case of multiple bulk blocks) to expand the device 1.

[0038] As is evident from Figures 2-4 and 5-8, one or more components of the device may be porous on the outer surface and / or in the bulk. For example, the preformed bulk block 3, 4 and / or the preformed fastener 5 and / or the fixation element 6 and / or the core 7 may be porous on the outer surface and / or in the bulk. The porosity of the components may be complete or partial, and the pore size may be uniform as in the examples or may be variable. The pores provide an interface for bone ingrowth in the bulk block. This may enhance bone integration, since the pores provide a favorable location for bone ingrowth while the fixation block holds the bulk block in place against loads acting on the bone. Good osseointegration is provided when the average pore size is 1.5 mm or less, such as 0.3 mm or more and / or 0.9 mm or less, although other pore sizes may be suitable as well. In this regard, the average pore size may be controlled with an accuracy of 10% or more, for example 1% or more. Obviously, if the porosity is uniform, all the pores will be of the average pore size, but the porosity may be non-uniform.

[0039] Thus, the device 1 can be integrated into the bone, i.e., can obtain bone growth on the interface between the device 1 and the bone, e.g., on the bony side 30, 40 of the bone material, and ingrowth within the device 1. Without being bound by theory, it is currently believed that this can occur because the outer surfaces of at least portions and the struts 33, 43 within the bulk blocks 3, 4 form a cell growth matrix. The cell growth matrix can be, for example, proteins, water molecules and / or lipids adsorbed to the surface. The matrix may also have platelets attached to the surface. After formation of the growth matrix, osteoblasts or their precursor cells, e.g. osteochondrogenic cells or mesenchymal stem cells, grow thereon and subsequently form bone on the surfaces of the blocks 3, 4 and, if present, the fixation block 5. In this regard, it should be noted that although Figures 2-8 show enlarged views, in reality the device 1 is sized to fit each bone and provided via a minimally invasive procedure. Thus, the grids or matrices shown here have small pitches or the like that act as pores. This applies equally to the examples of figures 25-30, where the open cells 32, 42 are in fact small enough to act as pores. The device 1 therefore acts as a scaffold for bone tissue. In this regard, the device 1 may be osteoconductive and / or osteoinductive.

[0040] As shown in Figures 5-8, the members of the device may have porous bone sides 30, 40 of the bulk blocks 4, 5 with an average pore size smaller than that of the porous bulk portion. This allows for effective support of existing bone, while below the surface, the device 1 may also osseointegrate from the other sides of the device 1. In this regard, in particular the load-bearing bone sides 30, 40 may have low porosity and / or pore size to ensure that pressure at this contact interface does not compress existing bone through the pores. The members may have porous interblock surface 31, 41 with an average pore size equal to or larger than that of the porous bulk of the member. This allows for good interpore communication between the pores of the different portions, in particular between each member and the block gap 11 (or the portion of the device residing therein).

[0041] For example, the porosity of the member may be at least one of the group consisting of 70%, 80%, 90% and less than 100%, such as, for example, less than one of the group consisting of 95%, 85%, 75%. The porosity of the member may (obviously) be at least 10%, at least 20%, at least 30%, at least 0%, such as, for example, at least 40%, at least 50%, such as, for example, at least 55%. The currently most preferred porosity is in the range of 50% to 80%.

[0042] The bulk blocks 3, 4 comprise a load-facing block 3 having a load-facing side provided with a load-bearing surface 30. A sealing block 4 is on another side of the load-facing block 3. The sealing block 4 has a bone-interfacing surface 40 that faces away from the load-bearing surface 30. The bulk block can move from the load-bearing surface 30 to the bone-interfacing surface 40 or vice versa.

[0043] In the example, the total volume of the bulk blocks in the expanded state is greater than the total volume in the non-expanded state. Thus, the dimensions of the passageway required to insert the device into the cavity 106 can be quite small, while the volume filled by the device 1 in the expanded state is relatively large. Thus, the required surgery can remain minimally invasive. This is an example obtained by the upper bulk block 3 extending in the non-expanded state through the lower bulk block and moving from the lower bulk block 4 (and / or vice versa) when the device 1 is expanded. Thus, in the non-expanded state, the total volume is the volume of the largest of the blocks, while the volume of the smaller of the bulk blocks is added to the combined volume in the expanded state. As shown in FIG. 2, in the non-expanded state, the blocks 3, 4 almost completely overlap, and considering that they are almost the same volume, the combined volume can be doubled, and the ratio of the combined volume in the expanded state to the combined volume in the non-expanded state is at most about 2. Furthermore, because both bulk blocks are at least partially or completely displaced from the volume occupied by tem in the unexpanded state, in this example the overall device volume of device 1 can be multiplied by a factor of up to about 3.

[0044] As shown in Figure 4, in the implanted state, the preformed blocks can form a continuous volume with the anchoring block 5 located in the block gap 11 between the bulk blocks 3, 4. Thus, the bond volume in the expanded state can be increased beyond that of the bulk blocks. This can further reduce the invasiveness of the surgery. More specifically, the device in the expanded state with a large volume can be introduced into the bone through a relatively narrow passage.

[0045] In the examples of Figures 2-8, the blocks 3, 4 are formed to operate and extend relative to one another as follows: the closed block 4 includes a first matrix 8 of unit cells 42 and the load-facing block 3 includes a second matrix 9 of open unit cells 32. The first matrix 8 includes a first overlapping portion that overlaps with at least a second overlapping portion of the second matrix, and the first overlapping portion extends through at least a second overlapping portion of the second matrix. The second overlapping portion includes a partial matrix in which each cell is formed by an open face and whose ends are defined by a continuous enclosure of struts 33.

[0046] In the illustrated embodiment, the first overlapping portion and the second overlapping portion, more generally blocks 3-5, comprise a three-dimensional array of p×q open cells, where n, p, and q are positive integers of at least 2. For example, (n and p) or (p and q) or (q and n) or (p, q, and n) can be the same or different values. Any of n, p, and q can be any value from the group consisting of 2, 3, 4, 5, at least 10, at least 20, at least 50, at least 100, such as at least 200, at least 500, or at least 1000, depending on the particular embodiment. The three-dimensional arrangement of the first overlapping portion extends through the three-dimensional arrangement of the second portion.

