Restoration of elbow function by intercostal nerve transfer for obstetrical paralysis with co-contraction of the biceps and the triceps.

Among the conservatively treated patients with obstetrical paralysis after delivery in the vertex presentation, cross reinnervation sometimes occurs in the course of their recovery and co-contraction of multiple muscles impairs smooth upper limb motion. Such co-contraction of the biceps and the triceps inhibits normal elbow motion, making it impossible to use the elbow effectively in daily activities, despite adequate strength in these muscles. To overcome biceps/triceps co-contraction, we performed intercostal nerve transfer to the musculocutaneous nerve for three patients of age 11 months, 6 years and 9 years, respectively, and to the motor branches of the triceps for two patients of age 4 and 14 year-old, respectively. During the average follow-up period of 5.6 (range 1-11.5) years, the power of the reinnervated muscle improved to more than M3, and smooth motion of the elbow independently of shoulder motion was restored.