COVER ARTICLE PRACTICAL THERAPEUTICS Common Conditions of the Achilles Tendon MICHAEL F. MAZZONE, M.D., and TIMOTHY MCCUE, M.D., Medical College of Wisconsin, Waukesha, Wisconsin The Achilles tendon, the largest tendon in the body, is vulnerable to injury because of its limited blood supply and the combination of forces to which it is subjected. Aging and increased activity (particularly velocity sports) increase the chance of injury to the Achilles tendon. Although conditions of the Achilles tendon are occurring with increasing frequency because the aging U.S. population is remaining active, the diagnosis is missed in about one fourth of cases. Injury onset can be gradual or sudden, and the course of healing is often lengthy. A thorough history and specific physical examination are essential to make the appropriate diagnosis and facilitate a specific treatment plan. The mainstay of treatment for tendonitis, peritendonitis, tendinosis, and retrocalcaneobursitis is ice, rest, and nonsteroidal anti-inflammatory drugs, but physical therapy, orthotics, and surgery may be necessary in recalcitrant cases. In patients with tendon rupture, casting or surgery is required. Appropriate treatment often leads to full recovery. (Am Fam Physi- cian 2002;65:1805-10. Copyright© 2002 American Academy of Family Physicians.) he Achilles tendon spans increased activity. The morphologic two joints and connects the changes such as decreased cell density, calcaneus to the gastrocne- decreased collagen fibril density, and loss mius and soleus muscles, of fiber waviness that occur with aging comprising the largest and predispose the tendon to injury.2 Tstrongest muscle complex in the calf The normal gait cycle requires ex- (Figure 1).The tendon is vulnerable to treme motion from within the ankle. injury because of its limited blood sup- With each step, the subtalar joint typi- ILLUSTRATION BY JOHN W. KARAPELOU ply, especially when subjected to strong cally moves 30 degrees (inverts 20 de- forces. grees, everts 10 degrees).3 This movement The blood supply to the tendon is pro- results in repetitive lengthening and Members of various family practice depart- vided by longitudinal arteries that run shortening of the Achilles tendon com- ments develop articles the length of the muscle complex. The plex. Running and jumping further in- for “Practical Therapeu- area of the tendon with the poorest blood crease the load on the Achilles tendon. tics.” This article is one supply is approximately 2 to 6 cm above Tendons that transmit large loads under in a series coordinated the insertion into the calcaneus.1 The these conditions are subject to injury. by the Department of Family and Community blood supply diminishes with age, predis- Extreme shear forces across the tendon Medicine at the Med- posing this area of the tendon to chronic complex are believed to cause prolonged ical College of Wiscon- inflammation and possible rupture. loading of the tendon, resulting in micro- sin, Milwaukee. Guest The Achilles tendon does not have a trauma and inflammation.4 editors of the series are true synovial sheath but instead has a Common conditions of the Achilles Linda N. Meurer, M.D., M.P.H., and Douglas paratenon. The paratenon is a connective tendon include tendonitis, peritendonitis, Bower, M.D. tissue sheath that surrounds the entire tendinosis, rupture, and retrocalcaneo- tendon and is able to stretch 2 to 3 cm bursitis. These conditions are usually with movement, which allows maximal caused by overuse and can occur in ado- gliding action. The Achilles tendon has lescents and adults (Table 1).Achilles ten- been shown to thicken in response to don injuries are increasing in prevalence as physical activity becomes more com- mon, especially in older patients. Men older than 30 years are particularly vul- The most vulnerable area of the Achilles tendon is between 2 and nerable to injuries of the Achilles tendon, 6 cm above the calcaneal insertion. but persons beginning a sport or increas- ing activity levels are also at risk. MAY 1, 2002 / VOLUME 65, NUMBER 9 www.aafp.org/afp AMERICAN FAMILY PHYSICIAN 1805 Soleus-gastrocnemius Achilles Tendonitis and Peritendonitis complex ILLUSTRATIVE CASE ONE . Tibia . A 45-year-old man presents with pain and a “knot” on his right heel after increasing his Achilles tendon . Fibula running frequency, training time, and dis- . tance in preparation for a marathon. Retrocalcaneal . Peroneus longus bursa . and brevis tendons INCIDENCE Achilles tendonitis occurs in about 10 per- cent of runners, but the condition also occurs Subcutaneous . in dancers, gymnasts, and tennis players.3,4 calcaneal bursa . Running produces forces up to eight times . the body’s weight, placing significant repeti- Insertion of tive stress on the tendon for prolonged peri- Achilles tendon ods.5 Tendonitis in athletes is usually caused ILLUSTRATION BY RENEE L. CANNON Calcaneus by training errors such as incorrect running technique or wearing improperly fitting FIGURE 1. Anatomy of the Achilles tendon. shoes; however, it is also related to hyperpro- TABLE 1 Summary of Achilles