When Patients With Diabetes Have Lower Extremity Nerve Entrapments
Although this procedure is fairly easy to perform, about 300 surgeons from all backgrounds are performing this “triple” decompression. It is strongly recommended that one should learn the procedure from someone trained at the Peripheral Nerve Institute at Union Memorial Hospital in Baltimore. The institute also offers an intense workshop with cadaver surgery and observation of live procedures.
Can The Procedure Have An Impact?
We see patients every day with various levels of neuropathy. In the past, we have been told it is a progressive disease that we can only treat by controlling the underlying cause and providing a battery of pain relievers (anticonvulsants, etc.).
No one disagrees on treating the underlying cause. However, with few exceptions, we have watched those patients go on a downward spiral. For 18 years now, I have been treating lower extremity complications in patients with diabetes and watch patients with neuropathy go from having a little numbness and tingling to developing ulcers, nasty infections, Charcot, amputations, etc. In 1999, there were 92,000 amputations directly linked to DPN in comparison to 54,000 in 1990.7 The cost alone of these complications is staggering. I wish I could go back and reevaluate those patients, and see how many had nerve entrapments that could have been treated before the problems became irreversible.
It is true there are not any very large, double-blinded studies on the surgical treatment of DPN. One interesting study in the Annals of Plastic Surgery in 2004 retrospectively looked at 50 patients who only underwent surgery on one limb. With an average follow up of 4.7 years, researchers found none of these limbs developed ulcers or were subject to amputations. The nonoperative limbs had 12 ulcers and three amputations, according to the study.8
Factors To Consider In Proper Patient Selection Or Referral
Prudent surgeons will weigh many factors when deciding which patients are suitable surgical candidates. I am certainly not advocating surgery for every patient with neuropathy. However, I do advocate looking for entrapments that may be present and responsible for a patient’s diabetic neuropathy.
Check for Tinel’s sign on the posterior tibial nerve and/or the common peroneal. Researchers have found that if there is a positive Tinel’s sign, there is a 93 percent chance of an excellent outcome with surgery. Without a positive Tinel’s sign, the odds drop to about 50 percent.9 Sensory testing is still the most reliable diagnostic procedure in comparison to nerve conduction velocity (NCV).10 Obtaining EMG and/or MRI might also be necessary to rule out a more proximal lesion.
All physicians work within their own personal comfort zones. We should all know what is available to our patients and be willing to refer patients if their care falls outside of our comfort zone. I think a great number of patients suffering from neuropathy would benefit from an evaluation and treatment for multiple compression problems.
Dr. Mowen runs a lower extremity neuropathy clinic in Ventnor, NJ. He is board certified in podiatric orthopedics and primary podiatric medicine. He is an Associate Member of the Academy of Ambulatory Foot Surgeons and a Member of the Fellowship of Peripheral Nerve Surgeons.