Chondromalacia patella is one of the most common causes of knee pain, especially in females. It typically affects adolescents and young adults. In this condition, there is weakening and softening of the cartilage on the underside of the patella (kneecap). The exact cause is unknown, but may be due to improper alignment of the patella in relation to the thigh bone (femur).
The patella normally moves in a groove in the end of the femurby the pull of the quadriceps (thigh) muscle. In patients with chondromalacia patella, the patella is frequently not properly seated in this groove and there is abnormal tracking toward the outer (lateral) side of the femur.
This slightly abnormal pathway allows the undersurface of the patella to grate along the femur, causing inflammation and pain. Some factors predispose to development of chondromalacia patella: females, knock-kneed, flat-footed runners, and those with an unusually shaped patellar or groove surfaces. Chondromalacia patella is different from knee osteoarthritis and does not lead to it.
There is pain or vague discomfort of the front of the knee, aggravated by activities (e.g. running, jumping, climbing, or descending stairs) and by sitting with a bent knee for long periods of time.
Patients are instructed to avoid motions or activities that irritate cartilage under the kneecap. Ice packs and antiinflammatory medications help reduce the pain. Certain exercises can strengthen the muscles that support your knees and control limb alignment, such as your quadriceps and hamstrings.
If nonsurgical treatment fails the patient may need surgery in the form of arthroscopy to treat the affected cartilage and to realign the patella in its normal place.