Arthroscopic debridement and closed pinning for chronic dynamic scapholunate instability

Purpose: For chronic dynamic scapholunate (SL) instability (> 3 months after injury) open procedures (capsulodesis, limited intercarpal fusions, tenodesis, SL ligament reconstruction) have become popular in recent years but their long-term results have been suboptimal. We evaluated retrospectively the results of aggressive arthroscopic debridement of the SL ligament to bleeding bone in an effort to induce scar formation and closed pinning of the SL joint in patients unwilling to have an open procedure. Methods: Eleven patients (mean age, 37 y) presenting with persistent posttraumatic pain and weakness to the wrist were diagnosed with dynamic SL instability (positive Watson scaphoid shift test result, SL gapping on grip-view radiographs, arthroscopic findings of a Geissler grade III or IV SL tear) and treated. Range of motion, grip strength, radiographic measurements, and the Mayo wrist score were used to evaluate the results. Results: The mean follow-up period was 33 months (range, 12-76 mo). Three patients had subsequent surgery 9 to 11 months after the procedure. Subsequent surgeries included a dorsal capsulodesis, a four-corner fusion, and a wrist arthrodesis. Of the 8 remaining patients there were 2 excellent, 4 good, 1 fair, and 1 poor result based on the Mayo wrist score. In these patients the mean range of motion was 650 of extension to 59 degrees of flexion and the mean grip strength was 82% of the uninjured contralateral extremity. Although persistent radiographic SL gapping in grip views was noted in all 8 patients none progressed to static instability or dorsal intercalated segment instability. Conclusions: The results of this technique are suboptimal; however, it may be an option for patients unwilling to have more than an arthroscopic procedure or those requiring maintenance of wrist motion, provided they understand the risks and benefits of this approach.