Would Achilles Have Been Stronger After Eccentric Training, Glyceryl Trinitrate, or Low Energy Shock Wave Treatment?
What are the latest recommendations for management of Achilles tendinopathy?
The residents and I recently evaluated a patient with midsubstance Achilles tendinopathy. I have a sensitive spot for sufferers of Achilles discomfort since I ruptured mine 20 years ago (ouch!). A recent “Top Paper” reviewed some helpful diagnostic hints with a focus on emerging therapies that were new to me. The discussion will be presented as numbered “take home” messages relevant to primary care.1
THE TAKE HOME MESSAGES
1. Who experiences Achilles tendinopathy? Anyone can be affected, but young, active people are especially prone. Certain activities increase the likelihood such as running (29% of runners in 1 study versus 4% in non-runners). A positive family history raises the risk of Achilles tendinopathy 5 times. Other medical risk factors include hypertension, elevated lipids, and diabetes.
2. What is the role of imaging in this disorder? Most diagnoses are reached clinically. However, MRI and ultrasound may be informative. MRI offers a view of every relevant portion of the “Achilles” unit including the tendon itself, the retrocalcaneal bursa, the calcaneus, the tendon insertion, and all surrounding tissues. Ultrasound is valuable for dynamic assessments and provides insight on neovascularization. Importantly, ultrasound can guide percutaneous interventions (if corticosteroids are injected, an uncommon intervention1). Overall, MRI is more sensitive (95% versus 80%), but specificities of both imaging modalities are similar.
3. Treatment option No. 1 for midsubstance Achilles tendinopathy. The evidence for benefit is highest with eccentric calf exercises (a 12-week program). Woodley and colleagues2 describe the exercise prescription. This intervention is supported by a meta-analysis of 11 randomized controlled trials that documented improvement in pain, function, and patient satisfaction.2 Not only are eccentric exercises beneficial initially, but results are durable. A 5-year follow-up study found long-term improvement as a result of this treatment modality.3
A caveat must be interjected. The benefit is limited to midsubstance Achilles tendinopathy. Eccentric exercises do not have significant benefit when used alone for insertional Achilles
tendinopathy.
4. Topical glyceryl trinitrate (GTN) is also helpful in treatment. GTN is a prodrug of nitric oxide,4 and it is marketed as a topical patch. Topical GTN has been compared with standard physical therapy again for non-insertional Achilles tendinopathy. Benefits at 6 months were similar.4 Although not all studies are supportive, the recommended dose for GTN is a 5 mg/24 hour patch cut into quarters with one-fourth placed over the site of tenderness for a 24-hour period over 12 weeks.1
5. Insertional tendinopathy is a horse of a different color. Eccentric loading exercises plus low energy shock wave therapy are recommended for this entity.1
6. The same controversy1 (that is, to operate versus not to operate) persists regarding conservative versus surgical therapy for tendon rupture. Non-surgical therapy may be better for older, less active persons. Older adults with Achilles tendon rupture are particularly prone to deep venous thrombosis as a complication!n
REFERENCES:
1. Asplund CA, Best TM. Achilles tendon disorders. BMJ. Accessed at www.bmj.com, March 13, 2013.
2. Woodley BL, Newsham-West RJ, Baxter GD. Chronic tendinopathy: effectiveness of eccentric exercise. Br J Sports Med. 2007;41:188-198.
3. Van der Plas A, de Jonge S, de Vos RJ, et al. A 5-year-followup study of Alfredson’s heel drop exercise program in chronic midportion Achilles tendinopathy. Br J Sports Med. 2012;46:214-218.
4. Lake JE, Ishikawa SN. Conservative treatment of achilles tendinopathy: emerging techniques. Foot Ankle Clin N Am. 2009;14:663-674.