Beneficial Effects of Nonsurgical Treatment for Symptomatic Thumb Carpometacarpal Instability in Clinical Practice: A Cohort Study

Objective: To describe outcomes of nonsurgical treatment for symptomatic thumb carpometacarpal joint (CMC-1) instability. Secondary, to evaluate the conversion rate to surgical treatment. Design: Prospective cohort study. Setting: A total of 20 outpatient clinics for hand surgery and hand therapy in the Netherlands. Participants: A consecutive sample of patients with symptomatic CMC-1 instability (N=431). Intervention: Nonsurgical treatment including exercise therapy and an orthosis. Main Outcome Measures: Pain (visual analog scale [VAS], 0-100) and hand function (Michigan Hand Outcomes Questionnaire [MHQ], 0-100) at baseline, 6 weeks, and 3 months. Conversion to surgery was recorded for all patients with a median follow-up of 2.8 years (range, 0.8-6.7y). Results: VAS scores for pain during the last week, at rest, and during physical load improved with a mean difference at 3 months of 17 (97.5% CI, 9-25), 13 (97.5% CI, 9-18), and 19 (97.5% CI, 12-27), respectively (P<.001). No difference was present at 3 months for MHQ total score, but the subscales activities of daily living, work, pain, and satisfaction improved by 7 (97.5% CI, 1-14), 10 (97.5% CI, 4-16), 5 (97.5% CI, 2-9), and 12 (97.5% CI, 2-22) points, respectively (P<.001-.007). After median follow-up of 2.8 years, only 59 participants (14%) were surgically treated. Both in the subgroups that did and did not convert to surgery, VAS pain scores decreased at 3 months compared with baseline (P<.001-.010), whereas MHQ total score did not improve in both subgroups. However, VAS and MHQ scores remained worse for patients who eventually converted to surgery (P<.001). Conclusions: In this large sample of patients with symptomatic CMC-1 instability, nonsurgical treatment demonstrated clinically relevant improvements in pain and aspects of hand function. Furthermore, after 2.8 years, only 14% of all patients were surgically treated, indicating that nonsurgical treatment is a successful treatment of choice