Achilles tendon tears (ruptures) most often result from ankle dorsiflexion, particularly when the tendon is taut. Diagnosis is by examination and sometimes MRI. Treatment is splinting in plantar flexion and immediate referral to an orthopedic surgeon; surgical repair may be necessary.
Achilles tendon tears are common. They typically occur during running or jumping and are most common among middle-aged men and athletes. Very rarely, spontaneous Achilles tendon tears have occurred in people who take fluoroquinolone antibiotics or corticosteroids.
Achilles tendon tears may be partial or complete.
Symptoms and Signs of Achilles Tendon Tears
Pain in the distal calf makes walking difficult, particularly when the tear is complete. The calf may be swollen and bruised.
Complete tears may result in a palpable defect and usually occur 2 to 6 cm proximal to the tendon's insertion.
Diagnosis of Achilles Tendon Tears
- Clinical evaluation
- Sometimes MRI or ultrasonography
Diagnosis of Achilles tendon tears is clinical (1). The patient's ability to flex the ankle does not rule out a tear.
If clinicians suspect an Achilles tendon tear, 3 main tests can be done to help confirm the diagnosis.
For the Thompson test (calf squeeze test), the patient is prone, and the calf is squeezed to elicit plantar flexion. Results include the following:
- If the tear is complete, ankle plantar flexion is absent or decreased.
- If the tear is partial, results are sometimes normal, so these tears are often missed.
The Matles test is used to assess resting tension. The patient is prone with the knee bent at 90° to shorten the gastrocnemius. The patient's feet are compared. Results include the following:
- If the Achilles tendon is intact, plantar flexion of the ankle to 20 to 30° occurs.
- If the Achilles tendon is torn, the foot falls to a neutral position.
The Matles test is 88% sensitive and 85% specific for tears.
For palpation of the tendon gap, the patient is asked to stand on the affected leg (if possible). Then the clinician gently palpates the course of Achilles tendon and feels for a gap; a gap indicates that the tendon is torn.
Physical examination is more sensitive than MRI for detecting a Achilles tendon tear (2). A study of patients with an Achilles tendon tear (2012) found that if all 3 tests (Thompson, Matles, palpation of the gap) are positive, sensitivity for an Achilles tear is 100%. According to the American Academy of Orthopedic Surgeons guidelines (2009), diagnosis of a tear requires only one of the following (3):
- 2 of these 3 tests are positive.
- 1 of the tests is positive and ankle plantar flexion is weakened.
Ultrasonography is being increasingly used to confirm tendon tears or to differentiate between partial and complete tears when imaging is required. Diagnostic accuracy appears to be good when done by experienced operators.
- 1. Maffulli N: The clinical diagnosis of subcutaneous tear of the Achilles tendon: A prospective study in 174 patients. Am J Sports Med 26 (2):266–270, 1998.
- 2. Garras DN, Raikin SM, Bhat SB, et al: MRI is unnecessary for diagnosing acute Achilles tendon ruptures: Clinical diagnostic criteria. Clin Orthop Relat Res 470 (8):2268–2273, 2012. doi: 10.1007/s11999-012-2355-y
- 3. Chiodo CP, Glazebrook M, Bluman EM, et al: Diagnosis and treatment of acute Achilles tendon rupture: Practice guideline. J Am Acad Orthop Surg 18 (8):503–510, 2010. doi: 10.5435/00124635-201008000-00007
Treatment of Achilles Tendon Tears
- Splinting in plantar flexion
- Immediate orthopedic referral
- Sometimes surgical repair
Initial treatment of Achilles tendon tears consists of splinting with the ankle in plantar flexion and immediate referral to an orthopedic surgeon.
Whether tendon tears should be treated surgically is controversial.
Treatment may involve a posterior ankle splint with the ankle in plantar flexion for 4 weeks and avoidance of weight bearing.