Devices, implements and methods for the treatment of a multi-axis joint
A system, devices and methods for performing an osteotomy on a bone of a multi-axis joint are provided. A cutting guide system is provided for performing one or more cuts to the bone, using the articular surfaces of the articulating bones as a reference. If desired, a prosthesis can be used to emulate the osteotomy and substitute for a damaged articular surface of a bone of a multiaxis joint.
1. A prosthesis for a first bone of a joint, comprising:
a head portion adapted to articulate with a second bone of the joint, said head portion including an articular surface emulating a native post-osteotomy articular surface of the first bone, said articular surface including a saddle shaped articular surface that is circularly concave in a dorsal-palmar plane and circularly convex in a lateral-medial plane;
the head portion including a dorsal lip and a palmar lip, the palmar lip protruding beyond the dorsal lip such that a line tangent to a most proximal point on the dorsal lip that is also tangent to a most proximal point on the palmar lip will be inclined at an angle of more than 270 degrees relative to a longitudinal axis through the prosthesis;
a stem portion adapted for insertion into the medullary cavity of the first bone; and
a keel portion extending from a palmar side of said stem.
2. The prosthesis of claim 1 , wherein the stem portion includes a proximal frusto-conical portion and a rounded distal portion.
3. The prosthesis of claim 2 , wherein the keel is configured to impede the rotation of stem portion in a medullary canal.
4. The prosthesis of claim 1 , wherein the head portion includes a generally ovoidal, peripheral surface of continuous curvature surrounding the head portion.
5. The prosthesis of claim 1 , wherein the head portion includes a transverse groove configured to allow the passage of the Flexor Carpi Radialis (“FCR”) tendon.
6. The prosthesis of claim 1 , wherein the head portion includes at least one suture hole traversing the head portion in a dorsal to palmar direction.
7. The prosthesis of claim 6 , wherein the at least one suture hole is disposed in a transverse groove of the head portion.
8. A set of prostheses of different sizes to accommodate varying anatomies, each prosthesis of said set of prostheses being configured according to claim 1 .
9. A method of installing a prosthesis, comprising:
exposing and resecting a first bone of a joint below an articular surface of the bone;
providing the prosthesis of claim 1 ; and
inserting the stem of the prosthesis into the medullary canal until a flat surface on the head portion abuts a surface of the resected first bone.
10. The method of claim 9 , wherein the the stem portion further includes a keel configured to impede the rotation of stem portion in a medullary canal.
11. The method of claim 9 , wherein at least one trial prosthesis is used to help select the size of a final prosthesis.
12. The method of claim 9 , further including the steps of:
before said inserting step, using a suture to place at least one locking stitch through the FCR tendon; and
passing the free end of the suture through the at least one suture hole and keeping the suture taut; and
after the inserting step, knotting the suture on the dorsal side of the prosthesis.
13. The method of claim 12 , wherein the head portion of the prosthesis additionally includes a transverse groove, said transverse groove including at least one suture hole through which the suture is passed and knotted in the knotting step.