Case Studies In Cryosurgery For Heel Pain

Cryosurgery is an effective pain relief modality that uses freezing temperatures for ablation of the nerves that provide sensation to the heel. While this treatment is relatively new for foot pain, physicians have utilized cryosurgery for pain relief for decades. This modality has proven to be a viable treatment and is an excellent choice for appropriate patients prior to considering more invasive procedures.

Heel pain has become an epidemic in our society. Diabetes, arthritis, weight gain, injuries, previous heel surgery and other medical conditions are known contributing factors. There is also a psychosocial aspect that one must recognize when treating the heel pain patient. When people live with pain on a daily basis, they have difficulty performing simple daily activities. Some have difficulty sleeping or simply walking. This often leads to depression, weight gain and stress. The cycle continues, leading to further distress and life changes that are difficult.

In addition, patients are unable to remain off from their jobs for long periods of time and are often involved in jobs that require standing and walking. Additionally, active patients are eager to return to exercise and activities.

In many cases, physicians can help facilitate heel pain relief with conservative therapy options including: orthoses, physical therapy, strapping/padding, night splints, stretching, cortisone injections and antiinflammatory medications.

When Conservative Therapy Fails
When a patient with heel pain does not respond to conservative or surgical therapy, the physician must reevaluate the patient and look for other causes of pain. Unfortunately, physicians often do not explore a diagnosis beyond plantar fasciitis. When conservative therapy fails, physicians often proceed to a fasciotomy.

It would be beneficial for the clinician to consider other etiologies prior to surgery. Patients who get no relief from plantar fasciotomy have often been misdiagnosed.

In addition, poor surgical incision planning for plantar fasciotomy and endoscopic procedures will often lead to a neuroma of the medial and sometimes the lateral calcaneal nerve branches. These scenarios are often written off as a failed surgery without taking the time to diagnose other causes of pain.

Where Does Cryosurgery Fit Into The Armamentarium For Heel Pain?
Cryosurgery, while relatively new in the podiatric community, is by no means in its infancy or experimental. Pain management specialists typically use the procedure for peripheral nerve pain throughout the body.1 Cryosurgery is a procedure that involves freezing the abnormal sensory nerves to relieve pain. In my opinion, one should consider cryosurgery prior to other surgeries because it is minimally invasive, quick healing and provides superior results with fewer complications.

Podiatry has the unique opportunity to embrace this technology and improve techniques through more widespread use. We are the experts in heel pain relief and should move to the forefront whenever technology is present and available. While not all podiatrists need cryosurgical skills, the podiatric community should look to qualified colleagues who have these skills and maintain a referral relationship to help patients with recalcitrant heel pain.

Indications for cryosurgery include pain relief from heel pathology. Heel pain often is a result of mechanical foot problems in combination with injury to the medial and lateral calcaneal nerves. Another possible cause is nerve entrapment. This occurs with supination and compression of the lateral calcaneal nerve, a branch of the sural nerve. Painful heel neuroma formation from poorly planned incision sites and pain secondary to syndromes, such as cuboid syndrome following fasciotomy, are other possible indications for cryosurgery.

While there are many techniques physicians use to freeze the nerve, I have found that using a nerve stimulator, which precisely locates the nerve prior to freezing, facilitates a superior technique. Another method of locating the nerve is palpating the maximal area of tenderness for the freeze location. This approach has been successful in the hands of some practitioners. However, if more precise technology is available, using the available technology is a win-win scenario for the doctor and patient.

Key Pearls On Diagnosing The Patient
Before performing cryosurgery, a systematic approach to diagnosis and patient selection is essential. Patients that fail conservative therapy are generally considered good candidates for cryosurgery if they have any level of nerve involvement. This is even true for patients who may have other related symptoms including fasciitis. Cryosurgery will still be effective at relieving pain and allowing a successful rehabilitation period.

In order to make a diagnosis, one must be astute in regard to the anatomy of the foot and nerve locations. The initial visit with the patient can be time consuming. Once one suspects a nerve lesion or neuritis, palpation of the nerve will sometimes produce a positive Tinel’s sign with radiation of pain into the heel or proximally. Dellon noted there may be from one to four medial calcaneal nerves innervating the heel.7 Physicians can usually palpate the nerve along the medial aspect of the calcaneal tuberosity. The lateral calcaneal nerve occurs near the lateral tubercle of the heel and is a branch of the sural nerve. One can easily palpate this nerve superficial to the bone.

In regard to diagnosis, it is important to use a small amount of anesthetic precisely at the point of pathology. Dropping less than 1 cc of anesthetic at the most tender area or typical anatomic site of the medial calcaneal nerve will result in significant pain relief within minutes. The patient will stand and give feedback regarding the relief. This can be quite dramatic with patients communicating that they have not had this kind of relief in years. Indiscriminate use of larger amounts of anesthetic will often result in a poor diagnosis and poor results. After confirming the pathologic area, one can consider the patient a candidate for cryosurgery, assuming there are no other contraindications. Contraindications to the procedure may include patients with vascular disease, Raynaud’s disease, heavy tobacco users or those on anticoagulants.

