WO2002067769A2

WO2002067769A2 - Stretchable clamp and cerclage device

Info

Publication number: WO2002067769A2
Application number: PCT/US2002/005897
Authority: WO
Inventors: Wesley D. Johnson; Christopher J. Hrabe
Original assignee: Orthopaedic Innovations, Inc.
Priority date: 2001-02-27
Filing date: 2002-02-26
Publication date: 2002-09-06
Also published as: AU2002245535A1; WO2002067769A3

Abstract

The present invention discloses a stretchable clamp device for use in a human to clamp together fastening portions of an orthopaedic apparatus comprising a clamp body (10) having an elastic first clamp portion (12) adjacent to an elastic second clamp portion (14) and at least a portion of the first clamp portion (12) and a portion of the second clamp portion (14) comprise an elastic material, applying a compression force directed between the first set of compression surfaces (16, 18) deforms the first clamp portion (12) elongating and opening the first hollow center (20) sufficient to receive a fastening portion of the orthopaedic device and where removal of the compression force causes the first clamp portion (12) to contract onto and releasably clamp the fastening portion, and such that applying a compression force directed between the second set of compression surfaces deforms the second clamp portion (14) elongating the second hollow center (22) along the second secondary axis, opening the second hollow center (22) sufficient to receive another fastening portion of the orthopaedic device and where removal of the compression force causes the second clamp portion (14) to contract onto and releasably clamp the other fastening portion.

Description

STRETCHABLE CLAMPAND CERCLAGE DEVICE

Field of the Invention

The invention relates to the field of clamping and fastening devices, and in particular, to such devices as are useful in the field of medicine for securing bones and prostheses.

Background of the Invention

In modern surgical techniques involving the implantation and securing of prostheses or the holding together of bones and bone fragments, a variety of fasteners are available to the surgeon. Perhaps the more widely used fastener is the bone screw, which is typically threaded into a pre-drilled guide hole into the bone or bone and prosthesis. See, for example, U.S. patents 5,466,238 and 5,474,553.

Bone screws commonly are expensive and must be stocked in a variety of sizes because of the high variability in patient sizes. Consequently, a hospital or surgery center must carry a large stock of screws to be ready for use whenever a patient is in the operating theater. Bone screws are invasive. Substantial effort must be taken by a surgeon to properly locate where a bone screw is to be placed because once a bone screw has been screwed into a bone, the position of the screw should not be changed. Rather, if a different location is required, a separate hole in the bone must be drilled. However, for each hole placed in the bone, the bone is incrementally weakened. Although bone screws may serve to strengthen a bone by securing a strengthening sheath or rod to the bone, the bone adjacent the bone screw becomes weaker as a result of focal damage to the bone by the bone screw creating a stress concentration around the screw hole. In addition, over a longer time frame, the bone becomes even weaker due to stress shielding of the bone by the implant.

More particularly, in the procedure for stabilizing a fractured bone or fusion site, it is common to use bone screws to secure a plate or rod to the bony structure and to provide interlock between the bone screw and plate or rod. The interlock between the screws and the plate or rod is typically mechanical and involves threaded fasteners, washers, and/or crimped junctions. Sufficient torque or other force must be applied to ensure proper locking and longevity of the interlock. Poor interlock systems may cause the juncture to loosen and fail, resulting in failure of the fracture, fixation or fusion. Hence, the success of interlock devices of this nature is highly dependent on the knowledge and skill of the surgeon.

Other fasteners have involved the use of cements such as the type employed for anchoring implanted hip stems in the proximal femoral intramedullary canal of a patient in the implantation of an artificial hip. Yet other fasteners involve metal cables that are, for example, passed around a splintered or fractured bone to hold the bone pieces in place, the ends of the band being held together by crimping or through use of threaded fasteners. An example of a clamp and band for passing around a bone fracture site is disclosed in U.S. Patent No. 5,683,404. Such a device is useful, but requires that for single operator use, the band must have a modified end to become fixed at one end while the operator simultaneously opens the clamp and applies traction to the other free end of the band.

