Load transmission characteristics of limited carpal fusions: a two-dimensional finite element study.

Although limited carpal fusion is a choice of treatment in several wrist disorders, little is known about the biomechanics of these procedures, especially the loads carried by the ligaments. In a finite element study, four types of limited carpal fusions (scaphotrapeziotrapezoid, capitohamate, four corner fusion with and without scaphoid excision) were simulated and the loads carried by the ligaments were recorded. Measurements were repeated with and without implantation. The load transmission through the ligaments varied by the type of the fusion but, radioscaphoid and long radiolunate ligaments carried significantly more loads if not excised during the operation. Implantation did not affect the results in most cases. The model of the present study may be useful in preoperative planning.