Clearing Up Misconceptions On Cryoneuroablation

      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       — Andrea Trescot, MD       President-Elect, American Society of Interventional Pain Physicians       Diplomate, American Board of Interventional Pain Physicians       Diplomate, American Board of Pain Medicine       Diplomate, American Academy of Pain Management       Fellow, Interventional Pain Practice References 1. Barrett SL. Should you change your approach to plantar fasciosis? Pod Today 19(11): 48-56, 2006. 2. Schneider RK, Mayhew IG and Clarke GL. Effects of cryotherapy on the palmar and plantar digital nerves in the horse. Am J Vet Res 46(1): 7-12, 1985. 3. Johannesen N, Madsen G, Ahlburg P. Neurological sequelae after cryoanalgesia for thorocotomy pain relief. Ann Chir Gynaecol 79:108-109, 1990. 4. Trescot AM. Cryoanalgesia. In: Boswell M (ed.): Weiner’s Pain Management: A Practical Guide For Clinicians, 7th edition. CRC Press, 2005.

Encouraging Debate On Plantar Fasciosis: Dr. Barrett Responds

      In response to several of the letters generated by my article (see “Should You Change Your Approach To Plantar Fasciosis?,” page 48, November 2006 and the “Letters” section, page 14-16, January issue), it seems to have generated some healthy academic debate, which it was partly intended to do. Healthy, professional academic debate should always be encouraged. In regard to those who wish to counter what is stated in the article with sound academic, peer-reviewed published scientific data, I encourage them to do so.       With this in mind, let me address several of the points that were raised in these letters.       In regard to whether I dismissed the fact that conservative care is very effective for the treatment of plantar fasiosis (fasciitis), there was no intent to dismiss the value of conservative care in this article. What I was dismissing was the notion that all plantar “fasciitis” cases are the same.       Without a better staging and grading system, and without accurate diagnostic modalities, long periods of conservative care are probably warranted solely on the basis that so many cases of heel pain syndrome have multiple etiologies that the patient is more likely to be harmed with an early, non-indicated intervention, whether it be extracorporeal shockwave therapy (ESWT), endoscopic plantar fasciotomy (EPF) or other types of treatment.       In regard to the general premise of this article, if we combine what we know in basic medical science with technologically better and objective diagnostic modalities, we should, as a profession, be able to treat heel pain more efficiently in a shorter period of time. This applies more to conservative modalities than interventional techniques. As illustrated in the article, there is no real consensus or outcome-based studies validating any specific method or concert of conservative care.       In regard to the assertion that using diagnostic ultrasound to diagnose plantar fasciitis is specious and is just being done for reimbursement purposes, I think it is specious for an expert in foot and ankle pathology to treat a person for lengthy periods of time with expensive conservative treatments for plantar fasciitis when, in fact, the patient does not have any objective findings of plantar fasciitis (fasciosis) or has multiple etiologies for his or her heel pain.       It is extremely well documented that there is a high prevalence of nerve entrapment in heel pain syndrome.1,2 With the use of diagnostic ultrasound (in less than 10 minutes) and at a cost much less than what is usually being billed for a night splint, one can objectively assess the patient’s plantar fascia and more likely craft a tailored treatment plan which truly addresses the etiology of the heel pain.       Accordingly, the treatment plan would be more efficient, not to mention cost-efficient. The value of diagnostic ultrasound is vastly superior to plain film radiography and MRI. It is also much less expensive and provides a baseline for future comparison after a period of conservative care, which is far better than the patient’s subjective response.       In regard to whether I dismissed complications of the EPF procedure, this article was not focused on any single interventional technique and there were simply two sentences dedicated to EPF. Endoscopic plantar fasciotomy is well established, and the complication rate has dropped now that we know how to manage the patients better postoperatively. Approximately 30,000 EPFs were performed in the United States last year.       When it comes to the assertion that Dr. Lemont’s histological work is “not germane” to the argument for treating plantar fasciitis, I disagree. Dr. Lemont’s work with plantar fascia is huge and needs to not only be lauded but integrated into more specific and effective treatment plans for cases of plantar fasciosis. His work correlates well with all the other research in basic medical science, which is being done in the study of tendonosis.3,4 It is also well documented that as soon as 21 days after tendon injury, there is a histological absence of inflammatory mediators.5 Very few patients with heel pain and a duration of symptoms of less than three weeks are seen clinically. We all know that NSAIDs work but this is not because of their antiinflammatory properties.       