What is clearly needed is device that provides a predictable, single operator friendly, reliable and consistent interlock for securing structures of metal, plastic, composite and/or ceramic to bone or to themselves. An interlock system is also needed to stabilize a total joint replacement to bone and to secure augments to the implant to accommodate bone loss or bony defects encountered in surgery.

Summary of the Invention

The present invention provides a clamp which, broadly speaking, is capable of rigidly but releasably fastening to an article that has fastenable portions of a predetermined shape and size that the clamp is adapted to releasably fasten to. In the field of medicine, the clamp can be used in connection with a wire, which encircles a bone to hold bone fragments together, or can be used to clamp together parts of a prosthesis, etc. The clamp comprises an elastic body that preferably is formed at least in part of superelastic alloy. The body has a primary passage and a secondary passage, both extending within and preferably through it along the same primary longitudinal axis. The passages being sized, at least in one dimension or axis perpendicular to the primary axis, slightly smaller than the diameters of the fastenable portions of the wire. The clamp includes compression surfaces, which may be used to apply an external compressing force in either of two different axes, or directions, that are both perpendicular to the primary axis and perpendicular to each other. The compression may be applied with variable magnitude to cause the respective passage to open elastically perpendicular to the direction of the compression force sufficiently to receive the corresponding fastenable portion of the wire. The mechanism for compressing the clamp may be inherent in the design of the implant, and external force may be applied to move the clamp relative to a locking mechanism. As the compression force is released, the opening elastically clamps upon the fastenable portion. In a preferred embodiment of the invention, a kit is provided comprising at least one article, such as a wire or band, having at least a fastenable portion with first and second sections of a predetermined shape and size, and a clamp for rigidly but releasably fastening to the article. The clamp comprises an elastic body having at least two passages extending within the body, the passages being shaped and sized slightly smaller than the first and second fastenable sections of the fastenable portion.

The clamp of the present invention makes use of an elastic clamp body that preferably is formed at least in part, of a superelastic alloy, such as nitinol. The elastic characteristic of the clamp body material enables it to enlarge in at least one or more dimensions of the passages in the planes normal to the primary longitudinal axis of the passages in response to a compressive force. The enlargement of the passages enable the passages to receive a band, wire, cable, rod or other fastenable portion of an article (including several articles that are to be clamped together) that otherwise would not fit through the passages when not under a compressive force. Upon release of the compressive force tending to enlarge the respective passage, the elastic characteristic of the walls of the respective passage provide the clamping effort down upon the fastenable portion of the article to clamp it in place. As used herein, "elastic", in reference to the clamp body, refers to the capacity of the body to be deformed from an original configuration upon application of an external force and to exert an internal elastic force to return toward its original configuration when the external force is released.

It will be understood that the compressing force that is applied to the clamp bodies of the invention may be so directed as to enlarge the opening in more than one direction to accommodate various structures to be clamped. For example, compressing forces may be applied to the clamp body in two directions at right angles to each other and perpendicular to the axis of the passages to more or less uniformly enlarge the passages so that a rod or tube may be received in the opening. Once the compressing forces are removed, the walls defining the opening squeeze down on the rod or tube with some circumferential uniformity to provide a secure grip.

Although the clamp body may be made of any appropriate elastic material such as polymers, composites, stainless steel and other metals or metal alloys, superelastic alloys are preferred. Superelastic alloys are those alloys that can be deformed to a greater degree than can other metals and metal alloys without taking a permanent set. Various alloys possess superelastic characteristics. Of these, a near stoichiometric mixture of nickel and titanium, commonly known as "nitinol," is the most widely used and successful. In addition to possessing desirable mechanical characteristics, nitinol also possesses excellent biocompatibility. Often, the characteristics of the nitinol may be altered by the introduction of another metal, for example aluminum or vanadium, which alters the superelastic characteristics.

Superelasticity refers to a phase transition that occurs in a superelastic alloy when a defonning stress is externally applied. Nitinol, as well as other superelastic alloys, (sometimes called shape memory alloys), basically exists in either of two crystallographic forms. Which crystal form the alloy will be in depends upon several variables including ambient temperature, chemical composition and thermomechanical history. Austenite is the parent phase, characterized by a body centered cubic crystalline structure. Martensite is a transition phase and is characterized by a monoclinic crystalline structure. Generally, austenite will be present at higher temperatures than will martensite. The transition temperature is controllable by changing the ratio of nickel to titanium and the addition of other trace metals to the alloy.

