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Patellofemoral Osteoarthritis

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Osteoarthritis is a common problem for many people after middle age. Osteoarthritis is sometimes referred to as degenerative, or wear and tear arthritis. Osteoarthritis may result from an injury to the knee earlier in life.

Fractures involving the joint surfaces, instability from ligament tears, and meniscal injuries can all cause abnormal wear and tear of the knee joint. Not all cases of osteoarthritis are related to prior injury, however. Research has shown that some people are prone to develop osteoarthritis, and this tendency may be genetic.

Patellofemoral (or sometimes called patellar-femoral) osteoarthritis is basically arthritis under the kneecap (patella). It’s very common. Often if arthritis occurs in the knee joint, it tends to start first at the patellofemoral joint. The patella can rub against the thigh bone causing wear, or there can be damage to the cartilage underneath the patella. Sometimes years of maltracking of the patella can also cause the problem.

Patellofemoral pain in the elderly patient is usually due to degenerative arthritis of the knee joint. Patients suffering from osteoarthritis at the patellofemoral joint often present with similar symptoms to that of chondromalacia patella. The main differential features are that osteoarthritis of the patellofemoral joint is exceedingly more severe and usually leads to a progressive and persistent disabling of the individual. Limitation of range of motion, swelling, crepitus and stiffness is common. The symptomology is due to joint space narrowing, sclerosis and osteophyte formation on both the patellar and femoral surfaces.

Arthritis of the knee is one of the main causes of disability throughout the US. It affects the patella causing pain in the front part of the knee, which makes it difficult to climb stairs or kneel down. The patella is a tiny bone that is located at the front part of the knee joint where the shinbone and the thighbone connect. It works to protect the knee and connect the muscles at the front of the thigh to that of the tibia.

Dysplasia or maltracking often occurs when the patella doesn’t properly fit into the trochlear groove of the femur. Due to this, whenever the knee moves, an increased amount of stress occurs on the cartilage, which causes it to wear down. Another common cause of this condition is that of a patella fracture which often damages the cartilage covering and protecting the underneath of the bone. Even though the bone will heal, the surface might not be as smooth. The friction can lead to arthritis down the line.

Patellofemoral Osteoarthritis Anatomy

The knee is one of the biggest and most complex of all joints found in the body. It joins the shin bone (tibia) and the thigh bone (femur) together. The smaller bone running alongside of the tibia and the patella are the two other bones that complete the knee joint. Tendons keep the leg muscles and knee bones connected to enable the knee joint to move. Ligaments join all of the knee bones and deliver stability to the knee.

Patellofemoral Ostearthritis anatomy image

The knee cap (patella) has two facets underneath it, a medial facet and lateral facet, and these connect/articulate with the femur. The knee cap is a sesamoid bone that is situated in the knee to provide muscle attachments to improve leverage of your leg muscles (hence making them more powerful, especially the quadricep muscles).

An X-ray showing patellofemoral osteoarthritis of the right knee

How To Treat Patellofemoral Osteoarthritis

1. Non-Steroidal Anti-Inflammatory Medication

Drugs like naproxen, aspirin and ibuprofen work to reduce swelling and pain. This should only be used short term.

2. Modification Of Activities

In many instances, avoiding those activities that bring about pain can be one of the best things for you to help alleviate pain.

3. Exercises

Regular exercise will help to strengthen and decrease stiffness in those muscles that support the knee. For those who have this condition, avoid engaging in any activities that place stress on the front part of the knee, such as squatting. If you regularly perform high-impact exercises, switching to a low-impact routine will help to minimise the amount of stress on the knee. Swimming and walking are both great low-impact activities.

4. Therapy

Although manual therapy to the knee cannot reverse osteo-arthritic changes to the patella, it can help prevent further wear and tear and reduce inflammation. Treatment will also improve mobility to the kneecap which often becomes stiff, and offload the patella by reducing tension in the muscles surrounding the knee. Physical therapy treatment can be very successful for treating patellofemoral osteoarthritis and other related conditions such as chondromalacia patellae.

5. Steroid Injection

A steroid injection may be used behind or around the patella to reduce inflammation and pain. Steroid injections can be short-lived if the patella is moderately arthritic.

Tips

  • If you are overweight, losing a few pounds could mean the difference in the amount of stress that is currently placed on the knee.
  • Physical therapy exercises can help to improve movement in the knee, while strengthening the quads and relieving pressure to allow you to straighten the leg.
Patellofemoral Osteoarthritis exercise image
  • Cortisone injections can help to reduce swelling in the affected area.
  • Consider changing your exercise routine to one that is going to help reduce pressure and pain in the knee.
  • Work with your Rehab My Patient therapist to improve your knee range of movement, muscle strength, and reduce inflammation.