Primary Trapeziometacarpal (TMC) Arthroplasty for Bennett Fracture in Setting of Severe Thumb Osteoarthritis: A Case Report

Bennett fractures are common intra-articular fractures of the base of the first metacarpal. Not optimal restoration of the articular surface often leads to osteoarthritis, with pain and limited movement. In patients with established and symptomatic TMC osteoarthritis, arthroplasty with MAIA® prosthesis could be a valid option. In July 2024, a right-handed man of 68 years old fell on his hand. Radiographs showed a Bennett fracture in a setting of Eaton–Littler stage 3 osteoarthritis, already painful and disabling according to the patient. For correct pre-operative planning, a 3D model of the affected hand was produced. The patient underwent TMC arthroplasty with a MAIA® prosthesis. Two months after surgery, the results reported no pain (VAS scale) and considerable functionality and mobility of the first ray (AROM, Kapandji score, and PRWHE were investigated). The mean pinch strength of the right hand was 7 kg and of the left hand 7.5 kg using a pinch meter. At one-year follow-up, no complications were reported: the implant did not show signs of loosening or subsidence. TMC arthroplasty in Bennett fractures could represent a safe procedure in patients with established TMC osteoarthritis; however, further studies are requested in order to clarify effectiveness and indications.