Technique for Reconstruction of Midcarpal Instability Associated with Lunotriquetral Coalition.

Carpal coalition is a rare congenital presentation of 2 or more fused carpal bones due to a failure of apoptotic segmentation during development. The most common subtype is lunotriquetral coalition (LTC). Most cases are asymptomatic and found incidentally on imaging; however, a few symptomatic cases requiring treatment have been reported. Surgical intervention of arthrodesis and proximal row carpectomy in adults have been reported where conservative management of splinting, physiotherapy, anti-inflammatory medication, or steroid injections have failed. We report a unique case of Minnaar type 2 LTC in a 20-year-old man with a 6-year history of daily right wrist pain and symptomatic wrist instability whose previous conservative therapies failed. Midcarpal instability and volar intercalated segment instability-volar flexion of the lunate-were present. A novel technique using the palmaris longus tendon to reconstruct the triquetrohamate, triquetrocapitate, and dorsal radiolunate ligaments was performed. The graft was secured dorsally to the hamate, triquetrum, and capitate. An additional graft from the lunate to distal radius acted as a biomechanical checkrein. There were no complications. Temporary Kirschner wires were removed 2 months postoperatively, followed by occupational hand therapy. At 1-year follow-up, the patient no longer reported pain or lunotriquetral tenderness. Midcarpal instability and volar intercalated segment instability resolved. Postoperative right wrist flexion and extension were 40 and 75 degrees, respectively. We discuss the successful outcome of this novel technique as an alternative to arthrodesis in the surgical management of LTC.