A new concept and technique for custom-made microvascular lunate bone reconstruction

Kienböck's disease is always a challenge, especially when the lunate is already fragmented. Despite the numerous methods to treat this wrist problem, results have often not been satisfactory. Swanson's silastic lunate prosthesis has not been a helpful solution for most patients over the long-term, and problems with artificial material have also become apparent. A proposal to create an autogenous microvascular total lunate bone reconstruction is presented. The second metatarsophalangeal joint was used in a new fashion to create a biologic substitute for the lunate bone. This is called a "neolunate." The lunate bones and neolunates created from the second metatarsophalangeal joints of fresh cadavers were compared. The possibilities of microvascular access to create a neolunate and its use in wrist reconstruction were studied in ten cadaveric wrists. The lunates and neolunates were compared. After a neolunate reconstruction, the specimen was inserted into the original cadaveric wrist and the ligamentous structures were repaired. The necessary architecture for ligament stability to prevent subluxation and DISI or VISI deformity was established. Radiological measurements confirmed the neolunate as a suitable model. The result was close to normal wrist configuration. So far, only one clinical trial using the proposed technique has been done. The proposed microsurgical neolunate transfer needs further clinical testing to prove its potential value. A disadvantage is that the method is technically demanding.