Common Knee Injuries

Acute knee injuries occur suddenly - from falling awkwardly, a forced twisting of the knee, a blow to the knee, etc. Acute knee injuries include knee sprain (torn knee ligaments - usually the acl), torn knee cartilage (torn meniscus), ruptured knee tendon, and knee fracture.

Overuse knee injuries are usually caused by increasing the intensity or duration of an activity increasing too quickly. Overuse knee injuries include knee tendonitis, knee bursitis, iliotibial band syndrome, and muscle strains. Overuse also contributes to runners knee.

ACUTE KNEE INJURIES

Torn ACL (also called Knee Sprain or Torn Ligament)

Four ligaments help stabilize the knee. Ligaments of the knee limit how far the bones of the joint (the thighbone and shinbone) can move to prevent dislocation of the knee joint. The two cruciate ligaments cross over each other on the inside the knee joint and limit front-to-back motion. The two collateral ligaments are outside the knee joint and limit side-to-side motion.

Ligaments on the outside of kneecap usually heal by themselves. Ligaments in the center of the knee rarely heal by themselves (because they are bathed in joint fluid and lack a blood supply) and may require reconstructive surgery. Surgery is not always necessary.

The ACL (anterior cruciate ligament), located in the center of the knee, is the most commonly injured ligament in the knee. ACL injuries are most common in people who play sports and women in sports are much more likely than men to tear this ligament. Twisting the knee is a common cause of overstretched or torn ligaments of the knee.

Symptoms of Torn ACL:
The knee may give out suddenly when the ACL is torn and there may be a popping sound upon injury. Symptoms of a torn ACL include knee pain, swelling, stiffness, and bruising. Walking is painful and the knee feels instable. The feeling of instability is caused by the bones in knee joint sliding too far (this can result in damaged cartilage).

Seek Immediate Medical Attention for Acute Knee Injuries. While waiting to see the doctor, to reduce swelling and pain apply ice immediately and leave on 15 - 20 minutes per hour. Elevate the knee above heart level if possible. Wrapping the knee in an ACE bandage (elastic bandage) provides compression and also helps limit swelling.

Treatment of Torn ACL:
The ACL cannot heal because of lack of blood supply. If the tear is small, the knee may be relatively stable and surgery may not be necessary. Exercises to strengthen the muscles that support the knee can help compensate for the lack of ligament stability.

Whether or not surgery is considered depends upon whether a person is active in sports. Being able to function adequately in daily activities is often possible with a torn ACL. Being able to safely perform the pivoting and sharp turning movements required in many sports cannot be safely performed with a torn ACL.

ACL Reconstruction:
If surgery is performed it is usually several weeks after the injury occurs to allow inflammation to subside. The ACL is not actually repaired, but reconstructed. The ACL is removed and reconstructed from a grafting a segment of a large tendon or ligament. As in any surgery, there are risks such as blood clots and infection.

Crutches are usually used for a couple of weeks following the surgery. Full recovery may take several months and varies from patient to patient. High-impact activities must be avoided until the knee has recovered sufficiently. Normal activities can be resumed before high-impact activities. Low-impact activities such as swimming help strengthen the muscles that support the knee joint (to take some load off the ligaments) without straining the joint.

Torn Meniscus (Torn Cartilage)

The meniscus (meniscal cartilage) is a spongy shock absorber that separates the thighbone and shinbone. This is the cartilage referred to when you hear "torn cartilage." There are two menisci in the knee - the medial (inner) meniscus and the lateral (outer) meniscus.

Meniscal tears may occur during participation in sports, often when the knee is twisted. These types of tears are usually vertical. Degenerative changes occur in the meniscus with aging, and meniscal tears may occur as a result. These types of tears are often horizontal. The degenerative tear may occur while kneeling or without any specific incident. Sometimes the person may not recall any specific injury.

