Endoscopic plantar fasciotomy vs. open release: Which is better?

Foot and ankle surgeons discuss the benefits of both treatment approaches in caring for patients with plantar fasciitis in part two of this round table.

Plantar fasciitis is the most common musculoskeletal problem of the adult foot. In most cases it is a repetitive tension stress injury of the broad tendon-like tissue in the arch of the foot, the plantar fascia.

The plantar fascia extends from the attachment at the calcaneal tuberosity, where most symptoms occur, to the base of the toes. As the toes are extended in walking, there is a passive stress on the plantar fascia. Active tension stress on the plantar fascia also occurs during walking. Some of the small muscles in the arch of the foot originate, in part, on the plantar fascia, giving rise to active forces. Heel pain may be caused occasionally by the compression of a small nerve that courses deep to the abductor hallucis fascia.

Plantar fasciitis is most common in middle-aged people, particularly those who are obese, as well as in runners of all ages. It is also a growing issue among work injury claims.

The most familiar symptom is pain under the heel, which typically occurs when a patient takes the first steps in the morning. Characteristic examination findings are pain when walking on the heels and tenderness medially under the heel just anterior to the calcaneal tuberosity.

Radiographs show a heel spur on the anterior edge of the plantar surface of the calcaneal tuberosity in about 50% of patients with symptoms. Orthopedists sometimes prescribe bone scintography and MRI studies to clarify the diagnosis.

Nonoperative care is usually successful, though it may require six or more months of treatment before the patient experiences relief. Though there are some foot and ankle specialists who claim they never operate for plantar fasciitis, some cases are refractory to conservative treatment. For those patients, shock wave therapy, endoscopic plantar fascia release and open plantar fasciotomy are options.

In this special round table, our panel of foot and ankle orthopedic specialists — all of whom have published on various aspects of plantar fasciitis — share current perspectives on treating the condition.

Ronald W. Smith, MD
Moderator

Moderator Ronald W. Smith, MD Director, Balance Orthopaedic Foot and Ankle Center, Long Beach, California; member of the Foot & Ankle Section of the Orthopedics Today Editorial Advisory Board Participants Richard G. Alvarez, MD Director, Southern Orthopedic Foot & Ankle Center, Chattanooga, Tennessee Glenn B. Pfeffer, MD Immediate Past President, American Orthopaedic Foot & Ankle Society; Board of Directors, American Academy of Orthopaedic Surgeons; Orthopedic surgeon, California Pacific Medical Center, San Francisco, California

Ronald W. Smith, MD: Dr. Pfeffer, though you have lectured on the operative treatment of plantar fasciitis, you have had a particular interest in studying nonoperative treatment methods and have addressed workers’ compensation issues. I would like to ask you questions that deal in part with those perspectives.

It has been said that plantar fasciitis is the most common foot problem among adults in general and also for workers’ compensation injuries. To what extent is this true in your experience, and is there data to put the magnitude of this problem in perspective?

Glenn B. Pfeffer, MD: The exact number of cases of proximal plantar fasciitis (PPF) is difficult to determine. There are estimates that between 4 and 8 million Americans are affected by PPF each year. The national databanks lump these cases into less-specific ICD-9 codes and do not keep specific track of the diagnosis of PPF. Approximately 4% of all running injuries relate to PPF.

There is no question that PPF is one of the most common nontraumatic injuries treated among workers who have foot and ankle complaints. We know that approximately 10% of work injuries are related to the foot and ankle, but there is no data I know of that specifically states the number of cases of PPF.

However, there has been a definite increase in the number of workers’ compensation cases related to PPF in California in the last five years. The cause is most likely an increased awareness among workers that PPF may be considered an occupational injury. If more cases are submitted as work-related injuries, there will clearly be an increasing number of patients who visit the doctor’s office and ultimately experience disability.

Smith: In your experience and in the data you have reviewed, what are the indicators in a patient’s history that suggest that plantar fasciitis is a work injury?

Pfeffer: The exact cause of PPF remains unknown; however, all indications are that it is a cumulative trauma type of disorder, similar to lateral epicondylitis of the elbow. In fact, in the past, PPF has been referred to as “tennis heel,” stressing the similarity between those two conditions.

There have been several recent excellent studies by Riddle, which demonstrate that obese patients and patients who are on their feet for the majority of the workday are at risk for developing PPF.

