Chondromalacia also call chondromalacia patellae, refers to softening of the articular cartilage of the kneecap. The disorder occurs most often in young adults and is caused by trauma, overuse, poor alignment or muscle weakness. Instead of gliding smoothly across the lower end of the thigh bone, the kneecap rubs against it, thereby roughening the cartilage underneath. Damage ranges from a slight abnormality of the surface of the cartilage to a surface that has been worn away completely to the bone. Traumatic chondormalaia occurs when a blow to the knee cap tears off either a small piece of articular cartilage or a large fragment containing a piece of bone known as an osteochondral fracture.
The most frequent symptom of chondromalacia is dull pain around or under the kneecap that worsens when walking down stairs or hills. Pain can also be experienced when climbing stairs or during other activities when the knee is weight bearing or straightened. The disorder is common in runners and is also seen in skiers, cyclists, and soccer players. For those affected, low-impact exercises that strengthen muscles, particularly the inner part of the quadriceps, without injuring joints is recommended. Swimming, riding a stationary bike and using a cross-country ski machine are acceptable as long as the knee is not bent more than 90 degrees. Electrical stimulation may also be used to strengthen the muscles. If conservative treatment fails, arthroscopic surgery may be necessary to smooth the surface of the articular cartilage and wash out cartilage fragments that are causing the joint to catch during bending and straightening. In severe cases surgery may be necessary to correct the angle of the kneecap and relieve friction involving the cartilage or to reposition parts that are out of alignment.
There are two menisci in the knee and they are easily injured by rotating force while weight bearing. A partial or total tear of a meniscus occurs when a person quickly twists or rotates the upper leg while the foot stays planted as often happens in basketball and tennis. A tiny meniscus tear is when the fibrocartilaginous structure stays connected to the front and back of the knee. If the tear is large, however, the meniscus might be left hanging by a thread of cartilage, the severity of a tear depends on location and extent.
Injury to the meniscus will cause mild pain, particularly when the knee is straightened, but the person may continue activity. Severe pain occurs if a fragment of the meniscus catches between the femur and tibia. Swelling will occur soon after injury if blood vessels are disrupted. Swelling may be delayed if the joint fills with fluid produced by the synovium or joint lining as a result of inflammation. When the synovium is injured, it will become inflamed and produce fluid to protect itself, this causes swelling of the knee. After any injury the knee may click, lock or feel weak. Symptoms of a meniscal injury may disappear on their own, but symptoms that persist or return will require treatment.
If the tear is minor and the pain and other symptoms go away a muscle-strengthening program will reinforce recovery. Surgery to repair a meniscus takes several weeks to recover from and post-operative activity is more restricted than when the meniscus is removed. Putting weight on the joint will, however, foster recovery. Regardless of the form of surgery, rehabilitation includes walking, bending the legs, and doing exercises that stretch and build up the leg muscles. The best results of treatment for meniscal injury are obtained in people who do not show articular cartilage changes and who have an intact anterior cruciate ligament.
Injury to the cruciate ligaments of the knee is sometimes referred to as a knee sprain. The anterior cruciate ligament is often stretched, torn, or both by a sudden twisting motion, as when the feet are planted one way and the knees turned another. The posterior cruciate ligament is most often injured by a direct impact, like a football tackle.
Injury to the cruciate ligaments may not cause pain, but a popping sound can be heard and the leg may buckle when weight bearing. For an incomplete tear, an exercise program to strengthen surrounding muscles may be recommended. A protective knee brace should be worn during activity as well. For a completely torn anterior cruciate ligament in an active athlete surgery is recommend. An exercise and rehabilitation program will strengthen the ligament, accelerate recovery and will enable a return to a normal lifestyle within 6 months.
The medial collateral ligament is more easily injured than the lateral collateral ligament. It is most often caused by a blow to the outer side of the knee, which occurs in contact sports like football and hockey, stretching and tearing the ligament on the inner side of the knee. When injury to the medial collateral ligament occurs, a pop of the knee may be audible and the knee may buckle sideways. Pain and swelling are common and a thorough examination is essential to determine the nature and extent of the injury.
Most sprains of the collateral ligaments will heal naturally with the assistance of a prescribed exercise program. In addition to exercise, cold therapy or ice packs will help reduce pain and swelling and a compression brace will protect and stabilize the knee. A sprain will take 2 to 4 weeks to heal, but a severely sprained or torn collateral ligament may be accompanied by a torn anterior cruciate ligament, which usually requires surgical repair.