PIP Joint Reconstruction for Proximal Phalanx Condyle Pseudarthrosis Using an Osteochondral Graft From the Fifth Metacarpal Base: A 10‐Year Case Report

Introduction Reconstruction methods for osteochondral defects of the proximal phalanx condyle are not well established, and data on long‐term clinical outcomes are limited. In many cases, joint preservation is abandoned in favor of arthrodesis or joint replacement. This report presents a case of reconstruction for pseudarthrosis of the radial condyle of the proximal phalanx of the middle finger using an osteochondral graft harvested from the fifth metacarpal base. Case Presentation The patient was a 24‐year‐old woman who presented with a mass and pain during movement in her right middle finger. Ten years earlier, trauma had resulted in pseudarthrosis of the radial condyle of the proximal phalanx. The patient underwent surgery for mass excision, which revealed a giant cell tumor of the tendon sheath. Following excision, pain at the pseudarthrosis site worsened, necessitating further treatment. Because the bone fragment at the pseudarthrosis site was too small for fixation, a 5‐mm‐wide osteochondral graft was harvested from the ulnar base of the fifth metacarpal and transplanted to the radial condyle of the proximal phalanx, with simultaneous collateral ligament repair. Postoperatively, the patient experienced mild pain during finger movement due to the fixation screw and Kirschner wires, which were removed 3 months after surgery. At a long‐term follow‐up of 10.5 years, the patient was asymptomatic at both donor and recipient sites. The transplanted osteochondral graft demonstrated excellent remodeling, and the joint space was preserved. Conclusions The ulnar base of the fifth metacarpal shares a morphological similarity with the proximal phalanx condyle, making it a viable option for reconstructing unilateral condylar osteochondral defects. However, reports describing this technique remain extremely rare. Although careful patient selection and precise surgical technique are essential, osteochondral grafting from the fifth metacarpal base is relatively minimally invasive and may represent a promising option for preserving joint function.