Osteoarthritis Behind the Kneecap
(Patellofemoral Osteoarthritis)

If you’re experiencing pain at the front of the knee, the cause could be patellofemoral osteoarthritis? But what is it? What are the symptoms of patellofemoral osteoarthritis? And how do you diagnose it?

What is patellofemoral osteoarthritis?

The patella is your kneecap, the small bone that sits at the front of your knee where the thighbone and shinbone meet. Because of the patella’s position, it needs to be able to move. Place your hand on the front of your knee joint, then bend and straighten your leg, and you’ll probably be able to feel the kneecap gliding up and down.

To enable the bone to move in a consistent direction, the patella sits in a sort of tramline (called the trochlear groove) in the thighbone, along which it can move. To ensure it glides smoothly, the surface of the thighbone, trochlear groove and the underside of the patella are all coated in articular cartilage.

When the cartilage in the joint begins to break down, the patella can become inflamed, causing pain in the joint. As the joint continues to wear, bone will begin to grind on bone. This is patellofemoral osteoarthritis.

>   How do you treat osteoarthritis behind the kneecap?

What causes patellofemoral osteoarthritis?

Common causes of patellofemoral osteoarthritis are:

Fracture: If you’ve ever fractured your kneecap there will be an increased risk that, although the bone may have healed, the surface of the joint will not be as smooth as it once was. This can cause friction as the patella moves, and eventually cause osteoarthritis.

Dysplasia and patella alta: People with dysplasia have a patella that is misaligned with the trochlear groove. People with patella alta have a kneecap that sits too high within the groove. Both conditions mean that, as the patella moves, it increases the stress forces on the joint and can cause scuffing. These can increase the risk of developing osteoarthritis.

What are the symptoms of patellofemoral osteoarthritis?

If you have patellofemoral osteoarthritis your knee – especially the front of the knee – will feel painful. It may be particularly painful after running, kneeling, squatting or going up/downstairs, but it’s possible the knee will remain painful even at rest.

You may hear a crunching sound when you bend your knee. You may also find the knee locks occasionally. This is often caused by loose fragments of cartilage getting caught in the mechanism of the knee.

How do you diagnose patellofemoral osteoarthritis?

Alex may combine a physical examination with x-ray (to assess the state of the bone and the alignment of the joint) and MRI scan (to understand the state of the cartilage).

How do you treat patellofemoral osteoarthritis?

Not every case of patellofemoral osteoarthritis requires surgery, but where the osteoarthritis has been caused by dysplasia or patella alta, you may benefit from an osteotomy (realignment surgery).

Find out more about non-surgical treatments and patellofemoral osteotomies.

If you are experiencing pain at the front of the knee, book an appointment with our knee clinic for Cheltenham, Gloucester and the Cotswolds.

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Appointments

To make an appointment please either fill in the contact form and you will be called back by our secretary to arrange a convenient appointment time or get in touch directly.

Call Chrissie Holmyard 01242 246549 at Nuffield Health, Cheltenham.