The menisci are moon shaped structures in the knee made of fibro-cartilage. The menisci function as shock absorbers and as guides to control the knee during bending. Sudden meniscal tears often happen during sports. Meniscal tears may also occur as a result of arthritis or aging. Just an awkward twist when getting up from a chair may be enough to cause a tear, if the menisci have weakened with age.
The kneecap connects the muscles in the front of the thigh to the shinbone (tibia). As you bend or straighten your leg, the kneecap is pulled up or down. The thighbone (femur) has a V-shaped notch (femoral groove) at one end to accommodate the moving kneecap. In a normal knee, the kneecap fits nicely in the groove. But if the groove is uneven or too shallow, the kneecap could slide off, resulting in a partial or complete dislocation. A sharp blow to the kneecap, as in a fall, could also pop the kneecap out of place.
- Knee buckles and can no longer support your weight
- Kneecap slips off to the side
- Knee catches during movement
- Pain with activity
- Pain when sitting
- Creaking or cracking sounds during movement
If the kneecap has been completely dislocated out of its groove, the first step is to return the kneecap to its proper place. This process is called reduction. Sometimes, reduction happens spontaneously. Other times, your doctor will have to apply gentle force to push the kneecap back in place.
A dislocation often damages the underside of the kneecap and the end of the thighbone, which can lead to additional pain and arthritis. Arthroscopic surgery can correct this condition.
If the kneecap is only partially dislocated, your doctor may recommend nonsurgical treatments, such as exercises and braces. Exercises will help strengthen the muscles in your thigh so that the kneecap stays aligned. A stabilizing brace may also be prescribed. The goal is for you to return to your normal activities within 1 to 3 months.
A chronic condition, in which the knee continues to be unstable, can often be corrected by surgery.
The quadriceps and patellar tendons can be stretched and torn. Although anyone can injure these tendons, tears are more common among middle-aged people who play running or jumping sports. Falls, direct force to the front of the knee, and landing awkwardly from a jump are common causes of knee tendon injuries.