[SL fusion - no alternative for the treatment of chronic scapholunate dissociation].

Indroduction: The treatment of chronic scapholunate dissociation (SLD) is currently uneven and still presents a major challenge. Both, the primary ligament suture and frequently applied ligament reconstruction techniques cannot provide a permanent stable connection between the scaphoid and lunate. For this reason, the present study evaluates the value of a bony compound as a treatment option for the treatment of chronic SLD.

Purpose: To evaluate the radiological and clinical outcome of scapholunate fusion for chronic SLD.

Patients And Methods: Ten patients with a scapholunate fusion with corticocancellous iliac bone graft interposition and Herbert screw fixation for symptomatic chronic SLD were retrospectively evaluated in terms of clinical and radiological findings after a mean of 7.6 years. The examination included range of motion, grip strength, pain, DASH, Krimmer and Modified Mayo Wrist Score (MMWS), and a radiological examination.

Results: Primary bone healing was achieved in 4 out of 10 patients. In 2 patients, bone healing of the scapholunate fusion was achieved after revision surgery, in one patient by including the capitate bone in the fusion. Two patients developed fibrous nonunion. In 2 patients, the SLD persisted, requiring a four-corner fusion and wrist denervation, respectively. In all patients, degenerative changes were seen in the radiocarpal joint at follow-up. In spite of the radiological results, the clinical results ranged from fair to good. Seven patients were pain-free at rest. The average MMWS Score was 72 (40-95), the Krimmer Score 78 (55-100), and the DASH Score 17 (0-60).

Conclusion: Although the clinical results were fair to good, scapholunate fusion cannot be recommended for the treatment of chronic SLD due to a primary failure rate of 60 % regarding bone healing and a 40 % rate of revision surgery.