Patellofemoral pain syndrome, often known as Runner’s Knee, is the term used to describe pain under or around the patella (kneecap), caused by one of a number of conditions that lead to unusual stress on the knee joint.
The knee is a complex, hinged joint, made up from three bones, the femur (thighbone), tibia (shinbone), and patella (kneecap). Strong ligaments attach the bones to each other, keeping the joint in correct alignment, and tendons run from muscle to bone. Within the joint, the ends of the femur and tibia are covered with smooth articular cartilage that allows them to slide over each other without friction.
Overuse: The term ‘runner’s knee’ indicates that overuse or excessive training might cause patellofemoral pain syndrome. Athletes participating in any sport that repeatedly puts heavy stress on the knee are vulnerable.
The kneecap may not track properly within the trochlea, the groove in the bottom of the femur, up and down which the patella slides as the knee bends and straightens.
The patella may have been dislocated, either partially or completely, thereby damaging the ligaments that hold the knee joint in correct alignment.
The quadriceps muscle in the front of the thigh might be too tight, pulling the patella out of position. Alternatively, it may be weak or imbalanced, allowing improper patellar tracking.
Damage to the patellar tendon that holds the kneecap in position.
Referred pain from an injury to the hips or the back.
Pain felt as a dull ache under or around the top part of the kneecap, where it comes into contact with the femur.
Pain worse when kneeling, walking up and down stairs, sitting for a long time or other situations when the knee is bent.
The knee may unexpectedly give way.
A grinding, catching or popping sensation when walking.
Your doctor will make a diagnosis based on your medical history and a thorough physical examination.
Questions you may be asked will relate to the onset, duration, severity of your symptoms and what makes them better or worse; any previous injuries to the knee; your lifestyle and, if you are an athlete, any changes in your exercise program such as intensity of training or using a different type of surface.
The physical examination will include manipulating and palpating (touching) all parts of the knee to evaluate joint alignment and determine the focus of the pain. The range of motion of your knees, hips, ankles, and feet will be assessed, as will the strength and flexibility of the thigh muscles.
Imaging tests such as x-ray, CT and MRI scans may be required to view the bones and soft tissues. Blood tests might be ordered if an infection is suspected.
Treatment of patellofemoral pain is usually non-surgical. Surgery may occasionally be required to remove or repair a piece of damaged cartilage, or to realign the patella. Arthroscopy is the preferred technique as it minimizes trauma to the knee.
Patellofemoral pain syndrome responds better to early treatment so, in order to gain relief from pain and to avoid doing further damage that may make treatment more difficult, follow the conservative treatments listed below, and arrrange to see your doctor.
Rest: Avoid any activity that aggravates the condition. Use crutches when walking to avoid putting weight on the knee. If you want to continue exercising, switch to an activity like swimming, which does not place weight on the knee.
Ice: Apply ice, crushed in a bag and wrapped in a towel, to the knee for as long as possible without causing great discomfort, several times a day. This will help to reduce swelling and inflammation.
Compression: Using a knee brace or taping the knee can relieve pain.
Elevation: Raise the knee above the level of your heart, as often as possible, to reduce swelling.
NSAIDs (non-steroidal anti-inflammatory drugs) such as ibuprofen, naproxen or aspirin, will help to relieve pain and reduce inflammation.
When no more pain is present, you will probably need to rehabilitate the knee. Your doctor or physiotherapist will provide a program of exercises designed to gradually stretch and strengthen the leg muscles.
Try to do these exercises twice a day. Repeat exercises with both legs to avoid developing an imbalance. Quad stretch:
Standing or lying down, hold the foot of the injured leg and draw it backwards towards the buttocks as far as possible until a stretch is felt in the front of the thigh. Hold 30 seconds. Repeat 5 times. Quad tightening:
Sitting on the floor with your injured leg straight out in front of you and the unaffected leg bent with the foot on the floor, contract the thigh muscles of the injured leg by pressing the knee towards the floor. Hold the position for 5-10 seconds. Repeat 10 times. Straight leg raise:
Lying on your back on the floor, bend your unaffected knee and rest the foot on the floor. Keeping the knee of the injured leg straight, contract the thigh muscles and lift the leg up about 6 inches off the ground. Hold for 5-10 seconds. Repeat 10 times. Iliotibial band stretch:
Stand with your right leg crossed in front of the left, both feet flat on the floor with the right foot only slightly in front of the other. Bend forward from the hips and reach your hands toward the floor, stopping when you feel a stretch in the outer part of the left thigh. Hold for 10-20 seconds. Repeat 10 times. Hamstring stretch:
Sit on the floor with your legs straight out in front of you. Lean forward from the hips until a stretch is felt under the thighs. Hold 30 seconds. Repeat 5 times. Calf stretch:
Stand facing a wall and place hands on it for support. Lean forwards until stretch is felt in the calves. Hold for 30 seconds. Bend at knees and hold for a further 30 seconds. Repeat 5 times.
Brace for patellofemoral pain syndrome:
Ask your doctor’s advice as to whether a knee brace would be helpful for you. There are many types available, and it is important that, should you wear one, it be properly fitted. A patellar stabilizing brace holds the kneecap in its correct position within the trochlea and can be useful until the leg muscles are adequately strong.
Maintain a healthy weight to avoid putting excessive strain on the knee
Always warm up and stretch properly before exercising
Exercise regularly to maintain flexibility and strength in the legs
Use properly fitted sporting equipment
Wear orthotics if necessary
Use good technique when participating in your particular sport