This is arthritis affecting the kneecap. It causes pain in the front of your knee and can make it difficult to kneel or climb stairs. Patellofemoral arthritis occurs when the slippery substance, articular cartilage, along the femoral groove and on the underside of the kneecap wears down and becomes inflamed. When cartilage wears away, it becomes frayed and when the wear is severe, the underlying bone becomes exposed and movement of the kneecap becomes painful.
Damage to the kneecap cartilage for whatever reason can lead to arthritis. This could be as a result of instability, fracture of the kneecap or developmental for example when a kneecap doesn’t fit properly into the groove.
The main symptom of patellofemoral arthritis is pain. The pain is often experienced in front of the knee. The pain can be severe and present at all times even when there is no activity at all. Most of the time, however, it is brought on by activities that put pressure on the kneecap such as climbing stairs or getting up from a low chair. There may be a crackling sensation with movement of the knee which can be painful or even loud enough for other people to hear.
Treatment of patellofemoral arthritis is similar to the treatment of knee arthritis in general. Most cases can be treated without surgery. Nonsurgical options include:
- Weight loss
- Exercises like swimming or walking can decrease knee stiffness and strengthen muscles
- Paracetamol and Anti-inflammatories like Ibuprofen can reduce pain and swelling
- Cortisone injection into the knee
If deemed necessary, there are a number of Surgical options to treat patellofemoral arthritis.
This is keyhole surgery where roughened arthritic joint surfaces can be trimmed and made smooth. This is an option in cases of mild to moderate cartilage wear and is usually a day case procedure following which the patient can walk out of the hospital on the same day.
Here the soft tissues on either side of the kneecap can be tightened or released to change the position of the kneecap in the groove. In distal realignment procedures the position of the kneecap can be changed to reduce the pressure on the arthritic areas and relieve pain.
When the cartilage of the kneecap is worn down to bone and there is constant pain, the only surgical treatment that can eliminate the symptoms is replacement knee surgery. Few patients may have isolated degeneration in the patellofemoral jopint and may be suitable for partial replacement (patellofemoral replacement) where arthritic surfaces are removed and replaced with metal and plastic (polyethylene) implants. In majority of patients however, with extensive arthritis, the whole knee is replaced (Total Knee Replacement).