Of importance to the present invention, the superelastic nitinol of choice will be n the austenite phase at least at or above room temperature and is transformable to stress-induced martensite when an external force deforms the alloy. The area of the alloy that is thus deformed will remain in the stress-induced martensite phase as long as the deforming force is maintained. When the stress is relieved, the deformed portion will tend to resume its original shape and in so doing will tend to revert back to the austenite phase. This phenomenon is the basis of superelasticity. The present invention makes use of superelastic alloys that, at the temperature of use (commonly room temperature up to body temperature or ambient temperature), are in the austenite phase and form stress-induced martensite when deformed by an external force. An additional benefit of superelasticity involves the ability of superelastic alloys to undergo great elastic deformation at substantially constant stress. Alloys that are not superelastic commonly exhibit approximate proportionality between increasing stress and resultant strain (Hooke's law) only until plastic deformation begins. If the stress is released after considerable plastic deformation, little shape recovery occurs. Superelastic alloys demonstrate proportionality between stress and strain within the Hooke's law region until a yield stress is reached, but thereafter elastically recoverable further strain occurs at substantially constant stress (as stress-induced martensite is formed). Upon release of the stress, the alloy returns elastically to essentially its original shape.

The present invention has particular utility in the medical field in which it can be employed to hold the ends of an encircling band, or wire, together to stabilize bone fragments, and to aid in the assembly of various bone prostheses such as pedicle screw devices, trauma fixation devices, external fixation devices, and for securing augments to implants to replace missing bone. The present invention may also be used to connect a series of bands or wires end to end with several clamps as a stand-alone device or as part of another device.

The invention has particular application for attaching augments to the body of a bone prosthesis implant. For example, in the case of a total knee replacement, augments under the tibial plateau or inside the femoral box are sometimes required to fill in and account for bony defects or missing bone in the supporting bony structure. In one embodiment, an augment is designed with a slot in its implant-facing surface to slide over a cylindrical peg extending from the implant surface where augmentation is needed. A locking band, preferably, also made of nitinol or other superelastic alloy, is stretched and secured around the augment and prosthesis and is held in place by a clamp body of the present invention. When released from the stretching force used to stretch the band, the band tends to shorten and to exert a clamping force on the augment, securing it to the implant. Similarly, augments may be readily attached by means of the invention to hip stems or acetabular cups in total hip replacement procedures.

As a further example of utility, trauma fixation devices may be assembled through use of the invention. In an exemplary embodiment, a bone plate of known construction is formed of two or more sections that are linked together by a sliding mechanism. The parts of the sliding mechanism can be secured together against sliding movement by compressing a clamp of the present invention so that the sliding mechanism parts are received in the passages of the clamp body. Upon release of the compressing force, the clamp securely locks the sliding mechanism parts together.

As yet another example of use, the invention may be used in connection with external fixation devices often used with fractured bones. External fixation involves placement of percutaneous pins into segments of a fractured bone and connecting the pins to an external structure to stabilize the fractured bone. The external structure employs a clamping mechanism locking the percutaneous pins to connecting rods. The connecting rods are typically telescoping and use clamps to lock the telescoping sections together. A clamp of the present invention may be configured to securely clamp together the pins and rods and to clamp together the telescoping rod sections against relative movement.

Brief Description of the Drawing Figure 1 is a perspective partial cross-sectional view of a clamp portion of a device of the present invention;

Figure 2 is an end on elevational view of the clamp portion depicted in Figure 1; Figure 3 is top plan view of the clamp portion depicted in Figure 1; Figure 4 is a top plan partial cross-sectional view of the clamp of Figure 1, with the clamp depicted as binding two ends of a single wire: and

Figure 5 is a perspective view of an alternative embodiment of the present invention.

Description of the Present Invention

Referring to Figures 1 through 4, wherein like numbers depict like components through out the various Figures, there is depicted a stretchable clamp device 10 comprising a first clamp portion 12 adjacent and attached to a second clamp portion 14 with a first compression surface 16 to the opposing side of first clamp portion 12 from second clamp portion 14 and a second compression surface 18 to the other opposing side of second clamp portion 14 from first clamp portion 12.

