Approximately 21 million Americans suffer from Peripheral Neuropathy or damage to the peripheral nerves. There are over 100 causes for this condition, with Diabetes and chemotherapy being the most common previously incurable causes in the US. Twenty percent of all senior citizens experience Peripheral Neuropathy which is often of an unknown cause. Symptoms in the hands and feet range from constant, severe tooth ache-type pain, intermittent burning or tingling and sometimes complete numbness resulting in loss of balance. The implications on healthcare in the U.S. are profound, when considering the related chronic pain, chronic wounds, infections, amputations, fractures, and deformities that must be treated, all of which are largely a result of Peripheral Neuropathy.
The reason for these devastating effects is simply that historically there have been no successful treatment options for Peripheral Neuropathy. Therefore, patients were instructed to pay special attention to their feet, cleaning and inspecting them daily, to take pain killers, and to report immediately to their foot specialist when infections developed. However, recent advancements in the diagnosis and treatment of Peripheral Neuropathy are offering a new sense of hope for people afflicted with this condition. Dr. Kyle Kinmon, through his comprehensive approach to the diagnosis and treatment of Peripheral Neuropathy, is able to offer hopes of both restoring sensation and decreasing pain related to this previously untreatable condition.
Treatment for Peripheral Neuropathy is designed to relieve pain and to restore strength and sensation. Accomplishing these goals leads to a decrease in the need for pain medication, less deformities, ulcerations, infections, and amputations, as well as fewer injuries due to falls. At Orthopaedic Surgery Associates, Inc., Dr. Kinmon emphasizes an attempt to achieve these results without dependence on powerful drugs by employing non-surgical or surgical means. Unique to South Florida, Dr. Kinmon is able to offer both scientifically proven methods of treatment through our practice alone. Therefore, patients are provided the option to make an educated, non-biased decision on their preference of treatment modality based on their individual needs.
Dr. Kyle J. Kinmon of Orthopaedic Surgery Associates, Inc. has studied on several occasions with A. Lee Dellon, MD, a professor of neurological and plastic surgery at Johns Hopkins University in Baltimore and founder of the Institute for Peripheral Nerve Surgery. Dr. Dellon discovered that by decompressing nerves in the upper extremity for carpal tunnel syndrome he could restore strength and sensation to the hands. He then conducted research on peripheral nerves in mice which confirmed these original incidental findings (2). The theory confirmed in Dr. Dellon’s studies is that the underlying metabolic changes which occur in certain types of Peripheral Neuropathy lead to an increased susceptibility of the peripheral nerve to compression. This is based on research conducted in 1973 by Upton and McComas which confirmed that once a peripheral nerve is insulted, the remaining distal portion of the nerve becomes more vulnerable to compression. (3.). they termed this phenomenon the “Double Crush Syndrome”. The original insult may either consist of a direct compression at a proximal level, or some metabolic abnormality manifesting a systemic problem such as diabetes or drug toxicity.
In the case of Diabetic Peripheral Neuropathy, sorbitol, a breakdown product of glucose accumulates in the peripheral nerve. Water then enters the nerve in order to maintain an isotonic environment, resulting in actual swelling of the nerve. Therefore, in tight anatomical tunnels which do not expand in the healthy patient, and much less in patients whose tissues are glycosylated, the nerves are compressed. The result of this compression is a decrease in the rate of axoplasmic flow, the inability of the nerve to heal itself distally, demyelination of the axons, and therefore the symptoms of neuropathy. It was proven first in mice, and later in humans, that when these nerves are decompressed in time they will regenerate, thereby relieving the painful manifestations of nerve compression and restoring sensation.
Additional underlying causes of neuropathy also result in swelling of nerves and compression in these tight anatomical tunnels. An example of a common clinical presentation of this is Chemotherapy Induced Peripheral Neuropathy, often associated with drugs such as Cisplatin and Vincristine. Many former cancer patients who have been successfully treated with these drugs suffer from severe pain in the extremities. These drugs cause peripheral neuropathy through a mechanism similar to that of lead poisoning, whereby the tight junctions of the capillaries in the epineurium are loosened, allowing fluid to leak into the perineurial space, and the nerve to swell. Again, axoplasmic flow is affected distally and peripheral neuropathy is the result. As of today, the results of nerve decompression in post chemotherapy patients have yet to be published. However, personal correspondence with Dr. Dellon boasts a 100% success rate with these patients for relieving pain in 14 cases so far.
The operative procedures which were developed by Dr. Dellon, and personally instructed to Dr. Kinmon, include decompression of peripheral nerves at three sites in the lower extremity. The sites were identified in studies conducted on cadavers by tracing the courses of nerves which innervate the foot. The common peroneal nerve is released at the fibular tunnel, just below the outside of the knee. The deep peroneal nerve is decompressed on the top of the foot where it is trapped between the tendon of the extensor digitorum brevis and the lateral aspect of the first metatarsal. The posterior tibial, medial plantar, lateral plantar and medial calcaneal nerves are decompressed about the inside of the ankle in the region of the tarsal tunnel and distally through a single incision.
Intra-operatively, the nerves commonly demonstrate a visible indention at the sites of compression and the distal portions are noted to be thinner and unhealthy in appearance relative to the proximal portions. Immediately post-operatively in the recovery room, many patients are able to feel light touch in areas of their feet that were previously numb. Also many patients report an immediate decrease in burning, tingling, and pain. However, there are a number of patients who will experience an increase in pain as the nerves regenerate distally. If present, this pain will occur for a period of time relative to the amount of preoperative nerve damage, predictable based on the fact that nerves regenerate at a rate of 1 millimeter per day or roughly 1 inch per month. Published studies indicate that of the patients who underwent this surgery, 90% report a significant decrease in pain and 80% a restoration of sensation. Also, at 4 year follow up of 44 neuropathic patients who underwent unilateral nerve decompression of the lower extremity, 0% of the operated extremities had reulcerated, while 9 of the non-operated limb had. (Submitted for publication)
Peripheral Neuropathy is a common, previously incurable condition imparting devastating effects on many people worldwide. Although a percentage of these patients remain without a cure, recent advancements offer hope that they all may live a significantly more enjoyable life.
The physicians of Orthopaedic Surgery Associates, Inc. are the first in South Florida to offer this comprehensive specialized approach to the treatment of Lower Extremity Peripheral Neuropathy. Please contact our office to schedule an appointment.
Kyle J. Kinmon, MS,DPM,FACFAS
Foot and Ankle Surgery