For the FDA heel pain syndrome study, patients were treated with shock waves on an outpatient basis. COURTESY OF HEALTHTRONICS

When I take a patient’s history to determine whether or not this condition should be considered work-related, I specifically consider the patient’s weight, the amount of weight that the patient has to carry during the workday and the amount of time that the patient is on his or her feet. The type of work shoes and walking surface are also critical factors.

If obesity predisposes a patient to PPF, then certainly a normal-weight person who is required to carry extra weight during the workday will also be predisposed to this condition. The number of patients with PPF that have an acute onset of pain at work, consistent with rupture of the plantar fascia, is very small. In a survey I performed of 695 orthopedic surgeons across the country, 77% of them consider PPF to be a work injury in a person who is on his feet for six or more hours in an eight-hour workday.

Of course, there are factors such as limited dorsiflexion and obesity that predispose a person to plantar fasciitis but are not related to specific work conditions. Riddle and colleagues showed that people with ankle dorsiflexion limited to less than 0º were at significantly greater odds of having plantar fasciitis than people with greater than 10º of dorsiflexion. They also showed significantly greater odds of having plantar fasciitis when having a body mass index of 30 kg/m² vs. a normal body mass index. An example of a 30 kg/m² body mass index is a person who is 5’5” and weighs 180 lbs.

Smith: What type of workers are most impacted by plantar fasciitis? Is prolonged standing more of a factor than prolonged walking? And does the type of floor surface play a role?

Pfeffer: There does not seem to be a clear difference between prolonged standing vs. walking, although patients who stand for a prolonged period of time may be at some benefit because they are able to stand on a cushioned mat. Retail checkers are a good example of patients who stand who are able to use a mat.

The weight carried by people because of their increased body mass index or the tools required for their trade, along with shoewear and walking surfaces, are key. In new military recruits, 9% of the foot and ankle injuries are PPF. We know from the literature that comfortable cushioned shoes decrease foot and ankle problems in the military. The same applies in an occupational setting.

Smith: How useful are bone scans, MRI, ultrasound and/or electrodiagnostic tests in confirming a diagnosis of plantar fasciitis? Also, what are the best criteria for going beyond nonoperative care and deciding on surgical treatment (ie, more than one year of symptoms, localized tenderness, positive bone scan or MRI)?

Pfeffer: PPF is a clinical diagnosis. A lateral radiograph of the heel is often important to include other problems such as the rare stress fracture of the calcaneus or tumor. An MRI can have a very important role in a contested workers’ comp case. In patients who have had more than six months of PPF, the MRI will always show significant thickening of the medial band of the plantar fascia. The normal thickness of this band is approximately 2 mm to 3 mm while in patients with PPF it is usually double that. If a person complains of significant PPF that impacts his or her work, and yet has a normal MRI, the diagnosis should be seriously questioned.

Ninety percent of patients with PPF resolve with a conservative program of stretching, night splints, heel cups and/or orthotics, use of cortisone injections, shoe modification and/or temporary work modification. If, after six months, the patient’s activity is impacted by his symptoms, I suggest operative care. The literature suggests that patients who have had symptoms for more than one year do not do as well with surgical intervention as those who are operated upon in the six-month to one-year window of symptoms.

Smith: What is your preference of treatment when recommending more than nonoperative care: shock therapy, endoscopic release or open release?

Pfeffer: For an injured worker who has had PPF for more than six months and finds that it impacts his work, I recommend endoscopic release of the plantar fascia. The morbidity from a partial release of fascia (endoscopically) is very low in experienced hands. I have an 85% success rate in patients who had PPF in one foot.

Patients with bilateral PPF do not do as well, however. An open release of the plantar fascia has a long recovery and I would prefer to see an endoscopic release. There is less than a 1% chance of making a person worse with an endoscopic release. At the very least, his case can be brought to a close within two months of the surgery.

I prefer not to use shock wave therapy in workers’ compensation cases. The variable results with that treatment in injured workers has led me to endoscopic release as the treatment of choice.

Smith: Using the American Medical Association (AMA) guidelines, what would you say is the “ideal” impairment of a lower extremity in which there is objective evidence of plantar fasciitis, such as a positive bone scan and localized tenderness, but no calf atrophy or loss of range of motion?

