Clinical failure after mid-substance achilles tendon rupture to avoid lengthening during physiotherapy: a cadaveric biomechanics study

Immediate mobilization shows neuromuscular benefits, but lengthening of Achilles tendon (AT) could be a devastating problem. Here we describe the AT angle of clinical failure (CF) during cyclical mobilization in human cadaveric specimens that were repaired using the Dresden technique. Eight lower limbs were repaired following complete AT rupture. A basal tension of 10 N at 30° of plantarflexion was placed. Ankle angle during CF (separation >5 mm) was tested via cyclical mobilization (100 cycles of plantarflexion between 30° and 15°; 15° and 0°; 0° and 15° of dorsiflexion; and 15° of dorsiflexion and full dorsiflexion). CF was determined using a Laplacian edge filter, and the angle was obtained using a rotatory potentiometer. Descriptive statistics was applied. The CF was 12.5° and the limit was 14.0° of plantarflexion. After 14.0° of plantarflexion, the technique was found insecure for cyclical mobilization exercises.