Clearing Up Misconceptions On Cryoneuroablation
- Volume 20 - Issue 2 - February 2007
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I read with interest the discussion of heel pain authored by Stephen Barrett, DPM (see “Should You Change Your Approach To Plantar Fasciosis?,” page 48, November 2006 issue). As a pain management physician who has treated podiatry failures for the last 15 years, I cannot agree more with his assessment of the misdiagnosis of “plantar fasciitis.”
I also find it interesting that he confirms the etiology (and, by extension, the appropriate treatment) of a heel tendonosis. Regenerative injection therapy, known in the past as prolotherapy, makes perfect physiologic sense as it creates a directed inflammatory response to stimulate the proliferation of fibroblasts. Radiofrequency lesioning, by creating a thermal inflammatory response, may accomplish the same result.
However, I strongly disagree with his dismissal of cryotherapy. Pronation of the foot leads to trauma and secondary entrapment of the medial calcaneal nerve. This leads to heel pain that is misdiagnosed as “plantar fasciitis.” With the proper diagnosis of medial calcaneal neuralgia, cryoneuroablation is a rational and effective treatment. It facilitates rehabilitation by providing a long period of pain relief as the patient is reeducated with gait and orthotic manipulations. The probe contains a nerve stimulator, which allows for extremely precise localization of the nerve, and gives instant (within 30 seconds) relief that lasts for several months. I have personally followed these patients for more than 10 years and have seen the gratifying results.
Dr. Barrett is absolutely wrong regarding the possibility of neuroma formation after cryoneuroablation. He stated “it is well documented that freezing peripheral nerves can result in neuromas in continuity, a serious nerve injury, instead of the desired conduction block.”1
Dr. Barrett apparently based his conclusion on a single abstract describing open versus percutaneous cryoneuroablation on horse hoof nerves.2 This abstract does not discuss the specific technique used but most likely reflects a procedure that must have been done under a general anesthetic since the horses would have not likely been
cooperative. Therefore, the patient feedback necessary for accurate placement was not available and likely necessitated multiple blind passes of the cryoprobe to increase the likelihood of contact with the nerve.
The abstract describes open exposure of the nerve as well to perform the cryoneuroablation under direct vision. It is well known that open exposure of nerves result in subsequent neuroma formation. All the horses were killed and the nerves were examined. Ten of 28 nerves were noted to have “neuromas-in-continuity” but no distinction was made comparing the results of percutaneous and open cryoneuroablation.2
Extensive review of the world’s literature on cryoneuroablation for the last 30 years revealed only one reported case of neuritis/neuroma in humans and that occurred after an intercostal nerve neurolysis.3 In fact, the beauty of cryoneuroabalation is that it destroys the nerve but leaves the myelin sheath intact, allowing the nerve to re-grow along its normal pathway. Accordingly, this would not cause neuromas.
Perhaps Dr. Barett’s concerns are for the newer application of cryoneuroablation in the treatment of the plantar fascia itself. A group of podiatrists, using a new probe that does not contain a stimulator, have been indiscrimately freezing heel tissue. This technique clearly is neither logical nor appropriate, and should be condemned.
With the correction of the misinformation regarding cryoneuroablation (and I would refer the reader to my textbook chapter on the technique), I would commend Dr. Barrett on his courage to debunk the myths regarding the treatment of “plantar fasciitis.”4