2015 ISAKOS Biennial Congress ePoster #105

The Achilles Tendon Resting Angle as an Indirect Measure of Achilles Tendon Length Following Rupture, Repair and Rehabilitation.

Michael Carmont, FRCS(Tr&Orth), Wolverhampton UNITED KINGDOM
Karin Grävare Silbernagel, PT, PhD, ATC, Newark, DE UNITED STATES
Annelie Brorsson, BSc, Gothenburg SWEDEN
Nicklas Olsson, Consultant, Mölndal SWEDEN
Nicola Maffulli, MD, PhD, MS, FRCS(Orth), London UNITED KINGDOM
Jon Karlsson, Prof., Mölndal SWEDEN

Princess Royal Hospital, Telford, United Kingdom, UNITED KINGDOM

FDA Status Not Applicable

Summary: The Achilles Tendon Resting Angle might be considered as a simple and effective means to evaluate function after one year following Achilles Tendon rupture.




Rupture of the Achilles tendon may result in reduced functional activity and reduced plantar flexion strength. These changes might arise from elongation of the Achilles tendon. The Achilles Tendon Resting Angle is a validated non-invasive method to evaluate the resting length of the Achilles tendon.


An observational study was performed to quantify this angle in patients following Achilles tendon rupture, surgical repair and rehabilitation. The relationship between the Achilles Tendon Resting Angle and the functional outcome after the treatment of Achilles tendon rupture was also evaluated.

Materials And Methods

Between 2011 and 2012, 26 consecutive patients (17 male), mean (SD) age of 42 (8) were included and evaluated following injury, repair and at 6 weeks, 3, 6, 9 and 12 months respectively. Surgical repair was performed using minimally invasive surgery using an absorbable suture. Following surgery, patients were mobilized fully weight bearing in a functional brace. Early active movement was permitted from two weeks. Outcome was measured using the Achilles Tendon Resting Angle, Achilles tendon Total Rupture Score (ATRS) and a heel-rise test.


Following rupture, the mean (SD) absolute Achilles tendon resting angle was 55° (8) on the injured side compared with 43° (7) (p<0.001) for the non-injured side. Immediately after repair, the angle reduced to 37°(9)(p<0.001). The difference between injured and non-injured sides, the relative Achilles Tendon Resting Angle was -12.5° (4.3) following injury; this was reduced to 7° (7.9) following surgery (p<0.001). During initial rehabilitation, at the 6 week time point, the relative angle was 2.6° (6.2) (P=0.04) and at 3 months -6.5° (6.5) (P<0.001). After the 3 months time point, there were no significant changes in the resting angle.
The ATRS improved significantly (p<0.001) during each time period up to 9 months following surgery, where a score of 85(10) was reported.
The heel-rise limb symmetry index was 66%(22) at 9 months and 82%(14) at 12 months. At 3 and 6 months, the absolute Achilles Tendon Resting Angle correlated with ATRS (r= 0.63, P=0.001, N=26), (r=0.46, P=0.027, N=23) respectively. At 12 months the absolute resting angle correlated with heel-rise height (r=-0.63, P=0.002, N=22).


The Achilles Tendon Resting Angle was an accurate diagnostic indicator of outcome following minimally invasive management of Achilles tendon rupture. The angle increases following injury, is reduced by surgery, and then increases again during initial rehabilitation. The angle also correlates to patient-reported symptoms early in the rehabilitation and with heel-rise height after one year. The Achilles Tendon Resting Angle might be considered as a simple and effective means to evaluate function after one year following Achilles Tendon rupture.