Tension Reducing Muscle Stretch Protocol to Obtain Full Distal Tendon Excursion: A New Rehabilitation Protocol after Flexor Tendon Repair

Abstract

Background: Flexor tendon rehabilitation protocols minimize repair tension by limiting range of movement to prevent tendon rupture. The resultant muscle contracture inhibits finger extension, increases resistance in tendon gliding distally, and progress to proximal interphalangeal (PIP) joint flexion contracture. This study describes our new rehabilitation protocol, the Tension Reducing Muscle Stretch (TRMS), designed to prevent flexor muscle contracture and obtain full distal tendon excursion. Methods: We reviewed retrospectively 14 fingers in 13 consecutive patients with primary repair of complete zone I or II flexor digitorum profundus (FDP) tendon rupture were treated with our protocol between 2007 and 2019. Our rehabilitation following FDP 4-strand repairs consisted of three steps. The first step comprised of exercises from traditional protocols such as Duran, Kleinert, Synergistic-wrist-motion, and Place-and-hold. The second step comprised the TRMS exercise to prevent the onset of muscle contracture. Anatomically, FDP tendons arise from the same FDP muscle belly. TRMS involved placing the affected finger in full passive flexion while unaffected fingers were passively extended to full extension. This made the affected FDP muscle stretched. The final step incorporated the early active flexion motion exercise, in which simple fisting was performed, from a fully extended position. Results: The mean total active motion at the final follow up was 235° (range 170–265). Using the Strickland criteria, eight achieved excellent, four had good, two had fair results. The mean angle of passive extension deficit at the PIP joint at four weeks after surgery was −7° (−30–0), and at the final follow up was −3° (−20–0). No tendon repair was ruptured. Conclusions: This protocol reduced tension in the affected tendon muscle and encouraged tendon excursion distal to the repair site without complications. It allows full tendon excursion and prevents PIP joint contractures.