The knee is a hinge joint where the tibia and femur meet. The back of the kneecap and the ends of the tibia and femur are protected by articular cartilage. There are also pads of cartilage --- meniscus --- that form cushions that act as shock absorbers to protect the bones. Other soft tissue includes several ligaments in the knee: the anterior cruciate ligament, the medial collateral ligament, the lateral collateral ligament and the posterior cruciate ligament. Any of these pieces of the knee may be injured during basketball, which will cause swelling and/or bruising.
Patella Tendonitis
A typical basketball injury is patella tendonitis, also called "jumper's knee." Patella tendinitis is inflammation of the patella tendon, which connects the kneecap to the tibia. Inflammation and irritation is caused by overuse, typically from constant jumping. Pain is located at the bottom of the kneecap and the tendon could appear swollen and bruised. Tendonitis may be mild, moderate or severe. In addition, a rupture of the tendon could occur during stress. See a health care provider to diagnose patella tendinitis.
Dislocation
A blow to the knee, such as during a trip and fall, can cause the kneecap --- patella --- to slide out of place, which is called dislocation. A portion of the patella may break off and lodge in the soft tissue, which requires surgery. Either of these scenarios will cause bruising and swelling. If surgery is not required, medical assistance is usually required to set the kneecap back into its proper place.
Ligament Injuries
The ACL, or anterior cruciate ligament, is the most commonly injured ligament in the knee. Injury is most often suffered in sports, especially those that requires twisting and jumping, such as in basketball. Severe sprains, tears or ruptures of the ligaments will all cause swelling and bruising in the knee. See a doctor if you think you have injured the ligaments in your knee.
Torn Meniscus
Damage to the cartilage is caused by jumping and twisting, as well as overuse. Typical injuries are to the medial or lateral meniscus. Usually the knee swells within 48 hours of the injury, and may be accompanied by bruising. The severity of the tear will dictate whether the injury requires surgery for repair. See a doctor if you suspect you have torn meniscus in your knee.