In regard to the question of indication for cryosurgery in the treatment of plantar fasciosis, Dr. Trescot makes the point that I was absolutely wrong about the possibility of neuroma formation after cryoneuroablation, which she states was due only to one abstract. The 1985 Schneider and Mayhew paper in the American Journal of Veterinary Research is a well-designed study. They included two groups in their study. One group of horses received general anesthesia and had their nerves visualized and directly frozen. The other group of horses had their nerves frozen percutaneously.       The group with open visualization developed 10 neuromas in continuity out of 28 nerves frozen. This was confirmed by histological examination. Interestingly, the group that had their nerves percutaneously frozen had only a 47.5 day average of sensory impairment compared to 156 days with the open group. This indicates a lesser degree of peripheral nerve injury in the percutaneous group.       Dr. Trescot is correct that neuroma formation is not possible if the myelin sheath is not disrupted. However, this depends solely on the level of freeze injury as it is documented that not only the myelin sheath but also the epineurium and perineurium can be destroyed by freezing with resulting neuroma in continuity formation.6 It is apparent from Dr. Trescot’s level of experience that her technique is such that she is most likely obtaining the desired conduction block (which still is a peripheral nerve injury), and not a neuroma in continuity as described above.       She is also correct in that indiscriminate freezing for the treatment of plantar fascia itself is “neither logical nor appropriate, and should be condemned.” This is especially true for two reasons. First, it is well documented that the neuroanatomy of the medial calcaneal nerve(s) is highly variable.7 Secondly, if there is only a disorder of the fascia, why would anyone want to take the chance of potentially harming the patient by injuring a peripheral nerve?       There is also the assertion that because the Schneider and Mayhew study was done in 1985 on “horses hooves,” it cannot be valid. The physiology of the peripheral nerve has not changed in the last 21 years. There is also the assertion that open visualization of the horses’ nerves prior to freezing could cause neuroma formation. If this were true, then every patient who undergoes a peripheral nerve decompression would develop neuromata.       In summary, too often clinicians attribute cases of complex heel pain to just being “plantar fasciitis” when, in fact, there is multiple etiology heel pain syndrome (MEHPS). Indeed, MEHPS is more prevalent than many practitioners believe and when there are more than two million patient visits per year in the U.S. because of heel pain, you know there are going to be many cases that are complex. Professionally, we need to constantly improve our understanding of heel pain, increasing our treatment efficacy and efficiency.       Finally, the use of cryotherapy to freeze the peripheral nerves for the treatment of plantar fasciosis is an egregious mistake. It is misguided, illogical and dangerous for the patient.       — Stephen L. Barrett, DPM, MBA       Associate Professor       Midwestern University College of Health Sciences       Arizona Podiatric Medicine Program References 1. Oztuna V, et al., Nerve entrapment in painful heel syndrome. Foot Ankle Int, 2002. 23(3): p. 208-11. 2. Rose, JD, Malay DS, and Sorrento DL. Neurosensory testing of the medial calcaneal and medial plantar nerves in patients with plantar heel pain. J Foot Ankle Surg, 2003. 42(4): p. 173-7. 3. Almekinders LC and Temple JD. Etiology, diagnosis, and treatment of tendonitis: an analysis of the literature. Med Sci Sports Exerc, 1998. 30(8): p. 1183-90. 4. Khan KM, et al. Time to abandon the “tendinitis” myth. BMJ, 2002. 324(7338): p. 626-7. 5. Ashe MC, McCauley T, and Khan KM. Tendinopathies in the upper extremity: a paradigm shift. J Hand Ther, 2004. 17(3): p. 329-34. 6. Davies E, et al. Cryosurgery for chronic injuries of the cutaneous nerve in the upper limb. Analysis of a new open technique. J Bone Joint Surg Br, 2000. 82(3): p. 413-5. 7. Dellon AL, Kim J, and Spaulding CM. Variations in the origin of the medial calcaneal nerve. J Am Podiatr Med Assoc, 2002. 92(2): p. 97-101.       Editor’s note: For related articles, see “Chronic Plantar Fasciitis: Is Cryosurgery The Answer?” in the May 2005 issue of Podiatry Today.

Taking Pride In The ‘P’ Word

      I just read the article by John McCord, DPM (see “Taking Pride In Being ‘Just A Podiatrist,’” page 81, December 2006 issue). I was impressed and glad to see the article in the journal.       I remember a story about my mentor, Gerard Yu, DPM, who once went to the AOFAS meeting in 2005. He went to this orthopedic meeting in Washington D.C. not to speak but to listen to the lectures in order to learn about the foot and ankle from the MDs (although it may be hard to picture him just sitting in the audience).       When he registered at the conference, Dr. Yu was given a badge which said “Gerard V. Yu, MD.” Without hesitation, he crossed out “MD” and put “DPM” after his name. Later, he jokingly said, “The registration was cheaper if you were a member of allied health.”       He was proud to be a podiatrist. Needless to say, the majority of his practice was surgical. However, Dr. Yu did not claim himself as a foot and ankle surgeon but always liked to use the “P” word. After being trained by him for three years, I noticed myself doing the same. I tell people that I am a podiatrist. If they do not know what podiatrists do, then I explain. He or she may not be lying by saying he or she is a foot and ankle surgeon. However, why not educate others on what podiatrists do? Why not spread the “P” word?       — Naohiro Shibuya, DPM

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