Funding from the Mark Cuban Foundation, run by the well-known owner of the Dallas Mavericks, will allow University of Michigan scientists and physicians to study how human growth hormone may aid recovery from an ACL tear - one of the most frequent, traumatic and dreaded knee injuries among athletes.
Despite advances in surgical techniques and accelerated rehabilitation, the nearly quarter of a million patients who suffer ACL tears each year still experience permanent weakness and muscle loss. This weakness largely limits their ability to return to the same level of sport performance, and can increase their chances of developing painful osteoarthritis later in life.
The clinical trial, which is set to open today, will study if growth hormone can safely improve recovery and help to prevent long-term osteoarthritis and knee joint weakness after an ACL tear.
"There is a large body of research on growth hormone, and our study will be the first of its kind to explore whether it may aid recovery from an ACL tear. We think that a brief treatment with growth hormone around the time of surgery will help to limit some of the otherwise irreversible loss in muscle mass and strength that occurs after these injuries," says principal investigator Christopher Mendias, Ph.D., ATC, assistant professor of Orthopaedic Surgery and Molecular & Integrative Physiology at the University of Michigan Medical School and MedSport researcher.
The study will be a two-year, double-blinded, placebo controlled trial. Neither the patients nor their doctors will know whether they are taking the drug or an inactive placebo until after the study has been completed. A safety committee composed of U-M physicians will closely monitor patient health and safety throughout the study. The trial will evaluate whether patients restore full knee strength within 6 months after surgery.
Growth hormone (somatropin) is a prescription medication that has been used to prevent muscle atrophy and wasting in patients with HIV and other severe illnesses. Recent work from the University of Copenhagen has also shown that growth hormone can prevent muscle loss in otherwise healthy individuals who are immobilized for a brief period of time. However, when abused and taken at a very high dose for prolonged periods of time, it can lead to large gains in muscle mass. Because of the potential for abuse, most professional sports leagues throughout the world currently ban growth hormone.
"There are a lot of assumptions about how growth hormone may impact athletic performance and sports injuries but these claims are not supported by strong scientific evidence," Mendias says.
"We hope our findings will help professional sports organizations make more informed decisions about whether growth hormone should remain a banned substance or be used as treatment that can safely aid healing in players, return them to their pre-injury strength levels and reduce other long-term musculoskeletal risks which result from these injuries. The dose and timing of growth hormone in this study was carefully chosen to prevent the loss in muscle mass following ACL tear and reconstruction, but not lead to muscle gains elsewhere in the body."
ACL tears strike nearly 250,000 people a year and are especially notorious among professional athletes. Almost a quarter of NBA players and a third of NFL players who suffer an ACL tear do not return to professional sports. The athletes who do return typically miss over three quarters of the regular season and require over a year of recovery time.
"Improving the recovery of professional athletes with ACL tears will likely have an important short term impact on their playing careers but also help avoid long term health problems like osteoarthritis that can diminish quality of life and limit how active they can be as older adults," says Mendias.
Mendias and colleagues at U-M's MedSport clinic have long had a special interest and expertise in sports medicine therapies, conducting several studies over the years to improve the treatment of patients that suffer from muscle loss after rotator cuff tears or ACL tears.
"We hope our results bring new insight into the field of sports medicine and the quest to help both recreational and professional athletes more easily return to the activities they enjoyed before, and improve their long-term quality of life."
This trial has been reviewed and approved by the Food and Drug Administration, and is registered on
Christopher Mendias, PhD, ATC (Principal Investigator)
Assistant Professor of Orthopaedic Surgery and
Molecular & Integrative Physiology
Ariel Barkan, MD
Professor of Endocrinology and Neurosurgery and Co-Director,
Pituitary and Neuroendocrine Center
Asheesh Bedi, MD
Associate Professor of Orthopaedic Surgery and Chief of Sports Medicine
James Carpenter, MD
Professor and Chair of Orthopaedic Surgery
Joel Gagnier, ND, PhD
Assistant Professor of Orthopaedic Surgery and Epidemiology
PhD Candidate, Molecular & Integrative Physiology
P Troy Henning, DO
Assistant Professor of Physical Medicine and Rehabilitation
Jon Jacobson, MD
Professor of Radiology and Chief of Musculoskeletal Radiology
Source: University of Michigan Health System