Burden and risk factors for Achilles tendon rupture in the military population from 2006 to 2015: A retrospective cohort study
Authors: Fraser John J. , Zellers Jennifer A. , Sullivan Christopher K , Janney Cory F. 
Published: October 2023

Background

Achilles tendon rupture (ATR) is a serious musculoskeletal injury that results in substantial functional decline, especially in highly physically demanding occupations such as service in the military

Purpose

The objective of this study was to evaluate the burden and associated factors of ATR in US military service members.

Study Design

Descriptive Epidemiology Study

Methods

The Defense Medical Epidemiology Database was used to identify all diagnosed ATR in military personnel from 2006 to 2015. Prevalence of ATR was calculated and compared by year, service branch, and military rank. Unadjusted and adjusted assessments of injury risk were calculated.

Results

Officers incurred 15 978 episodes at a prevalence of 7.43/1000 (male: 8.11/1000; female: 3.89/1000). Among enlisted personnel, there were 59 242 episodes of ATR that occurred at a prevalence of 6.23 episodes per 1000 (male enlisted: 6.49/1000; female enlisted: 4.48/1000). Apart from enlisted aviation specialists (where there was no significant difference in risk between men and women), both female officers and enlisted service members had significantly lower risk of ATR compared with their male counterparts in all occupations (prevalence ratio [PR]: 0.26-0.73). Aviation and service officers demonstrated significantly lower risk of ATR episodes (PR: 0.87-0.91) and administration, operations, intelligence, and logistic officers demonstrated increased risk (PR: 1.16-1.31) compared with ground and naval gunfire officers. Among enlisted specialties, all but mechanized/armor and combat engineers had significantly higher risk of ATR risk compared with infantry (PR: 1.14-2.13), with the highest risk observed in the administration, intelligence, and communication fields.

Conclusions

ATR was ubiquitous in the US military, with multiple risk factors identified, including male sex, older age, rank, military occupation, and service branch.

Clinical Relevance

Based on the burden of ATR in the US military observed in this study, these findings highlight both the need for prophylactic interventions and identification of the populations who can most greatly benefit from preventive screening and care.

What is known about the subject

In an earlier study of the ATR burden in US military members, 1441 ATR cases were identified between 1998 and 2001, occurring at a rate of 30.9 per 100 000 person-years. In a more recent study of care episodes for Achilles tendinopathy in the military, the prevalence was 17.65 per 1000 in officers and 12.22 per 1000 in enlisted members, with male sex, older age, senior rank, military occupation, and service branch found to be salient associated factors. It is highly plausible that occupation may also be a salient factor for ATR, given that tendinopathy may be a prodromal sign of future tendon failure.

What this study adds to existing knowledge

Due to the changes in operational requirements, training, engagement in overseas contingency operations, and force composition that have occurred over the past 22 years, this provides an updated assessment of burden and the associated risk factors of ATR.