Pfeffer: One of the limitations of the AMA guides is that pain is usually not a major factor in the impairment ratings. Plantar fasciitis can be quite disabling and yet have few objective findings. There is rarely calf atrophy or loss of range of motion, factors that are directly ratable. However, the AMA guides are what they are titled — guides.

The physician can give an impairment rating based on the physician’s assessment of the pain. For example, a case involving refractory plantar fasciitis may have a stated impairment of 5% of the lower extremity based on the estimate of the treating or evaluating physician. This would be comparable to ankle instability with mild radiographic laxity on stress radiographs.

Smith: From your study, what were the factors of greatest benefit in nonoperative care for plantar fasciitis?

Pfeffer: We studied 256 patients. They were prospectively randomized into four different groups of conservative care. The group with the greatest benefit performed plantar fascia stretching exercises and used a specific viscoelastic heel insert.

What we found interesting from that study was that patients who performed Achilles and plantar fascia stretching alone did better than patients who stretched and used a rigid orthotic. It makes sense that the use of a rigid plastic orthotic is not the best treatment for an inflamed heel.

Our study only dealt with the initial treatment of PPF for the first eight weeks and made no conclusions beyond the first eight weeks.

Smith: Dr. Alvarez, in addition to your extensive experience with the nonoperative care of plantar fasciitis, you have been one of the early researchers of shock wave treatment for plantar fascciitis. We would like to get more insight on this contemporary method of treatment.

There are at least two methods of shock therapy available for plantar fasciitis. Would you explain the difference and why you prefer one method over the other?

Richard G. Alvarez, MD: There are two types of shock wave-producing devices: high energy and low energy. Low-energy devices deliver smaller focus volumes with shallow penetration of the tissue. High-energy devices deliver a larger focus volume and penetrate the tissue deeper; thus more energy can be exchanged. Incidentally, the high-energy device can be used for osteogenesis. Multiple treatments are required of low-energy devices, whereas single treatments from high-energy devices usually suffice.

No low-energy devices are currently approved by the FDA for the treatment of plantar fasciitis.

An example of the high-energy device is the OssaTron [HealthTronics Surgical Services Inc.], approved for both proximal plantar fasciitis and tennis elbow. It is also the only device known to produce osteogenesis.

I prefer the OssaTron because it is FDA-approved for both tennis elbow and proximal plantar fasciitis and can produce osteogenesis. An added plus is that it usually requires one treatment. Finally, since its approval by the FDA, the OssaTron treatment protocols have not changed for each disease. The other two low-energy devices have changed their treatment protocols several times.

Smith: What are the most common complications following this treatment, and which complication should we be most concerned about?

Alvarez: During our FDA studies with the high-energy shock wave device (OssaTron), we encountered few complications, most of which were associated with numbness that may have been caused by the ankle and heel blocks. All resolved by the 12th week follow-up.

The low-energy devices also had few complications and most were associated with pain during treatment. Nothing permanent occurred with either device. Therefore, shock wave technology or orthotripsy has been proven to be safe, paralleling its sister, the lithotripter. Even better, few, if any patients were made worse.

Smith: What is the cost difference of the two main types of equipment?

Alvarez: The OssaTron and EPOS Ultra (Dornier MedTech) are comparable in device costs. The Sonocur device (Sonorex), being an in-office device, is approximately half the cost of the OssaTron or the EPOS Ultra. However, it only has application for tennis elbow. The OssaTron device is the device with approval for two applications: heel and elbow. Physicians have access to the OssaTron device at no cost to them though HealthTronics Surgical Services.

Smith: What is the average cost per case for the equipment/facility?

Alvarez: The average cost per case for the device, device staffing and facility costs for the procedure room, anesthesia supplies and supportive nursing services is around $2250.

Smith: What are the usual facility and equipment charges per case?

Alvarez: The average charge for the facility and device services is $4500.

Smith: What is the expected cost trend over the next five years? Will the price go down as we saw with computers?

Alvarez: As with any product, as utilization grows and additional applications are developed, the cost will decrease, as there are always economies in scale.

Smith: What improvements would be desirable in the equipment, if any? What about improvements in technique?

Alvarez: Physicians are always concerned about time. We started with a 2-hertz machine. A treatment with a 2-hertz machine takes about 30 minutes to perform. Now we have a 4-hertz machine, which takes half the time to perform the procedure. I can imagine an 8-hertz machine for the future.

