Testosterone Replacement Therapy Formulation and Potential Association With Risk of Revision Total Knee Arthroplasty.

The final cohort of 62 patients with hypogonadism and TKA was distributed across three TRT formulations.

• 33 patients (53.2%) utilized topical TRT
• 27 patients (43.55%) utilized injectable intramuscular (IM) TRT
• 2 patients (3.2%) underwent implantation of a TRT pellet
• Inclusion criteria required men aged 18 to 89 years, a TRT prescription, and follow-up of at least 90 days
• Retrospective cohort analysis was conducted at a multihospital health system

Six of 62 patients (9.7%) experienced TKA revision, with the majority occurring in the IM TRT group.

• Three revisions (4.8%) were for periprosthetic joint infection and three (4.8%) were due to loosening without infection
• Five of the six revisions occurred in the IM TRT group
• One revision occurred in the topical TRT group
• No revisions were reported in the pellet implantation group

Average serum testosterone levels were significantly higher in patients receiving IM TRT compared to topical TRT.

• Average testosterone serum was 652.6 ng/dL for IM TRT patients
• Average testosterone serum was 356.1 ng/dL for topical TRT patients
• The difference was statistically significant (P = 0.001)

Chi-square analysis demonstrated an increased likelihood of TKA revision in the IM TRT group compared to the topical TRT group.

• Chi-square (1, N = 60) = 3.96, P = 0.046
• Five revisions occurred in the IM group versus one in the topical group
• The analysis excluded the two pellet patients, yielding N = 60 for this comparison

Prior work identified a correlation between TRT and revision rotator cuff and quadriceps tendon rupture repair, providing context for the current investigation.

• TRT is a commonly utilized treatment for male hypogonadism
• TRT prescriptions are available in various formulations including creams, gels, solutions, patches, intramuscular injections, and subcutaneous pellet implantation
• The risk associated with TRT and total knee arthroplasty was not previously delineated prior to this study

The authors suggest that perioperative modification of TRT formulation may reduce modifiable risk for revision TKA secondary to infection.

• The study identified increased likelihood of revision in the IM TRT group compared to topical TRT group
• Three of the six revisions were specifically attributed to periprosthetic joint infection
• The authors recommend consideration of formulation modification in the perioperative TKA patient as a potentially modifiable risk factor