Testosterone: A Review for Orthopaedic Surgeons.

Testosterone replacement therapy (TRT) use is common and possibly increasing in prevalence.

• TRT prescriptions tripled between 2001 and 2011 in the United States.
• Estimated 2.3 million American men were prescribed TRT in 2013.
• Anabolic androgenic steroid (AAS) use is also described as common and possibly increasing.
• The review notes this trend is relevant for orthopaedic surgeons who will encounter these patients.

Diagnosing and treating hypogonadism in men is described as controversial.

• There is no universally agreed-upon threshold for defining low testosterone levels.
• Symptoms of hypogonadism overlap with normal aging, making diagnosis challenging.
• Different professional organizations have varying recommendations for when to initiate TRT.
• The controversy involves balancing potential benefits of treatment against risks.

Hypogonadism and AAS use appear to have detrimental effects on the musculoskeletal system.

• Both low endogenous testosterone (hypogonadism) and supraphysiologic AAS use are associated with musculoskeletal harm.
• AAS use has been linked to tendon injury and altered tendon biomechanical properties.
• Hypogonadism is associated with decreased muscle mass, bone density, and overall musculoskeletal health.
• The detrimental effects span multiple musculoskeletal tissue types including bone, muscle, and tendon.

Current literature on TRT and the musculoskeletal system shows an increased risk of tendon injury.

• TRT has been associated with increased tendon injury risk in the reviewed literature.
• The mechanism is thought to involve altered collagen synthesis and tendon structural properties under androgenic influence.
• AAS use at supraphysiologic doses is particularly implicated in tendon rupture risk.
• This finding has direct clinical relevance for orthopaedic surgeons managing tendon pathology.

There may be a role for testosterone supplementation in the postoperative period.

• The review identifies a potential beneficial role for testosterone supplementation following orthopaedic surgery.
• Testosterone's anabolic properties may support tissue healing and recovery in the postoperative setting.
• The evidence is described with qualified language ('may be a role'), suggesting it is not yet definitive.
• This represents an area of potential clinical application for orthopaedic surgeons to consider.

Testosterone has broad physiological effects relevant to the musculoskeletal system including effects on muscle, bone, and connective tissue.

• Testosterone is an anabolic hormone with effects on muscle protein synthesis and muscle mass.
• Testosterone influences bone mineral density and bone remodeling.
• Androgen receptors are present in musculoskeletal tissues including tendon, muscle, and bone.
• Both endogenous and exogenous testosterone affect collagen synthesis in connective tissues.