Achilles tendon rupture


Achilles tendon anatomy.
  • Most frequently ruptures 2-6cm above calcaneus (where blood supply is weakest)
  • Typical patient is 30-50yr old man who participates in strenuous activities on occasional basis
  • Quinolone-associated rupture occurs in only 12 per 100,000 treatment episodes, and risk may be equivalent to oral steroids or non-quinolone antibiotics [1]

Clinical Features

  • Sudden, severe pain typically with rapid acceleration or pivoting
  • May hear a "pop"
  • Inability to run, stand on toes, or climb stairs
  • Palpable defect in Achilles tendon 2-6cm proximal to calcaneus (SN 73% and SP 89% for partial tear)
  • 20-30% of ruptures will have some amount of active plantar flexion or be able to walk

Differential Diagnosis

Calf pain



Achilles tendon rupture. No fracture on radiograph (left) with discontinuity of tendon over several centimeters (right; red line).
Ultrasound of achilles tendon rupture, long axis view[2]

Thompson test

Positive Thompson test for left Achilles tendon rupture: no movement of the foot despite the calf being squeezed.

(SN 96% and SP 93%)

  • Lay patient prone with knee bent at 90°
  • In normal patient, squeezing calf results in plantar-flexion


  • Typically a clinical diagnosis (via positive Thompson test)



  • Outpatient with ortho referral


  1. Seeger, et al, "Achilles tendon rupture and its association with fluoroquinolone antibiotics and other potential risk factors in a managed care population." PMID: 16456878
  3. Cast or Walking Boot for Achilles Tendon Rupture?
  4. Plaster cast versus functional brace for non-surgical treatment of Achilles tendon rupture (UKSTAR): a multicentre randomised controlled trial and economic evaluation. Lancet. 2020 Feb 8;395(10222):441-448. doi: 10.1016/S0140-6736(19)32942-3.