Tendon Injury Is Associated With Sex Hormone Therapy in the Active-Duty Population

The impact of sex hormones on connective tissue is controversial. Previous investigations found that female estrogen contraceptive therapy use may have simultaneous beneficial and detrimental musculoskeletal health effects, whereas males receiving androgen therapy had an increased Odds Ratio (OR) (3.6) of rotator cuff tears and higher Achilles Tendon injury rates. Furthermore, males receiving androgen therapy had an increased OR (26.7) for rotator cuff revision within a year of primary surgery.

Our design involves an observational, retrospective study using de-identified data sourced from the Medical Assessment and Readiness System (MARS) at Womack Army Medical Center. We identified active-duty service members (ADSM) with and without connective tissue injuries, using ICD-9 and ICD-10 codes to capture tendon ruptures, strains, sprains (ligament injuries), and overuse injuries (e.g., trigger finger and carpal tunnel). We further identified current or prior androgen/estrogen therapy and included demographic, military, and health factor data.

Between January 2011 and June 2024, we observed 13,209 males, of whom 5,275 (39.9%) had an incident connective tissue injury. Males with current or prior androgen therapy had an increased risk for tendon rupture (adjusted hazard ratio [AHR] = 1.85; 95% CI, 1.71-2.00; P < .001), trigger finger (AHR = 2.03; 95% CI, 1.80-2.29; P < .001), carpal tunnel (AHR = 2.44; 95% CI, 2.33-2.55; P < .001), and (ligament injury) sprain (AHR = 1.50; 95% CI, 1.46-1.55; P < .001).

Our results demonstrate that estrogen contraceptive therapy minimally increases the time to connective tissue injury in female ADSM, while androgen therapy in male ADSM increased the risk of connective tissue injury by up to 200%. An anonymous survey of U.S. Army Rangers revealed that approximately 1/4 used an illegal steroid or other performance-enhancing drug (PED). While we could not capture the effects of PED, our study provides evidence that individuals using any androgens are at higher risk for connective tissue injury. While further investigation on dose response remains outstanding, our preliminary results highlight the increased risks of tendon rupture associated with pharmaceutical use.