Patella Femoral Syndrome is a common condition that involves inflammation of the patellar tendon in the knee that makes the person feel uncomfortable & painful. It is commonly called Runner’s Knee & is often mistaken for another knee condition, Chondromalacia Patellae.
The knee joint may look like a simple joint, but its one of the most complex. Moreover, the knee is more likely to be injured than is any other joint in the body. We tend to ignore our knees until something happens to them that causes pain. As the saying goes, however, “an ounce of prevention is worth a pound of cure.” The knee joint is a synovial joint. It is the largest & strongest joint in our body, consisting of 4 bones and an extensive network of ligaments & muscles. The 4 bones that make up the knee are femur (thigh bone, largest, longest & strongest bone in the body, attaches by ligaments & a capsule to your tibia), tibia (shin bone, second longest bone, runs from knee to ankle), fibula (outer shin bone, long & thin which runs along side to tibia from the knee to ankle) & patella (kneecap that rides on the knee joint as the knee bends). The main movements of the knee joint occur between the femur, patella & tibia.
The main parts of the knee joint are bones, ligaments, tendons, cartilages & a joint capsule all of which are made of collagen. The joint capsule is an envelope that surrounds the knee & attaches to the knee bones. On the inside of this capsule is a specialized membrane called the synovial membrane which nourishes the joint. Other structures include the infrapatellar fat pad & bursa which function as cushions to exterior forces on knee. A bursa is a little fluid sac that helps the muscles & tendons slide freely as the knee moves. The capsule itself is strengthened by the surrounding ligaments.
Ligaments are tough bands of tissue that connect the bones in your body. There are 4 ligaments of the knee that are prone to injury:
- Medial Collateral Ligament (MCL, tibial collateral ligament) – MCL runs between the inner surfaces of the femur & tibia. It limits sideways motion of your knee.
- Lateral Collateral Ligament (LCL, fibular collateral ligament) - This ligament travels from the outer surface of the femur to the head of the fibula. It limits sideways motion of your knee.
- Anterior Cruciate Ligament (ACL) – The ACL is the most important structures in the knee because injury to it may require extensive surgery & rehabilitation. The cruciate ligaments are so called because they form a cross in middle of the knee joint. The ACL runs from the front of tibia to the back of femur. It limits rotation & forward motion of the tibia. It is most commonly injured in twisting movements.
- Posterior Cruciate Ligament (PCL) - The PCL is the strongest ligament. It travels from the outer surface of tibia to the inner surface of femur. It is deep inside the knee behind the anterior cruciate ligament. It limits the backwards motion of knee.
Each knee joint has 2 crescent-shaped cartilage menisci. These lie on the inner & outer edges of the upper surface of the tibia. They are essential components acting as shock absorbers for the knee as well as allowing for correct weight distribution between the tibia & femur. The 2 main muscle groups of the knee joint are the quadriceps & hamstrings. Both play a vital role in moving & stabilizing the knee joint.
- Quadriceps- attach to the front of the tibia & originate at the top of the femur. They consists of a group of 4 different individual muscles located in the anterior thigh. They are Vastus Medialis, Intermedius, Lateralis & Rectus Femoris. Its main function is to extend the leg at the knee.
- Hamstrings- runs down the back of the thigh. They are primarily fast-twitch muscles responding to low reps & powerful movements. It helps to extend your leg straight back & bend your knee. There are 3 hamstring muscles: Semitendinosus, Semimembranosus & Biceps femoris.
Patella femoral syndrome is a syndrome characterized by pain or discomfort originating from around the kneecap (patella). The pain may be achy, dull or sharp and radiates to the back of the knee. Other names for this syndrome are: runner’s knee, patellofemoral disorder, retropatellar pain, anterior knee pain & patellar malalignment. Patellofemoral pain syndrome is sometimes mistaken for chondromalacia, a condition which damage (softening) the articular cartilage on the underside of the kneecap.
How does it occur?
Patients with patella femoral pain syndrome describe pain primarily in the front of knees. The pain occurs from overusing your knees in sports & activities such as jumping, running, squatting, stair climbing, walking or cycling. The kneecap is attached to the quadriceps (large group of muscles in the thigh) and to the shin bone (tibia) of the patellar tendon. Repeated straightening & knee bending can cause irritation and pain to the inside surface of the kneecap. Patella femoral syndrome also result from how your legs, hips, knees, feet are aligned. This alignment error may be caused by having wider hips, under-developed thigh muscles, genu valgum or having feet arches that collapse when walking or running (overpronation). Several anatomic & congenital factors may lead to a predisposition towards patellofemoral pain and/or instability.
What are the Symptoms?
