Scaphoid excision and four-corner fusion is an accepted treatment for scapholunate advanced collapse and for scaphoid nonunion with advanced collapse. Various implants have been used for intercarpal arthrodesis. A circular metal plate was introduced in 1999 with anticipation that it would provide a simple and sturdy method of fixation that would allow earlier mobilization and higher rates of union. However, outcomes have been mixed with some authors reporting high fusion rates and low complications and others reporting higher complication rates when compared with traditional methods of fixation. The purpose of this study was to determine the rate of fusion, identify complications, and to determine functional outcomes when using circular plate fixation for four-corner arthrodesis of the wrist.
The authors performed a retrospective review of 15 patients treated with the circular plate with a mean follow-up of 11 months. They report radiographic fusion in all 15 patients and only one post-operative complication (dorsal hardware impingement). This rate of fusion is much better than in other studies using the circular plate which have been reported to have nonunion rates of up to 39%. The authors admit the difficulty of determining radiographic fusion with metallic hardware but report seeing no clear signs of nonunion. Rates of complications in this study are also significantly better than in other reviews. They report only one complication in fifteen patients when other studies have reported implant breakage or back-out in up to 27% and hardware impingement in up to 25%.
The authors conclude that the circular plate is an acceptable implant and suggest that the factors that lead to poor outcomes while not completely understood, may not be implant related.