Patellofemoral Syndrome is pain in the knee that occurs from poorly aligned knee structures, trauma, or overuse. It is also called runner’s knee and Chondromalacia patellae. Patellofemoral syndrome results when the cartilage behind the kneecap is overstressed or deteriorates and causes pain and loss of function.
There are three bones that comprise the knee structure. The femur (thighbone) is positioned on top of the tibia (larger leg bone). The patella, (kneecap), glides in a groove on the end of the femur. Four main ligaments connect the knee bones together. Large muscle groups in the thigh provide strength, stability, and motion. Cartilage located on the end of the bones and underneath the kneecap allows the bones to glide easily during movement. The synovial membrane that covers the inside of the joint capsule secretes a fluid to lubricate the knee joint and nourish the cartilage. The cartilage and synovial fluid act as a shock absorber with walking and running.
Patellofemoral Syndrome occurs when the cartilage underneath the kneecap softens and degenerates. This may occur because of overuse, abnormally aligned knee structures, or trauma. Sports, such as skiing, cycling, running, and soccer are associated with Patellofemoral syndrome. Arthritic changes in the kneecap can occur from chronic Patellofemoral syndrome.
Patellofemoral syndrome can cause dull knee pain, swelling, and tenderness. Pain may increase after you have been seated for a long period of time or during certain activities, such as using stairs, kneeling, squatting, or getting out of a chair. You may notice that your knee grinds when you straighten it.
Your doctor can diagnose Patellofemoral Syndrome by reviewing your medical history. X-rays will be taken to check knee alignment and to evaluate for arthritic changes. In some cases, additional imaging tests may be ordered. CAT scans and MRIs are often uses to evaluate the tracking of the patella and to better see the cartilage surfaces.
The goal of treatment is to relieve pain while restoring motion and function of the knee. This may be achieved in several ways. You should rest and avoid strenuous activities until your pain resolves. A knee brace or custom-made shoe inserts can provide support during activities. Your doctor may recommend ice packs or non-steroidal anti-inflammatory medications to relieve pain and swelling. You will be referred to physical therapy for strengthening and flexibility exercises.