[The Graner capitate interposition arthroplasty in lunate malacia].

In capitate interpositional arthroplasty (Graner II) the necrotic lunate bone is removed and the congruity of the proximal carpal row is restored by interposition of the proximal half of the capitate. The carpal bones are fused except for the scaphotrapezial joint. In this fashion carpal instability can be safely treated. Good results are achieved for both grip strength and relief of pain. Motion is restricted but with a useful range of motion remaining. The arc of remaining motion can be shifted into extension through the use of an opening wedge osteotomy of the capitate. Capitate interpositional arthroplasty without an intercarpal arthrodesis has poor result because of remaining carpal instability.