The meniscus is a shallow bowl shaped piece of cartilage that is attached to the lower leg bone, or tibia. There is a medial meniscus (inner half of knee) and a lateral meniscus (outer half of knee).
The end of the femur (upper leg) bone has two protuberances called the femoral condyles, which rest on top of the meniscii (plural). In the standing position, the meniscii bear the full weight of the body above the knee. They serve as a cushion and shock absorber and protect both of the ends of the tibia and the femur. As the knee bends, the femoral condyles glide over the meniscii.
The knee is a very important, highly utilized weight bearing joint. It is held together by many ligaments, the primary being the anterior and posterior cruciate ligaments (ACL, PCL), the medial and lateral collateral ligaments (MCL, LCL), and the patellar tendons. It is a synovial joint, which means it is totally encapsulated and lined with synovium, a specialized tissue that secretes synovial fluid to lubricate the joint.
The slightest alteration in the inner workings of the knee will lead to problems. A common one is a meniscal tear. The two basic types are a radial tear and a vertical tear.
Meniscal tears are believed to come about by excessive pounding forces to the knee, which weaken the meniscii over time. Eventually a tiny tear forms, which grows in length as the individual continues to engage in the offensive activity (perhaps running on hard pavement, weight lifting, playing basketball, etc.). Sometimes small pieces break free and float loosely inside the knee space. This can cause the knee to swell and become stiff (difficult to fully bend). Pain is felt deep inside the knee and is worse with prolonged standing and transitioning from sitting to standing.
Meniscal tears increase the chances of accelerated knee osteoarthritis, as “bone on bone” contact occurs between the ends of the femur and tibia.
TREATMENT: Diagnosis is made with a knee MRI and arthroscopy. Meniscal tears will most likely require arthroscopic surgery involving repair to the tear. If you have a gradual onset of deep, focal knee pain accompanied by knee stiffness that doesn’t go away, see your doctor.
Prevention, as always, is the key. I advise against sports that involve consistent and prolonged pounding forces to the knee. This includes long distance running and frequent hard court basketball that involves jumping. Consider doing functional exercises that combine cardio and strength instead.
Most leg exercises will strengthen the knee. Do mostly closed kinetic chain exercises where the foot is immobilized. This includes squats and lunges.
Intermittent jumping exercises are ok as long as they are controlled and are not the focus of an exercise session. Power jumps and related plyometric exercises fall into this category.