A New Technique for Volar Capsulodesis for Isolated Palmar Scapholunate Interosseous Ligament Injuries: A Cadaveric Study and Case Report.

Abstract

Introduction Most surgical techniques for scapholunate interosseous ligament (SLIL) repair address only the dorsal component of the ligament, potentially leading to high surgical failure rates. We introduce a new technique to reconstruct the volar SLIL using a portion of the long radiolunate ligament (LRL). A biomechanical evaluation was performed to evaluate the rupture strength of this repair, and a subsequent anatomic study was performed to verify that this repair would not compromise the blood supply to either the scaphoid or the lunate. Methods A reconstruction of the volar SLIL was developed utilizing a lunate-based strip of the LRL. Fourteen cadaver arms were injected with red-colored epoxide and latex. The blood supply of the volar wrist capsule was dissected. The vascular supply to the ligaments, scaphoid, and lunate were investigated. The biomechanical strength of this reconstruction was tested on five cadaver arms by potting the scaphoid, lunate, and radius and subjecting the repair to a tensile load using a servohydraulic vertical displacement testing machine. Results In all arms, a branch of the radial artery or radiocarpal arch supplied the radioscapholunate ligament at the medial border of the LRL. The proximal half of the scaphoid was supplied by dorsal branches of the radial artery. In all cases, a vessel entered the lunate on its ulnar volar side, away from the repair. The average strength of the intact LRL strip was 97.4 N, and the average strength of the ligament-suture interface used for the capsulodesis was 43.5 N. Conclusion This volar approach to the SLIL does not compromise the vascularity of the scaphoid or the lunate. This approach allows the possibility of repairing or augmenting the volar SLIL. The strength of this repair appears to be less than the strength of the native SLIL. Further clinical studies are warranted.