The knee is a complex network that, when it functions correctly, allows us to walk, run and exercise. Knee injuries from trauma or overuse can cause pain, swelling and sometimes disability, short or long-term depending on how bad the injury is. Injuries can occur to the bones, the ligaments, the cartilage or the tendons.
Ligaments in the knee are often injured playing sports. The anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) are the two most commonly injured ligaments in the knee. ACL injuries occur when the knee is twisted one way while the bottom of the leg stays in place. PCL injuries occur when there is a direct blow to the knee. These types of knee injuries can stretch or tear the ligament. Symptoms of an ACL or PCL injury include pain, swelling and a popping sound from the knee. Depending on the severity of the injury, you may need a leg brace and crutches or surgery to repair or reconstruct the ligament.
The meniscus is a piece of cartilage that cushions and stabilizes the knee joint. A violent twisting of the knee can tear the cartilage. The knee may lock up if a piece of the cartilage comes loose and is caught in the knee joint. There is usually a feeling of something popping in the knee when this knee injury occurs. Pain and swelling may not set in until hours after the injury. Mild to moderate tears typically heal with rest and wrapping the knee with an elastic bandage. Surgery will be required if large pieces of cartilage have torn loose.
This type of knee injury can lead to tendinitis or a torn tendon, also called a ruptured tendon. Tendinitis is inflammation of the tendons in the knee. It commonly occurs in overuse injuries including playing sports, riding a bicycle or running. Torn tendons are the result of a fall or, in elderly people, weakened tendons. Jumper's knee is caused by a sport such as basketball, that requires repeated jumping. The stress of jumping can inflame or tear the tendon. Rest and anti-inflammatory medication are the typical treatment for tendinitis. For ruptured tendon knee injuries, surgery is needed to reattach the tendon ends.
Fractures of the kneecap commonly occur when there is direct trauma to the knee such as a fall or a car accident or slamming the knee into something. A leg brace or a cast and crutches are the treatment for simple breaks. A fracture of the kneecap that pulls the bone apart will need surgery to hold the bone together to heal properly.
Overuse injuries of the knee can cause bursitis. The bursae, sacs filled with fluid that cushion the joint, become inflamed, causing pain, swelling, warmth or redness around the knee. Infected bursae can cause fever in addition to pain and swelling of the knee. Treatment for this type of knee injury is rest and anti-inflammatory medication.