LAUSR

BACKGROUND Obstetric brachial plexus palsy (OBPP) can cause deformities of the upper extremity in up to 92% (S-OBPP). Reconstruction of the elbow is difficult because co-contraction of the elbow flexor (EF) and extensor (EE) muscles makes the traditional strategy of treatment ineffective. We propose a novel strategy to minimize the effect of co-contraction, comprising of transfer of an EF to the triceps, followed by a staged gracilis muscle transplantation (FFMT) to augment EF. We hypothesize this will lead to improved EE, maintaining the EF, as well as decrease elbow flexion contracture. METHODS A single-center retrospective review of patients who received a gracilis FFMT for EF after EF-to-EE transfer was performed. EF/EE strength and range of motion were collected from the last clinical visit. Patients were excluded if they had less than 1.5 years of follow-up. A control group who had S-OBPP but non-surgical treatment was used for comparison. RESULTS Twenty-one patients were included. Average age at muscle transfer was 7.6 ±5.5 (3-22) Y/O and at gracilis FFMT was 10.4 ± 6.0 (5-26) Y/O. Average follow-up was 7.3 ± 6.5 (1.5-14.8) years. After EF-to-EE transfer, EE strength increased significantly from MRC 2.2 ± 0.4 to 3.4 ± 0.5 (p<0.0001) and EF decreased from 3.2 ± 1.1 to 1.1 ± 1.1 (p<0.0001) and recovered to MRC grade 3.3 ± 0.7 after gracilis FFMT. EF contracture was significantly less compared to non-surgical cohort (p=0.029). CONCLUSION Patients who undergo EF-to-EE, followed by gracilis FFMT have equivalent EF strength with significantly improved EE and improved elbow flexion contracture.