The Unpredictable Palmaris Longus Tendon Variation in Distal Radio-Ulnar Joint Reconstruction: A Technical Consideration for Undersized Graft

Abstract

Background: Distal radioulnar joint (DRUJ) instability results from the disruption of the triangular fibrocartilaginous complex consisting of DRUJ’s primary and secondary stabilizers. The gold standard of stabilization procedure remains ligament reconstruction that utilizes tendon grafts to reanimate the volar and dorsal radioulnar ligament (RUL) as the primary stabilizers of the joint. The palmaris longus (PL) tendon, the graft of choice in reconstructive surgery, is commonly used in DRUJ reconstruction. However, it can exhibit anatomic variations from agenesis to the variation in morphology, location, and attachment that is rarely encountered other than in cadaveric studies. Case Presentation: We present a case of a 14-year-old boy with ulnar-sided wrist pain and instability following an injury in a boxing match four months before admission. The clinical and radiological results suggested a DRUJ injury with extensor carpi ulnaris (ECU) tendinitis. A ligament reconstruction using the PL tendon graft was planned. Intraoperatively, the PL was found anomalous with dual distal attachments and a short graft length. Results: We performed Adams ligament reconstruction technique with some modifications to the original design. To overcome the under-sized graft, instead of passing it around the ulnar neck, we added one more bone tunnel on the ulna to enhance the construct stability by a tendon to bone healing. Conclusion: In reconstructive surgeries, surgeons should consider the other sources of grafts as graft variations exist. Otherwise, as in our case, modifications to the standard technique can be made.