Definition
Chondromalacia patella is a softening or wearing away of the articular cartilage on the undersurface of the patella, more commonly known as the kneecap. Articular cartilage cushions the femur (thighbone) and tibia (shinbone) where they meet in the knee, allowing them to move freely and easily. But, when the articular cartilage softens or wears away, pain and inflammation result.
Treatment is done at home. Surgery may be needed in rare cases.
Causes
Chondromalacia patella is caused by repetitive motion and misalignment of the kneecap.
This can occur due to:
- Birth defect in knee alignment
- Weak quadriceps
- Muscle strength imbalance between the inside and outside of the thigh
- Direct trauma
Risk Factors
Chondromalacia patella is more common in adolescence and young adulthood. Other factors that increase your risk of chondromalacia patella include:
- Participation in activities like running, skiing, cycling, or soccer that put repeated pressure on the patellofemoral joint
- Knock-knee abnormality of the leg
Symptoms
Symptoms may include
- Acute or chronic knee pain that worsens slowly over time
- A popping or cracking sound as the knee is flexed and extended
- Increased pain when climbing stairs, squatting, kneeling, or running
- Pain and stiffness in the knee after it is flexed for a long period of time
Diagnosis
Your doctor will ask about your symptoms and medical history. A physical exam will be done. Tests may include:
- X-ray
- MRI
- Arthroscopy, rarely needed, but used to see the internal structure of the knee
Treatment
Talk with your doctor about the best treatment plan for you. Options include:
Acute Care
Your knee will need time to heal. Avoid activities that place extra stress on these your knee:
- Do not do activities that cause pain. This includes running, jumping, and weight lifting using the leg muscles.
- If normal walking hurts, shorten your stride.
- Do not play sports until your doctor has said it is safe to do so.
Apply an ice or a cold pack to the area for 15-20 minutes, four times a day, for several days after the injury. Do not apply the ice directly to your skin. Wrap the ice or cold pack in a towel.
To manage pain, your doctor may recommend:
- Over-the-counter medication, such as aspirin, ibuprofen, or acetaminophen
- Topical pain medication—creams or patches that are applied to the skin to help with soft tissue pain
- Prescription pain relievers
Compression can help prevent more swelling. Your doctor may recommend an elastic compression bandage around your knee. Be careful not to wrap the bandage too tight.
After treatment, you may need an elastic knee sleeve with the kneecap cut out to help support the knee joint.
Elevation can also help keep swelling down. Keep your knee higher than your heart as much as possible.
Surgery
In most cases, surgery is not needed. But for some patients who have continued pain, surgery may performed. Surgical procedures include the following:
- Moving the quadriceps muscle insertion on the lower leg to improve alignment
- Releasing the lateral thigh muscles and tightening the medial muscles
- Smoothing over the undersurface of the patella
- Implanting cartilage taken from one’s own knee
Prevention
To reduce your chances of chondromalacia patella, take these steps:
- Maintain a healthy weight to reduce stress on your knees.
- Properly warm up before excersing or doing any physical activity.
- Maintain proper strength by exercising the quadriceps, calf muscles, and hamstring muscles.
- Use proper footwear for your sport. You may need orthotic support to help correct misalignment.
- Slowly increase activity to avoid stress on the knee.
- Use proper form and technique for any sport.
Revision Information
- Reviewer: Lawrence Frisch, MD, MPH; Brian Randall, MD
- Review Date: 05/2013 -
- Update Date: 05/03/2013 -