With all the high tech approaches to sports medicine injuries, we sometimes don’t discuss some of the more common injuries we see. Today, let’s talk about knee meniscus injuries.
There are two menisci in the knee, one on the inside (the medial meniscus) and one on the outside (lateral meniscus). Each one is shaped like a "C" with a narrow inner concave margin and thicker outer margin. They match up with the two femoral condyles, those convex cartilage covered bumps on the end of the femur bone.
The meniscus provides substantial stability to the knee in twisting movements. In addition, by their shape they increase the joint contact area and because of this, lessen the contact force across the knee.
Blood vessels enter the meniscus along its periphery and supply the outer third of the structure. To an athlete, this has big implications. If a meniscus is torn in its periphery, it can be repaired and potentially heal.
However if it is torn towards its inner margin, the injury will never heal and the torn segment needs to be removed and not repaired. It is much more likely that a meniscus is torn in the portion without a blood supply, thus most meniscus tears are resected (removed) back to healthy cartilage. Recovery is relatively quick and prognosis usually good.
If a surgeon repairs the meniscus, an athlete must remain on crutches for at least a month and recovery is slow over 4-6 months. If healing is successful, the meniscus function becomes normal.
The most common situation that I repair a meniscus is in association with an ACL surgery. An athlete is already slowed down in the ACL recovery and meniscus healing is usually excellent because he/she is obliged to avoid sports stress for several months.
On rare occasions, a complete removal of the meniscus is necessary and we give consideration to meniscus transplantation from a cadaver source. Although these procedures can be successful to return an individual to pain free daily activities, it is not appropriate for them to return to heavy sports activities.