A Guide To Conservative Treatment Of Achilles Tendinopathy

Given the common nature of Achilles tendinopathy, these authors offer practical insights on conservative treatments for Achilles tendinopathy, including eccentric exercises, extracorporeal shockwave and injectable modalities.

Achilles tendinopathy is one of the most frequently encountered overuse injuries, especially in the athletic population, as this condition reportedly accounts for 5 to 18 percent of all running injuries.¹ Due to increasing interest in personal fitness, it is important for podiatrists to be knowledgeable on the diagnosis and treatment of Achilles tendinopathy.

To gain an understanding of the pathology, one should be familiar with the terminology and etiologies. The clinical presentation of pain, swelling and impaired function is what we refer to as Achilles tendinopathy.² We can use this term for acute and chronic forms. “Tendinopathy” is more appropriate than the term “tendonitis.” In a study involving 163 patients, Astrom and Rausing noted that histologic findings from the insertion of the tendon showed necrosis and mucoid degeneration rather than inflammatory infiltration.³

When determining the appropriate treatment algorithm for Achilles tendinopathy, you should determine whether the tendinopathy is insertional or non-insertional, and whether it is acute or chronic. No matter the type of tendinopathy, the major etiologies are typically similar with some exceptions and we can classify them as intrinsic or extrinsic. Intrinsic risk factors include increased age, increased or decreased gastrocnemius and soleus flexibility, decreased subtalar motion, increased pronation and decreased plantarflexor strength.¹ In the athlete, researchers have shown that excessive forefoot varus increases insertional complaints as well as paratenonitis.⁴ The cavus foot is reportedly associated with a higher incidence of insertional tendinopathy as authors have speculated that this foot type has poorer shock absorption and affects the lateral side of the tendon more due to lack of pronation in this foot structure.⁴

Although there are many etiologies, the prevailing theory is that decreased flexibility of the posterior muscle group is the greatest modifiable risk factor for Achilles tendinopathy. Rabin and colleagues showed the importance of ankle range of motion in their prospective study of 70 military personnel members.⁵ They concluded for every degree of increased non-weightbearing dorsiflexion, the odds of developing future Achilles tendonitis are reduced by 23 percent. For this reason, the equinus deformity tends to be the focal point of treatment.

Do Eccentric Exercises Make A Difference?
First-line conservative treatment for non-insertional Achilles tendinopathies should always consist of eccentric exercises. This type of exercise differs from concentric exercise in that it engages the muscle fibers as the muscle belly is lengthening. This is in contrast to concentric exercises in which the muscle belly is shortening. An example would be lifting a dumbbell during a bicep curl. In a prospective study involving 78 consecutive patients, Fahlstrom and colleagues demonstrated that during eccentric loading, the extreme range of motion that occurs acts on the specific source of the pathology.⁶

Patients should perform appropriate eccentric exercises by standing on the bottom step of a set of stairs. While holding on to the railing, they put their weight on the healthy limb and plantarflex the foot to elevate the body. When patients reach maximum plantarflexion, they should place the forefoot portion of the affected limb over the same step with the midfoot and heel hanging over the edge of the step. At this time, they switch their weight to the painful limb and slowly resist gravity as the heel drops below the step and the ankle joint reaches end range of motion. Patients should subsequently use the healthy limb to plantarflex back to the starting position and repeat the maneuver. If patients have an appropriate amount of balance, they can perform this exercise with the knee straight and bent. They should repeat this motion twice daily at 15 repetitions for a period of three months.

We know that eccentric exercise works well for non-insertional Achilles tendinopathy with success rates around 89 percent.⁶ However, a recent systematic review has shown that a successful outcome following eccentric loading exercise is less likely for insertional disorders with a success rate of only 32 percent.⁶ This exercise regimen, as described above, may cause the retrocalcaneal bursa to be compressed against the tendinopathic fibers of the anterior aspect of the Achilles tendon.⁷

In order to determine whether the effect of ankle dorsiflexion past 90 degrees during eccentric exercises was detrimental, Jonsson and coworkers modified the activities of 27 patients with painful Achilles tendons, eliminating the ankle dorsiflexion movement by using floor level exercises for 12 weeks so the ankle joint never went past neutral.⁷ With this program, they found improved outcomes in 67 percent of cases in comparison with 32 percent of cases in which patients with chronic (average of 26 months) insertional Achilles tendinopathy used the original eccentric exercises.

It is important to add pharmacologics, such as non-steroidal anti-inflammatory drugs (NSAIDs) or oral steroids, to the exercise regimen as well as cold therapy. For patients with chronic cases of insertional Achilles tendinopathy, NSAIDs provide anti-inflammatory as well as analgesic benefits.

What About Orthotics And Bracing?
Although there is limited research, one should consider semi-rigid orthotics for these patients. We know that orthotics can help prevent over-pronation. In these patients, orthotics can also theoretically prevent the heel from moving into a valgus position and subsequently prevent an oscillating force on the tendon as well as inhibit the shortening of the posterior muscle group to prevent contractures.

These patients can also benefit from a heel riser or immobilization. However, patients should avoid prolonged immobilization and a rational treatment plan following any immobilization should involve gradual integration of reduced load-bearing activities as well as a monitored physical therapy or stretching regimen.⁷ The period of rest required for treatment may increase with the duration of symptoms the patient has prior to beginning treatment.8 De Vos and colleagues showed the benefit of using a night splint in combination with eccentric exercises to reduce pain and improve functional outcome in patients with Achilles tendinopathy.⁹
Patients who have little improvement with the at-home conservative care regimen or those who want to have an adjunctive treatment should consider physical therapy.