Clamp portion 12 includes a longitudinal axis identified as A, which is the general axis of orientation for receiving a work article into a hollow center 20 of clamp portion 12 for clamping. Oriented at right angles to axis A is a secondary axis B, which is generally the axis of orientation along which a compressing force would be applied. Oriented at right angles to A and B is a tertiary axis C, which generally identifies the axis of elongation of the clamp in response to a compressing force along the B axis. Clamp portion 14 includes axes similarly identified as in clamp portion 12, but identified in the various figures as A', B', and C, with clamp portion 14 having a hollow center 22 for receiving and clamping a work article.

As discussed above, the present invention anticipates the use of many different elastic materials such as polymers, ceramics, composites, stainless steel and other metals or metal alloys, however superelastic alloys are preferred. Superelastic alloys are those alloys that can be deformed to a greater degree than can other metals and metal alloys without taking a permanent set. Various alloys possess superelastic characteristics. Of these, "nitinol," is the most widely used and successful. In addition to possessing desirable mechanical characteristics, nitinol also possesses excellent biocompatibility. An appropriate nitinol for the present invention would characteristically have a transition temperature below room temperature and be in the austenitic phase, so that deformation of the nitinol through the application of an external force would create stress-induced martensite. Any number of nitinol alloy formulations with these characteristics are well known in the art.

The features of the clamp portions 12, 14 are such that applying an external force, a deforming force, along an axis causes a change in the dimensions of the respective hollow centers 20, 22 along an axis generally orthogonal to the orientation of the deforming force being applied. Clamp portions 12, 14 are not limited to the shapes depicted in the Figures, rather, these clamp portions with their respective hollow centers may take on any number of internal and external geometries to meet the needs of the application. In orthopaedics, various work articles to be clamped may include such items as studs on the ends of pedicle screws, the heads of bone screws, - wires, circlage wires, rods such as Harrington rods, bolts, bolt heads and nuts. These work articles to be clamped may be of any number of shapes such as round, square, oval, rectangular, triangular, stellate, hexagonal, ridged, etc. The present invention anticipates the manufacture of clamp portions having geometries suitable for being deformed sufficiently to alter the opening to the hollow center, receiving the work article within the hollow center of the clamp portion, and clamping the work article when the deformation force is removed.

In the embodiment depicted in Figures 1-4, a deforming force is applied to clamp portion 12 by use of a tool adapted to fit to compression surfaces 16, 18 and apply a compressing force generally along axis B. However, this does not actually compress the material of the clamp, rather, the compressing force is used to cause a deformation of clamp portion 12 generally along the C axis. The overall result is to increase the dimension of hollow center 20 generally along the C axis while the overall dimension of hollow center 20 is decreased along the B axis. Preferably, the dimension of hollow center 20 along the C axis is less than the corresponding dimension of the work article to be clamped. Additionally, compression and deformation along the B axis must be sufficient increase the dimension along the C axis sufficient to at least match and accept the work article into hollow center 20. Consequently, the dimension of hollow center 20 along the B axis must be sufficient to accommodate the decrease in distance caused by the deforming compression force, but remain sufficiently wide enough to also accept the work article in this dimension. As is evident, once the dimension of a work article to be clamped is identified, a clamping material may be chosen and an appropriate geometry for the hollow center may be calculated based on the known elastic, or superelastic characteristics of the material used in the clamp, as well as, how much deformation must occur and the amount of clamping force to be delivered.

Another characteristic of the present invention is that the deformation of the clamp introduces stress and strain into the clamp material, however, when the work article to be clamped is placed within the respective hollow center and the external deforming force is removed, the inner dimensions of the respective hollow center are such that some portion of the inner surface of the hollow center abuts and conforms to the surface of the work article. This abutment of the surfaces serves to prevent the elastic return of the clamp portion to its original pre-deformation geometry such that the elastic deformation remains and the stress and strain imparted to the clamp portion remains to provide the clamping force. With a superelastic material such as nitinol, when the nitinol is defoπned to open the clamp, the austenite is transformed into stress-induced martensite. After the work article is placed within a hollow center and the external deforming compression force is removed, the nitinol of the clamp portion largely remains in this stress-induced martensite phase with the strain and stress of the stress-induced martensite providing the clamping forces.

