Clinical and radiological outcomes of 40 cases of SLAC and SNAC wrist treated by four-corner arthrodesis with locking plate.

The treatment of scapholunate advanced collapse (SLAC) and scaphoid nonunion advanced collapse (SNAC) wrist varies. No clear consensus exists on surgical indications. Scaphoid excision and four-corner arthrodesis with locking plate is one of preferred treatments for these lesions. The purpose of this study was to assess the clinical and radiological outcomes of locking plates for treating SNAC and SLAC wrist after a mean follow-up of 5 years and to compare these outcomes with the results reported in the literature. A retrospective study was conducted in two hospitals, involving 40 patients who underwent scaphoid excision and four-corner arthrodesis with locking plate between January 2006 and September 2016. All patients were reviewed as outpatients with clinical and radiographic measurements. At the last follow-up, the mean pain level on visual analog scale (VAS) was 2.5/10 [0-7] (SD: 1.7). Patients had a mean flexion of 46% and a mean extension of 46% compared to the contralateral side. An 18% gain was observed in grip strength. The mean postoperative QuickDASH score was 30 [0-57] (SD: 15.3). Seventy percent of patients were satisfied with the operation. Complete (all four joint interfaces) joint space fusion was achieved in 55% of patients. Only one patient (2.5%) had no joint fusion. The joint between the lunate and the capitate was fused in 38 patients (95%). Nine patients suffered complications; eight of them required surgical revision (20%). Four-corner arthrodesis with locking plate is a valuable surgical technique for treating SLAC and SNAC wrist because it preserve satisfactory range of motion and grip strength (64% compared to the non-operated side), maintains the height of the carpus and prevents the premature appearance of radiocarpal osteoarthritis, as long as the technical challenges of this procedure are mastered.