Four-corner fusion: Clinical and radiological outcome after fixation by headless compression screws or dorsal locking plate at minimum 5 years' follow-up.

INTRODUCTION

Among the various procedures for degenerative carpal lesions, four-corner fusion relieves pain while conserving motion and strength. There are various fixation options, not presently standardised.

HYPOTHESIS: Internal fixation by screws or dorsal locking plate provides good 5-year clinical results in four-corner fusion.

MATERIAL AND METHOD: A single-centre retrospective study included 18 four-corner fusions at a minimum 5 years' follow-up: 8 plate and 10 screw fixations. Endpoints comprised pain, wrist range of motion, grip strength, QuickDASH and PRWE scores, and immobilisation time. Radiographic analysis was performed and complications inventoried.

RESULTS

Pain VAS score fell to 1/10 in both groups. Flexion-extension was 56° with screws and 55° with plates. QuickDASH was 20.5 and 4.6 respectively, and PRWE 11 and 9. Grip strength was 16kg in both groups. The consolidation rate was 85.7% with screws and 57.1% with plates. Eighty percent of patients with screw fixation progressed toward radiolunate osteoarthritis. Four patients required revision surgery: 3 in the screw group and 1 in the plate group.

DISCUSSION: There was clear clinical and functional improvement in both groups at a minimum 5 years. Consolidation was better with screw fixation, but with risk of radiolunate osteoarthritis.

LEVEL OF EVIDENCE: IV, retrospective study.