What You Should Know About ESWT For Heel Pain
Extracorporeal shockwave therapy (ESWT) is a non-invasive treatment that involves the delivery of low-energy shockwaves to a specific site within the body. Shockwave started as a treatment in 1991 in urology to disintegrate kidney and ureteric stones, but this technique is currently in use for the treatment of tendinopathies throughout the body.¹⁰ Research has proven ESWT to be a reasonable adjunct to therapy when conservative treatment fails for Achilles tendinopathy. In a triple-arm, randomized, controlled trial involving a total of 75 patients, researchers compared eccentric loading, repetitive low-energy shockwave therapy and a wait and see policy in the treatment of midstance Achilles tendinopathy.^11,12 They found that eccentric loading and shockwave treatment yielded comparable results at 60 percent and 52 percent.

Rompe and colleagues also conducted a level 1 study involving patients with chronic insertional tendinopathy and comparing ESWT with typical eccentric exercise in which the ankle reaches maximum dorsiflexion.¹² In the study of 50 patients, they found superior results for ESWT at four weeks with 64 percent of the ESWT patients able to return to daily activities in comparison to 28 percent of the eccentric stretching group.

A Closer Look At Steroid, PRP And Amniotic Membrane Injections
The general consensus is that intratendinous steroid injections are contraindicated due to the risk of tendon rupture. These injections reportedly reduce pain and swelling, and improve the appearance of the tendon on ultrasound.13 There has been limited research dedicated to the efficacy of steroid injections for the Achilles tendon. For that reason, along with the inherent risk of rupture, we do not recommend these injections for Achilles tendinopathy. Some physicians advocate corticosteroid injections for patients who have symptoms of retrocalcaneal bursitis but the risk commonly outweighs the reward in the senior author’s experience.

Some minimally invasive treatments such as platelet rich plasma (PRP) and amniotic injections are proposed treatments for tendinopathies. Platelet-rich plasma is in wide use in various areas of orthopedics with some studies demonstrating improved tendon healing in comparison to controls. However, researchers have found no significant improvement in symptoms when using PRP for chronic Achilles tendinopathy.^14,15 A randomized, double-blind, placebo-controlled study evaluating eccentric exercises and PRP or saline injection in 54 patients with chronic Achilles tendinopathy showed no differences in improvement in pain and activity at a six-month follow-up.¹⁶

According to a recent meta-analysis, there may be benefits associated with using PRP to increase tendon healing strength during Achilles tendon repair of acute ruptures but the authors found no evidence of any benefit with the use of PRP in the treatment of chronic Achilles tendinopathy.¹⁷ Another study showed that two out of eight patients with insertional Achilles tendinopathy treated with PRP had dissatisfaction and went on to surgery.¹⁸

Amniotic membrane injections are a newer option of conservative treatment for a clinician’s treatment armamentarium. Current in vivo and in vitro studies show that the biochemical properties of amniotic membrane help reduce inflammation and enhance soft tissue healing. Amniotic membrane also has growth factors that stimulate epithelial cell migration and proliferation, protein and collagen synthesis, collagenase activity and chemotaxis of fibroblasts.¹⁹

In a feasibility study involving a total of 45 patients, the use of amniotic membrane injections for chronic, recalcitrant plantar fasciitis showed significant improvement of American Orthopedic Foot and Ankle (AOFAS) hindfoot scores in comparison to a control group.²⁰ In a small study of amniotic membrane injections in 23 patients with lower extremity tendinopathies, the authors found that 19 of the 23 patients experienced an increase in activity and function with a reduction in pain.²¹ More studies need to examine the outcomes with amniotic membrane injections and answer the question of whether these outcomes outweigh the potential costs.

In Conclusion
Non-insertional tendinopathy is more common than insertional tendinopathy and responds much better to conservative care. For those with chronic insertional tendinopathy, conservative care has poor efficacy, especially if the patients have signs of Haglund’s deformity or an enthesopathy compounded by intramural degeneration and thickening of the Achilles tendon visible on advanced imaging. For these patients, surgery may be inevitable.

Dr. DeHeer is a Fellow of the American College of Foot and Ankle Surgeons, and a Diplomate of the American Board of Podiatric Surgery. He is also a team podiatrist for the Indiana Pacers and the Indiana Fever. Dr. DeHeer is in private practice with various offices in Indianapolis and is the founder of Step by Step Haiti. Dr. DeHeer writes a monthly blog for Podiatry Today. One can access his blog at www.podiatrytoday.com/blogs/deheerblog/feed .

Dr. Wavrunek is a first-year resident at Community Westview Hospital in Indianapolis.

Dr. Hamilton is a first-year resident at Community Westview Hospital in Indianapolis.

References

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15.     De Vos RJ, Weir A, Tol JL, et al. No effects of PRP on ultrasonographic tendon structure and neovascularisation in chronic midportion Achilles tendinopathy. Br J Sports Med. 2011;45(5):387–392.
16.     De Vos RJ, Weir A, van Schie HT, et al. Platelet-rich plasma injection for chronic Achilles tendinopathy: a randomized controlled trial. J Am Med Assoc. 2010;303(2):144–149.
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For further reading, see “Current Concepts In Treating Achilles Tendinopathy” in the November 2014 issue of Podiatry Today, “Achilles Tendinopathy: What Are The Best Treatment Options?” in the October 2006 issue or “Are Custom Orthoses Beneficial For Achilles Tendinopathy?” in the January 2015 issue.