WO2008152499A2

WO2008152499A2 - Implantable corpectomy device

Info

Publication number: WO2008152499A2
Application number: PCT/IB2008/001549
Authority: WO
Inventors: Kirsten Schmieder; Armin Studer
Original assignee: Pechlivanis, Ioannis
Priority date: 2007-06-11
Filing date: 2008-06-11
Publication date: 2008-12-18
Also published as: WO2008152499A3; DE102007042946A1; DE102007042946B4

Abstract

A prosthetic implant for partial corpectomies, especially for the preservation of mobility following surgery involving a partial corpectomy in patients with degenerative, traumatic or tumorous diseases. The implant comprises a rigid, cage or plate-like implant (30) with flaps (31) for fixation into the corpectomy defect. Qn either or both ends of the implant, facing the adjacent vertebral bodies, there is a mobile joint-like element (35). This element has disc-like abilities providing mobility both in bending angle- and in rotation. This mobile joint element also provides means (36) of fixation to the adjacent vertebral body or bodies. Examples of such mobile joint elements can be elastomer material elements, ball and socket joints, sliding ball joints or curved slide joints. The device can be constructed having a length designed for partial corpectomies in one. or more adjacent vertebrae.

Description

IMPLANTABLE CORPECTOMY DEVICE

FIELD OF THE INVENTION

The present disclosure relates to the field of surgical partial replacement of vertebrae, and especially to devices and methods which do not involve spinal fusion, thus maintaining spinal mobility.

BACKGROUND OF THE INVENTION

Corpectomy is performed to compensate for degenerative or deteriorated disorders in bone. Following a partial corpectomy in patients with degenerative osteochondrosis and retrospondylosis or following traumatic vertebral fractures or in patients with tumorous lesions of the vertebral bodies, the surgeon needs to mechanically reconstruct the defect created and to provide long-term stability of the spine. This has been generally performed using spinal fusion. In current medical practice, a strut graft, often obtained from the patient's iliac crest, is typically inserted into the cavity created by the corpectomy, and this supports the anterior vertebral column. Sometimes a titanium or PEEK cage implant is used. Fusion is achieved with a plate fixation involving both adjacent vertebral bodies. Both disc spaces are removed and fused.

There exist in the art, many techniques and apparatus for performing spinal fusion, to provide for long-term replacement of the removed vertebral bone.

In US Patent No. 5,192,327 patent for "Surgical Prosthetic Implant for Vertebrae", there is described such a procedure using implants made of one or more stacked rigid annular plugs. In US Patent No. 4,657,550 for "Buttressing Device usable in a Vertebral Prosthesis", a corpectomy implant is described made up of a cavernous cylinder with top and bottom plates, adjustable in height by means of a threaded plug. The fixation into the adjacent vertebral bodies is rigid with a fixed orientation. In US Patent No. 6,193,756 for "Tubular Support Body for Bridging Two Vertebrae", a wedge-shaped body is described that can be adapted for the deviations from parallelism between adjacent vertebrae. US Patent No. 5,571 ,192 for "Prosthetic Vertebral Implant and US Patent No. 5,989,290 for "Height Adjustable Artificial Vertebral Body" describe other solutions for height adaptive devices. However, such fusion procedures result in loss of mobility to the spine in the region of the fusion.

In US Patent No. 5,782,832 for "Spinal Fusion Implant and Method of Insertion thereof there is described an implantation device, which maintains mobility of the spine, either using a ball and joint structure or an elastomer disc replacement insert, which fits entirely within the intervertebral space between adjacent vertebrae.

There therefore exists a need for a device and method for performing partial corpectomey, which overcomes at least some of the disadvantages of prior art systems and methods.

The disclosures of each of the publications mentioned in this section and in other sections of the specification, are hereby incorporated by reference, each in its entirety.

SUMMARY OF THE INVENTION

The present disclosure describes new prosthetic implants for use after performance of partial corpectomy, which provide firm spinal support yet are adjustable in height, and which preserve mobility for the treated vertebral region, both in tilt and in rotation. Examples of the device involve use of a generally rigid, cage-like implant, adjustable in height, with elements for fixation of the device to the remaining intact parts of the treated vertebra, and to the adjacent vertebrae. The device thus provides safe bridging of the removed vertebral body, stabilization of the vertebral levels adjacent to the operated vertebra, yet still maintaining the mobility function of the two adjacent disc spaces, both in tilt and rotation, following the associated discectomy procedure.

