The meniscus, a key piece of cartilage that provides cushioning in the knee, had its NBA moment when Portland’s Brandon Roy revealed last year that he has no meniscus left in either knee. This meant that, to at least some degree, the bones that make up Roy’s leg and the joint were rubbing together with each movement, a chronic problem that can lead to other chronic problems (i.e arthritis) and general deterioration.
Athletes actually damage that band of cartilage fairly often. Doctors try to preserve as much of the meniscus as possible, either by trimming away damaged areas or repairing them in hopes that everything will grow back properly. Between 1988-89 and 2008-09, the NBA recorded 147 injuries classified as tears of the meniscus, about seven per season, according to a study set to be published soon in The American Journal of Sports Medicine.
The study, conducted by surgeons associated with the prestigious Kerlan-Jobe Orthopaedic Clinic and in conjunction with Gary Vitti, the Lakers’ longtime athletic trainer, is based on an examination of those meniscal tears and is the first to look at long-term data for all 30 teams. And it unearthed this potentially crucial nugget: NBA players, by a huge margin, tend to injure one part of their meniscus, while regular folks tend to injure another part.
NBA players were disproportionately likely to injure the lateral side of their meniscus, the band that runs along the outside of the knee and — this is the important part — is considered a far more serious injury than a tear on the inside section of the knee (the injury found in the huge majority of injuries to non-athletes). Lateral tears accounted for about 60 percent of all meniscal tears during those 20 years, the study found. The trend is particularly strong among players with a higher Body Mass Index, though it appears to flip as players age. NBA players older than 30 have injury patterns closer to those of “normal” people, meaning they are more likely to tear their medial meniscus, according to the study.
Doctors and trainers almost universally consider a lateral tear far more serious than a medial tear. The lateral side of the meniscus is more flexible and mobile, allowing the knee to move around in ways that are crucial for NBA players, according to Peter Yeh and F.D. Kharrazi, two of the five listed authors (Kharrazi is a consultant for the Lakers). Also, there are sections of the medial side you can’t easily repair because of weak blood flow, according to Casey Smith, the Mavericks’ athletic trainer and chair of the National Basketball Athletic Trainers Association. Instead of fixing those irreparable chunks on the medial side, surgeons simply remove them, a procedure players can recover from more quickly than a surgical repair of damage on the lateral side.
The implications of this finding, if it holds up to further scrutiny, are unclear. If this injury pattern is just something inherent to basketball, perhaps there is nothing to be done about it.
“The thing about a data dive like this is: What does it mean?” Smith said in an interview with SI.com. “The ideal outcome would be to identify causal factors and mitigate them to reduce the occurrence of the injury. Saying it’s more common among basketball players may be true, but what does that mean?”
Smith suggests doing the same kind of study with other athletes who run and jump a lot, such as soccer players. Kharrazi says he’d love to do that, and that in his experience, meniscus problems among soccer players tend to mirror those of the general population. He says he has recently treated several WNBA players who have suffered meniscus tears, and that the last half-dozen such tears have involved the lateral meniscus — just like the majority of NBA players studied.
One other twist: The paper found that performance levels one year after surgery to repair a meniscal tear were about the same regardless of whether the tear was on the lateral or medial side. The recovery time was also about the same.
“That is going to be controversial when this paper comes out,” Yeh said. “Most sports physicians and trainers around the country say in their experience the lateral tear is much harder to take care of than a medial tear.”
The caveats here are huge, though, as the authors concede. They measured performance only in the season immediately after the operation, and they based their conclusions on John Hollinger’s Player Efficiency Rating, the best catch-all stat we have, but one that does not really account for minutes played. (Hollinger has created other stats to try to get at that issue.)
There is a long way to go before anyone can say anything definitive about performance outcomes. But given that the study looked at 20 years of injury data, the conclusion that NBA players — and especially young NBA players — are more likely to tear their lateral meniscus seems solid. That finding, combined with the notion that a lateral tear is more serious and carries more long-term degenerative consequences, raises a million questions about potential prevention methods and treatment decisions.
The next step will be to see if any of those questions have sound answers.