DOS 2018

212 · DOS Abstracts Validation of the Achilles Tendon Length Measure and the Achilles Tendon Resting Angle in relation to the Copenhagen Achilles Length Measure Maria Swennergren Hansen, Morten Tange Kristensen, Per Hölmich, Kristoffer W. Barfod Physical Medicine and Rehabilitation Research – Copenhagen (PMR- C),Department of Physiotherapy and Occupational Therapy, Copenhagen University Hospital, Amager-Hvidovre; Physical Medicine and Rehabilitation Research – Copenhagen (PMR-C),Department of Physiotherapy and Occupational Therapy and Department of Orthopedic Surgery, Copenhagen University Hospital, Amager-Hvidovre; Sports Orthopedic Research Center - Copenhagen (SORC-C), Arthroscopic Center, Department of Orthopedic Surgery, Copenhagen University Hospital, Amager-Hvidovre Background: Elongation of the Achilles tendon after rupture is a frequent and overlooked complication. The Achilles Tendon Length Measure (ATLM) and the Achilles Tendon Resting Angle (ATRA) are indirect length measures using the resting angle of the ankle. Copenhagen Achilles Length Measure (CALM) is a direct ultrasound measure. To examine the influence of elongation valid clinical measures of the length of the Achilles tendon are needed. Purpose / Aim of Study: To examine the concurrent validity of ATLM and ATRA in relation to CALM. Materials and Methods: The study was performed as a validity study. Data were gathered from patients included in a randomized controlled trial from February 2014 to December 2016. All patients were treated non-operatively with early controlled weight-bearing. Comparison between measures was per- formed using Pearson’s correlation at 2, 4, 6 and 12 months after injury. Findings / Results: 84 patients were included (18 women, 66 men), mean (SD) age 42.4 (11.2) years. The correlations between CALM and ATRA were 0.244 (p=0.03) at 2 months, 0.159 (p=0.15) at 4 months, 0.063 (p=0.57) at 6 months and 0.191 (p=0.08) at 12 months. Corresponding data between CALM and ATLM were 0.319 (p<0.01), 0.263 (p=0.02), 0.036 (p=0.74), 0.132 (p=0.23) and between ATRA and ATLM 0.633 (p<0.01), 0.461 (p<0.01), 0.463 (p<0.01), 0.476 (p<0.01). Conclusions: A very weak to weak positive correlation was found between CALM and ATRA/ATLM indicating that the two indirect measures does not measure the same construct as the direct ultrasound measure. The strong cor- relation between ATRA and ATLM indicate consistency between the indirect measures. The study cannot recommend one measure over the other. Further validation of these three clinically applicable measures against a true gold stan- dard seems highly needed. 153.