[0047] The first and second matrices 8, 9 can move relative to each other to change the combined shape of the blocks 3, 4. In the first overlapping portion, each cell includes a strut 43 that forms the end of the opening face 44 of the cell. The struts 43 include parallel struts 43'' that extend in the direction of uninterrupted movement. However, the lateral struts 43' of the struts 43 that extend transversely to the direction of movement of the preformed block are interrupted to allow the passage of the second overlapping portion. The gaps in the lateral struts 43' are at least as large as or wider than the thickness of the struts 33 of the second overlapping portion to allow them to pass. The second overlapping portion extends in an unexpanded state through the interrupted struts 43' of the closed block.

[0048] In the example of Figures 5-8, the rods of the frame 2 are thicker than the struts of the second overlapping section. The frame 2 extends in a non-extended position through the sub-matrix at the end of the overlapping section, with a gap equal to or wider than the thickness of the rods, allowing the rods to pass through and thus the block 4 to move relative to the frame 2. However, in the cells of the first matrix 8 closest to the block gap side, the gap is narrower than the rods but still wider than the thickness of the struts. Thus, the frame is form-closed but movably connected to the enclosed bulk block 4, while the load-bearing bulk block 3 can move completely out of the block 4 along a predetermined path defined by the guide rods 21 of the frame 2.

[0049] Now, referring to the example of Figures 5-8, the example shown here is similar to the example of Figures 2-4, but differs in the following points. Instead of a monolithic fixation block, the fixation block 5 in this embodiment is expandable and comprises a movable preformed fixation element 6, as shown in Figure 6. A preformed element fixture 7 (not shown) can be inserted into the intrablock space 12 when the element is moved. Figure 7A shows a non-expanded state, and Figure 7B shows the expansion of the bulk blocks 3, 4. In Figure 7C, the fixation block is shown sliding into the block gap 11 in a non-expanded state. As shown in Figure 7, in particular the arrows in Figure 7C where the fixation block 5 is in place, and in Figure 7D where the fixation element is expanded, the fixation element 6 is movable along a predetermined path in a second expansion direction, for example a lateral direction different from the movement direction of the preformed blocks 3, 4, and protrudes from the block gap 10.

[0050] The movable preformed fixation elements 6 can then be moved to protrude from the block gaps 10 to fix the device in a second direction, e.g. laterally. In this example, the fixation block 5 has two fixation elements 6 moving in opposite directions, so that the deployed device has a +-shaped cross section (transverse to the axial direction of the device).

[0051] 5 to 8 further includes a fixed element guide 60 for guiding the movement of the fixed element along a predetermined path. In this example, the guide 60 is formed by a ring-shaped member 61 at each axial end of the fixed block 5, and each ring-shaped member 61 is slidably attached to the axial ends of both fixed elements 6 by a form-closed connection. In this way, the ring defines the range of motion.

[0052] As shown in this embodiment, the fixation elements 6 interpenetrate in a similar manner as the bulk blocks 3, 4 of the embodiment of figures 2-4. Thus, in the expanded state, the size of the passageway required to insert the device into the cavity 106 can remain extremely small while increasing the total volume of the fixation elements 6, while the volume filled by the device 1 in the expanded state is relatively large. This can further ensure or enhance the minimal invasiveness of the procedure.

[0053] The fixation block further comprises a preformed element fixation portion for holding the element in place when the configured shape is expanded, in this example in the form of a preformed block-like core 7, not shown in FIG. 7. FIG. 24 shows examples of suitable cores 7', 7", 7'". When the fixation element 6 is moved to protrude from the block gap 10, an intra-block space 11 is formed, which is then filled by the fixation core which fits into the intra-block space, thereby preventing the fixation element from moving towards the center of the device and fixing the position of the device. The ring-like member 61 repositions the element 6 in the opposite direction, away from the center, thus fixing the position of the element 6.

[0054] 5-8, the bulk blocks 3, 4 further include an actuator interface 10 for engaging an actuator, not shown, which actuates movement of the bulk blocks 3, 4 along a predetermined path. In this example, the device 1 has opposing axial ends 14, 15, and the actuator interface 13 includes protrusions 35, 45 on each bulk block 3, 4 that protrude with respective protrusions 35, 45 beyond the respective axial ends 14, 15 for engaging the actuator.

[0055] The bulk blocks 3, 4 further comprise passages 37, 47 which extend from the first axial end 14 to the second axial end 15 and are open at both ends. The projections forming the actuator interface are here formed by bars 38, 48 inserted in the protruding passages, each projection 35, 45 being provided at one or more ends. After actuating the movement of the bulk blocks 3, 4 and fixing the position of the bulk blocks 3, 4, for example by inserting a fixing block 5, these bars 38, 48 can be removed. This makes it possible to avoid unnecessary protrusions, which may be the cause of postoperative complications. The open passages 37, 47 can then be left during the harvesting with regenerated bone tissue.

[0056] The porous parts of the components 3, 4, and generally the components 3, 4, can be of any suitable type, the first matrix 8 and the second matrix 9 can for example comprise or consist of an open-cell solid foam. The foam can for example be made of a biocompatible metal and be an open-cell metal foam. The foam can for example be a self-forming structure and form a three-dimensional network of cells. The open-cell metal foam can for example be a reticulated solid foam, for example as shown in the examples. The foam can also be a regular foam or a putative foam. In the illustrated example, for example, the foam is a regular reticulated foam formed by a matrix of cubic unit cells. The matrix can comprise a single type of metal foam, but also a mixture of foams (for example of different types of unit cells, for example of different geometric shapes), such as a mixture of reticulated foams with different pore sizes.

[0057] As shown, in these examples, the matrix 8, 9 is internally porous and at least a portion of its surface is open or externally porous as well. In this example, the external pores are provided on the complete surface and the matrix is ​​open on all sides. The porous interior is in fluid communication with the external pores into which bone can ingrowth. For example, the internal and external pores may form an integral network of porous cells. The openness of the porous outer surface of the matrix may be, for example, at least 5%, such as at least 10%, preferably at least 50%, such as at least 80%. Of course, the openness may be less than 100%, for example less than 90%, for example less than 70%. The openness is defined as the ratio of the total area of ​​the unclosed portion of the external pores occupied by the outer surface to the total area of ​​the outer surface.

