Microsurgical reconstruction of the scaphoid and lunate bones with small, free vascularized iliac crest bone grafts

Abstract

The primary surgical goal in repairing a scaphoid nonunion, particularly one associated with avascular fragments, or reconstructing the lunate is to prevent progressive carpal collapse. In patients with persistent nonunion of the scaphoid and progressive aseptic necrosis of the lunate bone, reconstruction can be managed with a small microvascular iliac crest bone transfer. This retrospective study reports on the anatomical fundamentals, the operative procedure (particularly the harvesting of the bone flap and microsurgery), the assessment of the viability of the bone graft and the postoperative results in 80 out of a total of 210 patients on whom the surgery had been performed. From 1985 until 1998, 210 carpal bone reconstructions (134 scaphoid bones and 76 lunate bones) were performed using small, free vascularized iliac crest bone grafts. Of these, 80 patients were preoperatively evaluated and postoperatively followed up clinically and by means of conventional radiography and magnetic resonance imaging (MRI). The total rate of viability and bony union was 91.2%. This means a bone flap loss-rate and, consequently, a progressive arthrosis/necrosis/persistent nonunion of 8.8%. The patients who had vital reconstructed carpal bones did not report pain, but motion and grip strength were decreased as compared with the uninvolved side. This procedure offers stability and vascularity to treat avascular scaphoid nonunion and has proved beneficial in achieving union in avascular scaphoid pseudoarthrosis and lunate necrosis. It can be considered to be the definitive alternative technique. The high rate of union and the absence of progressive carpal arthrosis are the best evidence for the vascularity of the bone graft.