The corpectomy implant described in this disclosure generally has a central structural element, generally in the form of a caged structure, whose height can be adjusted to suit the individual vertebral dimensions of the subject being treated. This structure is firmly fixed into the partial corpectomy cavity produced in the vertebral body treated. Flexible joint elements are attached to the extremities of the cage structure, and these flexible joints are fixed to the surfaces of the adjacent vertebral bodies. The flexible joints thus provide motion with disc-like properties, variable in both tilt angle and rotation, to the vertebral assembly treated using the device. The device is thus an implantable, prosthetic device for repair of diseased vertebra after partial corpectomy, combining a rigid adjustable element with mobility generating extremity sections. The flexible joint may be an elastomer material, which can be chosen to imitate the disc properties. The properties of the elastomer material should be chosen to provide ease of turning and bending for the subject, and to prevent excessive straining of the material and the entire device. The elastomer material may be bonded to the end surfaces of the implant, or a mechanical device, such as a ball and socket or a curved slide type of joint.

The outer ends of the flexible joints can be fixed to the adjacent vertebral bodies with flaps having a hole enabling a bone screw to be inserted, or a toothed or spiked surface used to bite into the bone surface and ensure firm fixation. The central structure can also be affixed to the sound remaining vertebral bone by means of flaps and bone screws, of by means of toothed or spiked surfaces for biting into the bone surface after being wedged into the cavity. Bone growth enhancing media can be used to encourage bone growth through holes in the end plates or in the walls associated with the central cage, thereby increasing the strength of the devoice fixation.

According to other examples of the device, a flexible joint can be provided only at one end of the device. The other end may then be made angularly adjustable to provide a predetermined angular orientation.

The above devices have been described in terms of their ability to bridge one vertebral level. According to yet a further example of the devices described herewithin, the device can also be constructed of sufficient length that its generally rigid, cage-like implant can be inserted into the cavities of two, or even more, partially resected adjacent vertebral bodies, so that it bridges more than one vertebral level.

Furthermore, although the central section of the devices are described in this disclosure as being generally rigid, cage-like implants, it is to be understood that this implementation is only a commonly used practical example of the structure proposed, providing strength with lightness and the ability to incorporate bone growth elements within the cage. However, the invention is not intended to be limited by this described structure, and for instance, without departing from the intended invention, the implant could be in the form of a solid element rather than a cage.

There is therefore provided, according to one exemplary implementation of the present invention, an orthopedic device comprising:

(i) a body with at least one attachment element for fixation of the body to at least one partially resected vertebra by means of a cavity formed in each of the at least one partially resected vertebra, and

(ii) at least one flexible joint element having a first end part attached to an extremity region of the body, and disposed to face the surface of a vertebral body adjacent to one of the at least one partially resected vertebra, the at least one flexible element further having at least one fixation element for attaching its second end part to the adjacent vertebral body.

In the above described device, some useful examples of suitable joints for the at least one flexible joint element may be either an elastomer material insert, a ball and socket joint, a sliding ball joint or a curved slide joint, or any other suitable joint mechanism. In any event, the at least one flexible joint should enable at least one of angular tilt motion and rotational motion.

Other implementations may further involve the above described devices wherein the height of the body is adjustable. This may be advantageously achieved if the body were to comprise an external section and an internal section which slide relative to each other, and if the internal and external sections could be fixed at a preselected relative position by means of a clamping screw. In such a device, each of the opposite ends of the external and internal sections may be ultimately attached to one of the two vertebra adjacent to the at least one partially resected vertebra, such that the adjacent vertebrae can be distracted by adjustment of the relative position of the internal and external portions.

In any of the above-described systems the body may be a cage structure.

Furthermore, in any of the above-described systems, the at least one attachment element may comprise at least one side flap, such that the body may be fixed into the at least one cavity by use of at least one screw inserted though the at least one side flap into a lateral part of the at least one partially resected vertebra.

As an alternative to the last mentioned method of fixing the body into the at least one cavity, the at least one attachment element may comprise side walls associated with the body, the side walls having at least one of toothed and spiked protrusions which interact with the bone wall of the at least one cavity such that the body may be thus fixed within the at least one cavity.

Additionally, another implementation of any of the above-described devices may involve a device wherein the at least one flexible joint has at least one flap, such that it may be fixed to a vertebra adjacent to the at least one partially resected vertebra cavity by use of at least one screw.

