Relative motion flexion splinting for the rehabilitation of flexor tendon repairs: A systematic review.

Introduction: Relative motion splinting has been used successfully in the treatment of extensor tendon repairs and has recently been applied in flexor tendon rehabilitation. The purpose of this systematic review was to identify articles reporting use of relative motion flexion (RMF) splinting following flexor tendon repair and to examine indications for use and clinical outcomes. Methods: Seven medical databases, four trials registries and three grey literature sources were systematically searched and screened against pre-specified eligibility criteria. Screening, data extraction and quality appraisal were independently performed by two reviewers. Results: A total of 12 studies were identified, of which three met the review eligibility criteria: one retrospective case series; one cadaveric proof of concept study; and one ongoing prospective case series. The type of splint (including metacarpophalangeal joint position and available movement), exercise programme, and zone of tendon injury varied between studies. Both case series presented acceptable range of movement and grip strength outcomes. The prospective series reported one tendon rupture and two tenolysis procedures; the retrospective series reported no tendon ruptures or secondary surgeries. Discussion: We found limited evidence supporting the use of RMF splinting in the rehabilitation of zones I-III flexor tendon repairs. Further prospective research with larger patient cohorts is required to assess the clinical outcomes, patient reported outcomes and safety of RMF splinting in comparison to other regimes. Application of the relative motion principles to flexor tendon splinting varied across the included studies, and we suggest an operational definition of relative motion in this context.