Four-corner fusion

Four-bone fusion is a procedure indicated for osteoarthritis of the wrist, most commonly following scaphoid non-union (SNAC) or scapholunate dissociation (SLAC). Following removal of the scaphoid, the four carpal bones (lunate, triquetrum, capitate and hamate) are fused using a plate or screws, in order to relieve pain whilst preserving some of the wrist’s range of motion. Bone union is expected within 2 to 3 months, followed by gradual rehabilitation. The main complications include pseudarthrosis, delayed union, impingement with the implant, persistent pain or the subsequent development of osteoarthritis. Despite a reduction in range of motion, this technique generally results in a stable, relatively pain-free wrist that is functional for activities of daily living.