Testosterone Therapy Before Knee Surgery: What a Major New Study Reveals About Hidden Risks

If you're taking testosterone and planning knee replacement surgery, new research suggests you need an urgent conversation with your doctor. A groundbreaking study presented at the 2026 Annual Meeting of the American Academy of Orthopaedic Surgeons found that patients using testosterone in the 12 months before total knee arthroplasty (TKA)—a common joint replacement procedure—faced significantly higher risks for serious post-surgical complications compared to those not taking the hormone.

Why This Study Matters Now More Than Ever

Testosterone replacement therapy (TRT) has exploded in popularity over the past five years. Prescriptions jumped from 7.3 million in 2019 to more than 11 million in 2024—a 50% increase in just five years. Meanwhile, knee replacement surgeries are expected to exceed one million procedures annually by 2030, making this research particularly timely for millions of Americans.

The study, led by twin brothers Argen and Arsen Omurzakov—both third-year medical students at Case Western Reserve University and Weill Cornell Medical College—reviewed the post-surgical health of more than 13,000 people who received knee replacement. What makes this research unique is that it included nearly equal numbers of men and women, addressing a critical gap in sexual health research that has historically focused on men.

What Were the Actual Risks Found?

The findings were striking. At 90 days after surgery, testosterone users experienced significantly higher rates of serious complications:

• Blood Clots: Testosterone users had a 1.6% rate of pulmonary embolism (blood clots in the lungs) compared to 1.2% in non-users
• Pneumonia: 3.3% of testosterone users developed pneumonia versus 1.9% of those not taking the hormone
• Kidney Damage: Acute kidney injury occurred in 4.2% of testosterone users compared to 2.9% of non-users
• Sepsis: A life-threatening blood infection developed in 1.9% of testosterone users versus 1.1% of non-users

By one year after surgery, the gaps widened further. Testosterone users had double the rate of deep vein thrombosis (blood clots in the legs)—4.5% versus 3.3%—and nearly triple the rate of periprosthetic joint infection (infection around the artificial knee), at 2.4% versus 0.9%.

Even more concerning, these complications persisted at the five-year mark. Testosterone users experienced periprosthetic joint infections at nearly 2.3 times the rate of non-users (4.3% versus 1.9%), and were significantly more likely to need revision surgery—where the artificial knee must be replaced again—at 4.1% versus 2.7%.

How Does Testosterone Affect Surgical Healing?

The researchers aren't yet certain exactly why testosterone increases these risks, but they have compelling theories. "Studies suggest that testosterone influences the way our bones naturally rebuild themselves over time," explained Arsen Omurzakov. His brother Argen added that "testosterone levels may also affect the immune system and the microbiomes that affect the immune system, healing and other key functions in the body".

The hormone has already been linked in previous research to higher risks for blood clots—a finding that helps explain the elevated rates of pulmonary embolism and deep vein thrombosis seen in this study. Additionally, testosterone may interfere with how the body's natural defenses respond to surgical trauma and foreign materials like artificial joints.

Steps to Take If You're on Testosterone and Need Surgery

• Disclose All Medications: Tell your orthopedic surgeon and anesthesiologist about any testosterone therapy you're using, including the dose, form (injection, gel, patch), and how long you've been taking it
• Discuss Timing Options: Ask whether stopping testosterone before surgery—and for how long—might reduce your risk, and when it would be safe to resume after recovery
• Request Enhanced Monitoring: If you decide to continue testosterone, ask about more frequent post-operative check-ups, blood work, and imaging to catch complications early
• Review Your Specific Situation: Work with your doctor to weigh the benefits you're getting from testosterone against the surgical risks in your particular case

The Bigger Picture: Testosterone's Complicated Medical History

Testosterone therapy remains medically controversial, despite decades of research supporting its safety for appropriate patients. The hormone's troubled past in medicine helps explain why some doctors remain cautious. For 60 years, physicians avoided prescribing testosterone because of a single study from the 1940s by Nobel Prize winner Charles Huggins, who concluded that testosterone activated prostate cancer. However, that landmark study was based on just one patient treated for 18 days—a fact that wasn't widely known until decades later.

Dr. Abraham Morgentaler, a pioneering urologist at Harvard Medical School, spent four decades systematically proving that testosterone therapy in men with low testosterone does not increase prostate cancer risk. "The first indication I had there was something wrong with the story was my guys were doing well," Morgentaler explained, noting that his patients showed no signs of cancer despite his intensive monitoring. Today, the medical consensus aligns with his clinical evidence, yet ambivalence toward testosterone persists in some medical circles.

The current controversy around testosterone is different from the old prostate cancer fears. Modern research shows testosterone can benefit people with genuine low levels of the hormone, but the hormone is increasingly prescribed for broader purposes—improving sex drive, building muscle, and treating menopausal symptoms—sometimes without careful consideration of individual circumstances.

What Experts Say About Treating Testosterone as Individual, Not Just Numbers

Dr. Tami Rowen, president-elect of the International Society for the Study of Women's Sexual Health (ISSWSH), emphasizes an important distinction: "Testosterone therapy should treat symptoms and goals, not hormone levels or deficiencies". This means the decision to use testosterone shouldn't be based solely on blood test results, but rather on whether a person is actually experiencing symptoms that testosterone might help—and whether the benefits outweigh the risks in their specific situation.

This nuanced approach is especially important given the new surgical findings. A person taking testosterone for legitimate reasons—such as low libido or menopausal symptoms—may need to make a temporary sacrifice if they're facing major joint surgery. The key is having an informed conversation with healthcare providers who understand both the benefits and the risks.

The research also highlights a critical gap in sexual health funding and research. While breast cancer receives $800 million in annual research funding, conditions like vulvodynia (chronic pelvic pain) receive only $4 million—roughly one-fifth the amount. This disparity means that sexual health decisions are often made with incomplete information, and patients may not have access to specialists who can help them navigate complex situations like surgery while on hormone therapy.

For the millions of Americans currently taking testosterone, this new study doesn't mean the hormone is unsafe—it means that timing matters. If you're considering knee replacement or other major surgery, discussing your testosterone use with your surgical team isn't optional; it's essential to your safety and recovery.