Background: The thumb's radial collateral ligament (RCL) plays an important role in stabilizing the first metacarpophalangeal joint (MCP-1). RCL injuries are rare and treatment recommendations are inconsistent in the current literature. The aim of this study was to report on long-term outcomes following surgical repair of thumb RCL tear and to identify prognostic risk factors for treatment failure.
Methods: Patients with RCL tear from 10/1998 to 10/2019 were included in the present retrospective single center cohort study. In follow-up visits, participants were assessed regarding pain, range of motion and strength as well as with disability of shoulder, arm and hands (DASH), and the Short-Form 36 (SF36) questionnaires. Finally, predictive factors of postoperative deficits were identified.
Results: 43 patients fulfilled inclusion criteria. Median age was 43.5 years (range 18-80 years). The most frequent mechanism of injury was a fall or impact. Bony avulsions were identified in 46.5% (20/43). Time from injury to surgery was 12 days (0-276 days). One Stener-like lesion was observed intraoperatively among our patients. After surgical repair, the MCP-1 joint was stable in every patient. Mean time to follow-up was 5.3 years (1 month to 17 years). Persistency of pain in the MCP-1 joint was reported by 11 patients. Postoperative averaged score was 3.75 on DASH and 44.96 on SF36, respectively. The average grip and pinch strength was 32.7 kg and 8.37 kg, respectively. Predictive factors of postoperative deficits were delay of surgery of > 3 weeks (OR 10.72, p 0.017) and palmar subluxation prior to surgery (OR 8.86, p 0.019).
Conclusion: Long-term follow-up has proven that surgical repair of RCL enables the patient to regain adequate stability and strength of the MCP-1 joint and minimizes disability. Predictive risk factors of pain persistency after surgery are surgical delay and palmar subluxation of the MCP-1 joint.
Keywords: Metacarpophalangeal joint-1; Radial collateral ligament; Stener lesion; Thumb.