Class IV laser therapy for trapeziometacarpal joint osteoarthritis: Study protocol for a randomized placebo-controlled trial.

Objective: Osteoarthritis (OA) is a chronic and prevalent joint disorder with great impact on quality of life and high economic burden. Although a number of conservative therapies have proven to be effective for the management of hand OA, only modest treatment effects were reported for most individual interventions. The aim of the proposed study is to assess the effect of Class IV laser therapy (LT) on pain and pinch strength in patients with thumb carpometacarpal (TCMC) OA.

Methods: A randomized, controlled, single-centre, double-blind, clinical trial, with 1:1 allocation ratio, will be carried out involving patients presenting TCMC-OA Grades 1-2 (aged >18 years). Both assessor and statistician will remain blinded. Patients with TCMC-OA will be randomly assigned to the experimental group (will receive LT) and control group (will receive a placebo treatment). Outcome measures will be pain scores at the base of the thumb measured with visual analogue scale (0-10: 0, no pain and 10, worst pain) and changes in pinch strength, both collected at baseline, 4, and 12 weeks. Statistical analyses will be based on an intention-to-treat analysis using the last value forward method. A two-tailed independent Student's t test for the continuous variable of age and baseline scores will be used for comparison of baseline characteristics and outcome variables. Paired Student's t tests will be used to determine the level of significance of the differences between the pretreatment and posttreatment measurements of the individual groups. Repeated measures analysis of variance will be used to determine the differences in time as the within-subjects factor and group as the between-subjects factor.

Discussion: To our knowledge, the results of this study will provide the first double-blinded evidence for Class IV LT in patients with TCMC-OA.