A Guide To Treatment And Post-Op Expectations
The procedure is minimally invasive and takes 15 to 30 minutes. During a typical in-office procedure, one would raise a local anesthetic wheal in order to introduce the cryoprobe without discomfort. Insert the probe through a small stab incision that requires no sutures. Use the neurostimulator function to locate the nerve, using feedback from the patient. Then one would initiate the freeze cycles to produce an anesthetic effect and give long-term pain relief.

I have found that two or three two-minute freezes with 20-second defrost intervals to be the most effective regimen. Following the freeze cycles, if you stimulate the nerve again, it should no longer be responsive. However, in my experience, it is wise to move the probe carefully to other locations to attempt localization of additional nerve branches.

Cryosurgery has advantages over alcohol injections, radiofrequency neuroablation and neurectomy due to the fact that stump neuromas do not form when one performs neuroablation with appropriate freeze times.

Patients may perform most of their regular tasks immediately. However, advise patients to decrease their normal level of activity over the first 48 hours. Postoperative discomfort is minimal. Use a local anesthetic and corticosteroid injection postoperatively for pain and inflammation control in the surrounding tissues.

A Guide To Common Clinical Scenarios Of Common Heel Pain
Having performed approximately 600 cryosurgery procedures, I have found two common scenarios in which patients benefit from cryosurgery. There is the patient with plantar fascial pain and associated medial calcaneal nerve entrapment and, less frequently, lateral calcaneal nerve entrapment. If patients can obtain pain relief through cryosurgery techniques, they will easily tolerate rehabilitation of the fascia with conservative therapy while they are being treated for the nerve pathology.

The second scenario is a patient who is misdiagnosed with fasciitis when, in reality, he or she has nerve entrapment or damage.
A less common scenario is a heel neuroma secondary to a surgical procedure for fascial release. The neuromas are the result of poor surgical planning or poor knowledge of the anatomy. Another clinical scenario may involve cuboid syndrome that causes chronic pain due to excessive fascial release. One can accomplish pain relief with the freezing of branches of the sural and/or superficial peroneal nerves.

Pertinent Pearls To Consider With Cryosurgery
Some physicians make a practice of freezing the fascia. While cryosurgery rarely results in complications, I believe that freezing the fascia is not an appropriate treatment for fasciitis. Indiscriminate freezing of the fascia can result in weakening of the fascia and often leads to pain in other areas of the heel due to this trauma. Freezing, as noted in the literature, is associated with death and destruction of tissue.

Physicians often use cryosurgery for the destruction of soft tissue tumors. However, one should bear in mind that this technique can injure the lateral plantar nerve. The lateral plantar nerve supplies motor function to many of the intrinsic muscles of the foot. Indiscriminate freezing may lead to foot weakness and the development of foot deformities. If the lateral plantar nerve does have a true entrapment, then a surgical release may be indicated to preserve motor function to the musculature.8,9 For true plantar fasciitis, the patient would be better served with prolotherapy, which ultimately will strengthen the fascia and decrease symptoms.10

I have also found that freezing of localized points of tenderness and pain in the heel is not the best use of cryosurgery. Besides indiscriminate damage to tissues, the nerve causing the painful stimulus should be located proximal to the painful site to ablate all branches of the nerve leading to the area. In my experience, this technique has proven to provide greater success and relief.

In the following cases, all patients received a diagnostic injection with less than 1 cc of lidocaine and signed a cryosurgery consent during a prior visit. I performed cryosurgery using a nerve stimulator and ultrasound guidance. Following surgery, all patients had physical therapy to strengthen intrinsic and extrinsic musculature. Most continued or were fitted with custom orthoses to address the underlying mechanical problems that led to their pathology and pain. All patients were able to return to regular activities within one week.

Case Study: When Longstanding Heel Pain Becomes Progressively Worse
A 60-year-old female presented with left heel pain. She reported having the pain for 15 years but noted that it had become more progressive over the last year. The pain was burning and radiating in nature, and the patient rated the pain as between 7 to 9 out of 10 on a pain intensity scale.

Three podiatrists diagnosed her with plantar fasciitis. They prescribed her multiple orthotic devices (which caused increased medial pain regardless of the material), injections, antiinflammatory medications, ice and stretching, which provided little to no relief. The patient had to stop all of her activities, which resulted in significant weight gain. She had pain with activity as well as intermittent morning pain.

The patient’s review of systems (ROS) was unremarkable. The patient’s past medical history was remarkable for controlled hypertension, osteoarthritis and deep vein thrombosis (DVT), which was diagnosed in 1992. Her vascular exam was normal. Fluoroscan showed large bony spurs bilaterally. There was mild pain along the medial fascia with no tarsal tunnel pain. The gait analysis revealed calcaneal eversion with forefoot abduction.

There was a positive Tinel’s sign with palpation of the medial calcaneal nerve branch at the medial heel. Following injection, the patient had relief from her pain of about 80 percent.

We diagnosed medial calcaneal neuritis with fasciitis, and confirmed this with a diagnostic injection of 0.8 cc of lidocaine. The patient underwent cryosurgery of the medial calcaneal nerve and had significant pain relief. This allowed her to obtain long-term relief of her fasciitis following physical therapy and weight loss. She was also better able to tolerate orthoses. Multiple follow-up visits confirmed long-term pain relief.