Alternatively, the at least one flexible joint may have at least one of toothed and spiked protrusions on a surface remote from its attachment to the body of the device, such that the protrusions may interact with the surface of a vertebral body adjacent to the at least one partially resected vertebra, such that the at least one flexible joint element may thus be fixed to the surface of the vertebral body.

In any of the above described devices, any of the body and the surfaces of the device may have holes through which bone growth can be achieved.

In accordance with yet further examples of the devices described above, the at least one flexible joint element attached to an extremity region of the body may be two flexible joint elements, each attached to opposite extremity regions of the body, and each being disposed to face the surface of one of the vertebral bodies adjacent to the at least one partially resected vertebra, and that part of each of the two flexible joint elements remote from its attachment to the body may then be attached to one of the vertebral bodies adjacent to the at least one partially resected vertebra.

In such a case, at least one of the flexible joint elements may comprise a plate with a base which can slide within a curved slide assembly, the curved slide assembly being disposed on the body. Alternatively, both of the flexible joint elements may comprise a plate with a base which can slide within a curved slide assembly, and the sliding surfaces of the curved slide assemblies may then be oriented at an angle to each other such that the plates can be mutually inclined in more than one plane. The curved sliding surfaces of the curved slide assemblies may advantageously be oriented at right angles to each other.

Additionally, in any of these examples using a plate with a base which can slide within a curved slide assembly, the base of any of the plates may have an essentially circular base, such that the plate can rotate about its axis. Furthermore, any of said plates may have at least one of toothed and spiked protrusions on a surface remote from the base, such that the protrusions interact with the surface of at least one vertebra body adjacent to the at least one partially resected vertebra, such that the plate is fixed to the surface of the vertebral body.

According to further aspects of the present invention, there is provided an orthopedic device comprising:

(i) a body with at least one attachment element for fixation of the body into a cavity of a partially resected vertebra,

(ii) at least one flexible joint element attached to an extremity region of the body, and disposed to face the surface of a vertebra body adjacent to the partially resected vertebra, and

(iii) at least one fixation element for also attaching the at least one flexible joint element to the adjacent vertebra.

Another example of such an orthopedic device may comprise: (i) a body with at least one attachment element for fixation of the body into cavities formed in two adjacent partially resected vertebra,

(ii) at least one flexible joint element attached to an extremity region of the body, and disposed to face the surface of a vertebra body adjacent to at least one of the two partially resected vertebra, and

(iii) at least one fixation element for also attaching the at least one flexible joint element to at least one of the two adjacent partially resected vertebra.

Yet other implementations of the invention described in this disclosure involve a method of performing a partial corpectomy on a vertebra, comprising the steps of:

(i) resecting the vertebra to generate a cavity in the vertebral body, (ii) providing a body having at least one flexible joint element attached to one of its extremity regions,

(iii) fixing the body into the cavity by means of at least one attachment element, and

(iv) fixing the end region of the at least one flexible joint element remote from the attachment of the flexible joint to the body, to a vertebra adjacent to the partially resected vertebra. The implants described are especially advantageous for use in the cervical spinal region.

BRIEF DESCRIPTION OF THE DRAWINGS

The presently claimed invention will be understood and appreciated more fully from the following detailed description, taken in conjunction with the drawings in which:

Fig.1 shows schematically a cross section of a vertebral body, showing a partial corpectomy cavity prepared by the surgeon;

Fig. 2 illustrates schematically an anterior view of a prior art method by which a partial corpectomy procedure may be performed for a single vertebral level;

Fig. 3 illustrates schematically an exemplary vertebral implant system for use in a partial corpectomy procedure, providing stability, rigidity and adjustability, yet allows mobility of the spine in the region of the procedure;

Fig. 4A is a schematic rendering of the manner by which the device of Fig. 3 may be mounted in the patient's spine to bridge one vertebral level, while Fig. 4B shows a similar device to that of Fig. 4A but bridging two vertebral levels;

Fig. 5 is an exploded illustration of one example of a device for use in partial cervical corpectomy, showing the component parts of the device;

Figs. 6A to 6B show the device of Fig. 5 assembled, Fig. 6C shows the device extended;

Figs. 7A to 7D illustrate the way in which the angular bending motion of the device shown in the previous drawings, is executed; and

Figs. 8A to 8C are schematic illustrations showing an alternative method of mounting the end plates onto the caged structure of the present device.

