Surgery and ulcer healing in patients with equinus

Achilles tendon lengthening and gastrocnemius recession both increase ankle joint dorsiflexion and reduce plantar forefoot pressures in patients with diabetes and equinus deformity, but experts continue to debate which is best for managing forefoot ulcers and minimizing reulceration.

By Barbara Boughton

Although total contact casting is the gold standard for healing and preventing diabetic foot ulcers, practitioners have increasingly turned to surgery—specifically gastrocnemius recession and Achilles tendon lengthening—for more effective long-term management. Both Achilles tendon lengthening and gastrocnemius recession increase ankle joint dorsiflexion in patients with diabetes equinus deformity, and reduce plantar forefoot pressures. Although both these surgeries are effective, there continues to be debate over whether gastrocnemius recession or Achilles tendon lengthening is best for diabetic patients who have forefoot ulcers or a high risk for ulceration.

One of the first papers on these surgeries¹ compared Achilles tendon lengthening to total contact casting, and found the surgery was significantly more effective than casting at reducing recurrence of neuropathic ulceration on the plantar aspect of the forefoot. In a 2003 study by Mueller et al,¹ researchers at Washington University in St. Louis compared immobilization in a total contact cast alone with total contact casting combined with percutaneous Achilles tendon lengthening in 64 patients with neuropathic plantar forefoot ulcers.

They found 88% of ulcers healed in the total contact casting group after a mean of 41 days, while 100% of ulcers healed in the Achilles tendon lengthening group after a mean of 58 days. The group treated with Achilles tendon lengthening demonstrated greater dorsiflexion right after surgery and at seven months after the procedure compared with the total contact casting group. Compared with those who underwent total contact casting, patients in the Achilles tendon lengthening group also had a 75% lower risk for ulcer recurrence at seven months and a 52% lower risk at two years from baseline.

“Although total contact casting may be adequate to heal simple ulcers, it’s more likely that a patient will need a surgical approach as his or her diabetes progresses,” noted Paul J. Kim, DPM, director of research and associate professor in the Department of Plastic Surgery at Georgetown University Hospital in Washington, DC.

Often clinicians will try a total contact cast first to heal and off­load a diabetic forefoot ulcer, since it is a conservative measure without the risks of surgery, said John Steinberg, DPM, a professor in the Department of Plastic Surgery at Georgetown. Although total contact casting does have a high success rate for wound healing, there are two important problems with this modality, Steinberg noted. Although a cast may allow the ulcer to heal, it doesn’t address any underlying equinus deformity that may contribute to recurrent ulceration.

“It’s also hard for many patients to accept a nonremovable, bulky cast that they have to wear even while sleeping. Patients really dislike it,” Steinberg added.

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Photos illustrate intraoperative Achilles tendon lengthening procedure. Limited ankle dorsiflexion is evident prior to the procedure (far left) and significantly improved afterward (far right). (Photos provided by David Armstrong, DPM, MD, PhD.)

Literature reviews

More recent studies have also validated the effectiveness of surgical approaches to healing and preventing diabetic foot ulcers compared with total contact casting. In a review published in the Journal of Foot and Ankle Research in 2015, Australian researchers performed a meta-analysis of randomized controlled trials that assessed outcomes of Achilles tendon lengthening, gastrocnemius recession, and total contact casting in patients with diabetic ulcers on the forefoot or midfoot.² All Achilles tendon lengthening and gastrocnemius recession surgeries included in the meta-analysis were performed to address limited ankle joint dorsiflexion or equinus deformity.

The analysis of 11 studies (614 participants) indicated the time to ulcer healing and the rate of healed ulcers was similar among patients who had surgery and those who wore a total contact cast. But the rate of ulcer recurrence was significantly lower in those who had surgery—either Achilles tendon lengthening or gastrocnemius recession—than with total contact casting, the authors noted.

In the Australian study, researchers did not separate the results achieved with Achilles tendon lengthening versus gastrocnemius recession, but other studies have attempted to tease out the benefits and drawbacks of each of these surgeries. While Achilles tendon lengthening has long been the standard for alleviating equinus deformity, an increasing number of studies have begun to establish the benefits of gastrocnemius recession.

In 2015,³ researchers performed a systematic review of 18 studies on gastrocnemius recession, including five in which the procedure was the primary treatment for diabetic ulcers on the plantar midfoot and forefoot. With clinical enthusiasm for gastrocnemius recession increasing, the researchers aimed to find scientific support for this treatment, according to Christopher DiGiovanni, MD, a review author. They concluded there was growing evidence and scientific support for using isolated gastrocnemius recession as an effective treatment strategy for midfoot or forefoot ulcers, but noted more carefully controlled investigations were needed to define the true efficacy of the surgery.

