Comparison of two relative motion extension approaches (RME with versus without an additional overnight orthosis) following zones V-VI extensor tendon repairs: A randomized equivalence trial.

Abstract

Multi--center randomized controlled trial with two intervention parallel groups. An equivalence trial. Relative motion extension (RME) orthoses are widely used in the postoperative management of finger extensor tendon repairs in zones V-VI. Variability in orthotic additions to the RME only (without a wrist orthosis) approach has not been verified in clinical studies. To examine if two RME only approaches (with or without an additional overnight wrist-hand-finger orthosis) yields clinically similar outcomes. Thirty-two adult (>18 years) participants (25 males, 7 females) were randomized to one of two intervention groups receiving either 1) a relative motion extension orthosis for day wear and an overnight wrist-hand-finger orthosis ('RME Day' group), or 2) a relative motion extension orthosis to be worn continuously ('RME 24-Hr' group); both groups for a period of four postoperative weeks. Using a series of linear mixed models we found no differences between the intervention groups for the primary (ROM including TAM, TAM as a percentage of the contralateral side [%TAM], and Millers Criteria) and secondary outcome measures of grip strength, QuickDASH and PRWHE scores. The models did identify several covariates that are correlated with outcome measures. The covariate 'Age' influenced TAM (P = .006) and %TAM (P = .007), with increasing age correlating with less TAM and recovery of TAM compared to the contralateral digit. 'Sex' and 'Contralateral TAM' are also significant covariates for some outcomes. With similar outcomes between both intervention groups, the decision to include an additional night orthosis should be individually tailored for patients rather than protocol-based. As the covariates of 'Age' and 'Sex' influenced outcomes, these should be considered in clinical practice. A relative motion extension only approach with or without an additional overnight wrist-hand-finger orthosis yielded clinically similar results whilst allowing early functional hand use, without tendon rupture.