Patellofemoral pain syndrome is one of the most common disorders of the knee, accounting for up to one in every 4 knee injuries.
Patellofemoral pain syndrome usually involves pain in or around the kneecap. People tend to notice the pain particularly when going up or down stairs, squatting, kneeling or running. It may also be aggravated by long periods of sitting with the knees bent, and because of this it is also known as ‘movie-goers knee’. Swelling is not usually a major feature of this condition.
In this syndrome, the pain is usually the result of the kneecap not tracking smoothly through the groove in the underlying bone when the leg is being bent and straightened.
A combination of factors may result in the kneecap not tracking smoothly. Tightness of the outside thigh muscles (which pull the kneecap outwards) is often accompanied by weakness of the inner thigh muscle. This results in the kneecap being pulled towards the outside of the leg. Abnormalities of coordination among these various muscle groups may also contribute.
Often the pain develops as an overuse injury seen in long-distance runners or cyclists, or it may be initiated by a twisting injury to the knee.
When the symptoms first develop they are best treated by icing the knee for 10-20 minutes after activity. Taking simple painkillers such as paracetamol and, sometimes, anti-inflammatory medications may help. It is also advisable to avoid any activities that exacerbate the pain.
Taping the kneecap may also be of benefit in the early stages of recovery. A doctor or physiotherapist will be able to show you how to tape the kneecap correctly to pull it back into alignment. Occasionally, biomechanical correction of lower limb alignment abnormalities through the use of arch supports or orthotics is recommended.
In the longer term, stretching and strengthening exercises for the leg muscles are important for full recovery.
Weak quadriceps (front thigh) muscles are a common cause of patellofemoral pain syndrome and quadriceps strengthening exercises are often a cornerstone of treatment. Similarly, tight hamstrings, iliotibial bands (the muscle down the outside of the thigh, sometimes called the ITB), calf or hip muscles can be a cause, and regular stretching of these muscle groups is important.
Your doctor or physiotherapist can design an individual exercise programme for you. Such a programme will include a graded increase in activity. It is important to do these exercises on a daily basis to maximise the chance of recovery, which will generally take about 6 weeks.
Rarely, surgery may be required if the condition is not improving.
Last Reviewed: 25 July 2008