“The evidence for gastrocnemius recession continues to mount, although the quality of the evidence is not as good as it should be,” said DiGiovanni, who is chief of the Division of Foot and Ankle Surgery at Massachusetts General Hospital in Boston and at Newton Wellesley Hospital.

Pros and cons

Gastrocnemius recession achieves a less powerful correction to ankle dorsiflexion than Achilles tendon lengthening, increasing ankle joint range of motion by up to 18° versus 30° or more with Achilles tendon lengthening, according to recent studies.^4,5 However, because the Achilles tendon has poor blood supply, lengthening of this tendon is also associated with a risk for rupture.⁵ It also has a higher incidence of wound complications than gastrocnemius recession due to the fragility and thinness of the skin over the tendon, according to Robert Santrock, MD, associate professor and chief of foot and ankle surgery at West Virginia University in Morgantown.

Achilles tendon lengthening surgery is also associated with a greater risk of overlengthening than gastrocnemius recession, and as a result, calcaneal gait can occur,² according to David Armstrong, DPM, MD, PhD, professor of surgery and director of the Southwestern Academic Limb Salvage Alliance at the University of Southern California in Los Angeles.

“Gastrocnemius recession has a lower risk for complications,⁶ but the amount of correction you get is also less,” Armstrong said.

Armstrong prefers to perform Achilles tendon lengthening procedures for equinus deformities in diabetic patients because he finds it is easier to achieve optimal results with this procedure than with gastrocnemius recession, he said. But gastrocnemius recession is currently more popular than Achilles tendon lengthening, partly due to the lower risk for complications with this surgery, according to Santrock.

In one of the largest studies on gastrocnemius recession, published in 2006,⁶ researchers retrospectively reviewed the morbidity associated with this surgery in 126 patients. Ten patients underwent isolated gastrocnemius recession, while the rest had the surgery with an additional foot and ankle procedure. Patients were followed for a mean of 19 months to assess postoperative complications. Postoperative complications developed in only 6% of patients; the most common were scar problems in four patients (4%) and nerve problems in three patients (2%). No patient had a limp or gait disturbance afterward, and none developed persistent decreases in muscle strength or calcaneal gait.

“The most prevalent complication with gastrocnemius recession is weakness, and there is less weakness after these surgeries than with an Achilles tendon lengthening,” said Monroe Laborde, MD, assistant professor of orthopedic surgery and director of the foot clinic and at Louisiana State University in New Orleans.

Gastroc-soleus recession

Laborde said he prefers to use a gastrocnemius-soleus recession in diabetic patients with equinus. This type of gastrocnemius recession also includes intramuscular lengthening of the soleus muscle.

“Gastroc-soleus recession provides additional lengthening compared to gastrocnemius recession alone, so it’s helpful when more correction is needed,” Laborde said. “But a gastrocnemius
recession alone will also cause less weakness afterward than a
gastrocnemius-soleus recession.”

Laborde has authored a number of studies on gastrocnemius-soleus recession,^7-9 and has found these surgeries result in effective outcomes but lower complication rates than Achilles tendon lengthening. Although transfer ulcers or heel ulcers are rare after all these surgeries, they can occur, as the surgeries redistribute plantar pressures from the forefoot to the heel. Yet there are fewer transfer ulcers after gastrocnemius recession than after Achilles tendon lengthening, Laborde said.

In a 2008 study of 16 patients with 19 ulcers, for instance, Laborde and fellow researchers found that 18 of 19 ulcers healed and three of 18 ulcers recurred after gastrocnemius-soleus recession. In addition to an amputation, the complications included one heel ulcer, two toe ulcers, and one toe dislocation at 45 months follow-up.^7,8 In a review of studies on gastrocnemius recession and Achilles tendon lengthening, published in 2010,⁷ however, Laborde and fellow researchers found Achilles tendon lengthening resulted in more complications than those gastrocnemius recession. In one paper published in 2004, for instance, Achilles tendon lengthening in 68 patients resulted in healing of 68 of 75 ulcers, but complications included two amputations, 11 heel ulcers, and seven Achilles tendon ruptures after one year of follow-up.⁹

Postoperative considerations

Recovery after a gastrocnemius recession is also quicker and less onerous than after an Achilles tendon lengthening procedures, according to clinicians interviewed by LER. Most patients who have gastrocnemius recession can bear weight in an orthopedic walking boot the same day as the surgery, can walk without a boot within four weeks, and can run at six to seven months after surgery, according to Laborde. After an Achilles tendon lengthening, however, the patient will spend at least four to six weeks in a cast or splint and then a walking boot.

