Corrective Osteotomy of a Malunited Volar Lunate Facet Fragment: A Case Report

Abstract The volar lunate facet fragment in distal radius fracture is known to be at risk of secondary displacement after volar plate fixation. Loss of fixation of the fragment can lead to wrist dysfunction. A 47-year-old male presented 7 months after volar locking plate fixation for a distal radius fracture with left wrist pain and radiographic malunion of the volar lunate facet. Computed tomography demonstrated pronated and ulnarly displaced healing, with the original plate positioned too radially to support the fragment. Arthroscopy-assisted intra-articular osteotomy was performed, followed by placement of the volar locking plate at the distal and ulnar aspect of the radius. A volar radioulnar ligament suture technique was added to counteract ulnar traction forces. The pronated and ulnarly displaced fragment was adequately reduced, and symptoms improved without any complications. At 1-year follow-up, reduction was maintained and functional scores normalized. A recent anatomic study has demonstrated that tensile forces acting on the volar lunate facet fragment are greater in the radioulnar direction than in the sagittal plane. This finding is consistent with previous reports showing that the volar lunate facet fragments tend to displace ulnarly with pronation. Therefore, conventional volar locking plates intended to provide buttress support may not be sufficient to maintain fixation. Suturing the volar radioulnar ligament to the volar plate may counteract the traction force acting on the volar lunate facet fragment in the ulnar direction. By combining this technique with the intra-articular osteotomy and placing the plate in the optimal position, we were able to achieve and maintain stable fixation of the volar lunate facet fragment.