Long-term follow-up of non-surgical treatment for thumb carpometacarpal osteoarthritis

Abstract

Background: Treatment guidelines for thumb carpometacarpal (CMC-1) osteoarthritis (OA) advise starting non-surgical treatment. The combination of exercise therapy and the use of orthotics can result in a short-term decrease of pain and increase of function with a follow-up of one year. However, the existing evidence on the long-term effectiveness of non-surgical treatment, especially exercise therapy, is limited. Furthermore, the actual conversion to surgery has hardly been described.

Aim: To describe the outcomes of non-surgical treatment, consisting of exercise therapy and the use of orthotics, on patient reported pain and limitations in activities of daily life (ADL) in patients with CMC-1 OA after at least 5 year follow-up. Secondary outcomes include conversion to surgery within a follow-up period of at least 5 years and possible predictors at baseline, patient satisfaction and quality of life.

Methods: This is a multicenter, prospective cohort study with observational data investigating outcomes of an orthosis and exercise therapy using two samples. The primary outcomes were pain and limitations in ADL, expressed in the Michigan Hand Outcomes Questionnaire (MHQ) subscales pain and ADL respectively and were analyzed using linear mixed model analysis on sample 1. Timepoints included baseline, 3 months, 1 year and >5 years. Conversion to surgery was extracted from patient records and was analyzed using a Kaplan Meier survival analysis on sample 2.

Results: A total of 170 participants were included in sample 1 and the median follow-up time was 6.6 years (range 5.1-8.7 years). For the MHQ subscales pain and ADL a mean difference of respectively 17.9 and 13.4 points between baseline and >5 years is present. Conversion to surgery was studied of 465 patients in sample 2 and we found a conversion rate of 16.3 % after a median follow-up of 7.0 years (range 5.5-9.2 years).

Conclusion and key findings: We found positive outcomes at >5 year follow-up for nonsurgical treatment of CMC-1 OA. Moreover, only 16% required additional surgical treatment. Our findings support non-surgical treatment as a first treatment option and suggest that treatment effects are sustainable, although this should be confirmed in a standardized setting such as a randomized controlled trial.