[Advanced carpal collapse (SLAC-wrist) in scaphoid pseudarthrosis. Therapy concept: medio-carpal partial arthrodesis]

Longstanding unstable scaphoid nonunions inevitably lead to carpal collapse and symptomatic secondary arthrotic changes, ruling out reconstructive procedures to the scaphoid itself. Partial mediocarpal fusion, however, can preserve some wrist motion and markedly reduce or even eliminate wrist pain. By correcting the malalignment of the lunate and capitate, carpal height is restored. By excision of the scaphoid, its destroyed articular surfaces are removed. In 26 of 31 patients undergoing mediocarpal fusion, complete or at least significant reduction of wrist pain was observed. Average grip strength increased by 23%, whereas wrist mobility decreased by 33 to 40% with a relatively short follow-up of 14 months. Total wrist fusion remains the last line of defense.