The challenge with such a recovery is patient compliance, as patients who remove their brace or splint are at risk for an Achilles tendon rupture or tear.

“We aim to enhance patient compliance after an Achilles tendon lengthening procedure by doing a lot of education preoperatively,” Steinberg said.

Achilles tendon lengthening can now be performed as an open surgery or percutaneously. Lin, who does Achilles tendon lengthening surgeries primarily for equinus deformities, favors the percutaneous approach because he finds it a more controlled, reliable technique. Triple hemisectioning of the Achilles tendon through a percutaneous approach is a popular technique because it’s a relatively simple surgery and can provide 3° to 12° of increased ankle dorsiflexion for each centimeter of lengthening, according to Kim and other researchers.^10,11 However, an open Achilles tendon lengthening procedure does offer better visualization of the tendon during surgery.⁵

Most surgeons agree both Achilles tendon lengthening and gastrocnemius recession are fairly safe, even for patients with comorbidities. The standard for selecting the type of surgery is the Silfverskiöld test, which assesses ankle dorsiflexion range of motion. If there is limited dorsiflexion in the gastrocnemius muscle alone, then a gastrocnemius recession is the preferred surgery. However, if there is limited dorsiflexion in both the gastrocnemius and soleus muscles, then an Achilles tendon lengthening is the right procedure, according to DiGiovanni.

Yet, even this test is controversial. Some surgeons question whether it is truly useful in a diabetic population, and others find it more helpful to base their surgical decision on the amount of correction they hope to obtain.

“We do use the test, but we generally still perform the Achilles tendon lengthening in our highest-risk patients because we have found that we get a more durable correction with this surgery in either gastroc or gastroc-soleus equinus,” Armstrong said. “Sometimes the choice of surgery will come down to the individual surgeon’s preference.”

Physical therapy and orthoses

Both surgeries improve gait, but the associated offloading of the forefoot also can affect balance, according to Steinberg.

“Patients can have the sensation that they are falling forward,” Steinberg said, adding this is why physical therapy, including gait training, is important.

As well as working on exercises that improve gait, it’s crucial for physical therapy to provide stretching and tensioning of stretches in the muscles involved in the surgery, according to Clarke Browne, PT, DPT, athletic trainer and owner of BrownStone Physical Therapy in Macedon, NY.

“Since both Achilles tendon lengthening and gastrocnemius recession make the distance from the knee to the calcaneus longer, we want to apply significant stretches to the gastrocnemius and soleus so that the muscles do not contract again,” he added.

Yet there are challenges to physical therapy after both gastrocnemius recession and Achilles tendon lengthening, according to Browne. If the foot is still tender, it can be difficult for a patient to hook a towel or strap around the foot to stretch. Thus, physical therapists often prescribe gentle exercises that can be done while wearing diabetic footwear.

“We also lighten the intensity of exercise, but lengthen the duration,” Browne said.

The exercises used to recover from both surgeries include pulling up and contracting the tibialis anterior muscle. Standing calf stretches are also used. Patients are given range-of-motion exercises to aid their recovery, and are encouraged to ride stationary bikes with light tension, as long as they are wearing protective footwear, Browne said.

Orthotic devices can also aid patient recovery.

“An orthotic with the right amount of cushioning can help the diabetic foot feel comfortable after surgery and reduce pressure on the foot,” Browne said.

He often incorporates a heel lift into orthotic devices, so it is easier for patients to walk around and exercise.

“Once the calf muscles are sufficiently stretched out with physical therapy, we take the heel lift out,” he said.

Compression stockings

To prevent vascular problems and alleviate swelling after surgery, Browne also prescribes compression stockings for his patients who undergo Achilles tendon lengthening and gastrocnemius recession.

“Compression stockings can help with poor circulation, and by using them, wound healing after these surgeries can be hastened,” he said. “Both activity and compression stockings aid blood circulation, and compression stockings help move the blood toward the heart. As a result, compression stockings can prevent the blood from collecting in the lower leg.”

There are definite differences in recovery time and potential complications between gastrocnemius recession and Achilles tendon lengthening, and controversy about which procedure is associated with the best outcomes in which patients. But the literature strongly suggests these procedures often have benefits for diabetic patients with equinus who are at risk for ulceration.

“They can be tremendous procedures because they provide diabetic patients with the ability to have an active lifestyle that can be free of recurrent ulcers,” Steinberg said.

Barbara Boughton is a freelance writer based in the San Francisco Bay Area.

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