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.

• Primarily history and physical examination

• Sometimes MRI or ultrasound

Diagnosis of Achilles tendon tears is clinical (1). The patient's ability to flex the ankle does not exclude a tear.

If clinicians suspect an Achilles tendon tear, 3 main tests can be performed 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 Thompson test is 96% sensitive and 93% specific for Achilles tendon tears (1).

Thompson Test for Diagnosis of Achilles Tendon Tears

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Video by Walter A. Schrading, MD, FACEP, FAWM; Associate Professor, Department of Emergency Medicine; Director, Office of Wilderness Medicine; UAB Medicine, The University of Alabama at Birmingham.

Unilateral Abnormal Thompson Test

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Video courtesy of Danielle Campagne, MD.

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 Achilles tendon tears (1).

Matles Test

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The purpose of the Matles test is to have the examiner look for natural plantar flexion in the foot with an intact Achilles and for the absence of plantar flexion (indicating a positive Matles test) in the injured ankle. In the Matles test, the patient lies prone with the knees flexed, and the examiner assesses how the foot lies. In this image, the foot in front shows absence of plantar flexion (ie, the foot falls completely flat (to the neutral position with 0° plantar flexion). This result is a positive Matles test. The foot in the background shows 20 to 30° plantar flexion, indicating that the Achilles tendon is not ruptured (ie, the Achilles tendon is intact).

Image courtesy of Danielle Campagne, MD.

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 an 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 (2010), 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.

Ultrasound is increasingly being used to confirm tendon tears or to differentiate between partial and complete tears when imaging is required. Diagnostic accuracy appears to be good when performed by experienced operators.

• 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.

Achilles tendon tears can be treated with nonoperative management (splinting and progressive range of motion rehabilitation) or with surgical repair.

Nonoperative management includes a posterior ankle splint with the ankle in plantar flexion initially and then progressive plantar flexion to neutral positioning range of motion exercises.

Surgical repair of the tendon can be performed with an open technique as well as a minimally invasive/percutaneous approach.

Nonoperative management has a slightly higher re-rupture rate but otherwise operative and nonoperative approaches have similar long term outcomes (1).