A large-scale study presented at this week’s American Academy of Orthopedic Surgeons (AAOS) meeting indicated serious health risks for testosterone users who undergo total knee arthroplasty (TKA).

Argen Omurzakov, a third-year medical student at Case Western Reserve University and his twin brother Arsen M. Omurzakov, a third-year medical student at Weill Cornell Medical College, reviewed the post-surgical health of over 13,000 people who received TKA. They found that patients who took testosterone in the year before surgery faced higher post-op risks for infection, blood clots, kidney damage, pneumonia, and knee instability than those not taking it.

“With more people taking this hormone than ever, and TKA surgeries expected to exceed one million per year by 2030, we wanted to dive deeper into the question of testosterone’s post-surgical effects,” said Dr. Brian Chalmers, the senior author of the study.

The study retrospectively followed adults undergoing primary TKA before February 2020 through five years of follow-up using a national electronic health record (EHR) database.

At 90 days, testosterone replacement therapy (TRT) users had higher rates of pulmonary embolism (PE) (1.6% vs. 1.2%), pneumonia (3.3% vs. 1.9%), acute kidney injury (AKI) (4.2% vs. 2.9%), and sepsis (1.9% vs. 1.1%). At one year, it was also related to increased rates of PE (2.6% vs. 2%), deep vein thrombosis (DVT) (4.5% vs. 3.3%), cardiac events (3% vs. 2.4%), pneumonia (6% vs. 4%), AKI (7.9% vs. 5.2%), and sepsis (2.4% vs. 0.9%).

Periprosthetic complications at one year were also much higher in TRT users, including periprosthetic infection, periprosthetic fracture, aseptic loosening, instability, and revision surgery. These remained elevated at five years.

“Studies also suggest that testosterone influences the way our bones naturally rebuild themselves over time,” said Arsen Omurzakov. “Testosterone levels may also affect the immune system and the microbiomes that affect the immune system, healing and other key functions in the body,” added Argen Omurzakov.