Poor association between tendon structure and self-reported symptoms following conservative management in active soldiers with mid-portion Achilles tendinopathy

Abstract

Introduction Mid-portion Achilles tendinopathy (mid-AT) is currently the preferred term for persistent Achilles tendon pain, defined as located 2–7 cm proximal to the calcaneus, and with loss of function related to mechanical loading. Histologically, mid-AT is considered to represent a degenerative condition. Therefore, monitoring of tendon structure additional to pain and function may be warranted, to prevent progression of degeneration or even tendon rupture. The aim of this study was to determine the association between pain and function, relative to the Achilles tendon structure, in soldiers treated with a conservative programme for mid-AT. Methods A total of 40 soldiers (40 unilateral symptomatic tendons) were included in this study. Pain and function were evaluated with the Victorian Institute of Sports Assessment -Achilles (VISA-A) questionnaire. Tendon structure was quantified using ultrasound tissue characterisation (UTC). We quantified both the Achilles tendon mid-portion (2–7 cm) and the area of maximum degeneration (AoMD) within the tendon mid-portion. VISA-A and UTC measurements were taken at baseline and after 26 weeks of follow-up. Spearman’s rho was used to determine the correlation between VISA-A and UTC. Correlations were calculated for baseline, follow-up and change score values. Results Negligible correlations were found for all analyses, ranging from −0.173 to 0.166 between midportion tendon structure and VISA-A, and from −0.137 to 0.150 between AoMD and VISA-A. While VISA-A scores improved, on average, from 59.4 points at baseline to 93.5 points at follow-up, no detectable improvement in aligned fibrillar structure was observed in our population. Conclusion Pain and function are poorly associated with Achilles tendon structure in soldiers treated with a conservative programme for mid-AT. Therefore, we advise clinicians to use great caution in communicating relationships between both clinical entities.