title: Randomized control trial to evaluate the effects of acute testosterone administration in men on muscle mass, strength, and physical function following ACL reconstructive surgery: rationale, design, methods.
abstract: BACKGROUND
  The anterior cruciate ligament (ACL) is one of four major ligaments in the knee that provide stability during physical activity. A tear in the ACL is characterized by joint instability that leads to decreased activity, knee dysfunction, reduced quality of life and a loss of muscle mass and strength. While rehabilitation is the standard-of-care for return to daily function, additional surgical reconstruction can provide individuals with an opportunity to return to sports and strenuous physical activity. Over 200,000 ACL reconstructions are performed in the United States each year, and rehabilitation following surgery is slow and expensive. One possible method to improve the recovery process is the use of intramuscular testosterone, which has been shown to increase muscle mass and strength independent of exercise. With short-term use of supraphysiologic doses of testosterone, we hope to reduce loss of muscle mass and strength and minimize loss of physical function following ACL reconstruction compared to standard-of-care alone.
  
  
  METHODS
  This study is a double-blinded randomized control trial. Men 18-50 years of age, scheduled for ACL reconstruction are randomized into two groups. Participants randomized to the testosterone group receive intramuscular testosterone administration once per week for 8 weeks starting 2 weeks prior to surgery. Participants randomized to the control group receive a saline placebo intramuscularly instead of testosterone. Lean mass, muscle strength and physical function are measured at 5 time points: 2 weeks pre-surgery, 1 day pre-surgery, and 6, 12, 24 weeks post-surgery. Both groups follow standard-of-care rehabilitation protocol.
  
  
  CONCLUSIONS
  We believe that testosterone therapy will help reduce the loss of muscle mass and strength experienced after ACL injury and reconstruction. Hopefully this will provide a way to shorten the rehabilitation necessary following ACL reconstruction. If successful, testosterone therapy may also be used for other injuries involving trauma and muscle atrophy.
  
  
  BACKGROUND
  NCT01595581, REGISTRATION: May 8, 2012.
authors.affiliation: Keck School of Medicine, University of Southern California, Los Angeles, CA, USA. brianwlwu@gmail.com.
authors.forename: Brian W
authors.initials: BW
authors.lastname: Wu
authors.forename: Max
authors.initials: M
authors.lastname: Berger
authors.forename: Jonathan C
authors.initials: JC
authors.lastname: Sum
authors.forename: George F
authors.initials: GF
authors.lastname: Hatch
authors.forename: E Todd
authors.initials: ET
authors.lastname: Schroeder
mesh_terms: D000293:Adolescent; D000328:Adult; D000070598:Anterior Cruciate Ligament Injuries; D059549:Anterior Cruciate Ligament Reconstruction / Q000534:rehabilitation; D004311:Double-Blind Method; D006801:Humans; D007273:Injections, Intramuscular; D008297:Male; D008875:Middle Aged; D053580:Muscle Strength / Q000187:drug effects*; D018482:Muscle, Skeletal / Q000187:drug effects* / Q000502:physiology; D059035:Perioperative Period; D020127:Recovery of Function; D013739:Testosterone / Q000008:administration & dosage*; D055815:Young Adult
chemical_list: D013739:Testosterone