Note: This is another in a series of posts I am writing to highlight important studies from the 2011 Annual Meeting of the American Orthopaedic Society for Sports Medicine. Read my thoughts about the study in an article from US News & World Report’s Health Day.

ACL injuries are among the more devastating injuries in sports, as they usually end the athlete’s season and require surgery. The surgery, which involves creating a knee ligament from tissue from the patient’s knee or from a donor, aims to restore stability to the knee and help get the athlete back to sports. Unfortunately, athletes can damage other structures (meniscus, articular cartilage, etc.) in the knee at the time of injury, and these have potentially long-term effects.

A new study presented at the American Orthopaedic Society for Sports Medicine’s Annual Meeting looked at factors associated with increased risk for damage to the articular cartilage in the knee among athletes who had suffered a torn ACL. Researchers from Norway reviewed 15,783 patients who had undergone primary ACL reconstructions over a 4-year period. 6.4% of the patients were found to have full-thickness defects in the articular cartilage at the time of surgery. Males were more likely to have full-thickness cartilage defects than females, and patients who waited over 12 months after their injury to have surgery also were more likely to have these cartilage defects. Tweet this statistic.

“Having articular cartilage lesions is considered a predictor of future osteoarthritis – a debilitating joint condition,” claimed the study’s lead author Jan Harald Roetterud, MD, from Akershus University Hospital, Lørenskog, Norway. “Our research is exciting because it highlights the possibility of gender as a significant risk factor, along with age, knee trauma and time between injury and surgery exceeding 1 year, in these types of injuries.”

Note how the femoral attachment of the graft (right side of image) inserts at the 2:00 or so position in the notch.

One of the concerns about an athlete who tears his or her ACL is stabilizing the knee to prevent it from buckling or giving way when the athlete returns to jumping or cutting/pivoting sports. If that buckling continues to occur, further damage to the knee, especially meniscal tears or damage to the articular cartilage, can occur. I think that the finding that increased time between injury and surgery leads to a higher chance of having a full-thickness cartilage defect makes sense for that reason. Therefore, if an athlete injures his or her ACL, I would point out that he or she should at least consider surgerywithin the first few weeks of injury (if he or she wants to do surgery at all) in order to minimize this risk.

As for the finding that males were more likely to have cartilage defects than females, I think more research needs to be done to try to determine why that seems to be the case. ACL injuries are much more common in female athletes, and a tremendous number of studies are attempting to assess risks among females athletes and then directing injury prevention programs based on these risks. What specifically is different about the nature of the trauma to the knee in male athletes compared to females that more often damages the cartilage is not known at this time.