Foot Drop and Leg Paralysis

What is a drop foot?

Injury to the anterior leg muscles or nerve along the lateral knee (peroneal nerve) can impair ones ability to elevate the foot. Weakness or inability to lift the foot is frequently referred to as a ‘foot drop' and can significantly impair normal walking.

How is foot drop treated?

Treatment is determined by the cause of the impairment. A foot drop produced by pressure or trauma to the motor nerve are treated with regard to the degree of injury and potential for spontaneous recovery.

Mild pressure or stretching of the peroneal nerve can produce a temporary impairment of local circulation that interrupts normal nerve conduction. This is referred to as neuropraxia and usually resolves within days to weeks with return of good function.

More substantial trauma can lead to destruction of the nerves electrical conduction cells (axons). If their biologic insulation and tube like pathways remain undamaged then axon regeneration and spontaneous recovery can be anticipated within several months. This process of nerve injury and regeneration is referred to as axonotemesis.

When all the nerve components are damaged then an obstructing scar develops and little to no recovery will develop without surgical intervention. Impaired nerve function can also result from local compression. The surgical release of constrictive tissue (nerve decompression) can increase circulation within the nerve improving its ability to conduct electrical signals.

Severely damaged nerve segments can also be reconstructed using segments of expendable sensory nerves. The damaged segments are identified with intraoperative nerve conduction studies. The nonfunctional segments are removed and replaced with healthy nerve grafts. The grafts are secured into place using an operating microscope and stitches finer than a hair (microneurosurgery) and provide a biologic guide for regenerating nerve cells.

Alternately, nerve function may be normal and damaged or missing anterior leg muscles are responsible for the foot drop. Reconstruction can be accomplished by rerouting tendons from undamaged local muscles to restore foot elevation (tendon transfer). When an undamaged expendable local muscle is unavailable then a healthy muscle can be imported from a distant site. A muscle typically obtained from the leg or back is transplanted to replace the damaged anterior leg muscle. During the transplantation process an operating microscope, fine jewelers instruments and micro-sutures are utilized to restore circulation and normal nerve connections. The transplanted muscle does not begin to function immediately. Nerve regeneration proceeds slowly at approximately an inch per month (1mm/day). Muscle tone often returns by 6 months with gradual improvement in strength for two years. Physical therapy and electrical stimulation are utilized to enhance recovery.

Loss of Foot Elevating Muscles	Microsurgical Nerve Repair
Functional Muscle Transplant	Post Op for Fuctional Muscle Transplant