THE SCAPHOLUNATE ALLOGRAFT - A BIOMECHANICAL FEASIBILITY STUDY

The feasibility of a new method for reconstruction of the isolated sca pholunate ligament tear iii with a scapholunate allograft was studied biomechanically using a fresh cadaver upper extremity model. Seven spe cimens were first tested intact for wrist range of motion, contact cha racteristics of the radiocarpal articulation, and relative motion of t he scaphoid with respect to the lunate. Then a segment consisting of t he radial third of the lunate, the adjoining scapholunate interosseus ligament, and the proximal pole of the scaphoid was resected. This seg ment was matched to a donor allograft of similar size and geometry, wh ich was then placed into the recipient carpus and secured with one cen tral transverse Kirschner wire and two shorter interfragmentary Kirsch ner wires placed into the lunate and scaphoid. The allografted specime n was subjected to the same tests as the intact wrist. Results showed that there were no significant differences in wrist range of motion, r adiocarpal articular surface contact area and pressure, and relative f lexion-extension rotation between the scaphoid and lunate during passi ve radioulnar deviation between the intact and allografted wrists.