[0058] 9 shows another example such as those of FIGS. 2-4 and 5-8, but in which the preformed blocks 3, 4 contact each other in the unexpanded state of the device 1, in an embodiment on respective contact surfaces of the block gap sides 31, 41. In the expanded state, the contact surfaces define respective sides of the block gap 11. However, the bulk blocks each have a comb-shaped block gap side with a plurality of intersecting fingers 36, 46 in the unexpanded state. Thus, the diameter of the device is relatively small in the unexpanded state, whereas in the expanded state, the diameter can be larger compared to the unexpanded state.

[0059] Next, an example of the implantation use of the device will be described with reference to Figures 10-21. In this example, the device is implanted into a vertebra to stabilize and support the vertebral body, such as in the case of a fracture or localized deterioration of bone strength due to osteoporosis or other conditions. First, the dimensions of the delivery site are determined and an access angle and path are selected. Then, access is created and an intraosseous cavity is created at the delivery site. With reference to Figure 10, for example, a trocar 200 can be positioned, for example, under fluoroscopic imaging, to enter the pedicle 100 between the vertebrae 102 and 104 along the coronal plane.

[0060] Alternatively, as shown in Figure 11, the trocar 200 can be positioned relative to the pedicle 100 along the sagittal plane. The trocar 200 is driven into the tissue and / or bone to achieve the proper position, for example, within the first third of the vertebral body 101, to fix the axis for the remaining steps of the procedure. Imaging devices, such as x-ray imaging, can be used, for example, along the coronal or sagittal planes, to ensure proper positioning of the trocar.

[0061] As can be seen with respect to FIG. 12, the stylus of the trocar 200 can be replaced by a pin 202 that can be secured to the medium of the vertebral body 101, after which the trocar can be removed. Imaging, such as x-ray imaging, can be used, for example, along the coronal or sagittal plane, to ensure proper positioning and fixation of the pin. As shown in FIG. 13, once the pin 202 is properly positioned, a radius, such as square radius 204, can be positioned to slide over the pin 202 in a manner sufficient to puncture the cortical portion of the pedicle, facilitating insertion of the drill. Thereafter, if necessary, a protective sleeve can be positioned to facilitate delivery of the canal guide.

[0062] As can be seen with respect to FIG. 14, the drill 206 may be assembled and then placed at the delivery site. For example, the drill 206 may be partially assembled with the application of a brake washer and a tube guide 208, and the entire assembly may be placed over a pin. For example, the positioning of the drill 206 may allow the tube guide 208 to be guided medially relative to the pin. Imaging devices such as x-ray imaging may be used, for example, along the coronal or sagittal planes, to ensure proper positioning of the drill and / or tube guide. Such imaging is important to prevent pedicle rupture. As shown in FIG. 15, the tube guide 208 may be positioned to be inserted into the proximal cortical pedicle and secured to the pedicle, for example, by screwing. For example, the tube guide may include one, two, three, or more threads, such as at 120°, to stabilize the tube guide 208 within the pedicle. Specifically, the tube guide may be inserted through soft tissue with a counterclockwise force applied to the tube guide, but may be secured to the bone by a clockwise movement (e.g., clockwise screwing). Once the tube guide 208 is secured to the proximal pedicle cortex, the pin may be removed prior to drilling, for example, as shown in FIG.

[0063] Once the drill 206 is properly positioned as shown in Figure 17, both the pedicle and vertebral body 100 may be drilled in a manner to create an intraosseous cavity of selected dimensions for device delivery, positioning, and / or expansion. Once the vertebral body 100 has been drilled, the drill may be removed as shown in Figure 18. If desired, a probe may be used to confirm the access and / or delivery site.

[0064] The gauge 210 can be inserted into the prepared access as shown in Figure 19. The device gauge 210 can be inserted into the access to prepare the device site, for example to adjust the depth to ensure optimal positioning of the device. The device gauge 210 can then be removed as shown in Figure 20. The probe can be used to assess the configuration of the access and / or implant bed (e.g., cavity) prior to device insertion.

[0065] Fig. 21 shows the insertion of the device 1. The device 1 is fixed to the holder 101 and the fixed assembly is inserted into the access hole prepared by, for example, a drill, until the brake washer is stopped by the tube guide. Then, as shown in Fig. 22, the device 1 can be adjusted, for example, so that its expansion plane is parallel to the mechanical axis of the vertebrae, for example, so that the expansion of the device is parallel to the handle of the device holder.

[0066] Once properly positioned, the device 1 can be brought from an unexpanded state to an expanded state, as shown with reference to FIG. 1, to restore vertebral body height.

[0067] As shown in Figures 23A and B, the surgical method described with respect to Figures 10-22 can be repeated to implant one or more additional expandable and implantable devices at a second location in the bone. For example, a second implantable device can be inserted into the vertebral body 102 via a second pedicle. As shown in Figures 23A and B, a second pedicle in the pedicle 100 can be accessed for delivery and implantation of the second expandable device. An anterior view of the vertebral body 100 with one holder 101a and a cannula plug inserted into the vertebral body 100 via two different pedicle access points is shown in Figure 23A. Figure 23B shows a posterior view of the vertebral body 100 of Figure 23B with two holders 101a and 101b inserted into the vertebral body 100. As shown, the holders 101a and 101b each include an expandable and implantable device 1. Once inserted and properly positioned within the vertebral body 102, the device can be, for example, incrementally expanded to allow for fracture reduction and / or at least partially or completely re-establish the original height of the vertebral body. Note that the device can also be expanded simultaneously, if desired. The fracture reduction can be imaged by methods known in the art, such as X-ray imaging or fluoroscopic monitoring. After the desired expansion is achieved, the device holder can be released from the device, for example, by loosening the expansion handle, and the device holder can be.

[0068] FIG. 4 shows a set of cores 7', 7", 7'" for fixing blocks of devices of different sizes. These can be provided in a kit of parts that also includes an expandable implantable device such as the embodiment. During surgery, the surgeon can select a suitable set of blocks that fit into the intra-block space 12 created during surgery. The surgeon can then place the selected blocks into that space 12. Alternatively, or in addition, the set may include complete fixation blocks 5 of different sizes, and a suitable block can be selected to fit into the inter-block gap 11 created during surgery, as described above.

[0069] The set or kit, or simply the device, may be provided as a single package. The package may further include a package insert and instructions for using the items in a mammalian bone surgery procedure or an indication of the usefulness of the items. For example, the instructions may be for reducing a fracture or treating osteoporosis. The package may, for example, be a sterile package, where the items are sealed to maintain sterility.

