Tendon prosthesis

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is illustrated by the accompanying drawings wherein;

FIG. 1 is a perspective view of the tendon prosthesis;

FIG. 2 is a plan view of the prosthesis with portions removed for clarity;

FIG. 3 is an enlarged perspective view of one end of the prosthesis showing a method of suture attachment, and

FIG. 4 is a perspective view showing the tendon prosthesis in final position.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to the drawing in more detail it will be seen that this invention basically includes an elongated member 12 made from a substantially inert material having flaps at each end adapted to overlap a repaired or reconstructed tendon 16. In addition a suture material 18 is incorporated within the elongated member 12 and each, flap 14 has a mesh or netting 2® on its inner surface as shown in FIGS. 1 and 2.

As shown in the figures the tendon prothesis 10 is preferably an elongated member 12, however, it may be fabricated to any desired size and shape. The elongated member 12 is preferably fabricated from a sheeting material and may be reinforced as shown in FIG. 2 by a Dacron mesh 15 or similar material. The reinforcing increases the strength of the elongated member and prevents stretching during suture attachment. In addition, the elongated member 12 may be modified by the doctor sculpturing it to any desired size and shape at the time of surgery.

It is extremely important that the material used to form the elongated member 12 be substantially inert to prevent foreign body reactions. In addition the material must be compatible with the physiological processes of the human body and preferably has nonwetting surfaces which minimize sticking or encrustation. Further the material should contain the quality of nonadherence to tissue and is preferably resistant to adsorption, hardening and degeneration. A flexible silicone elastomer manufactured by Dow Coming sold under the trademark “Silastic” has been found to substantially meet the above mentioned qualifications. In addition other medical-grade silicone elastomers, or material similar to “Silastic” or equivalents thereof have been found as satisfactory material for the elongated member 12.

As best shown in FIGS. 1 and 2 a suture material 18 may be fabricated within the elongated member 12 by bonding two or more layers of sheeting material around the suture material. The ends of the prosthesis 10 are then spread apart to form a pair of flaps 14 for overlapping the repaired or reconstructed tendon. On the inside surface of each flap 14 there is secured a mesh or netting 20 forming suitable end plates for tendon anastamosis. The flaps 14 with the mesh or netting 20 are devised to facilitate rapid and accurate areas of anastamosis with minimal exposure.

It is important that the mesh or netting 20 be made from a material or materials that cause fibroblastic infiltration to occur between the severed ends of the tendon 16 and the mesh 20 thereby firmly anchoring the prothesis 10 with, a strong, functional anastamotic union. One such material is polyester, however, similar materials or equivalents thereof have been found as a satisfactory mesh materal.

FIGS. 3 and 4 show how the suture attachment is performed in more detail. The flaps 14 overlap the tendon 16 with the mesh material resting against the outer surface of the tendon while the suture material 18 may be attached to each end of the tendon as shown in these figures. It should again be noted that the suture material 18 runs the full-length of the prosthesis 10 providing a strong durable means for attaching the prosthesis. The fibroblastic infiltration which occurs between the severed tendon 16 and the mesh 20 of each flap insures a strong, functional anastamotic union.

The use, operation and function of this invention are as follows:

The results from experiments and clinical use of this invention have been very favorable. The tendon prosthesis 10 allows the patient to regain essentially full range of motion within a short time after cast removal. In addition the prosthesis does not cause restrictive adhesions, infections or extrusions. Further, the tendon prosthesis can withstand full weight bearing capacity with no gross deformity including the ability for full active extension, and flexion.

3,545 3

On reexploration of experimental uses of this invention each of the tendon prostheses were in good position and completely covered with a layered fibroblastic membrane. This delicate membrane was vascularized and substantially resembled normal synovial tissue. In fact the appearance of the entire tendon prosthesis 10 is very similar to a normal tendon.

Functionally, the tendon prosthesis, and to a lesser degree its fibroblastic membrane, were found to move through the surrounding tissue with very little resistance. ₁₀When the membrane was dissected, the respected tendon ends were noted to be firmly anchored to the prosthesis by the mesh material of the end flaps 14. In addition the membrane encasing, caused by the material of the elongated member, extended distally and around the normal 15 tendon to reinforce the anastamosis.

It should be emphasized that the tendon prosthesis 10 was designed primarly as a full-function, tendon after only one surgical procedure. Further surgical operations such as revision or replacement are not contemplated with this 20 invention. However, it may be noted that if separation of an anastamosis did occur, it could be removed easily and the reactive membrane formed around the prosthesis could be utilized as a sheath for an autologous graft.