Muscles located below the knee that serve to lift the front portion of the foot can sometimes become paralyzed, causing the foot to point toward the floor at the ankle. This condition is known as foot drop. In addition to muscle weakness, our patients at Florida Plastic Surgery Group often complain of a “numb” front or side of their leg and top of their foot. Foot drop can be caused by herniation of the lumbar disc, which is characterized by damage to the root of a nerve in the lumbar spine; lumbosacral plexus nerve damage; or peroneal nerve damage (often in locations close to the knee). An injury to the leg or the back, a sprained ankle, surgery involving the knee or surrounding areas, or even simple repetitive activities such as crossing your legs for a prolonged period of time can lead to foot drop.
Preparing for Foot Drop Surgery
What are the non-surgical treatment options for my foot drop?
Patients who believe they may be suffering from drop foot are advised to consult with a medical professional as soon as possible to seek appropriate treatment and reduce the risk for additional complications. A medical or surgical specialist can evaluate your spine to determine if your muscle weakness is due to a nerve root compression. They will typically gather your history, perform a physical examination, and may order tests such as an X-ray, MRI or electrodiagnostic testing (EMG/NCS). If there is no focal abnormality causing your foot drop, your doctor may recommend foot drop braces/splints (orthoses) and/or physical therapy. A foot drop brace keeps the ankle at 90 degrees to aid in keeping the toes from dragging while walking as well as to help keep the Achilles tendon from over-tightening. Specialized physical therapy for foot drop may include gait training as well as Achilles tendon stretching and muscle stimulation.
Are there surgical treatment options for my foot drop?
If the cause of your foot drop is due to compression on the peroneal nerve, an advanced surgical procedure can relieve the pressure on the nerve with the goal of restoring muscle function. The peroneal nerve is a branch of the sciatic nerve that travels from behind your knee around the fibula. After the common peroneal nerve passes the fibula, it travels through several potential areas where it is vulnerable to compression, prior to reaching the muscle it controls. Nerve compression is similar to standing on a garden hose that causes the water pressure to drop to a slow trickle or even stop altogether. In the case of nerve compression, the signal that is traveling along the nerve to muscle is decreased, resulting in muscle weakness/paralysis or foot drop. The tight areas of peroneal nerve compression may be released surgically through a small incision that allows the nerve to function properly and ultimately restore muscle function.
In certain instances, nerve transfers are used. A nerve transfer procedure involves taking donor nerves with less important roles and transferring them to restore a more crucial nerve functions. In the case of foot drop, this may involve transferring a nerve that supplies one of the muscles that push the foot down to a nerve that will restore lost function, allowing the muscles to now lift the foot up. As the transferred nerve must learn a new function, physical therapy is required to help retrain the mind to use this transferred nerve.
In cases where weakness is caused by compression of a nerve root inside the lumbar spine, a neurosurgeon or orthopedic spine surgeon can often perform surgery to open the spinal foramen (the space where the nerve exits the spine). The goals of these operations are typically to remove a herniated disk or open the foramen. In more complex or severe cases, a combination of these approaches may be necessary to fix the bones together, with or without a fusion, to avoid problems with movement.
Recovering After Foot Drop Surgery
The timing of recovery to restore function to alleviate foot drop is variable, depending on the procedure you had. For peroneal nerve decompression surgery, typically patients see small signs of recovery within 3-6 months. For nerve transfer surgery, it may take up to a year to see any signs of recovery. No matter which procedure was performed, continuation of your foot drop brace and physical therapy is important. It is also important to note that some patients will have persistent/permanent foot drop even with surgery and will require a tendon transfer or ankle fusion to place the foot in a more functional position.
To learn more about surgical and nonsurgical treatments for foot drop, and how our plastic surgeons can help you regain lost movement in your ankle, please contact our office today and schedule a consultation.