Mod Quad Surgery

The need for secondary surgery does not mean that the primary surgery failed. It describes another type of surgery done later in time used to correct muscle imbalances that occur as a normal result of having a brachial plexus injury.

The situation of muscle imbalance is very common especially among those who have upper trunk (Erb’s Palsy) injuries. In our experience the majority of children whose injury does not completely resolve by 3 to 4 months of age will end up with a specific series of arm restrictions caused by a muscle imbalance between injured and uninjured muscles.

At the same time, the internal rotators (muscles that turn the arm and palm inward) and adductors (muscles that pull the arm to the side) of the arm are not involved in the injury because they are supplied by the lower roots of the plexus. Therefore, these strong muscles overpower the weak muscles and over time the child cannot lift the arm over the head or turn the palm out, because of the muscle imbalance.