[0070] The example shown in Figures 25-30 may be provided in the package as well. This example is the same as the examples in Figures 2-4, 5-8 and 9, except as follows.

[0071] In the example of Figs. 25 and 26, a load-bearing block 3 and a sealed block 4 are shown with complementary bone sides 30, 40 in an unexpanded state that form the outer surface of the device body 19 when the space sides 31, 41 between the blocks contact each other. More specifically, the bone sides 30, 40 are each elongated in shape extending from a first lateral end to a second opposite lateral end, with lateral ends 320-322, 420-422 between the lateral ends that each define a side of the bone side. The bone sides 30, 40 are curved laterally about a longitudinal axis, thus each defining a cavity with an open side directed towards the other block. In other words, each block 3, 4 forms a partial device body whose interior forms an interface with the other block and whose bone side 30, 40 defines the outward facing side of the other. When the blocks 3, 4 are placed with the bone sides 30, 40 in contact with each other over the lateral sides, i.e., when the ends 320-322, 420-422 abut as shown in FIG. 26, the blocks 3, 4 together form the device body 19, which is continuous in the circumferential direction, and the bone sides 30, 40 together sleeve-like envelop the inside of the device body 19. More specifically, in this example, the contact on the lateral ends results in a flat overall surface where the bone sides 30, 40 are horizontal with each other at the lateral ends. Thus, the shape of the device body 19 is smooth. Furthermore, in this example, the casing is in the axial direction of the unexpanded implant, as shown by the arrow a in FIG. 26, and there are no discontinuous steps or protrusions. This allows the expandable implantable device to be smoothly inserted in an unexpanded state through an access to a vertebra or other bone. In this example, the body 19 is cylindrical, although other shapes may be used, but may alternatively be a non-circular elliptical cylinder or other suitable cylinder, such as a hexagonal or other polygonal cylinder, and generally other elongated shapes such as a spindle, cigar or lemon shape or a rectangle. Preferably, the end shapes are rounded.

[0072] As shown, each bone side 30, 40 of the blocks is a cross-section of the outer surface of the device body 19 defined by a cross-section parallel to the radial direction, which in this example extends through the axial end of the device body 19. More specifically, the cross-sectional plane separating the two bone sides is parallel to the longitudinal axis of the device body 19, which in this example is perpendicular to the direction of movement of the blocks 3, 4 (indicated by arrow r in FIG. 26). The combined blocks together have complementary shapes that form a complete device body 19, e.g., a cylindrical or other elongated shape, when the ends 320-322, 420-422 are correctly positioned relative to one another and the insides of the blocks 3, 4 are positioned interlocking with one another. In this example, the cross-section is discontinuous in the longitudinal direction, i.e., there is a step in the cross-section. Thus, each lateral end of the bone sides 30, 40 exhibits a step 322, 422 in the longitudinal direction, which separates a first portion 420 from a second portion 421 of the end. In the first portion 320, 420, the end is located further from the longitudinal axis of the surface 30, 40, as viewed laterally, than in the second portion 421, the end being located closer to the longitudinal axis of the bone side surface 30, 40. In other words, the step 322, 422 separates a first side surface of the bulk block 3, 4, in which the bone side surface 30, 40 has a side lobe, from a second side surface in which the bone side surface 30, 40 surrounds a smaller segment. It will be clear that this transition is also gradual and that the side lobes 300, 400 may, for example, have curved ends.

[0073] Each bulk block 3, 4 has a matrix or matrices 8, 9 of unit cells at the interblock sides 31, 41 which may be accommodated inside the other bulk block. Like the example of Fig. 9, in this example the blocks 3, 4 interdigitate in an unexpanded state and can move relative to one another in the radial direction shown in Fig. 26 by arrow r to extract the interdigitated portions from one another. However, like the example of Fig. 9, instead of the fingers, i.e. ribs, extending transversely as in the examples of Figs. 25 and 26 where the ribs extend longitudinally, the fingers extend transversely.

[0074] In Fig. 25, 26, each block 3, 4 divides its interior into 16, 17 parts. In the first part 16, one or more porous elements are placed, in this example a panel-shaped sub-matrix of the matrix 8, 9. The second part 17 of the interior space is divided into slots in which the porous elements of the other block can be placed. In Fig. 25, the part 16 with the porous elements is away from the side lobes 300, 400 of the surface 30, 40, and on the sides, also called longitudinal direction, of the bulk blocks 3, 4 there is a gap between the lobes 300, 400 and the porous elements. The divided slot-in-slot part 17 of the interior space is divided in the slot by ribs, of which only the rib 49 of the sealing block 4 is visible in Fig. 25. In the slot, the porous elements can be admitted. The ribs 49 protrude in the elongation direction from the inside to the inside of the bone side surface 30, 40, parallel to each other. The ribs 49 therefore guide the movement of the porous element, and thus of the other block 3, 4, until it exits the slot.

[0075] In the example of figures 25 and 26, the ribs 49 run parallel to the axial direction of the implantable device 1 from each axial end of the bulk blocks 3, 4 inwardly towards the other axial end, the blocks being open at the axial ends. The ribs 49 therefore provide an open structure in the expanded state which promotes bone ingrowth and bone ingrowth, and in the unexpanded state hold the matrix firmly in the slots. The ribs 49 also provide passages through which the slots pass, which allows the ingrowing bone to propagate between the slots and promotes osseointegration after implantation. However, despite its openness, the overall structure is still very strong and can withstand compressive external loads applied during and after implantation. The ribs 49 are implemented in the example shown as side passages of unit cells, so that the ribs 49 together form each matrix of the unit cells and therefore sub-matrices of the matrices 8, 9 of the bulk blocks 3, 4, although other methods can be implemented.

[0076] The illustrated porous panel is formed as a panel with sub-matrices of the matrix 8, 9, the shape of each panel fitting into the slot of the other block 3, 4. The overall matrix 8, 9 in this example is thus formed by the arrangement of sub-matrices present on one side of the gap, i.e. the panels, and sub-matrices present on the other side of the gap, i.e. the ribs. In this example, the matrix further comprises side lobes equally with the open sides of the unit cells. Thus, in this example, the matrix of each bulk block 3, 4 extends through the matrix of the unit cells of the other bulk block 3, 4 when the panel is in the slot. The overlapping parts of the matrices 8, 9 comprise the porous elements, the ribs and, if present, the side lobes.

