Isolated Volar Scapholunate Ligament Tear Treated with Palmaris Longus Tenodesis

Abstract Scapholunate ligament tears typically involve both the dorsal and palmar bands. There is prior biomechanical evidence that the palmar band has lower yield strength than the dorsal band; however, isolated palmar tears are scarcely reported in the literature. The purpose of this case report is to describe a reconstructive technique that can successfully address this rare issue. A 23-year-old man was referred for persistent wrist pain following a basketball injury with scapholunate diastasis. Workup demonstrated isolated volar band scapholunate interosseous ligament (SLIL) rupture with the dorsal band intact. Isolated autograft reconstruction of the volar band using palmaris longus resulted in improvement of wrist function and pain. At 32 months, he was continuing to pursue all activities without limitations. Arthroscopic and open approaches to addressing volar scapholunate ligament pathology have been reported, primarily in biomechanical studies or in conjunction with managing a dorsal tear. Only one other case of isolated palmar SLIL tear has been reported in the literature. However, this was treated using a long radiolunate ligament-based flap with a suture anchor in contrast to using a palmaris longus autograft. This study confirms biomechanical studies regarding the difference in yield strength between the volar and dorsal bands of the SLIL and also demonstrates that isolated tears of the volar SLIL can result in symptomatic scapholunate instability. This can be successfully treated with a palmaris longus autograft tenodesis reconstruction.