Achilles Tendon Rupture

Lateral view of the ankle shows an avulsed bone fragment (arrow) from the donor site (arrowhead) at the attachment of the Achilles tendon.

Facts

• Achilles tendon is the thickest and strongest tendon in the human body
• It is also the most commonly ruptured tendon
• Most frequent mechanism is a sudden, forceful contraction of gastrocnemius
• Most common at zone of avascularity 2-6 cm above the calcaneal insertion

Clinical

• 30-50 years old, recreational athletes (usually playing basketball, racket sports, soccer or softball)
• Sudden pain after a pushing-off movement, audible pop, immediate weakness, palpable defect. Positive Thompson test
• Clinical confounders: tear of other tendons (plantaris, flexor, peroneal), soft tissue edema limiting physical exam by palpation
• In young, active patients, full-thickness tear is frequently treated by surgery. Nonsurgical options are considered in partial-thickness tear, sedentary, and high surgicalrisk patients

Role of Imaging

• To assess if there is an avulsed bone fragment (radiography)
• To differentiate between partial and full thickness tear (ultrasound, MRI)
• Findings of full-thickness tear (both US and MRI): non visualization of tendon, tendon retraction, fat herniation into the tendon gap.
• Additional findings seen on US of full-thickness tear: posterior acoustic shadowing due to refraction of sound beam at the frayed tendon, visualization of plantaris tendon

Our case: ruptured Achilles tendon associated with calcific tendinopathy

References:

1. Hartgerink P, et al. Full- versus partial-thickness Achilles tendon tears: sonographic accuracy and characterization in 26 cases with surgical correlation. Radiology 2001; 200:406-412.

2. Skinner HB. Current diagnosis and treatment in orthopedics. McGraw-Hill Professional, 4th edition, 2006.