Treatment outcome of various reconstructive procedures of brachial plexus lower trunk injuries: a comparative study

Objective To evaluate the treatment outcome of various reconstructive procedures of brachial plexus lower trunk injuries. Methods 26 cases of adult lower trunk injuries treated from October 2001 to August 2004 were reviewed. Three neurotization methods were applied to repair the median nerve for restoration of finger flexion. In group A (n=6) brachialis muscle branch of the musculocutaneous nerve was transferred. In group B (n=10) contralateral C 7 transfer was done. In group C (n=10) the intercostal nerves were sutured to the median nerve. The average follow up period was 15 months. Restoration of median nerve function was evaluated by measuring the grip strength, muscle power, median nerve conduction velocity (MNCV) and compound muscle action potential (CMAP).Results Finger flexion was achieved in 5 cases of group A. No finger flexion was observed in the rest one due to limited 6 months postoperative duration. 5 out 10 cases in group B recovered finger flexion while the other 5 cases had no sign of recovery. For group C, finger flexion was seen in 6 cases but absent in 4 cases. Grip strength and muscle power tested 3 months, 6 months, and 12 months postoperatively were better in group A than in groups B and C. The difference was statistically significant(P0.05). There was no difference between group B and group C(P0.05). MNCV was faster in group A than in groups B and C. CMAP of group A also showed shorter latent period and larger amplitude(P0.05). No difference was seen between group B and group C. Conclusion Transfer of brachialis muscle branch of the musculocutaneous nerve to the median nerve is a better option for restoration of finger flexion in that neurotization is located closer to the target muscle.