Smith: When more than one treatment is necessary, how are the treatments spaced?

Alvarez: For the OssaTron, usually one treatment is necessary for PPF and tennis elbow. However, occasionally a second treatment is needed at 12 weeks for PPF and at eight weeks for tennis elbow.

For the Epos Ultra, three treatments spaced weekly for heel pain is recommended. For the Sonocur, six to eight treatments for tennis elbow spaced weekly is recommended.

Smith: What are the anesthesia requirements?

Alvarez: Because of the high energy and larger focus volume, anesthesia (short general or block) is required for treatment of tennis elbow and PPF using the OssaTron. For the Epos Ultra and Sonocur, technicians are allowed to turn down the amount of energy delivered to the tissue so the patient can tolerate the procedure.

Smith: How long does the postoperative pain last?

Alvarez: Using the OssaTron, the only significant pain that occurs is during the procedure. Patients receive a prescription for Darvocet N100. Rarely does the patient get the prescription filled. Post-treatment pain with the low-energy device Epos Ultra is similarly low.

Smith: In the postoperative course, when does the patient return to initial weight-bearing?

Alvarez: With post-treatment with shock wave devices (OssaTron and Epos Ultra), the patients return to full weight-bearing immediately in a soft sole shoe. This is the major advantage over the procedures requiring an incision.

Smith: When can they expect to be full weight-bearing, such as they would need for walking in a grocery store?

Alvarez: Activity post-high-energy shock wave treatment can begin immediately. Walking in a grocery store is OK in a running shoe or other supportive soft sole shoe. The amount of activity should be reduced by 50% for two to four weeks. This means that if the patient walks three miles a day pre-treatment, the walk is reduced treatment to 1½ miles/day for about one month. Running activities are managed similarly.

Smith: Are there patients who develop a recurrence after a period of six months or more?

Alvarez: Durability of high-energy shock wave treatment of PPF has been remarkable. Our FDA studies with one-year follow-ups show that recurrences in successfully treated cases are rare. Once it works, the incidence of recurrence is about 4% at one year. This is comparable to surgically treated patients.

Smith: What is the likelihood of improvement in recurrences?

Alvarez: Recurrences for proximal plantar fasciitis have not been a problem. This is similar to the recurrence rate of successful surgery whether it be endoscopic release or an open procedure. Out of the first two FDA studies I participated in, I can recall only one case of recurrence. She was five years post-treatment. Her recurrence was successfully treated in a viscoheel.

Smith: Are there factors of duration, thickness of the plantar fascia on MRI or bone scan, history of acute rupture, or calcification in the soft tissues of the proximal plantar fascia which influence selection of patients for shock treatment?

Alvarez: In our studies, the one factor that influenced outcome of high-energy shock wave treatment was duration of symptoms. Those patients who had heel pain for less than one year did better than those who had symptoms for more than one year. Our studies did not include MRIs or bone scans. We chose to order an MRI only for those patients who we felt might have a mass on clinical examination. We rarely order an MRI for a fascia tear.

Smith: Recently, there has been an emphasis on stretching not just the calf but the plantar fascia as well. Following endoscopic plantar fasciotomy, what is the role of stretching exercises in postoperative rehabilitation?

Alvarez: For our pre- and post-treatment orthotripsy, stretching is a very important part of our protocol. As a matter of fact, we are very aggressive. We ask patients to stretch for one minute 12 times a day everyday, not for 12 minutes once a day. We hope to get patients in the habit of stretching so that they do so until they are 98 years old.

To do this, we ask that they stretch when they are on the phone, going into a building, going to the bathroom, waiting on the elevator, getting out of their care, etc. One rarely sees a patient with proximal plantar fasciitis who has stretched-out heel cords.

In light of the 2003 article in the Journal of Bone and Joint Surgery by Dr. Judy Baumhauer’s group emphasizing the importance of stretching the plantar fascia and calf, we have added to our protocol a massage of the fascia with the toes manually pulled into dorsiflexion.

The round table continues next month with discussions on endoscopic plantar fasciotomy and open release as treatments for plantar fasciitis.

Part 1: [Endoscopic plantar fasciotomy vs. open release: Which is better?]