The common symptom is a dull, aching pain under or around the front of the kneecap where it connects the lower end of the thigh bone. Pain usually occurs when walking up or down the stairs, kneeling, squatting & sitting on a bent knee for a long period of time. Patients describe pain to get worse when walking downstairs. Your knee swells at times and you may hear or feel snapping or grinding of your knee. You often experience pain with prolonged sitting (watching a movie, riding on a plane) and have to occasionally straighten your legs out to decrease discomfort. It is generally an aching pain that can become sharp in nature and even be associated with a burning sensation. On occasion, patients describe a sense that their knee may give out on them. This occurs especially while going down the stairs. The onset of symptoms is usually associated with the start of a new activity or increase in level of intensity of an existing activity.
How is PFPS treated?
Patellofemoral pain syndrome can be a chronic disorder, but rarely results in severe, permanent damage to the knee. Learning to care your knees with appropriate treatment over the long run is the key. Treatments include:
- Ice your knees 20-30 mins every 2-3 hrs for the first 3-4 days till the pain goes away.
- Raise your knee placing a pillow under your leg when knee hurts.
- Taking anti-inflammatory drugs like ibuprofen helps reduce pain, swelling and inflammation.
- Exercises advised by your doctor are essential for the rehabilitation of the knee (bike riding & swimming).
Your doctor may recommend you to:
- Use custom-made arch supports (orthotics) for overpronation. Bracing your knee with a patella stabilizing brace may be helpful.
- Use an infra-patellar strap, placing beneath your kneecap over the tendon.
- Use a neoprene knee sleeve to support the knee and patella.
While recovering from injury, you need to switch your sports or activities so that does not make your condition worse. For instance, you may need to swim instead of run. Surgery may be recommended in cases of severe patella femoral pain syndrome. Your doctor will show exercises to help decrease pain around your kneecap.
When will I be able to return to my sports or activities?
The aim of rehabilitation is to return you safely to your activity as soon as possible. Returning too soon may worsen your condition leading to permanent damage. Everyone recovers at a different rate. Returning back to your activities depends on how soon your knee recovers. In general, the longer you’ve symptoms before you start treatment, the longer it takes to heal. You can start your sports or activities when:
- Your injured knee can be fully bent & straightened without any pain.
- Your knee & leg have regained normal strength compared to the uninjured knee & leg.
- You are able to jog without limping.
- You are able to sprint without limping.
- You are able to do 45-degree & 90-degree cuts.
- You are able to do 20-yard, 10-yard figure-of-eight runs.
- You are able to jump on both legs without any pain.
How to prevent patella femoral pain syndrome (PFPS)?
Patella Femoral Pain Syndrome Rehabilitation Exercise
Start doing the Hamstring Stretch right away. Start the patellar mobility exercises as soon as it is not too painful to move your kneecap. When the knee pain has reduced, you can start the quadriceps stretches and start strengthening your thigh muscles.
Hamstring Stretch - Stand with the knee of your injured leg resting on a stool that is atleast 15 inches high. Keep your knee straight and lean your hips forward keeping your shoulders in line with your trunk till you feel a stretch in the back of your thigh. Hold this position for 30-60 seconds. Return to the starting position. Do not round your shoulders and bring your head towards the toe. This stretches your low back instead of your hamstrings. Repeat this thrice.
Patellar Mobility – Sit with your injured leg stretched in front and the muscles on the top of your thigh relaxed. With your index finger & thumb, slowly press your kneecap down towards your foot. Hold this position for 15 seconds. Return to the starting position. Next, pull your kneecap up towards your waist and hold it for 15 seconds. Return to the starting position. Next try to gently push your kneecap inward towards your other leg and hold for 15 seconds. Repeat these for 5 mins.
Quadriceps Stretch – Stand an arm’s length away from the wall facing straight. Brace yourself by keeping the hand on your uninjured side against the wall. With your other hand, hold the ankle of the injured leg and pull your heel up to your buttocks. Do not twist your back. Hold this position for 30 seconds. Repeat this thrice.
Quadriceps Set - Sit on the floor with your injured leg straight in front. Tighten up your muscles at the top of your thigh by pushing the back of your knee down to the floor. Concentrate the contraction on the inside area of your thigh. It is essential to strengthen this part of your quadriceps muscles (vastus medialis) . Hold for 10 seconds. Repeat 5 times.
Straight Leg Raise – Sit on the floor with your injured leg straight and the other leg bent with foot flat on floor. Pull the toes of your injured leg towards you while tightening the muscles on top of your thigh. Raise your leg 6 inches off the floor. Hold for 5 seconds and slowly lower your leg. Repeat this 5 times.
Very rarely this condition requires surgery, and it is usually when none of the mentioned measures gives any positive results. The procedures helpful in cases of patella femoral syndrome are arthroscopy and realignment. Arthroscopy procedure consists of removing fragments of the cartilage that is damaged with the help of an arthroscope. Realignment is advised only in severe cases in which the angle of the kneecap needs to be realigned so that the pressure on the cartilage would be relieved.