Comparison of Normal Capitate Mid-Carpal Joint Mechanics With the Effects of Scapholunate Dissociation Injury

The wrist is one of the most complicated multibody joints in the human body. It can be subject to many injuries. Scapholunate (SL) dissociation is a relatively common injury that is particularly difficult to diagnose and treat. Without treatment, SL dissociation is known to progress to scapholunate advance collapse (SLAC wrist) and associated osteoarthritis (OA) [1]. Traumatic arthropathy of the wrist due to scapholunate dissociation has a definitive pattern from onset to severe bone and joint degeneration. The altered radiocarpal and SL mechanics with SL dissociation may be accompanied by a secondary carpal collapse between the capitate and lunate [2]. The initial SL disruption causes apparent changes in joint kinematics and contact patterns. Thus, understanding normal and abnormal in vivo contact mechanics as a result of SL ligament injury may lead to more effective treatments that may even prevent the onset of OA. In addition, in vivo contact mechanics data after surgical treatment may help determine the effectiveness of various surgical techniques which are used to correct SL injury.