Achilles tendinopathy: An overuse injury
Achilles tendinopathy (AT) is typically an overuse injury incurred by athletes, although it is sometimes seen in patients who are sedentary and overweight. With a prevalence among runners of approximately 11%, AT is sometimes called the “runners’ disease.”4
Tendinopathy is a more accurate description than tendonitis, as histologic studies of affected Achilles tendons suggest that AT is a degenerative, rather than an inflammatory, condition.38 A diagnosis of AT can be further classified as midportion or insertional.
Midportion Achilles tendinopathy (MAT), characterized by pain that occurs in the body of the Achilles tendon and worsens with activity, is often a clinical diagnosis. Physical findings suggestive of MAT are tenderness to palpation of the midportion of the Achilles tendon, with thickening of the tendon, warmth, crepitus, or palpable nodules in the tendon body. Onset is insidious and is commonly associated with an increase in activity.
Treatment: Orthotics or a heel lift. Like that of plantar fasciitis, treatment of midportion Achilles tendinopathy is primarily conservative. The use of orthotics, or a heel lift, is one of the most cost-effective interventions, and they are widely used, despite limited evidence of efficacy.39 Custom orthotics are costly, and patients often benefit from trying prefabricated orthotics first to determine whether they will help.
Eccentric exercises. One of the most studied interventions for MAT is eccentric exercise training. Studies of eccentric exercises have been very favorable, and the exercises can be taught during routine PT sessions.19-22 Modalities such as ultrasound therapy and extracorporeal shock wave therapy (ESWT) have also been studied. But because results have been inconsistent, they are generally reserved for treatment-refractory cases.23
In patients with no contraindications, NSAIDs may be a good choice for pain management with relatively favorable results in the literature.24 Corticosteroid injections should not be used, as they have been directly linked to rupture of the Achilles tendon.23
Other interventions, such as plasma-rich protein injections and prolotherapy—a technique in which an irritant is injected into the tendon in an attempt to create an inflammatory reaction, thus increasing local blood flow and healing—are being studied for the treatment of AT, but are not routinely used or covered by insurance for this purpose. Surgical intervention may be considered for patients whose symptoms last for more than 3 to 6 months despite conservative treatment.
Insertional Achilles tendinopathy (IAT) can be clinically differentiated from MAT by the location of symptoms and tenderness to palpation at the insertion site of the Achilles into the calcaneous. Like MAT, IAT is exacerbated by activity. Other conditions that may contribute to, or be mistaken for, IAT are a Haglund deformity and retrocalcaneal bursitis.
Treatment: Footwear modification. Treatment of IAT, like that of MAT, is primarily conservative. Orthotics or heel lifts are commonly used. However, there is greater emphasis on footwear modification due to the mechanical irritation and resultant posterior heel swelling often associated with IAT. While eccentric exercises play a role in IAT treatment, the benefits are limited.25
As with MAT, corticosteroid injections are contraindicated due to the risk of tendon rupture. Modalities such as ultrasound, ESWT, plasma-rich protein, and prolotherapy lack sufficient evidence to be widely recommended.
For refractory cases of IAT, surgical intervention often relieves the pain.
Return to running. After an initial rest of 2 to 4 weeks, patients may return to running while completing therapy. It’s not necessary to wait until the patient is completely pain free, but pain should be used to guide decisions about intensity and duration of activity.
CASE When Jim returns 6 weeks later, he reports that he took 3 weeks off from running because of the pain. Initially, he used contrast baths daily, Jim says, but now he uses them only when he is symptomatic, and he discontinued the NSAID a few weeks ago. Jim tells you he went to the local running store for a new pair of running shoes and that he is now able to run at his previous pace while remaining relatively pain free.
CORRESPONDENCE Jessica Favero Butts, MD, One American Square, Suite 185, Indianapolis, IN 46282; Jbutts2@iuhealth.org