Surgical treatment possibilities of advanced carpal collapse (SNAC/SLAC wrist)

Abstract

Longstanding and untreated scaphoid fractures and scapholunate dissociations lead to painful destruction of the wrist with carpal collapse. The severity of degenerative arthrosis is classified in three stages and can be treated adequate operatively. SNAC wrist (scaphoid nonunion advanced collapse) after failed fusion of the scaphoid and SLAC wrist (scapholunate advanced collapse) after scapholunate dissociation should be differentiated. The reconstruction of the scaphoid or scapholunate ligament in stage II and III is no reasonable option. Motion preserving procedures such as proximal row carpectomy or midcarpal arthrodesis are preferable in this situation. Thirty-one male patients (average 41 years) were treated for SNAC or SLAC wrist with midcarpal arthrodesis. All patients were reexamined, the mean follow-up was 15 months. Grip strength was measured with the Dexter-System, pain was evaluated by a visual analogue scale (VAS 0-100). Patients' daily activities and general quality of life were estimated with the DASH-questionnaire. Pain was reduced to 50% compared to the preoperative situation. Grip strength improved to 60% of the opposite side. Active range of motion reached 50% of the contralateral wrist. Total DASH-score reached 39.0. Nonunion at the fusion site necessitated additional surgery in four patients resulting in total wrist arthrodesis. 80% of the patients returned to their original occupation. Midcarpal fusion is a reliable procedure for treating the difficult condition of advanced carpal collapse if proper realignment of the carpus is performed. The DASH-score reflects the subjective impressions of the patients in daily life and justifies the choice of a salvage procedure preserving wrist mobility. Total wrist fusion represents the last line of defense.