Outcomes of gracilis free-flap muscle transfers and non-free-flap procedures for restoration of elbow flexion: A systematic review

Purpose: Elbow flexion is one of the most important functions to restore following brachial plexus damage. The authors sought to systematically review available evidence to summarize outcomes of free gracilis and non-free muscle transfers in restoring elbow flexion. Methods: MEDLINE, EMBASE, and Cochrane were searched to identify articles reporting on elbow flexion reanimation in terms of transfer failure rates, strengths, range of motion (ROM), and/or Disabilities of the Arm, Shoulder and Hand (DASH) scores. A systematic review was chosen to select studies and reported according to PRISMA guidelines. Results: Forty-six studies met the inclusion criteria for this study. A total of 432 cases were gracilis free-flap muscle transfers (FFMT), and 982 cases were non-free muscle transfers. FFMT were shown to have higher Medical Research Council (MRC) strength scores than non-free muscle transfer groups. However, 42 studies, totaling 1,266 cases, were useful in evaluating graft failure, showing failure (MRC<3) in 77/419 (∼18.4%) of gracilis free-flap transfers and 215/847 (∼25.4%) of non-free muscle transfers. Sixteen articles, 285 cases, were useful to evaluate ROMs (total range: 0–140°), and eight articles, 215 cases, provided DASH scores (total range: 8–90.8). Conclusions: Of patients who underwent gracilis FFMT procedures, higher mean strength scores and lower failure rates were observed when compared with non-free muscle transfers. Articles reporting non-free muscle transfer procedures (pectoralis, pedicled, Steindler, vascularized ulnar nerve grafts, Oberlin, single/double nerve transfers) provided comprehensive insight into outcomes and indicated that they may result in pooerer poorer DASH scores and ROM.