Effect of Knee Position on Gap Size Following Acute Achilles Rupture

SLR - June 2011 - Jonathan L. Brown (3)

Reference:  Trickett, R; Hodgson, P; Lyons, K; Thomas, R:  (2011).  Effect of Knee Position on Gap Size Following Acute Achilles Rupture. Foot & Ankle International, 32(1): 1-4.

Scientific Literature Review

Reviewed by:  Jonathan L. Brown, DPM
Residency Program:  DVA San Francisco

Podiatric Relevance: 
Achilles tendon rupture is a common pathology encountered by the practicing podiatric physician.  Conservative treatment is commonly used with favorable outcomes, however, there is debate over leg and foot position during immobilization.

Methods: 
Prospective data was collected on 25 patients with a history and examination consistent with acute Achilles tendon rupture who were assessed with ultrasonography by a single musculoskeletal consultant radiologist.  Measurement of tendon gap was determined with the knee flexed to 90 degrees, the ankle neutral, and full tolerable plantarflexion.  This process was then repeated with the knee in full extension.  A power calculation was first performed with a pilot study of 10 patients, which determined that 11 more patients were required for adequate sample size.

Results: 
No significant difference was detected in the tendon gap with the knee flexed or extended when the foot was in full equinus (p > 0.05).

Conclusions: 
Regarding acute Achilles tendon ruptures, there is no statistically significant difference in the tendon gap between positions with the knee flexed and knee extended as long as the ankle remains fully plantarflexed.  This study does not support the continued use of above-knee immobilization in the conservative treatment of acute tendon ruptures.