Delayed Anatomical Repair of Ruptured Ulnar Collateral Ligament Injuries of the Thumb Using a Dissolvable Polylactic Acid Bone Anchor

Abstract

BACKGROUND: We describe late anatomic repair of complete distal ulnar collateral ligament (UCL) avulsions of the thumb in the absence of metacarpophalangeal joint arthritis using a dissolvable polylactic acid (PLA) bone anchor in two cases, one of which had a Stener lesion. METHODS: Patients presented for surgery respectively at 5 months and 2 years after injury. Preoperative X-ray films showed subtle volar subluxation of the proximal phalanx. Volar plate release corrected this in both cases and a transarticular k-wire was not used. Satisfactory repair was achieved in both cases using a dissolvable PLA bone anchor. Flexion-extension mobilization was supervised by a hand therapist from day 1 after surgery. A low profile radial-sided thermoplastic splint to prevent reinjury of the UCL repair was used allowing interphalangeal joint and base of thumb movement, and was worn between therapy sessions for 4 weeks. RESULTS: In both patients, satisfactory UCL stability was maintained at 3-year follow-up after surgery. DISCUSSION: Dissolvable PLA bone anchors may be used to satisfactorily restore stability and function in late presenting complete distal UCL avulsions of the thumb with or without accompanying Stener lesions.