Let me first familiarize you with the structure of the knee joint before I answer your questions.
Three bones of the lower extremity come together to form the knee joint, the thigh bone (femur), shin bone (tibia) and knee cap (patella). The joint is enclosed by a connective tissue capsule whose inner lining secretes a liquid material called synovial fluid that fills the joint cavity and lubricates the joint.
The knee joint is stabilized by strong bands of connective tissue called ligaments. It is moved by the knee muscles (i.e., the muscles that go across the joint). In addition to moving the joint, the knee muscles also strengthen the joint.
The surfaces of the femur, tibia and patella that communicate with each other in the knee joint are covered with cartilage ("gatil," in Filipino). These articular cartilages reduce friction between the surfaces of the bones and enable the bones to move smoothly against each other within the joint.
Aside from the articular cartilages, two other pieces of cartilage are present in the knee joint, the lateral meniscus and medial meniscus. The menisci (plural, for meniscus) are C-shaped cartilages that are sandwiched between the articulating surfaces of the thigh bone (femur) and the shin bone (tibia). Their function is to serve as cushion between the two bones and to distribute body weight evenly across the joint. If the menisci are not present, body weight will be unevenly shared out between the femur and the tibia and cause specific areas of bones to receive excessive forces and accelerate degeneration of these areas.
Hence, there are two sets of cartilages present in the knee joint: the articular cartilages and the menisci. The articular cartilages are usually the cartilages that are subjected to wear and are the ones often involved in degenerative arthritis (osteoarthritis) of the knee. The menisci, on the other hand, are the cartilages that are more commonly torn. Hence, when most experts say cartilage tear, they usually refer to a tear in either the lateral or medial meniscus. In all probability therefore, your problem is a torn meniscus.
Tear of a meniscus is usually the result of trauma (e.g., sports injuries, which happened to you) or degenerative process (e.g., cartilage tears in elderly people)—with age, cartilage becomes more brittle and susceptible to injury.
When a meniscus is torn, the torn edge of the cartilage sometimes impinges on the other structures in the knee joint. This causes pain, swelling and occasionally "locking" of the joint. Often, the joint also becomes tender and occasionally, it pops or clicks from within.
History and physical examination together with X-ray and MRI exams are usually enough for a physician to diagnose a torn meniscus.
Now, let me answer your second question first. Cartilages have poor blood supply and therefore, their healing capacity is minimal. Furthermore, this capacity diminishes with age. Hence, at your age, it is very unlikely for your meniscus to heal on its own.
Should you undergo an operation? That’s really up to you.
Surgery is the only definitive treatment for a torn meniscus, but not all people with the condition need to undergo surgery. Many people with a minor tear can live normal lives, provided they do not carry out activities that will unduly stress their knee.
In as much as you are not experiencing any pain or swelling at the moment, there is really no urgency in having a surgery, especially if you do not intend to play basketball or any other physically demanding sport again. But if the pain and the swelling recur, then it is time to seriously consider surgery.
Address inquiries on health matters to Dr. Eduardo G. Gonzales, DLSU College of Medicine, Dasmariñas, Cavite 4114.
