Long-term results of midcarpal arthrodesis in the treatment of scaphoid nonunion advanced collapse (SNAC-Wrist) and scapholunate advanced collapse (SLAC-Wrist)

SUMMARY: Outcome evaluation of midcarpal arthrodesis in the treatment of scaphoid nonunion advanced collapse (SNAC-wrist) and scapholunate advanced collapse (SLAC-wrist). PURPOSE: Scaphoid nonunion or scapholunate ligament instability results in carpal collapse and subsequent arthrosis. These conditions, termed SLAC-wrist and SNAC-wrist, are the most common patterns of arthrosis in the wrist. The purpose of this retrospective study was the evaluation of functional outcomes following midcarpal arthrodesis and of patients' satisfaction with these outcomes. METHODS: Forty-nine patients were reexamined at a mean follow-up time of 47 months. Active range of motion (AROM) was verified with a goniometer; grip strength was measured with a JAMAR-Dynamometer II. Pain was evaluated by a visual analogue scale from zero to 100 (VAS 0-100) for stress and under resting conditions. Patients' upper-extremity functioning was captured with the Disabilities of the Arm, Shoulder and Hand (DASH) questionnaire. Radiographic evaluation of bony consolidation was verified by conventional x-ray. RESULTS: Postoperative AROM was 56% and grip strength was 76% compared with the contralateral side. The DASH score was 29 points. Pain relief was 34% at rest and 31% after stress. Forty-five patients demonstrated bony consolidation in x-ray control. Six patients (12%) further required a total arthrodesis of the wrist because of pain or absence of bony consolidation. CONCLUSION: Our data demonstrate that midcarpal arthrodesis is a reliable procedure for treating SLAC- and SNAC-wrists in stages II and III and, furthermore, one which preserves some range of motion. Total wrist fusion should only be used in exceptional circumstances.