DETAILED DESCRIPTION OF EMBODIMENTS

Reference is now made to Fig. 1 , which illustrates schematically a cross section of a vertebral body 10, showing the partial corpectomy cavity 14 prepared by the surgeon after removal of the diseased bone. The spinal column channel 12 is shown at the end of the opening. Reference is now made to Fig. 2 which illustrates schematically an anterior view of a prior art method by which such a partial corpectomy procedure is performed for a single vertebral level. The healthy vertebrae 20 are shown on either side of the diseased vertebra 22, whose central region has been removed to prepare for receipt of the implant 26. The discs at either side of the diseased vertebrae have also been resected. The implant used extends the whole height of the operated vertebra 22, and is generally adjusted so that the end faces of the adjacent vertebrae abut thereon. Once the implant is firmly wedged in place, a fusion plate 24 is screwed into it and into the adjacent healthy vertebrae, such that a firm structure is generated. Implanted bone growth can be used to assist the achievement of a rigid structure, fusing together the three vertebrae shown.

Reference is now made to Fig. 3 which illustrates schematically an anterior view of an exemplary novel vertebral implant device for use in a partial corpectomy procedure. The device provides stability, rigidity and is adjustable for distraction purposes, and yet allows mobility of the spine in the region of the procedure. The system may have a rigid, cage-like implant 30 dimensioned for insertion into the resected vertebral body. The inner part of the cage-like implant 30 may be in the form of a chamber 32, which can be filled with bone or bone substitutes. Attachments may be provided for the fixation of the implant to the remaining bony parts of the partially resected vertebral body. In the exemplary device of Fig. 3, these attachments are shown in the form of flaps 31 on either side, with fixing screw holes. It is also to be understood though, that fixation with a flap on one side only may also be feasible, especially if the chamber is wedged into the cavity, as now described. According to other examples of the device, the cage can be wedged into the resected vertebral cavity by pressure, or using side walls having teeth or spikes which firmly grip the adjacent bone wall. The side walls can have holes through which bone growth can take place into the chamber 32, to ensure firm attachment. Various combinations of wedging, side walls, and a flap or flaps may also be used, as appropriate.

Unlike the prior art devices, where the implant is rigidly attached to the neighboring vertebrae, in the devices shown in this disclosure, the rigid, cage-like implant 30 is attached flexibly to one or both of the adjacent vertebrae. In the implementation shown in Fig. 3, on the top extremity of the rigid implant, a flexible segment is added which can vary its orientation angle and can rotation. According to one example, the flexible segment contains two plates 33, 34, with a joint 35 between them. One of the plates 33 is attached to the rigid implant 30, and the other is attached to the adjacent vertebral end face. The flexible joint 35 can be of any biocompatible type known in the art. Some such possible flexible joints are those based on elastomer inserts, which provide characteristics close to those of the removed disc, or on sliding ball joints, or on sliding curved surfaces. The flexible joint 35 may alternatively be attached directly to the extremity of the cage- like implant 30, without an intermediate plate, as shown at the lower end of the device. Attachment to the adjacent vertebral body may be achieved using any suitable method, such as flaps 36 with screw holes, or walls having teeth or spikes which firmly grip the adjacent vertebral end surfaces. The plates can have holes through which bone growth can take place to ensure firm attachment.

The devices described in this disclosure can therefore be summarized as generally being composed of two or three sections, a rigid implant section, labeled 37 on the right hand arrowed scale of Fig. 3, for attaching to the partially resected vertebral body, and at least one flexible joint section, labeled 38 on the right hand scale of Fig. 3, for attaching to the adjacent healthy vertebral body or bodies. According to some implementations of the device, it can be attached flexibly on both ends, and according to other implementations, flexibly only on one end, and rigidly on the other. Therefore, either one or two flexible joints may be used. Where only one mobile joint element is used, the end plate on the opposite end of the device should have some means of angular adjustment for orientating purposes. The adjustability and specific modes of flexibility of the device will be shown hereinbelow in the specific implementations shown in Figs. 5 to 8C.