Case Study: When A Patient Fails To Achieve Pain Relief After Surgery
A 56-year-old female presented with severe sharp aching pain of one year’s duration. She rated the pain as 7 out of 10 on a pain intensity scale in the heel, arch and ankle of the left foot. She had undergone a fasciotomy with no relief and was experiencing “new pain.” The pain radiated from the heel to the foot in the arch region and into the ankle.

The ROS was unremarkable. Her past medical history was remarkable for hypertension, ankle pain, foot cramps, ingrown toenails and swollen ankles. She had a normal neurovascular exam. She had mild pronation bilaterally.

A fluoroscan exam showed a heel spur, degenerative changes of the left first metatarsophalangeal joint and a dorsal talar exostosis. I noted a surgical incision at the medial aspect of the left foot, which was from a previous fascial release surgery. Palpation of the incision caused significant throbbing pain. There was a positive Tinel’s sign of the medial calcaneal nerve branch, which was entrapped within a surgical scar with likely neuroma formation.

Injection of the area with anesthetic provided this patient with significant relief. We diagnosed medial calcaneal neuritis with stump neuroma and nerve entrapment. We confirmed this with a diagnostic injection of 0.8 cc of lidocaine. Keep in mind that physicians could have easily mistaken this for tarsal tunnel syndrome.

The patient underwent cryosurgery of the medial calcaneal nerve and had complete resolution of her symptoms. I performed the procedure proximal to the neuroma site. Multiple follow-up visits confirmed long-term relief and she was able to return to exercise.

Case Study: When A Patient Has Pain, Numbness And Swelling
A 43-year-old female presented with left foot pain, numbness, swelling and a “pins and needles” sensation. She reported that her pain was worse with activity but she had no morning pain. The patient had pain for the past two years, had multiple steroid and alcohol injections, as well as physical therapy with no relief. Her previous physicians ordered a nerve conduction study, which showed an L5 nerve entrapment.

The previous physicians started her on pregabalin (Lyrica, Pfizer), diazepam (Valium) and a Lidoderm Patch (Endo Pharmaceuticals) with temporary relief. She had a subsequent diagnosis of tarsal tunnel syndrome.

The ROS was unremarkable and she had a normal neurovascular exam. Her past medical history was significant for low blood pressure, sinus problems and “weight loss from constant pain.” She had multiple drug allergies.

There was pain with palpation of the medial heel area with mild fasciitis. The patient had an abnormal gait pattern with increased pressure on the lateral left heel. Tarsal tunnel compression was asymptomatic. There was a positive Tinel’s sign at the more proximal branch of the medial calcaneal nerve. The patient had radiating pain from just distal to the tarsal tunnel into the bottom of the heel.
Following a block using a minute amount of lidocaine, the patient experienced resolution of her pain. She was able to apply full pressure to the bottom of her foot. We diagnosed heel pain secondary to medial calcaneal neuritis and confirmed this with a diagnostic injection of 0.8 cc of lidocaine. The patient underwent cryosurgery of the medial calcaneal nerve and had complete resolution of her symptoms. Multiple follow-up visits confirmed long-term relief and a return to exercise.

Case Study: When A Patient Has Lateral Heel Pain After A Fascial Release
A 72-year-old female presented with left heel pain. She had pain on the lateral side of the heel for about 2.5 years. Prior to that, she had a fascial band release that resolved most of her medial pain. The lateral pain developed within a few months of the fascial release. She described the pain as “generalized with intermittent burning and pulling pain.” She used narcotics for relief. Other conservative measures had failed.

The ROS was normal. Her past medical history was significant for arthritis, back problems, chest pain, vein problems, ear problems, eye problems, foot/leg cramps, headaches, heart disease, high blood pressure, rheumatic fever, shortness of breath, sinus problems and ulcers.

The exam revealed palpable pulses, bilateral lower extremity edema, varicosities and a normal Semmes-Weinstein monofilament test. She had pain along the lateral foot extending from the lateral malleolus. The cuboid area was tender. I was able to elicit a Tinel’s sign of the sural nerve. The patient had a semi-rigid cavus foot structure with contracted digits. There were mild degenerative changes on the X-ray. There was no heel spur.

We diagnosed cuboid syndrome with sural nerve involvement. We confirmed this with a diagnostic injection of 0.8 cc of lidocaine. The patient underwent cryosurgery of the sural nerve at the lateral malleolar area and had resolution of her major pain. She did have some residual aching that resolved with orthoses and physical therapy. Multiple follow-up visits confirmed long-term pain relief.

In Conclusion
Cryosurgery adds another valuable treatment option for heel pain relief and one should utilize it, when appropriate, prior to more invasive surgery. The procedure is cost effective and provides the patient with minimal downtime as well as a low complication rate. I encourage our profession to embrace this technology, either by performing these procedures or referring to colleagues when other options have not provided the patient with relief.

Editor’s note: For a related article, see “Chronic Plantar Fasciitis: Is Cryosurgery The Answer?” in the May 2005 issue.
 

References:

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