Compression surfaces 16, 18 are depicted as rounded in the various Figures. However, this geometry is also adaptable to any number of other geometries, including the addition of slots or tabs for gripping by a tool. The present invention anticipates the use of any geometry for suitable mating to the working end of a compression tool such that the clamp of the present invention will not slip or from the tool while an external deforming forming force is applied by the tool to the respective clamp portion.

In operation, and relying on the discussion above, clamp device 10 is first grasped by a tool (not depicted) at compression surfaces 16, 18 and an external compression force is applied along the B axis, which results in elongation of clamp portion 12 along the C axis. Incidentally, there is also elongation of clamp portion 14 along the C axis, however, as will be seen below, this elongation is not relied on by the present invention for reasons to be made apparent. Once the external force is applied, clamp portion 12 may be slipped over a suitable work article and positioned. When satisfied the position and orientation of clamp device 10, the operator removes the externally applied force and clamp portion 12 is clamped to the work article.

As eluded to above, the activation of clamp portion 14 is different than that of clamp portion 12. An externally applied deforming force is applied to clamp portion 14 by attaching a suitably matched tool (not shown) to clamp portion 14 so that the externally applied deforming force is directed along the C axis. The compression of clamp portion 14 along the C axis provides for elongation of clamp portion 14 along the B' axis. This deformation force along the C axis is not transmitted to clamp portion 12. Consequently, deformation of clamp portion 14 occurs independent of clamp portion 12 and clamp device 10 does not move or slip in relation to the first work article clamped within hollow center 20 while the second work article is being positioned within hollow center 22 for clamping. Once a second work article is positioned within hollow center 22 and proper orientation and position are achieved, the externally applied force along the C axis may be removed and clamp portion 14 now clamps the second work article at a fixed orientation and position to the first work article. The present invention is also releasable to provide for removal or re- positioning, allowing the operator to check her work and, if needed, reapply an external deforming force at either axis to remove either clamping force from the respective work article to reposition and reorient as desired.

As depicted in Figure 4, a work article such as a wire end 30 has been first inserted within hollow center 20 and clamped within clamp portion 12. Similarly, a wire end 32 has been inserted into hollow center 22 and clamped within clamp portion 14. By way of example, wire ends 30, 32 may be two ends of a single wire that has been placed around two or more bone fragment. After first clamping wire end 30 in clamp portion 12, an external deforming force may be applied to clamp portion 14 opening hollow center 22 to receive wire end 32. While still holding open clamp portion 14, traction may be applied between clamp device 10 and wire end 32 to draw the wire through hollow center 22 and to tighten the wire around the bone fragments and hold the bone fragments securely in place when the external force is removed and clamp portion 14 clamps wire end 32.

Figure 5 is an alternative embodiment of the present invention depicting a stretchable clamp device 110 comprising a first clamp portion 112 adjacent and attached to a second clamp portion 114 with a first compression surface 116 to the opposing side of first clamp portion 112 from second clamp portion 114 and a second compression surface 118 to the other opposing side of second clamp portion 114 from first clamp portion 112

Although not drawn in, similar to the description given above for clamp device 10, clamp portion 112 includes a longitudinal A axis, which is the general axis of orientation for receiving a work article into a hollow center 120 of clamp portion 112 for clamping. Oriented at right angles to axis A is a secondary B axis, which is generally the axis of orientation along which a compressing force would be applied. Oriented at right angles to A and B is a tertiary C axis, which generally identifies the axis of elongation of the clamp in response to a compressing force along the B axis. Clamp portion 114 includes axes similarly identified as in clamp portion 12, but with the A' axis at an angle to the A axis of clamp portion 112. Consequently, clamp portion 14 has a hollow center 22 for receiving and clamping a work article that is at an angle to a work article clamped within hollow center 120. Maintaining the B to B' axis keeps the device simple in that clamp device 110 may still be grabbed by a suitable tool to the outside of the entire device to apply the initial external deforming force along the B, B' axis. And as with the first embodiment, application of an external deforming force along the C axis of clamp portion 114 will independently deform clamp portion 114 relative to clamp portion 112. The present invention anticipates that the angle between the A axis of clamp portion 112 to the A' axis of clamp portion 114 may be manufactured from 0° to 180°. This adaptability for supplying a clamp device of the present invention with an angle between the axes of clamping is useful for those orthopaedic applications where the orthopaedic apparatus is carried over a curve or angle, such as spinal fixation or stabilization.