[0077] As further shown, the panels are formed as elongated matrix blocks, located at the other ends of the bulk blocks 3, 4, except for the ends where the ribs 49 of the bulk blocks are located. These matrix blocks extend from the axial end opposite the axial end where the ribs 49 are located towards the ribs 49, in the transverse direction where they are located at the same positions as the slots, so that the matrix can be placed into the slots of the other blocks without causing an offset of the sections and therefore without deformation of the complete shape of the joined preformed blocks 3, 4.

[0078] As shown in FIG. 25, in the transverse direction, the matrix blocks 8, 9 are separated as well as the ribs 49, and in each block, a central slot exists in the unexpanded state extending from one axial end to the other axial end. Through the central slot, an actuator 18 or other object can be inserted to protrude at both axial ends of the implantable device 1, for example as shown in the figure. 29 and 30 comprise threaded rods. In the transverse direction, the matrix 8, 9 is slightly recessed with respect to the outer end of the bone side surface 30, 40. In this example, the surface 30, 40 has knobs 301, 401 at the transverse ends of the area of ​​the matrix 8, 9, which protrude laterally beyond the matrix block, as shown by reference number 401 in FIG. 25. In the unexpanded state, the lateral leaflets 300, 400 of the other block cover the matrix and abut the protruding knobs 401 at the ends. Thus, in the unexpanded state, a relatively high stiffness is obtained without a large amount of structure.

[0079] In Fig. 25, the bone sides 30, 40 are porous and have respective open cells 32, 42. As shown, each of the surfaces 30, 40 has multiple types of pores. In this example, the pores in the side lobes 300, 400 are different from the pores present towards the center of the surface 30, 40. The side lobes 300, 400 have a rectangular unit cell, while the pores in other parts of the surface 30, 40 are heptagonal. Furthermore, the pores in the side lobes 300, 400 are smaller than those in the center of the surface 30, 40. This allows the resulting open structure to still be very strong and able to resist the loads acting during injection and expansion.

[0080] 26, the axial ends of the two blocks 3, 4 are chamfered such that when the two blocks 3, 4 slide against one another, for example in the unexpanded state of the device 1, the chamfered ends of the blocks protrude and a notch 110 is formed between the protruding ends 35, 45 with which the actuator 18 can engage, as will be described in more detail below. In this example, the chamfered ends 35, 45 are formed by the angled axial sides of the ribs 49 and side lobes 300, 400 at one of the axial ends and the angled axial sides of the matrices 8, 9 at the other axial end.

[0081] With reference to FIG. 27, the blocks 3, 4 of the example shown are shown. The blocks 25 and 26 may be formed in close contact with each other by respective ring-like members 62, 63. In this example, each member 62, 63 includes two parallel closed loops 64 fixed by a bridge and spaced apart from each other. The loops 64 are held in shape in this example by the bridge and are fixed in position and orientation relative to each other. The loops 64 may be made, for example, from metal or hard plastic. Although not shown in this exploded view, as indicated by the arrows in FIG. 27, the ring-like members om 63 each extend through holes in the matrix 8, 9 of each block, each member forming a closed loop around each strut 43 and passing through the matrix. Thus, the rotational movement of the bulk blocks 3, 4 relative to each member 62, 63 is limited, preferably blocked. In this example, the loop 64 also passes through the central slot and through the matrix blocks on either side of the slot, but it is clear that each matrix block may, for example, comprise separate loops.

[0082] Each block 3, 4 further has a gap that can admit the members 62, 63 of the other block. In the example of FIG. 27, the gap is located as seen in the axial direction a between the matrix 8, 9 and the rib 49, separating the rib 49 from the matrix block of each block 3, 4. In this example, the members 62, 63 are inserted in the gap without being attached to the block. The freedom of movement of the bulk blocks 3, 4 is therefore not restricted by the members 62, 63 (attached to the other bulk block) that are admitted in the gap. Thus, the overall range of expansion can be increased. As shown in FIGS. 29 and 30, an elongated object can extend axially through the loops 64 of both members 62, 63. The object is formed in a closed state in each block, and a movable connection between the bulk blocks 3, 4 can be obtained with a large degree of freedom of movement. In the connection, the loops 64 guide the movement of the blocks 3, 4 and define a path along which the blocks can move relative to the elongated object. Preferably, as in the example, the connection provides a single degree of freedom in the radial direction r from the unexpanded state to maximum expansion, with other degrees of freedom being restricted, e.g. blocks 3, 4 being able to rotate about an axis extending radially of body 19 relative to one another within a very limited range, e.g. 5 degrees or less, e.g. less than 2 degrees, for an intentional or unintentional clearance of less than 2 degrees, which is, for example, not significant in practice.

[0083] FIG. 27 further shows axially spaced apart fixation blocks 5. In this example, there is a fixation block 5 at each axial end, and the fixation blocks 5 can translate in the axial direction a. In this example, the fixation blocks 5 have implant faces 50 shaped to engage the spaces between the protruding ends 35, 45 at the axial ends of the blocks 3, 5. In the expanded state, the fixation blocks are disposed between the bulk blocks 3, 4, maintaining the separation therebetween and preventing the bulk blocks 3, 4 from moving towards each other. In this way, the fixation blocks 5 prevent the implantable device 1 from collapsing into a non-expanded state and fix the expanded state. In addition to fixing the expanded state when in place, the fixation blocks 5 can also expand further when the fixation blocks 5 are moved. More specifically, the fixation blocks 5 can move relative to each other, and when the implant facing faces 50 come into contact with the protruding ends 35, 45, they exert a force on the axial ends of the bulk blocks 3, 4 as they move axially relative to each other, pushing the bulk blocks radially outward. In this example, the protruding ends 35, 45 form an inclined contact surface facing the implant side surface 50, and the movement force exerts pressure on the contact surface with the radial components, causing the bulk blocks 3, 4 to move radially outward. For example, as shown in FIG. 29, the height of the implant-facing side 50 may be equal to or less than the radial dimension of the device body 19 in the unexpanded state, and preferably the entire fixation block 5 does not protrude radially beyond the device body 19. Thus, the device 1 has a closed shape that can be smoothly inserted into bone in the unexpanded state. In this example, in the unexpanded state, the implant-facing side contacts the inclined surfaces of the protruding ends 35, 45, closing off the axial ends of the device 1 in the contact area. Thus, as seen in the axial direction a, the fixation block 5 and the device body 19 form a continuous body in the unexpanded state, which makes it easier to insert the device 1 through the bone and into the cavity 116.