Reference is now made to Fig. 4A, which is a schematic anterior view of the manner by which the device of Fig. 3 may be mounted in the patient's spine. Like features are labeled with the same reference numbers as in Fig. 3. Three vertebral bodies are shown - a central one 41 , having been partially resected to remove the diseased bone material, and two adjacent vertebral bodies 42, 43. The device is shown attached to the remaining bone material of the central vertebra 41 by means of flaps 31 and screws 46 inserted therethrough. The central vertebral body and its implanted device are shown attached to the adjacent vertebral bodies 42 43, by means of the flaps 36 and screws 45 inserted therethrough. The end plates 34 have a sufficiently large contact area with the end surfaces plates of the adjacent vertebral bodies, that it is possible to equip the endplates with spikes or teeth which enter the end surfaces of the vertebral bodies, thereby ensuring improved fixation of the entire device. This can be provided in addition to, or in lieu of the flap and screw fixing.

According to further examples of the present device, the frontal part and/or the lateral part of the rigid cage-like implant 30 can be equipped with holes or slits, allowing bone growth through and towards the remaining adjacent vertebral body. The posterior wall of the rigid cage-like implant 30 should generally be a closed wall structure, to ensure the safety of the neural structures lying posterior in those implementations where bone substitutes (granula) or spongious bone chips are used to fill the cage, to encourage bone growth. Furthermore, the implant can be constructed to be adjustable in order to fit different heights of vertebra by distraction.

Reference is now made to Fig. 4B, which shows an exemplary device, similar to that of Fig. 4A, but with a longer central insert section 40, such that that section will fit into the cavities formed by partial corpectomy performed in two adjacent vertebrae 47, 48. In the exemplary device shown in Fig. 4B, the central rigid insert 40 is attached using bone screws 46 and flaps 31 to the two resected vertebral bodies 47, 48, effectively fusing them together. The device then bridges between two non-adjacent vertebrae 42, 43, to which are attached the flexible joints 35 of the device with their associated fixing plates 34 and flaps 36. The long body 40 may be constructed in the form of a cage, with one or more openings 32 for filling with bone grafts if desired. Additionally, it may be adjustable, as in the example of Fig. 4A, to fit the vertebral spacing required. The other features of the implementation of Fig. 4B are marked with the same signs as those of Fig. 4A.

The above description has shown the schematic concept of the device of the present application. These schematic concepts can be implemented in a number of specific ways. Figs. 5 to 8C now show a number of drawings, illustrating engineered solutions to the ideas illustrated hereinabove for the example of a single level device. It is to be understood however, that these drawings are only some examples of implementing the present invention, which is not intended to be limited by any specific one of these implementations, or by any of these implementations. Reference is made to Fig. 5, which is an exploded illustration of one example of a device for use in partial cervical corpectomy, as described in this disclosure, showing the component parts of the device. The rigid, cage-like implant may be made up of two parts, an inner sliding section 51 , which has a sliding fit into an outer fixed section 52. This arrangement enables the implant to be adjustable in height. The outer fixed section 52 sits within the partial corpectomy cavity of the vertebral body, and the inner sliding section 52 is adjusted in order to distract the vertebrae to the desired height to relieve pressure on the spinal cord and/or any nerve roots affected. Once the desired distraction is achieved, a fixing screw 53 clamps the two sections into one rigid cage. The entire cage assembly may be affixed into the partial corpectomy cavity by means of two angled side walls 54, optionally having teeth or spikes which firmly grip the adjacent vertebral cavity bone surfaces. The side walls may have flaps with screw holes for bolting to the healthy remaining bone of the vertebral body, by means of screws 55.

The two ends of the rigid cage structure have curved slide surfaces 56, 57, which may be advantageously arranged at right angles to each other. The slide surfaces have internal channels 60 with shoulders. Onto each of these slide surfaces a curved end plate 58 may be fitted, by sliding the enlarged base 50 of the end plate into the channel 61 , where it is held in place by the shoulder. (The base 50 illustrated is that of the bottom end plate, since that of the top end plate is hidden from view in the perspective of Fig. 5.) In order to limit the extent of the sliding motion of the end plates in their channels, a motion limiting screw 59 is inserted into each end plate once the end plates are slid into position in their respective curved channels. This limits the angular motion which each end plate can make, as will be described more clearly in Figs. 6A and 6B hereinbelow. By this means, the end plates can provide limited angular motion relative to the rigid cage structure of the device in two orthogonal directions, and also to rotate relative to the rigid cage structure. The outer surfaces of the end plates 58 are teethed or spiked to enable them to be firmly affixed to the adjacent vertebral body end faces. Since the rigid caged structure is firmly affixed into the partially resected central vertebral body, this arrangement thus enables the adjacent vertebrae to have angular mobility for bending of the spine in essentially any direction, and for rotation of the spine at the regions fitted with this device. Reference is now made to Figs. 6A and 6B which show the device of Fig. 5 assembled. Fig. 6A is an overall outer view, while Fig. 6B is a cut away view to show the internal structure. From 6A, it is clearly seen how the two curved slide surfaces 56, 57, are arranged angularly to each other, most conveniently at right angles to each other, so that the mutual bending motion of the end plates, and thus of their attached vertebrae, can take place through essentially any angular sector. In Fig. 6B, the inner shoulders 61 of the curved slide surface is shown to illustrate how the end plates are held within the slide surfaces as they move. In the example of Fig. 6B, the top slide surface has its internal channel arranged such that the top end plate 62 can move in a direction into and out of the plane of the drawing, while the bottom slide surface has its internal channel arranged such that bottom end plate 63 can slide right and left in the sense of the drawing plane. Since the inner base shoulder 64 of the end plates are segments of a sphere, and the opposing shoulder surfaces of the inner channels of the curved slide are matching spherically curved, the end plates can also rotate freely about their axis. This construction is more clearly shown on the endplates 58 illustrated in the disassembled device of Fig. 5. A motion limiting shoulder 65 is also provided, against which the motion limiting screw 59 abuts in order to limit the angular bending of the device.

