Background: Anabolic steroid use at supraphysiologic doses has been associated with an increased risk of tendon injury. However, the musculoskeletal effects of testosterone therapy in the clinical setting are not well understood.
Questions/purposes: (1) Is prescription testosterone associated with a higher odds of subsequent quadriceps muscle or tendon injury? (2) Is prescription testosterone associated with a higher odds of surgical repair of the quadriceps tendon?
Methods: The PearlDiver Database, which contains data on Medicaid, Medicare, and commercially insured patients, allows for a large representative sample of the US population including both publicly and privately insured patients. The database was queried for all patients between 2011 and 2018 who filled a testosterone prescription. Additionally, all quadriceps injuries using ICD-9 and ICD-10 codes between 2011 and 2018 were queried. Propensity score matching based on age, sex, Charlson comorbidity index, and specific comorbidities allowed us to create matched control groups. We used the t-test and chi-square analysis to compare the unmatched and matched cohorts. A total of 151,797 patients (123,627 male patients and 28,170 female patients) with a history of filled testosterone prescriptions were included in the study after matching with the control group, which was of equal size and representation of age, male-female proportions, and comorbidities. Chi-square and logistic regression analyses were performed to compare odds of quadriceps injury and quadriceps tendon repair among the testosterone groups to that of their respective control groups by age and sex.
Results: Within 1 year of filling prescriptions for testosterone, 0.06% (97 of 151,797) of patients experienced a quadriceps injury compared with less than 0.01% (18 of 151,797) of patients in the control group (OR 5.4 [95% CI 3.4 to 9.2]; p < 0.001). Within the sex-specific matched groups, filling a testosterone prescription was associated with an increase in the odds of quadriceps injury in male patients within 1 year of the prescription (OR 5.8 [95% CI 3.5 to 10.3]; p < 0.001). Additionally, patients who filled a testosterone prescription were at increased risk of having quadriceps tendon repair within a year of the injury than were patients in the matched control group (OR 4.7 [95% CI 2.0 to 13.8]; p = 0.001).
Conclusion: Considering these findings, it is important for physicians to counsel patients receiving testosterone replacement therapy of the substantially increased odds of quadriceps tendon injury. Future investigations into the mechanisms of influence of exogenous anabolic steroids on tendon injury remains of interest.
Level of evidence: Level III, therapeutic study.
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