A 36-year-old woman comes to the emergency department with severe left calf pain. While she was running on a racetrack, she heard a loud snap and then felt an "excruciating pain" in her left calf area. She was a marathon runner in the past, but stopped running 2 years ago after she had her first baby. She started retraining a week ago for an upcoming race. She has no other medical problems. She does not use tobacco, alcohol, or illicit drugs. Her mother has a history of osteoporosis. Vital signs are within normal limits. Which of the following is the most accurate test to confirm complete Achilles tendon rupture in this patient?

Question

A 36-year-old woman comes to the emergency department with severe left calf pain.  While she was running on a racetrack, she heard a loud snap and then felt an "excruciating pain" in her left calf area.  She was a marathon runner in the past, but stopped running 2 years ago after she had her first baby.  She started retraining a week ago for an upcoming race.  She has no other medical problems.  She does not use tobacco, alcohol, or illicit drugs.  Her mother has a history of osteoporosis.  Vital signs are within normal limits.  Which of the following is the most accurate test to confirm complete Achilles tendon rupture in this patient?

Quizplus · Accepted Answer

Explanation: The Achilles (calcaneal) tendon is composed of the gastrocnemius-soleus complex tendons and is commonly injured or ruptured when athletes abruptly increase their activity, as seen in this patient. The most appropriate physical examination maneuver to test for complete rupture of the Achilles tendon is the Thompson test, which has a sensitivity of 96% and specificity of 93%. With the patient lying in the prone position, feet hanging off the table, the clinician should squeeze the patient's calf muscles and observe for the presence of plantar flexion of the foot. If plantar flexion is observed on calf squeeze, the test is negative and indicates normal function of the Achilles tendon. Thompson test Achilles tendinopathy without rupture requires no further imaging. Magnetic resonance imaging is the diagnostic modality of choice for Achilles tendon rupture and particularly useful in the setting of high clinical suspicion with a negative Thompson test or if partial tendon tears are suspected. (Choice A) Foot eversion is a function of the fibularis muscles (fibularis longus, brevis, and tertius). Fibularis longus and brevis are innervated by the superficial fibular nerve, whereas fibularis tertius is innervated by the deep fibular nerve. (Choice B) Absence of active plantar flexion is not as reliable as the calf-squeeze test to rule out Achilles tendon rupture because the patient can also use accessory muscles (fibularis longus, fibularis brevis, plantaris, and tibialis posterior) to actively plantar flex and falsely reassure the clinician. (Choice C) Leg-length discrepancy can be due to a variety of causes (including hip, knee, and spine pathology) and is screened by observing for pelvic obliquity or measuring the distance from the anterior superior iliac spine to the medial malleolus. (Choice E) Plantar sensory loss is seen in pathology affecting the medial and lateral plantar nerves and/or the medial calcaneal nerve, all of which are branches of the tibial nerve. A defect of the tibial nerve would result in loss of both gastrocnemius-soleus motor function and plantar sensory. Educational objective: Complete rupture of the Achilles tendon is a clinical diagnosis that can be supported with a positive Thompson test, which is >90% sensitive and specific. The Thompson test observes for plantar flexion of the foot when the calf muscle is squeezed. The absence of plantar flexion signifies complete rupture and a positive test result. References: Imaging in chronic Achilles tendinopathy: a comparison of ultrasonography, magnetic resonance imaging and surgical findings in 27 histologically verified cases. (http://www.ncbi.nlm.nih.gov/pubmed/8915043) The clinical diagnosis of subcutaneous tear of the Achilles tendon. A prospective study in 174 patients. (http://www.ncbi.nlm.nih.gov/pubmed/9548122)

A 36-Year-Old Woman Comes to the Emergency Department with Severe