Rupture occurs most frequently in middle-aged males involved in athletic activities, but patients with other systemic conditions, steroid injections, or fluoroquinolone use are predisposed. Rupture occurs 2 to 6 cm above the tendon’s attachment to the calcaneus. Patients may hear or feel a pop and subsequently develop weakness when pushing off the foot; pain, edema, and ecchymosis may develop. Note that loss of plantar flexion is not necessarily seen as there are other tendons that can compensate. Thompson test can be diagnostic of an Achilles rupture; the patient is placed in a prone position or kneeling on a stool, the knee and ankle are flexed to 90 degrees, and the gastrocnemius muscle should be grasped and squeezed. If the Achilles tendon is even partially intact, then the foot will plantar flex; if ruptured, there will be no foot movement. Radiographic analysis should include a lateral view of the ankle as the Achilles tendon can sometimes be seen. Ultrasound can also be diagnostic.
Management and Disposition
Treatment is either operative or conservative. In either case, the extremity is immobilized in slight plantar flexion, and the patient is made non–weight bearing upon ED discharge. Acute treatment also involves elevation, analgesia, and ice. These patients can be discharged home with orthopedics follow-up.
Approximately 25% of these injuries are initially misdiagnosed as ankle sprains.
Palpation of the tendon alone may not
Achilles Tendon Rupture. Note the loss of the normal resting plantar flexion due to right Achilles tendon rupture (A). Swelling is also apparent over the injury site. Similar findings are present due to left Achilles tendon rupture (B). (Photo contributor: Lawrence B. Stack, MD.)
Thompson Test. There is no plantarflexion with squeezing the calf of the affected leg, or less plantarflexion compared with the normal leg. (Adapted with permission from Stone CK, Humphries RL. Current Diagnosis and Treatment Emergency Medicine. 7th ed. Copyright © The McGraw Hill Companies, 2011. Figure 28-20.)