Patient-matched osseointegrated prostheses for thumb amputees: a cadaver and feasibility study.

Thumb amputations affect 50% of hand functionality. Common solutions consist of microsurgical treatments or silicone vacuum prosthesis. Not all patients are eligible for microsurgical treatment and the use of vacuum prosthesis is often discouraged because of their instability. On the contrary, osseointegrated prosthesis provide stable retention and osseoperception. This cadaveric study evaluated the process of a patient-matched osseointegrated prosthesis for the treatment of thumb amputees. Computed tomography (CT) medical images reconstruction provided information on metacarpal stump, used as input for the parametric screw design. Preoperative planning guided the surgeons in the surgery: postoperative placement confirmed the accuracy of the preoperative planning. Surgeons were directly involved in the implant design to meet their requirements and patient needs. Implants were inserted into cadaveric specimens in one-stage surgery. A similar process can be adopted and exploited for the treatment of different levels of thumb amputations and long finger amputations.