Biomechanical Analysis of Three-Dimensional Osteotomy at the Distal End of the Radius for Kienböck’s Disease with Flexion Deformity of the Lunate

Failure of radial closing wedge osteotomy for advanced Kienbock’s disease frequently reveals a flexion deformity of the lunate and the collapse and fragmentation of its volar half. We performed biomechanical analyses including a rigid-body spring model and the finite-element method and demonstrated that the flexion deformity of the lunate increases contact pressure at the volar half of the radiolunate and capitolunate joints. The increased contact pressure could therefore lead to collapse and fragmentation of the volar half of the lunate. A new three-dimensional osteotomy, consisting of a radial closing wedge osteotomy and an extension osteotomy, was developed to achieve better alignment of the capitolunate joints. The three-dimensional osteotomy may therefore be an effective procedure for Kienbock’s disease having a flexion deformity of the lunate.