Patellofemoral (kneecap) pain syndrome is a common knee disorder that causes pain around the front of the knee. It is sometimes referred to as runner’s knee.
The Patellofemoral (Kneecap) Joint Anatomy
The patella (kneecap) is a small, triangular bone in the front of the knee that moves with the knee as it flexes. As the knee bends and straightens, the patella glides up and down along a track or slot known as the trochlear groove, which is located at the end of the femur (thighbone). The patella moves in many directions within this groove to provide efficient, frictionless movement up and down, side-to-side, rotational, and tilting. The patella gives the quadriceps (front thigh muscles) extra leverage for straightening the leg. It also protects the other bones in the knee against collisions and falls.
Patellofemoral Pain Syndrome
Patellofemoral pain syndrome is a generic term that refers to pain around the front of the knee. This pain usually starts gradually and then increases over time. The condition is sometimes referred to as anterior knee pain or runner’s knee. It is common in teenagers and athletes.
Causes Patellofemoral Pain Syndrome
Patellofemoral pain syndrome is essentially the result of repeated abrasion on any of the surfaces of the patella. This can lead to damage to the cartilage on the underside of the patella itself, resulting in pain and inflammation.
There are a variety of factors that can lead to this condition, but it is typically the result of overuse or misalignment.
- Overuse: Repetitive bending and straightening of the knee—such as what occurs in running—can lead to patellofemoral pain syndrome as a result of increased pressure between the patella and femur. This can irritate the patella and cause a bone bruise to form.
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Misalignment: Patellofemoral pain syndrome can occur when the patella does not track correctly as the knee is bent and straightened. This can result in increased pressure on the contact areas of the patella and femur. Misalignment can be the result of a variety of factors, including:
- Muscle Weakness or Tightness: Several muscles work together to move the patella. If any of these muscles are particularly tight or weak, this causes an imbalance which can result in the patella being pulled out of line, usually towards the outside of the knee.
- Q Angle: The Q Angle refers to the quadriceps alignment between the hip and the knee. Individuals with a larger than normal Q angle (greater than 20 degrees) may be more susceptible to patellofemoral pain because the patella has a tendency to track toward the outside of the knee. A larger Q angle is common in women due to their wider pelvis.
- Flat Feet: Individuals with flat feet—little or no arch and excessive pronation—are at risk of patellofemoral pain syndrome because the foot rolls inward and compromises the normal mechanics of the patellofemoral joint.
Symptoms of Patellofemoral Pain Syndrome
The main symptom of patellofemoral pain syndrome is knee pain. This knee pain may occur when:
- Sitting with bent knees
- Jumping
- Squatting
- Walking up or down stairs
- The pain is often worse after sitting with bent knees for extended periods of time.
- The pain is a dull and aching. It sometimes occurs at the front of the knee around and under the patella, but often the pain is not necessarily in one specific area. Sometimes there is tenderness along the inside border of the kneecap and swelling after exercise.
Patellofemoral pain syndrome can also be characterized by decreased kneecap motion. Symptoms may be present in one or both knees.
Diagnosis of Patellofemoral Pain Syndrome
There are three components to diagnosing patellofemoral pain syndrome:
- History: The first step in diagnosing patellofemoral pain syndrome is to discuss the history of the pain. The doctor will want to know about the location of the pain, when it began, and whether it is injury-related. What’s more, the doctor will inquire about activity level and any recent changes in duration and intensity of activity and/or changes in footwear, running surface, and more.
- Physical Examination: A physical examination of the knee will help determine the cause of the pain. A doctor can usually reproduce the symptoms by pressing on the kneecap, particularly when the knee is bent and then straightened. A doctor will also examine patellar motion, tenderness, alignment, and muscular strength.
- Imaging: A doctor may order X-rays, MRI (magnetic resonance imaging) or CT scan (computed tomography) to rule out other damage to the structure of the knee and tissues surrounding it.
Treatment of Patellofemoral Pain Syndrome
More often than not, patellofemoral pain syndrome can be effectively treated without surgery; however, sometimes surgery is required.
Non-Surgical Treatment of Patellofemoral Pain Syndrome
Non-surgical treatment of patellofemoral pain syndrome typically involves a combination of the following:
- Modify Activity: Decrease the amount of physical activity and avoid activity that involves impact (such as running). Instead, most doctors recommend swimming or bicycling. In addition, it’s important to avoid bent-knee exercises (such as squats) and sitting or kneeling in the bent-knee position for long periods of time.
- Ice: Icing the aggravated area can help reduce pain and swelling.
- NSAIDs: NSAIDs are non-steroidal anti-inflammatory medications, such as aspirin and ibuprofen. These medications can help reduce pain and swelling.
- Use Pain as Guide: Avoid any exercise or activity that causes pain.
- Physical Therapy: A qualified physical therapist can provide exercises to help strengthen and rebalance the muscles surrounding the knee joint. Specifically, many people benefit from strengthening the vastus medialis oblique (VMO), a quadriceps muscle located on the inside of the knee.
- Brace or tape: Taping or bracing the knee can help stabilize the kneecap and help the patella track properly during movement.
- Orthotics: Orthotics or special footwear can help support the arch and absorb impact.
It can take six weeks or more to notice improvement. If after six weeks of conservative treatment, there is no improvement in symptoms, then surgery may be necessary.
Surgical Treatment for Patellofemoral Pain Syndrome
Surgery is considered a last resort for patellofemoral pain syndrome after conservative treatment has failed to alleviate symptoms. The surgery is performed arthroscopically with instruments inserted through tiny incisions. During the surgery, a surgeon can remove fragments of the damaged kneecap cartilage and realign the patella if necessary.
Recovery from Patellofemoral Pain Syndrome
Recovering from patellofemoral pain syndrome can be a lengthy process. It usually takes six weeks or more to recover with non-surgical treatment, but it can take longer if surgery is required. It’s important to build strength and flexibility in the muscles surrounding the knee and to return to activity gradually and cautiously.
If you suffer from Patellofemoral Pain Syndrome, our team of orthopedic and sports medicine specialists offer state-of-the-art treatment and highly personalized care. Contact the OSMI office or call 817-529-1900 today!
