Should we immobilize the wrist after flexor tendon repairs?
Woythal L et al: Splints, with or without wrist immobilization, following surgical repair of flexor tendon lesions of the hand: A systematic review. Hand Surg Rehabil 2019 May 24. pii: S2468-1229(19)30073-8.
Investigators in Denmark sought to answer this important question by performing a systematic analysis. They reviewed studies, all languages and no date restrictions, involving adults over age 18 who underwent surgical repair of flexor tendon lacerations in the hand. Their initial screen produced 2270 articles. After eliminating duplicated or irrelevant articles, 154 were left. The investigators read the full text of these articles, and unfortunately none of articles met their inclusion criteria because they were not randomized controlled trials or observational comparative studies or that the patients had undergone concomitant nerve repairs.
Undaunted, the investigators summarized the three relevant studies that shed at least some light on their original research question.
- A prospective study compared results in patients receiving the Modified Belfast protocol (early active motion with the wrist immobilized) to patients receiving a splint that allowed synergistic wrist motion. The second group achieved better functional outcomes, but the results were possibly biased because the second group received their therapy from a single clinical specialist whereas the wrist-immobilized group received their rehabilitation from a variety of therapists with different skill levels. Other issues with the study included a lack of description of injury severity, and issues of group allocation, motivation, and compliance.
- A retrospective study compared two types of splint treatment following repair of zone II flexor tendon injuries. One group wore a dorsal orthosis holding the wrist in neutral and blocking mp joint extension at 30 degrees. The other group used the Manchester short splint which allows 45 degrees of wrist extension, full wrist flexion, and all but 30 degrees of wrist extension. The total range of motion was not significantly different between the two groups after 3 months, but the Manchester short splint group had 22% excellent results compared to 6% for the traditionally splinted group. Selection bias is likely in that only patients deemed to be highly compliant were treated with the Manchester short splint.
- One team repaired the tendons in such a way that they used no postoperative immobilization at all. Passive E/F exercises began the first day after surgery, and active mobilization began two days later. Eight out of 14 fingers in 13 patients achieved excellent outcomes. There were no tendon ruptures. The small cohort and no control group are study weaknesses.
COMMENT: Despite the authors’ herculean effort to review over 2000 articles, their results are woefully and entirely inconclusive. The articles that they did summarize offer a glimpse of what a carefully designed and executed prospective, randomized trial might reveal regarding this important and commonly encountered problem. Certainly flexor tendon repair rehabilitation protocol has come a long way from initially not repairing in “no man’s land” at all but rather performing a tendon graft later on. Then Kleinert and others greatly advanced our understanding by advocating early passive flexion and active extension. The more recent understanding that wrist extension combined with digital flexion and wrist flexion combined with digital extension allows for maximal gliding and minimal tension is an intriguing advance, we just do not yet know whether this less encumbering immobilization is truly effective.