A torn meniscus is a very common, painful and debilitating injury that occurs quite commonly from auto accidents.
Since so many people suffer from torn menisci, I thought it may help to provide some information about torn menisci and how serious such an injury can be. I therefore provide the following courtesy of The University of Virginia:
The ends of the three bones in the knee – the femur, tibia, and patella – are covered with cartilage (a smooth material that covers bone ends of a joint to cushion the bone and allow the joint to move easily without pain) that acts as a shock absorber. Between the bones of the knees are two crescent-shaped discs of connective tissue, called menisci, which also act as shock absorbers to cushion the lower part of the leg from the weight of the rest of the body.