Arthroscopic Limited Wrist Fusion

Abstract

Limited wrist fusion is indicated in painful, localized arthritis of the wrist and in chronic carpal instability or deformities. It is a reliable symptomatic treatment which can relieve pain by eliminating motion of the diseased segment(s), correct carpal alignment, restore stability, preserve motion at neighboring unaffected articulations, and maintain carpal height and grip strength. Common indications include post-traumatic degeneration such as SLAC and SNAC wrist, avascular necrosis, and carpal instabilities. An arthroscopic approach preserves vascularity which is necessary for bone union and may result in less capsular fibrosis and stiffness than an open approach. First, scaphoidectomy is performed from the midcarpal joint leaving the distal pole of the scaphoid to preserve the scapho-trapezial ligament. The fusion site is prepared by uniform excision of cartilage of the capitolunate joint down to the subchondral bone to maximize contact area for fusion. Bone graft is seldom required. Fixation is performed by two cannulated screws inserted retrogradely from the dorsal distal part of the capitate to the lunate, or by K-wires if bone is too osteopenic for good purchase. In four-corner fusion, in addition to the capitolunate articulation, cartilage denudation of the triquetrohamate, lunotriquetral, and proximal part of the capitohamate articulations is also performed. Fixation is performed using one screw through the capitolunate joint followed by one screw in each of the lunotriquetral and capitohamate joints or triquetro-capitate interval. Long-term results have shown predictable and lasting pain relief and preservation of a functional range of motion, with a good union rate.