SLAC Wrist: Midcarpal Fusion

Scapholunate advanced collapse (SLAC) wrist is a degenerative arthritis of the wrist characterized clinically by wrist pain and decreased range of motion and radiographically by scapholunate diastasis with dorsal intercalated segment instability and signs of progressive arthritis such as carpal joint destruction, sclerosis, and subchondral cyst formation. SLAC wrist is staged based on the extent of joint involvement and associated predictable arthritic progression (Watson and Ballet, J Hand Surg Am. 9:358–65, 1984). Treatment options depend on this staging and can range from conservative management to surgical intervention based on a variety of factors. The focus of this chapter will be on one such management option, scaphoid excision and midcarpal fusion. Midcarpal fusion is a clinically proven treatment for SLAC wrist and can be accomplished via a variety of techniques ranging across isolated capitolunate fusion, two-column fusion, and three- or four-corner fusion with none having been proven superior to the others. Some factors such as the presence of a type II lunate, proximal hamate arthritis, and lunotriquetral instability may influence the choice of technique. Four-corner fusion has been the preferred method over the past three decades, but more limited options such as capitolunate arthrodesis and two-column fusion have gained renewed interest as less complex alternatives with the advantages of decreased need for bone graft, faster OR times, and lower implant costs while maintaining similar outcomes and union rates as compared to four-corner fusions. In this chapter, we present a patient with stage 3 SLAC wrist treated with scaphoid excision and capitolunate fusion. We discuss the rationale behind the treatment choice, the surgical technique, and the potential benefits of capitolunate fusion as compared to other midcarpal fusion techniques. The current literature on midcarpal fusion is then reviewed, highlighting the importance of tailoring treatment to the patient’s specific needs and the surgeon’s expertise. In conclusion, this chapter provides a comprehensive overview of midcarpal fusion in the management of SLAC wrist, emphasizing the importance of individualized treatment approaches and the potential advantages of capitolunate fusion in select cases.