Another feature of the present invention, though not shown, is that the orientation of the clamp portions may be turned relative to one another in yet another way. This is easily understood by noting that clamp portion 12 or 112 may be rotated and manufactured in relation to clamp portion 14 or 114 so that the B axis of clamp portion 12 or 112 is parallel to the C axis of clamp portion 14 or 114 or at some intermediate angle between the orthogonal configuration of the depictions in the various Figures to the parallel form, or from 0° to 90°. Consequently, the externally applied deforming force applied to clamp portion 12 or 112 along the B axis will be independent of, and not affect clamp portion 14 or 114. This additional configuration still provides for the manufacturing of an angle of from 0° to 180° between the A axis and the A' prime axis.

The foregoing description is considered as illustrative only of the principles of the invention, since numerous modifications and changes will readily occur to those skilled in the art. While a preferred embodiment of the present invention has been described, it should be understood that various changes, adaptations and modifications may be made therein without departing from the spirit of the invention. Consequently, it is not desirable to limit the invention to the exact construction and operation shown and described herein. Accordingly, all suitable modification and equivalents may be resorted to, falling within the scope of the present invention.

Claims

WE CLAIM:

1. A stretchable clamp device for use in a human to clamp together fastening portions of an orthopaedic apparatus, the stretchable clamp device comprising: a clamp body (10) having an elastic first clamp portion (12) adjacent to an elastic second clamp portion (14) and at least a portion of the first clamp portion (12) and a portion of the second clamp portion (14) comprise an elastic material; the first clamp portion (12) having a first longitudinal axis, a first secondary axis and a first tertiary axis, each orthogonal to the others, and a first hollow center (20) open at both ends with the openings of the first hollow center aligned along the first longitudinal axis; the second clamp portion (12) having a second longitudinal axis, a second secondary axis and a second tertiary axis, each orthogonal to the others, and a second hollow (20) center open at both ends with the openings of the second hollow center aligned along the second longitudinal axis; a first set of compression surfaces (16, 18) aligned generally at opposing ends of the first secondary axis; and a second set of compression surfaces aligned generally at opposing ends of the second tertiary axis and orthogonal to the first secondary axis; such that applying a compression force directed between the first set of compression surfaces (16, 18) deforms the first clamp portion (12) elongating the first hollow center (20) along the first tertiary axis, opening the first hollow center (20) sufficient to receive a fastening portion of the orthopaedic device and where removal of the compression force causes the first clamp portion (12) to contract onto and releasably clamp the fastening portion, and such that applying a compression force directed between the second set of compression surfaces deforms the second clamp portion (14) elongating the second hollow center (22) along the second secondary axis, opening the second hollow center (22) sufficient to receive another fastening portion of the orthopaedic device and where removal of the compression force causes the second clamp portion (14) to contract onto and releasably clamp the other fastening portion.

2. The stretchable clamp device of claim 1 wherein the clamp body is formed in part from a material talcen from a list of materials consisting of: stainless steel, nickel, vanadium, titanium, nickel or an alloy of any of these metals.

3. The stretchable clamp device of claim 1 wherein the clamp body is formed in part from a material taken from a list of materials consisting of: ceramic, polymer, or composite of polymeric materials.

4. The stretchable clamp device of claim 1 wherein the clamp body is formed in part from a superelastic alloy.

5. The stretchable clamp device of claim 1 wherein the first longitudinal axis is at an angle to the second longitudinal axis.