[0084] Although other shapes are similar, in this example the fixation block 5 is wedge-shaped, tapering from the base to the other fixation, with its two surfaces meeting each other at a ridge on the implant side 50. This shape allows precise control of the expansion of the device 1. The widest part of the wedge determines the maximum distance the bulk blocks 3, 4 can be pushed outward. As shown, in this example the wedge-shaped fixation blocks face each other with their sharp sides. When the fixation blocks 5 are moved relative to each other, the wedges slide over the chamfered protruding ends 35, 45, pushing the bulk blocks 3, 4 outward in a radial direction r, as indicated by the arrow in FIG. 30. Alternatively, the fixation block 5 may be oriented with its angled surface pointing away from the other fixation block, and the angled surfaces of the bulk blocks 3, 4 may be correspondingly oriented, in which case the bulk blocks 3, 4 can be pushed radially outward by moving the fixation blocks 5 away from each other.

[0085] In this example, the base 51 is of a similar shape to the case, e.g. cylindrical. Through the base extends a passage 52, which is an extension of the central slot when the device 1 is assembled, and through which, e.g., a threaded rod or other actuator 18 (or other object) can extend, by means of which the actuator can engage the fixed block 5, although other types of engagement are possible as well. The actuator 18 engages the fixed block 5 to move relative to one another, thereby actuating the movement of the bulk blocks 3, 4 and thus the expansion of the device 1. This movement can be precisely controlled, so that the device 1 has a controlled expansion. The passage 52 can be threaded to engage a threaded rod, such that the fixed blocks move towards one another, thus actuating the movement of the bulk blocks 3, 4.

[0086] FIG. 28 shows a threaded rod 18 that can be inserted through the closed loop of the fixation block and the ring-like members 62, 63. It will be equally clear that the rod 18 has a hexagonal wrench end 180 on which a compatible socket can be placed to rotate the rod 18 about its axis, and that other rotation interfaces can be hexagonal sockets or view-specifying screw heads, etc. At the opposite end, the rod has a stop 181 that holds the fixation block 5 in its end position and prevents the block 5 from moving off the rod 18. As shown more clearly in FIGS. 29 and 30, in the assembled device 1, the rod 18 extends with the end 180 protruding at one of the axial ends through a central slot, and the stop 181 protruding at the other axial end of the implantable device 1.

[0087] As further shown, the rod 18 extends through the loop 64 and is thus form-closed but movably connected to each bulk block 3, 4. As both bulk blocks are form-closed connected to the rod in this manner, a form-closed connection between the bulk blocks 3, 4 is obtained with a relatively large degree of freedom of radial movement.

[0088] As shown in Figure 29, in the unexpanded state, the rods 18 extend through the fixed blocks and through loops 64 in the central slots, holding the fixed blocks in position relative to one another and forming a closed, but movably attached, connection between the bulk blocks 3, 4. The bulk blocks 3, 4 extend from one another in this state.

[0089] By rotating the rod in one direction, the threaded engagement with the fixed block 5 actuates a translational movement of the fixed block 5 axially towards each other. Contact with the inclined surfaces of the bulk blocks 3, 4 causes the bulk blocks 3, 4 to be pushed radially outwards expanding the device 1, which is no longer in a non-expanded state. The degree of expansion can be precisely controlled by the rotation of the rod 18. In this regard, it will be apparent that the ratio of the rotation of the rod to the expansion of the device depends on the inclination angle of the inclined surfaces as well as the lead of the screw, which can be selected to obtain a desired ratio.

[0090] More specifically, by rotating the threaded rod, the rod moves translationally relative to the loop 64 that engages the thread and thus relative to the bulk blocks 3, 4. The end with the stop is moved inwardly into the block gap and thus the fixed block in its position (left side, Figs. 29 and 30) is moved as well. In this respect, it is clear that this fixed block does not engage the thread in this embodiment and remains in position relative to the rod. At the same time, due to the rotation, the other fixed block that engages the thread moves in the opposite direction over the rod into the block gap and thus towards the other fixed block, resulting in the expansion of the device 1 as shown in Fig. 30. It will be clear that in this example, the loop 64 acts as a threaded bore of the threaded rod and can be implemented with alternative shapes that perform this function, for example, and that another threaded mechanism that causes linear displacement of the rod relative to the bulk blocks 3, 4 can also be used.

[0091] By rotating the rods in the opposite direction, the fixation blocks 5 are actuated apart from each other and thus the bulk blocks 3, 4 are moved to collapse the device 1 under the external load applied to the bulk blocks. Thus, a precise and reversible control of the expansion of the implanted device 1 by the physician is obtained. Thus, the device can be placed, for example, in the cavity, expanded to a certain extension and then slightly contracted to ensure that the expansion sufficiently plastically deforms the bone.

[0092] As can be seen in FIG. 30, loop 64 determines the maximum distance between blocks 3, 4 in the expanded state. The inner diameter of loop 64 in the radial expansion direction r, as indicated by arrow d, determines the maximum displacement of each block in that direction relative to the rod in this example. In this example, loops 64 are of equal diameter, but instead, for example, the inclination angle of the side of the wedge facing sealing block 4 may be a different inclination angle than the side of the wedge facing load-bearing bulk block 3, such that the ratio of the displacement of load-bearing bulk block 3 to the displacement of sealing block 4 is not equal to 1. In such a case, each loop may be of equal diameter and different.

[0093] In Figure 30, the difference in wedge height is greater than the maximum displacement, so the fixed block 5 exerts an expansion force on each block opposite the force exerted by the loop 64 on the blocks, displacing the fixed block 5 until it reaches the maximum displacement of the bulk blocks 3, 4 determined by the inner diameter of the loop, thus fixing the bulk blocks 3, 4 in position relative to the rod 18.

[0094] In the above specification, the invention has been described with reference to specific examples of embodiments thereof. However, it is clear that various modifications and changes can be made without departing from the scope of the invention as set forth in the appended claims, and that the examples are not intended to be limiting, and the claims should not be construed as being limited to the specific examples shown. Also, in the examples, any preferences shown are not meant to be limiting, but rather to show that various alternatives are possible, which are currently considered to be more preferred, to which reference is made.

