Hoffa’s Fat Pad Impingement

Hoffa’s fat pad impingement is a condition where a soft tissue structure called the infrapatellar fat pad—located just below and behind the kneecap—becomes pinched or irritated (Figure 1). This fat pad acts as a cushion in the front of the knee, but it can become inflamed if it’s compressed during movement. People with this condition often feel sharp pain at the front of the knee, especially when straightening or fully bending the leg. Swelling and tenderness just below the kneecap are also common. It usually affects athletes, particularly runners, dancers, or anyone who regularly puts stress on their knees. It can happen after a direct hit to the knee or from overuse.

How Hoffa’s Fat Pad Impingement Is Diagnosed

To diagnose Hoffa’s fat pad impingement, a doctor will ask about your symptoms and examine your knee for pain, swelling, and tenderness. They may press on the area around the bottom of the kneecap to check for discomfort. If the diagnosis is unclear, the doctor may order an MRI (Figure 2), which can show swelling or thickening in the fat pad and rule out other problems like a meniscus tear or cartilage damage. X-rays might also be done to check the position of the kneecap and to rule out bone problems.

Treating Hoffa’s Fat Pad Impingement

Treatment for Hoffa’s fat pad impingement usually starts with conservative (non-surgical) care. This includes resting the knee, using ice packs, and taking anti-inflammatory medications to reduce pain and swelling. Avoiding activities that make the pain worse—like deep squatting or jumping—is important while the knee heals. Physical therapy can help strengthen the muscles around the knee and improve movement patterns to reduce pressure on the fat pad. Sometimes, taping or bracing the knee is used to help control kneecap movement and relieve pain.

When Surgery Is Needed

Surgery is rarely needed to treat Hoffa’s fat pad impingement, but it may be considered if pain continues for several months despite treatment. If surgery is required, it is usually done with arthroscopy, a minimally invasive procedure where a camera and small tools are used to remove part of the inflamed fat pad or fix any other issues inside the knee. Surgery is typically only used in severe or chronic cases that interfere with daily activities or sports.

Long-Term Outlook

The long-term outlook for Hoffa’s fat pad impingement is generally very good, especially with early diagnosis and proper treatment. Most people get better with rest, therapy, and avoiding painful activities. Recovery can take a few weeks to a few months, depending on how irritated the fat pad is. Once healed, many people return to their regular activities without any lasting problems. Staying active with proper technique and avoiding overuse can help prevent the problem from coming back.

Edited by Stephen Pinney MD, August 3rd 2025.