Symptoms of Meniscus Tear:
There may be a popping sound upon injury. Most people are able to walk immediately after a meniscus tear but begin limping as swelling sets in. Symptoms include pain along the inner or outer side of the knee, stiffness, swelling, and sometimes "locking of the knee. A piece of torn cartilage may get caught between moving parts of the knee joint and limit motion or lock the joint. A clicking sound may be heard when moving the knee. The pain may be worse when squatting.

Seek Immediate Medical Attention for Acute Knee Injuries. While waiting to see the doctor, to reduce swelling and pain apply ice immediately and leave on 15 - 20 minutes per hour. Elevate the knee above heart level if possible. Wrapping the knee in an ACE bandage (elastic bandage) provides compression and also helps limit swelling.

Treatment of Torn Meniscus:
Unless it is a small tear on the outer edge, a torn meniscus will not heal on its own because of its lack of blood supply in its center. A meniscus tear sometimes can be repaired with sutures, but more often the damaged area of the meniscus is trimmed. The torn piece of meniscus may be surgically removed through arthroscopic surgery. As in any surgery, risks include blood clots and infection. Full recovery takes up to six weeks.

Not all meniscus tears require surgery. Some people can function with a torn meniscus. Pain and swelling often resolve within 6 weeks, even though the meniscus hasnt actually healed.

Surgery is often recommended. Depending upon the nature of the tear, a torn piece of cartilage may cause damage to the smooth cartilage that covers the ends of the knee bones. If the knee becomes locked, normal functioning is not possible and the muscles that support the knee weaken from lack of normal use.

The meniscus plays an important role in absorbing shock. If the entire meniscus or a large part of the meniscus is removed, the knee usually develops degenerative arthritis (osteoarthritis) within ten years. The articular cartilage that covers knee bones to help them glide over one another breaks down. Avoiding high-impact activities may slow down damage to the articular cartilage. Strengthening the muscles that support the knee, especially the quadriceps, help take stress off the knee joint and may also slow down the development of osteoarthritis.

Knee Fractures

Caused by a forceful blow to knee as in contact sports or a fall. Symptoms are knee pain, moderate to severe swelling, there may be an inability to walk or to withstand weight on leg and/or muscles going into spasms upon slightest movement of knee. X-ray can confirm fracture. Sometimes the knee being set in a splint or cast is enough. Whether or not surgery is required depends on the type of fracture.

Seek Immediate Medical Attention for Acute Knee Injuries. While waiting to see the doctor, to reduce swelling and pain apply ice immediately and leave on 15 - 20 minutes per hour. Elevate the knee above heart level if possible. Wrapping the knee in an ACE bandage (elastic bandage) provides compression and also helps limit swelling.

Ruptured Tendon (Torn Tendon)

Tendons attach muscle to bone. The quadriceps tendon and patellar tendon connect to form one continuous tendon that covers the patella (kneecap). The quadriceps tendon connects quad muscles to the patella; the patellar tendon connects the patella to the shinbone.

If the quadriceps contract forcefully and suddenly (as when trying to break a fall), the tendon may tear where it attaches to the bone (either above or below the kneecap).

If the tendon is completely torn, straightening the leg will be difficult (not just because of the pain).

A completely torn tendon can be surgically reattached. If the tendon is only partially torn, surgery may not be necessary. A cast is usually worn for several weeks. When the leg is immobilized, muscles and tendons weaken. Rehabilitative exercises help restore strength and flexibility to the knee/leg.

Seek Immediate Medical Attention for Acute Knee Injuries. While waiting to see the doctor, to reduce swelling and pain apply ice immediately and leave on 15 - 20 minutes per hour. Elevate the knee above heart level if possible. Wrapping the knee in an ACE bandage (elastic bandage) provides compression and also helps limit swelling.

Tendonitis is inflammation of a tendon. Tendonitis of the knee may be caused an acute injury but is more often caused by overuse.

Continue to Overuse Knee injuries on next page...