Testosterone Levels Before and After Anterior Cruciate Ligament Reconstruction A Prospective Observational Study.

Purpose: Over 200,000 anterior cruciate ligament (ACL) reconstructions are performed in the US each year. The recovery process following surgery can be slow and difficult with patients suffering persistent strength and endurance deficits. Testosterone is an important anabolic hormone responsible for maintenance and development of muscle mass. While the response of the hypothalamic-pituitary axis (HPA) to surgery has been investigated, no studies exist tracking the HPA response, specifically that involved in testosterone homeostasis, to ACL reconstructions. The purpose of this study was to explore the response of endogenous testosterone production after ACL reconstruction and determine a possible correlation between perioperative testosterone levels in males and postoperative strength and clinical outcomes.

Methods: This was a single-center, prospective observational study measuring preoperative and postoperative testosterone levels. Plasma testosterone, follicle stimulating hormone (FSH), and lutenizing hormone (LH) were measured before 10:30 am on the day of surgery. These were then checked at the same time of day at 1 week, 6 weeks, and 12 weeks postoperatively. Patients were also evaluated with the visual analog scale for pain (VAS), Tegner, and Lysholm scales preoperatively and at postoperative visits. Statistical analysis was performed using ANOVA and were considered significant at p < 0.05.

Results: Twenty male patients with a mean age of 34.0 ± 9.2 years undergoing ACL reconstruction were enrolled between October 2017 and April 2018. Results showed a decrease in testosterone (3.7 ng/mL vs. 2.9 ng/mL, p = 0.05), free testosterone (8.2 pg/mL vs. 6.8 pg/mL, p = 0.05), and follicle stimulated hormone (1.8 mIU/mL vs. 1.7 mIU/ mL, p = 0.83) between the preoperative plasma draw and 1-week postoperative follow-up visit. Luteinizing hormone (1.1 mIU/mL vs. 1.5 mIU/mL, p = 0.11) increased postoperatively. By week 6, testosterone returned to baseline (3.7 ng/mL vs. 3.9 ng/mL), while free testosterone continued to increase through week 12. Lutenizing hormone peaked at the 1-week postoperative visit and trended downward until week 6 (1.5 mIU/mL vs. 1.4 mIU/mL, p = 0.79). Follicle stimulating hormone continued to increase after the week-1 visit through week 12. Patient reported outcomes exhibited a trend similar to hormone levels, with the lowest patient reported outcome (PRO) scores reported at week 1 and a constant trend upward. Although there were similar trends, there were no significant correlations between change in hormone levels and change in PRO scores.

Conclusion: Our study emphasizes the crucial period of hormonal decrease and their return to baseline. This knowledge will contribute to the understanding and timing of hormone therapy supplementation. Short-term testosterone replacement may be beneficial to return patients to work and physical activity at a faster rate.