Fig. 6C illustrates the assembled device of Fig. 6B, but with the inner sliding section 51 extended and clamped with the fixing screw 53, to illustrate how the device is adjusted to suit different vertebral spacings, according to the subject and the distraction used.

Reference is now made to Figs. 7A to 7D, which illustrate more clearly the way in which this angular bending motion is executed. Figs 7A and 7B are side views of the device, to illustrate how forward and backward tilting can be achieved. In Fig. 7A, which is a cut away view, the bottom end plate 63 is shown in its furthest rearward inclined position, as limited by the contact of the motion limiting screw 59 with the motion limiting shoulder 65. The top end plate 62, is constrained by its slide channel to move in the plane perpendicular to that of the drawing plane. Fig. 7B is an external view of the device, also taken from the side, showing the extent of the forward tilting motion of the bottom end plate 63.

Figs. 7C and 7D are anterior cut away views of the device, to illustrate the right-left tilting motion afforded to the device, in this example by the top end plate 62 slide. Fig. 7C shows the end plate62 tilted maximally right, while Fig. 7D shows the end plate 62 tilted maximally left. The bottom end plate 63 can tilt in the plane into and out of the plane of the drawing.

Reference is now made to Figs. 8A to 8C, which are schematic illustrations showing an alternative method of mounting the end plates onto the caged structure. According to this method, and as seen in Fig. 8C, the widened base 80 of the end plate 81 does not extend over 360 degrees, but only over two opposing sectors of the base. The other opposing sectors of the base 82 are thus narrower. The rear channel of the curved slide is constructing having a slot width 83 such that only the narrow sector of the base of the end plate will enter it. The end plate is mounted onto the device by inserting this narrow dimension of the base into the slot of the channel 83, and then rotating the end plate through a right angle such that the widened base 80 now abuts the inner shoulder 84 of the channel, preventing the end plate from coming out, but still enabling it to tilt by sliding along the channel, and to rotate freely. The rotation must be limited to less than a right angle, to avoid the danger of the end plate base being able to come out of its channel. However, it is believed that such a rotation in a single vertebral level would be physiologically impossible. Figs. 8A and 8B are cut away drawings showing how this mounting and tilting motion is effected. In Fig. 8A, the top end plate 85 is shown, after being inserted and rotated so that its broad base dimension is held within the channel slot 86 by the shoulder 87, enabling it to tilt into and out of the plane of the drawing.

It is appreciated by persons skilled in the art that the present invention is not limited by what has been particularly shown and described hereinabove. Rather the scope of the present invention includes both combinations and subcombinations of various features described hereinabove as well as variations and modifications thereto which would occur to a person of skill in the art upon reading the above description and which are not in the prior art.

Claims

CLAIMSWe claim:

1. An orthopedic device comprising: a body with at least one attachment element for fixation of said body to at least one partially resected vertebra by means of a cavity formed in each of said at least one partially resected vertebra; and at least one flexible joint element having a first end part attached to an extremity region of said body, and disposed to face the surface of a vertebral body adjacent to one of said at least one partially resected vertebra, said at least one flexible element further having at least one fixation element for attaching its second end part to said adjacent vertebral body.

