Implant arthroplasty of the scapho-trapezial joint

Degenerative changes in the scapho-trapezial-trapezoidal (ST) joint may occur as an isolated process or more frequently as a dominant part of pantrapezial degenerative joint affections. In the present study results of surgery on 24 hands with isolated degenerative changes in the ST joint have been assessed. Arthrodesis was previously the sole procedure and has resulted in normal hand function in those cases where bony union was achieved without complications. The ST joint is difficult to fuse, however, and prolonged immobilization implies obvious risks of rigidity and impaired hand function. During the last 5 years a new technique for implant arthroplasty of the ST joint has been tried. The distal articular surface of the scaphoid has been resected and replaced with a heat-molded silicone rubber implant. In the present paper the method is presented and anatomical and technical points and pitfalls are discussed. It is concluded that implant arthroplasty may become a useful method for treatment of isolated ST arthrosis provided that the implant material will tolerate the compressive stress created during pinch.