Individuals who play sports that require running or jumping are prone to injuries involving the patellar tendon -- the tendon that attaches the bottom of the knee cap to the top of the shinbone. Injury and pain make it hard to straighten your knee. If the pain you are feeling in the front of your knee is caused by fat pad impingement (or Hoffa's syndrome), a sports medicine doctor or physical therapist can help. Depending on the severity, treatment when the fat pad becomes impinged (pinched) varies.

Understanding What Causes It

The fat pad is the soft tissue below the kneecap and behind the patellar tendon. It acts as a cushion to protect the underlying structures of the knee from forceful pressure. Sometimes the fat pad becomes inflamed and swollen following a fall or direct blow to the knee. When that happens, the bottom of the patella (kneecap) can pinch the mass of fatty tissue below your kneecap. Activities that put excess stress on the knees can also cause impingement.

Identifying the Symptoms

Different from patellar tendinitis, fat pad impingement causes pain on either side of the patellar tendon, not just at the patellar tendon. The area surrounding the tendon may be swollen. Pain usually gets worse when you stand for prolonged periods of time, walk the stairs, jump, or make movements that push the knee joint beyond its normal range of hyperextension.

Getting a Diagnosis

While tenderness under the kneecap and swelling that causes the kneecap to tilt outward are signs of fat pad impingement, performing a Hoffa's test helps diagnose this type of injury. After asking you to lie down with your knee bent, your doctor or PT will examine the area by gently pressing both thumbs along either side of the patellar tendon just below the kneecap. Typically, a physical examination is adequate to diagnose the condition, but your doctor may order an x-ray of your knee. Pain when you straighten your leg is another sign of fat pad impingement.

Knowing Your Treatment Options

Although treatment for fat pad impingement generally includes rest and limiting physical activities or movements that make the pain worse, full recovery can take a long time. Stretching your quadriceps (the large muscle at the front of your thighs) and hip flexor muscles reduces some of the pressure the patella puts on the fat pad. Strengthening exercises also help by making the muscles surrounding your knee stronger.

When you first experience symptoms, apply ice or a cold pack to the area for 20 minutes at a time several times during the day to help reduce pain and swelling, recommends the American Academy of Orthopaedic Surgeons. Wrap the ice in a wet towel before putting it against your skin.

Your doctor may prescribe anti-inflammatory medications for pain, as well as tape the patella to give the knee joint and muscles support and stability while the injury heals. Wrapping the knee should not make it hurt worse. If inflammation is severe, corticosteroid injections may be necessary. Sometimes the condition requires surgery to trim or remove the fat pad.