Scapholunate ligament reconstruction using a bone-retinaculum-bone autograft: a biomechanic and histologic study

Abstract

A new surgical technique has been recently described that involves reconstruction of the dorsal aspect of the scapholunate ligament (DSLL) with a bone-retinaculum-bone (BRB) autograft preparation from Lister's tubercle. In this study, the mechanic and histologic properties of the 2 tissues were compared. The BRB and DSLL specimens were harvested from 6 fresh-frozen human cadaveric forearms. The specimens were measured and then tested in tension with an MTS 810 servohydraulic materials testing machine at a rate of 10 mm/min. The BRB autograft was significantly weaker than the DSLL. However, because the mean cross-sectional area of the DSLL was more than 3 times as large as that of the BRB autograft, the failure stress (failure force/cross-sectional area) of the BRB autograft was not significantly different from that of the DSLL. Histologically, the DSLL and BRB autograft were also similar. These findings suggest that the BRB autograft may be appropriate graft material for scapholunate ligament reconstruction, but that structural parity with DSLL will ultimately depend on remodeling and hypertrophy during healing. This also highlights the importance of using a large BRB autograft to approximate the strength of the DSLL as much as possible, and that the BRB autograft must be protected postoperatively as it heals and remodels.