[0095] For example, the matrix of the overlapping parts, and more generally the parts of the device 1, may be made of any suitable biocompatible material. The material may include, for example, materials outside the group consisting of metals, metal compounds, metal alloys, metal composites, polymers, ceramics, and combinations of materials from this group. The biocompatible material may contain metals from the group consisting of titanium, tantalum, niobium, stainless steel, cobalt chromium alloys, zirconia, or compounds, alloys or composites thereof. Other suitable biocompatible materials may contain polymers from the group consisting of polyaryletherketones, polyetheretheretherketones, polyetherketoneketones.

[0096] Also, in the examples of Figures 25-30, the blocks 3, 4 are in this example identical. However, depending on the particular embodiment, the load-bearing block 3 may differ from the sealing block 4. For example, the sealing block 4 may have ribs 49, slots at both axial ends and a load-bearing block matrix block at both axial ends, which fits into the slots. Similarly, in these examples, the blocks are symmetrical parts from which the device body 19 is constructed, but the device body may have, for example, a cross section that is parallel without steps but does not obviously coincide with the longitudinal axis dividing the parts.

[0097] Additionally, in embodiments, the porous portion is implemented as a regular matrix, but may instead be partially or entirely irregular, and in embodiments, all cells of the matrix are open, but alternatively, some cells may be closed, and portions of the matrix may be non-porous.

[0098] It is clear that by providing and / or moving the bulk blocks and / or the fixation elements 6, if any, in an appropriate manner, the device 1 may have, in the expanded state (in a cross-section perpendicular to the longitudinal direction of the device along which it is inserted), two or more legs which in the unexpanded state protrude from the axial centre of the device. These legs may, for example, comprise two or more legs extending transversely to one another and / or two or more legs extending parallel to one another. Thus, the device may, for example, have a cross-sectional shape in the expanded state which is, for example, +-shaped (after insertion of the core 7 in FIG. 7D), T-shaped, l-shaped (as in FIG. 7B), O-shaped (as in FIG. 7D), U-shaped.

[0099] Similarly, where movement of an object is described (e.g., relative to another object), unless explicitly specified otherwise, this is relative movement, and thus depending on the chosen frame of reference, the object may move relative to the observer while the other object is static, the other object may move while being static relative to the observer, or both objects may move relative to the observer but differently.

[0100] The device can also be provided as a tangible object. Alternatively, however, data representing a model of the device can be provided. In that case, the data is loaded into a data processing device, for example an embedded control system or other type of computer controlled computer, and the data processing device is operated to control the forming by the manufacturing device to obtain a shape according to the data. The model can be obtained in any manner suitable for the particular implementation. The design can be stored, for example, on a tangible data carrier, or the assembly can be stored, as computer-loadable data representing the model of the device. In this respect, the data carrier can be, for example, a tangible non-transitory computer-readable storage medium or a computer-readable transmission medium. These computer-readable media can be permanently, removably or remotely coupled to the computer. The computer-readable transmission medium can be a data transmission medium, such as a wired or wireless transmission medium, to name a few examples. Computer-readable storage media may include, for example, but are not limited to, magnetic storage media including disk and tape storage media; optical storage media such as compact disc media (e.g., CD-ROM, CD-R, etc.) and digital video disc storage media; non-volatile memory storage media including semiconductor-based memory units such as FLASH (registered trademark) memory, EEPROM, EPROM, ROM, etc.; ferromagnetic digital memory; MRAM; volatile storage media including registers, buffers or caches, main memory, RAM, etc.

[0101] Also, the fixation block 5 of the second embodiment of Figs. 5-8 includes a core. This may be a non-expandable core, but the core itself is implemented as a further fixation block that can expand beyond the intrablock space 12, which in turn has the core as yet another expandable fixation block, etc. This allows the expanded device to be gradually expanded and given a flexible shape, thus improving the filling of the intrabone cavity. Furthermore, in the embodiment, the matrix is ​​open on all sides. However, it will be clear that in some applications one, or more than one, or all of the outer surfaces of the matrix may be closed on one or more sides, e.g. some sides may be closed without any holes.

[0102] Additionally, the fixation block and bulk block may be implemented in any manner suitable for a particular implementation. One or more, and preferably each, of the blocks may be, for example, a monolithic element and made of a single piece of material. This provides a strong block that can withstand forces encountered during implantation and post-implantation. Alternatively, one or more of the blocks may be made of multiple pieces attached to each other, for example if the reference block may be folded during use.

[0103] The top or load of the bulk block 3 can for example be made of the same material as the bottom or closed bulk block 4. This allows both blocks to be manufactured simultaneously, for example by additive manufacturing. Alternatively, the blocks may differ in the material they are manufactured from. This allows for example the first block to be rigid and the second block flexible. One, or more than one, or all of the blocks may be non-degradable in vivo or in situ. This allows for example to be a permanent structure, if a permanent support to the bone is required and bone regeneration after implantation is not expected to be sufficient.

[0104] Alternatively or additionally, one or more or all of the preformed blocks 3-5 may be biodegradable in vivo. This allows, for example, temporary devices or devices with temporary components to be placed without surgery to remove the device. For example, the core 7 or full fixation block 5 may be non-degradable and the bulk blocks 3, 4 may be of a degradable material. This allows for permanent support, for example, when it is presumed that bone will only partially regenerate in the outer parts of the cavity 106, but not enough in the center of the cavity 106. The degradable blocks may then disappear while the cavity space around the non-degradable blocks is filled by bone regeneration.

[0105] Moreover, terms such as "front," "rear," "top," "closed," "upper," "lower," and the like in the specification and, if any, in the claims are used for purposes of explanation and not necessarily to describe permanent relative positions, and it will be understood that such terms are interchangeable under appropriate circumstances such as operating the embodiments described herein in the orientations illustrated or other orientations other than those described herein.

[0106] However, other modifications, variations, and alternatives are possible. Accordingly, the specification and drawings are to be regarded in an illustrative rather than a restrictive sense.

