Evaluating Elbow Flexion After Free Functional Gracilis Muscle Transfer in Adult Brachial Plexus Lnjury

Overview

* Study Overview This single-arm prospective clinical trial evaluates the efficacy of gracilis free functional muscle transfer (FFMT) for restoring elbow flexion in patients with late-presenting brachial plexus injuries (≥12 months post-injury) or failed prior reconstructive surgery. The gracilis muscle is the preferred donor due to its reliable vascular pedicle, adequate excursion, long motor nerve, and minimal donor-site morbidity . * Primary Objective To assess postoperative elbow flexion strength using the British Medical Research Council (BMRC) grading system following gracilis FFMT neurotized by intercostal nerves (ICN) or spinal accessory nerve (SAN). * Secondary Objectives * Evaluate active range of motion (AROM) * Measure time to first detectable muscle contraction and time to maximum power * Assess functional improvement via DASH scores * Compare outcomes between ICN and SAN neurotization groups * Compare outcomes between pediatric and adult patients * Document complications, particularly elbow flexion contracture * Key Inclusion Criteria * Age 4-50 years * Elbow flexion loss or severe weakness for \>12 months following brachial plexus injury (obstetric or traumatic) * Weak ipsilateral latissimus dorsi and pectoralis major (\<M3), unsuitable for local muscle transfer * Key Exclusion Criteria * Age \<4 years (microvascular anastomosis feasibility concerns) * Age \>50 years (diminished regenerative capacity) * Presentation within 12 months of injury * Reconstructable by local muscle or nerve transfer * Elbow joint stiffness or contracture * Uncontrolled comorbidities or inability to comply with rehabilitation * Intervention Gracilis FFMT harvested from the contralateral thigh with: * \*\*Neurotization:\*\* ICNs (50%) or SAN (50%) * \*\*Vascular anastomosis:\*\* Thoracoacromial artery (77%), thoracodorsal artery (13.6%), or subscapular artery (9.2%) * \*\*Muscle tensioning:\*\* Elbow flexed 90-110° during inset * Primary Outcome Measure Postoperative elbow flexion power (BMRC grade) at 24-month follow-up * Secondary Outcome Measures * Active range of motion (goniometry) * Time to first clinical contraction * Time to maximum power achievement * DASH score * Complication rate (flap loss, flexion contracture, scarring) * Sample Size 22 patients (17 male, 5 female; mean age 13.4±8.7 years) * Statistical Considerations * Paired t-test for continuous outcomes * Wilcoxon signed-rank test for non-parametric data * Fisher's exact test for categorical comparisons * Significance threshold: p\<0.05 * Expected Outcomes Based on existing literature, 68-76% of patients achieve functionally useful elbow flexion (≥M3) following gracilis FFMT, with significant improvements in AROM and DASH scores . ICN neurotization may offer faster recovery to maximum power (approximately 9 months vs. 14 months for SAN) without compromising final strength . * Trial Registration:\*\* Not reported (retrospective/prospective case series design)