No clinically relevant difference between operative and non-operative treatment in tendon elongation measured with the Achilles tendon resting angle (ATRA) 1 year after acute Achilles tendon rupture.

Abstract

Studies have shown that elongation of the injured Achilles tendon after acute Achilles tendon rupture (ATR) is negatively associated with clinical outcomes. The difference between operative and non-operative treatment on the length of the Achilles tendon is only sparsely investigated. The aim of the study was to investigate if the operative and non-operative treatment of ATR had different effects on tendon elongation. The study was performed as a registry study in the Danish Achilles tendon database (DADB). The primary outcome of the study was an indirect measure of Achilles tendon length: the Achilles tendon resting angle (ATRA) at 1-year follow-up. The variable of interest was treatment (operative or non-operative). From August 2015 to January 2019, 438 patients (154 operatively treated and 284 non-operatively treated) were registered with full baseline data and had their ATRA correctly registered at 1-year follow-up in DADB. The analysis did not show a clinically relevant nor statistically significant difference in ATRA between operative and non-operatively treated patients at 1-year follow-up (mean difference - 1.2°; 95% CI - 2.5; 0.1; n.s) after adjustment for potential confounders. There were neither clinically relevant nor statistically significant differences in terms of the ATRA at 1-year follow-up between the operative and non-operatively treated patients. This finding suggests that operative treatment does not lead to a clinically relevant reduction in tendon elongation compared to non-operative treatment and it should therefore not be used as an argument in the choice of treatment. Level III.