Biomechanical Comparison of 3 Methods of Scapholunate Ligament Reconstruction

PurposeTo compare the biomechanical characteristics of 3 methods of scapholunate (SL) ligament reconstruction, including 1 that provides a biological central axis tether.MethodsTwelve fresh-frozen cadaver limbs were mounted on a jig that allowed for wrist and finger motion by tendon loading. The specimens were randomized to receive the SL axis method (SLAM) reconstruction, the Blatt capsulodesis (BC), or the modified Brunelli tenodesis (MBT). Fluoroscopic images were taken to measure the SL interval and SL angle in various positions. The specimens were evaluated in 4 states: intact, with the SL and radioscaphocapitate ligaments cut, after reconstruction, and after reconstruction followed by 100 cycles of simulated motion.ResultsAfter cycling, the MBT and the SLAM reconstructions performed significantly better than the BC in recreating the intact SL interval in a clenched fist posture. The SLAM SL interval trended to be closer to the intact state than the MBT SL interval. The SLAM reconstruction also trended toward greater restoration of the native SL angle in the clenched fist posture than either the MBT or the BC.ConclusionsThe SL ligament reconstruction that uses a 2-tailed tendon autograft placed along the axis of rotation of the SL joint and secured both at the scaphoid and the lunate minimized creep and reconstructed the critical dorsal SL ligament. The SLAM achieved improved the SL interval and SL angle correction compared with conventional techniques of SL ligament reconstruction.Clinical relevanceThe SLAM method may be a useful alternative for SL ligament reconstruction.