6. The stretchable clamp device of claim 5 wherein the angle is an angle in the range from 0° to 180°.

7. A stretchable clamp device for use in a human to clamp together fastening portions of an orthopaedic apparatus, the stretchable clamp device comprising: a clamp body having an elastic first clamp portion adjacent to an elastic second clamp portion and at least a portion of the first clamp portion and a portion of the second clamp portion comprise an elastic material; the first clamp portion having a first longitudinal axis, a first secondary axis and a first tertiary axis, each orthogonal to the others, and a first hollow center open at both ends with the openings of the first hollow center aligned along the first longitudinal axis; the second clamp portion having a second longitudinal axis, a second secondary axis and a second tertiary axis, each orthogonal to the others, and a second hollow center open at both ends with the openings of the second hollow center aligned along the second longitudinal axis; a first set of compression surfaces aligned generally at opposing ends of the first secondary axis; and a second set of compression surfaces aligned generally at opposing ends of the second tertiary axis and parallel to the first secondary axis; such that applying a compression force directed between the first set of compression surfaces deforms the first clamp portion elongating the first hollow center along the first tertiary axis, opening the first hollow center sufficient to receive a fastening portion of the orthopaedic device and where removal of the compression force causes the first clamp portion to contract onto and releasably clamp the fastening, and such that applying a compression force directed between the second set of compression surfaces deforms the second clamp portion elongating the second hollow center along the second secondary axis, opening the second hollow center sufficient to receive another fastening portion of the orthopaedic device and where removal of the compression force causes the second clamp portion to contract onto and releasably clamp the other fastening portion.

8. The stretchable clamp device of claim 7 wherein the clamp body is formed in part from a material taken from a list of materials consisting of: stainless steel, nickel, vanadium, titanium, nickel or an alloy of any of these metals.

9. The stretchable clamp device of claim 7 wherein the clamp body is formed in part from a material taken from a list of materials consisting of: ceramic, polymer, or composite of polymeric materials.

10. The stretchable clamp device of claim 7 wherein the clamp body is formed in part from a superelastic alloy.

11. The stretchable clamp device of claim 7 wherein the first longitudinal axis is at an angle to the second longitudinal axis.

12. The stretchable clamp device of claim 11 wherein the angle is an angle in the range from 0° to 180°.

13. A stretchable clamp device for use in a human to clamp together fastening portions of an orthopaedic apparatus, the stretchable clamp device comprising: a clamp body having an elastic first clamp portion adjacent to an elastic second clamp portion and at least a portion of the first clamp portion and a portion of the second clamp portion comprise an elastic material; the first clamp portion having a first longitudinal axis, a first secondary axis and a first tertiary axis, each orthogonal to the others, and a first hollow center open at both ends with the openings of the first hollow center aligned along the first longitudinal axis; the second clamp portion having a second longitudinal axis, a second secondary axis and a second tertiary axis, each orthogonal to the others, and a second hollow center open at both ends with the openings of the second hollow center aligned along the second longitudinal axis; a first set of compression surfaces aligned generally at opposing ends of the first secondary axis; and a second set of compression surfaces aligned generally at opposing ends of the second tertiary axis and at an angle to the first secondary axis; such that applying a compression force directed between the first set of compression surfaces deforms the first clamp portion elongating the first hollow center along the first tertiary axis, opening the first hollow center sufficient to receive a fastening portion of the orthopaedic device and where removal of the compression force causes the first clamp portion to contract onto and releasably clamp the fastening, and such that applying a compression force directed between the second set of compression surfaces deforms the second clamp portion elongating the second hollow center along the second secondary axis, opening the second hollow center sufficient to receive another fastening portion of the orthopaedic device and where removal of the compression force causes the second clamp portion to contract onto and releasably clamp the other fastening portion.

14. The stretchable clamp device of claim 13 wherein the clamp body is formed in part from a superelastic alloy.

15. The stretchable clamp device of claim 13 wherein the first longitudinal axis is at an angle to the second longitudinal axis.

16. The stretchable clamp device of claim 15 wherein the angle is an angle in the range from 0° to 180°.

17. The stretchable clamp device of claim 13 wherein the second set of compression surfaces aligned generally at opposing ends of the second tertiary axis and at an angle to the first secondary axis is an angle in the range from 0° to 180°.