Rehabilitation Approach for Relative Motion Flexion Orthoses After Flexor Digitorum Profundus Zone I–II Repair: A Prospective Case Series

Background:Relative motion flexion orthoses (RMFOs) are a type of early mobilization based on the "quadriga effect." Currently, there are few published clinical outcome data and no documented treatment protocols. This study aimed to standardize our a rehabilitation protocol for early mobilization with relative motion for flexor tendon injuries within a 9-week program.Methods:A prospective study was conducted from April 2023 to June 2024, which included all patients who had undergone relative motion orthoses and rehabilitation for flexor digitorum profundus repair in zone I or II. The exclusion criteria were as follows: age younger than 18 years, more than 3 injured fingers, and lack of adherence, associated fracture, and surgical repair for more than 10 days. Final measurements at weeks 8 and 12 included total active motion; Strickland and Glogovac formula; Quick Disability of the Arm, Shoulder, and Hand questionnaire; grip strength (Jamar); and pain.Results:Ten patients underwent the RMFO protocol between April 2023 and June 2024, with at least 3 months of follow-up. Two patients were excluded from the study; the remaining patients (8) showed improvements in range of motion; Disabilities of the Arm, Shoulder, and Hand; Jamar; and visual analog scale scores. No complications such as proximal interphalangeal joint contracture, tenolysis, or rupture were reported. All patients returned to work by week 10.Conclusions:In this small prospective case report of RMFOs, we continue to increase the number of patients in the literature, and our results are compared with those of previous studies. In addition, we present our step-by-step approach to a 9-week program.