[0107] In the claims, reference signs placed between parentheses shall not be construed as limiting the claims. The term "comprising" does not exclude the presence of other elements or steps recited in the claim. Moreover, the terms "a" or "an" are used herein to mean "one or more". Also, introductory terms such as "at least one or more" and "one or more" in the claims shall not be construed as meaning that the introduction of another claim element by the unclear article "a" or "an" limits a particular claim containing such introduced claim element to inventions containing only one such element, even if the same claim contains the introductory phrase "one or more" or "at least one or more" and an unclear article such as "a" or "an". Unless otherwise indicated, words such as "first" and "second" are used to distinguish in any way between the elements they represent. Thus, such terms do not necessarily indicate a chronological or other priority between the elements. The mere fact that certain measures are recited in different claims from one another does not indicate that a combination of these measures cannot be advantageously utilized. [Explanation of symbols]

[0108] 1 device 2 Frames 3, 4 Bulk Block 5 Fixed Blocks 6 Fixed elements 7 cores 8 The First Matrix 9 The Second Matrix 10 Actuator Interface 11 Block gap 12. Space within a block 13 Fixed interface 14, 15 Axial end 16, 17 Bulk block parts 18 Actuator 19. Device body 21 Guide rod 22 Horizontal Bars 30, 40 bone side 31, 41 Block gap side 32, 42 Open Cell 33, 43 Cell support 33' Horizontal support 34, 44 Opening surface 35, 45 protrusion 36, 46 Finger Aisles 37 and 47 38, 48 bars 49 Ribs 50 Implant facing surface 51 Base 52 Passage 60 Fixed element guide 61 Ring-shaped member 62, 63 Ring-shaped member 64 Closed Loop 100 stems 101 Holder 102 vertebrae 103 Intervertebral disc 104 vertebrae 106 Intraosseous Cavity Aisle 108 109 End Plate 110 Notch 111 Front wall 180 End 181 Stops 200 Trocar 202 pin 204 Earl 206 Drill 208 Tube Guide 210 Gauge 300, 400 Side lobe 301, 401 knob 320, 420 outer end 321, 421 outer end 322, 422 steps

Claims

1. 1. An implantable, expandable bone support device that can be implanted into a bone of a human or non-human mammal, comprising: a first and second preformed bulk block for filling an intraosseous implant cavity of a bone in an expanded state of a bone supporting device, the preformed bulk block being movable along a predetermined path to protrude in the expanded state of the bone supporting device relative to a non-expanded state of the bone supporting device, the volume of the bulk block in the expanded state being greater than the volume of the bulk block in the non-expanded state; Each of the bulk blocks comprises: a load bearing surface for supporting a load acting on the bone; a fixation interface for interfacing with a preformed fastener, the fixation interface holding the preformed bulk block in place against the load in an expanded state of the bone support device and preventing the bone support device from collapsing from the expanded state to a non-expanded state; Including, the first and second bulk blocks form a cylindrically shaped body in the unexpanded state; the first bulk block includes a first matrix of unit cells and the second bulk block includes a second matrix of unit cells, the first matrix including a first overlapping portion that overlaps and extends through at least a second overlapping portion of the second matrix in the unexpanded state; the first and second bulk blocks are interlocking in the unexpanded state and are movable relative to one another to separate interlocking portions. Device.

2. 2. The apparatus of claim 1, wherein in the unexpanded state, lateral ends of the load bearing surfaces of the first and second bulk blocks are flush and in contact with one another to form a plane.

3. The device of claim 2 , wherein in the unexpanded state, the body has no steps or protrusions in an axial direction of the body.

4. The device of any one of claims 1 to 3, wherein in the unexpanded state, the body is one of a cylindrical shape, an elliptical cylindrical shape, a spindle shape, a cigar shape, and a lemon shape.

5. The device of any one of claims 1 to 4, wherein the first bulk block moves away from the second bulk block and / or vice versa when the device is expanded.

6. 2. The device of claim 1, wherein the bulk blocks each have a comb-shaped interblock side with a plurality of ribs, the ribs of the blocks interdigitating in an unexpanded state.

7. 7. The device of claim 1, wherein at least one of the blocks has a rib dividing at least a portion of the interblock side within a slot, and at least one other of the blocks has a porous element extending into the slot, the rib extending in a longitudinal direction of the device.

8. The apparatus of claim 1, wherein the first matrix and the second matrix are movable relative to each other to change the combined shape of the blocks.

9. 9. The apparatus according to claim 8, which is dependent on claim 7, wherein the porous element is a panel-like sub-matrix of the first and second matrices, and optionally the ribs comprise passages which communicate with the slots.

10. 2. The apparatus of claim 1, wherein in the first overlapping portion, each cell has a strut forming an end of a surface of the cell, and all of the struts extending transversely to the direction of movement of the bulk block are blocked to allow passage through the second overlapping portion.

11. The apparatus of claim 10 , wherein the struts include parallel struts extending in a direction of movement, the parallel struts being uninterrupted.

12. the second overlapping portion includes a sub-matrix in which each cell is formed with an open face and has an end defined by a continuous enclosure of struts; the second overlapping portion extends through the interruption strut of the sealing block in an unexpanded state; An apparatus according to any one of claims 1 to 11.

13. an actuator interface for engaging an actuator that actuates movement of the bulk block along a predetermined path; and a guide defining a predefined path along which said bulk block may move; The apparatus according to any one of claims 1 to 12, comprising:

14. movement of the bulk blocks from the unexpanded state to the expanded state creates block gaps between the bulk blocks defined by a fixed interface; 14. The apparatus of claim 1, wherein the preformed fixture comprises a preformed fixture block that slides into a block gap and prevents the bulk blocks from moving against each other when positioned within the block gap between the bulk blocks.

15. The device according to any one of claims 1 to 14, wherein the ratio of the volume in the expanded state to the volume in the unexpanded state is at most 2.

16. A device according to any one of claims 1 to 15 for treating or preventing bone destruction.

17. The device of any one of claims 1 to 16, dimensioned for percutaneous placement within a vertebral body.

18. The device according to any one of claims 1 to 17, wherein at least one member of the group consisting of preformed bulk block, preformed fixture has a porous outer surface and / or a porous bulk portion.

19. 14. The apparatus of claim 13, further comprising a frame to which the bulk block is movably mounted, the guide comprising at least one rod of the frame along which the bulk block can move, the rod extending in a direction of movement of the bulk block and comprising a first rod end and a second rod end, the rod end defining a range of movement of the bulk block.

20. 20. A package comprising a packaging material, a device according to any one of claims 1 to 19, and instructions for using said device or an indication of the usefulness of said device in a method of mammalian bone surgery.

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