Tendon Injuries Predisposing Rate of Age of Recovery Injury factors onset onset Symptoms Signs Treatment time Tendonitis Increased Gradual Any Pain over tendon, heel pain, Tenderness with palpation; NSAIDs, ice, rest, Weeks to activity, stiffness tendon thickened; pain increased months poor-fitting with range of motion warm-up/ footwear, stretching, excessive heel lifts pronation, poor flexibility Rupture Explosive Sudden Late 20s Feeling of being kicked in Swelling, inability to palpate Surgery or 6 to 12 movements, back of ankle; feeling or Achilles tendon or palpable long-term months chronic hearing a “pop”; mild to defect; small knot or bulge immobilization tendonitis moderate pain; inability at proximal portion of Achilles; to continue activity inability to perform single-leg toe raise on affected side; abnormal Thompson test* Bursitis Low-riding Very Late 40s Pain in back of heel, worsening Tender, palpable bursa Ice, stretching, Weeks shoes gradual with initiation of activity, posterior to calcaneus NSAIDs, heel improving with rest; pain cups while wearing shoes; limp develops over time NSAIDs = nonsteroidal anti-inflammatory drugs. *—An abnormal Thompson test is defined as no movement in a dorsiflexed foot with squeezing of the calf of a supine patient. 1806 AMERICAN FAMILY PHYSICIAN www.aafp.org/afp VOLUME 65, NUMBER 9 / MAY 1, 2002 Achilles Tendon nation of the foot and contracture of the gas- trocnemius-soleus complex.6 Abnormal bio- Even with appropriate treatment, symptoms of acute ten- mechanics and friction from extrinsic or donitis may persist for several months. external pressure are believed to cause symp- toms.7 Achilles tendonitis is common when persons first take up athletic activities. Achilles tendonitis often interferes with of the Achilles tendon often elicits tenderness activities. One study8 showed that 56 percent along the tendon. Active range of motion may of competitive track and field athletes with also elicit discomfort. It is important to assess Achilles tendonitis discontinued all sporting the thickness and consistency of the tendon activities for a minimum of four weeks to pro- and palpate for a discrepancy in thickness mote healing. Delayed or missed diagnosis of between right and left legs. Range of motion Achilles tendon rupture is also common, with of the ankle joint should also be evaluated. 23 percent of patients initially being misdiag- Pain elicited by rubbing the tendon between nosed.9 The tendon defect can be disguised by the fingers is a sign of peritendonitis. Crepita- hematoma. Plantar flexion power (from tion is often present within the Achilles ten- extrinsic foot flexors) may continue to be pre- don, and a slight thickening of the paratenon sent, and the Thompson test can be falsely may be felt. More serious injuries to the ten- normal if accessory ankle flexors are squeezed don, such as tears and ruptures, must be con- during the physical examination.2 Conse- sidered during the examination. quently, all patients with heel pain should be evaluated for Achilles tendonitis. TREATMENT It is important to inform patients that symp- DIAGNOSIS toms may persist for several months. The early A detailed history is necessary, including phase of treatment emphasizes control of level of training, technique, footwear, previ- inflammation and pain using ice, rest, and non- ous injury, and treatment. Injury typically steroidal anti-inflammatory drugs (Figure 2). occurs in persons who are physically active Control of biomechanical factors by correcting and subject the tendon to repetitive forces malalignment with appropriate shoes, using beyond its ability to heal.10 The typical symp- appropriate training techniques, and losing tom of tendonitis is pain or tenderness prox- weight is important to reduce further inflam- imal to or at the insertion to the calcaneus. mation of the tendon. A slow, gentle warm-up Peritendonitis, an inflammation of the ten- before exercise and icing after exercise will help don sheath, commonly leads to localized ten- patients who want to continue athletic training. derness and burning that eventually develop If conservative measures fail, physical modali- into pain about 2 to 6 cm above the tendon ties such as ultrasound therapy and flexibility insertion. This pain is related to exercise. In training may be added to the treatment proto- tendonitis and peritendonitis, symptoms col. Stretching may stimulate a healing re- usually develop gradually, and the patient sponse, and one study11 showed that calf muscle typically presents with pain and stiffness over training is associated with a faster recovery time. the Achilles region. The pain may lessen with Referral for possible surgical intervention walking or when heat is applied to the area should be made if no improvement occurs after and worsen with more strenuous activity. six months of nonoperative treatment. A thorough physical examination is very important to the diagnosis, and it should be Tendinosis performed with the patient lying prone, feet Tendinosis is a diffuse thickening of the hanging off the examination table.