2. A device according to claim 1 and wherein said at least one flexible joint element comprises any one of an elastomer material, a ball and socket joint, a sliding ball joint and a curved slide joint.

3. A device according to either of claims 1 and 2 and wherein said at least one flexible joint enables at least one of angular tilt motion and rotational motion.

4. A device according to any of the previous claims and wherein the height of said body is adjustable.

5. A device according to claim 4 and wherein said body comprises an external section and an internal section which slide relative to each other, and wherein said internal and external sections may be fixed at a preselected relative position by means of a clamping screw.

6. A device according to claim 5 and wherein each of the opposite ends of said external and internal sections are ultimately attached to one of the two vertebra adjacent to said at least one partially resected vertebra, such that said adjacent vertebrae can be distracted by adjustment of said relative position of said internal and external portions.

7. A device according to any of the previous claims and wherein said body is a cage structure.

8. A device according to any of the previous claims and wherein said at least one attachment element comprises at least one side flap, such that said body may be fixed into said at least one cavity by use of at least one screw inserted though said at least one side flap into a lateral part of said at least one partially resected vertebra.

9. A device according to any of claims 1 to 7 and wherein said at least one attachment element comprises side walls associated with said body, said side walls having at least one of toothed and spiked protrusions which interact with the bone wall of said at least one cavity such that said body is fixed within said at least one cavity.

10. A device according to any of the previous claims and wherein said at least one flexible joint has at least one flap, such that it may be fixed to a vertebra adjacent to said at least one partially resected vertebra cavity by use of at least one screw.

11. A device according to any of claims 1 to 9 and wherein said at least one flexible joint has at least one of toothed and spiked protrusions on a surface remote from its attachment to the body of said device, such that said protrusions may interact with the surface of a vertebral body adjacent to said at least one partially resected vertebra, such that said at least one flexible joint element may be fixed to said surface of said vertebral body.

12. A device according to any of the previous claims and wherein any of said body and said surfaces of said device have holes through which bone growth can be achieved.

13. A device according to any of the previous claims, and wherein said at least one flexible joint element attached to an extremity region of said body is two flexible joint elements, each attached to opposite extremity regions of said body, and each being disposed to face the surface of one of the vertebral bodies adjacent to said at least one partially resected vertebra; and wherein that part of each of said two flexible joint elements remote from its attachment to said body is attached to one of said vertebral bodies adjacent to said at least one partially resected vertebra.

14. A device according to claim 13 and wherein at least one of said flexible joint elements comprises a plate with a base which can slide within a curved slide assembly, said curved slide assembly being disposed on said body.

15. A device according to claim 14 and wherein both of said flexible joint elements comprise a plate with a base which can slide within a curved slide assembly, and wherein the sliding surfaces of said curved slide assemblies are oriented at an angle to each other such that said plates can be mutually inclined in more than one plane.

16. A device according to claim 15 and wherein said curved sliding surfaces of said curved slide assemblies are oriented at right angles to each other.

17. A device according to any of claims 14 to 16, and wherein any of said plates has an essentially circular base, such that said plate can rotate about its axis.

18. A device according to any of claims 14 to 17, and wherein any of said plates has at least one of toothed and spiked protrusions on a surface remote from said base, such that said protrusions interact with the surface of at least one vertebra body adjacent to said at least one partially resected vertebra, such that said plate is fixed to said surface of said vertebral body.

19. An orthopedic device comprising: a body with at least one attachment element for fixation of said body into a cavity of a partially resected vertebra; at least one flexible joint element attached to an extremity region of said body, and disposed to face the surface of a vertebra body adjacent to said partially resected vertebra; and at least one fixation element for also attaching said at least one flexible joint element to said adjacent vertebra.

20. An orthopedic device comprising: a body with at least one attachment element for fixation of said body into cavities formed in two adjacent partially resected vertebra; at least one flexible joint element attached to an extremity region of said body, and disposed to face the surface of a vertebra body adjacent to at least one of said two partially resected vertebra; and at least one fixation element for also attaching said at least one flexible joint element to at least one of said two adjacent partially resected vertebra.

21. A method of performing a partial corpectomy on a vertebra, comprising the steps of: resecting said vertebra to generate a cavity in the vertebral body; providing a body having at least one flexible joint element attached to one of its extremity regions; fixing said body into said cavity by means of at least one attachment element; and fixing the end region of said at least one flexible joint element remote from said attachment of said flexible joint to said body, to a vertebra adjacent to said partially resected vertebra.