PATELLOFEMORAL SYNDROME

PATELLOFEMORAL SYNDROME

The patellofemoral syndrome is a group of conditions in which the hallmark is pain beneath or surrounding the patella (kneecap). The patella is a unique bone in the leg because it does not directly bear weight. Weight is borne from the femur (thigh bone) through the tibia and fibula, which continue down to the ankle where they form the “dome” of the ankle joint.

 

The patella sits in front of the knee joint and is held, as it were, on a bowstring; the patellar tendon attaches it to the front and is held, as it were, on a bowstring; the patellar tendon attaches it to the front of the tibia below and the quadriceps complex, four powerful thigh muscles, attach it to the hip and femur above.

As the knee flexes and extends (bends and straightens), the patella tracks along a groove in the front of the femur. Any factor which disrupts this normal “tracking mechanism” can result in inflammation or pain to the undersurface of the patella. When mild, the undersurface may simply be inflamed. When more severe, the cartilage may actually become damaged or arthritis may develop. When the tracking is poorly controlled or poorly aligned, instability of the patella may result, with subluxation or actual dislocation. Most commonly in athletes, there has been too rapid an increase in training duration, intensity or other sudden changes.

• Who is at the risk of PFS

There are several factors which predispose toward this syndrome. It is more common in women, people who are knock-kneed, flat-footed, have excessive flexibility of their joints, or are overweight. The “malicious malalignment syndrome” is characterized by excessive internal rotation of the hips, knock knees, flat feet, with what is known as an increased “Q” angle. The Q angle is the angle hat the quadriceps makes as it encompasses the patella. This puts excess stress on the knees during the course of flexion and extension and results in an increase frequency of symptoms.

• What are thw symptoms of PFS

In its mildest state, patients report stiffness after prolonged sitting or initially in the morning. There is pain around or under the kneecap after activity, especially activities in which there is a lot of knee motion, e.g. ascending or descending steps, bicycling, and running. Symptoms are worsened by prolonged sitting with inadequate legroom, e.g. in a restaurant or movie theater. Patients prefer to sit with their legs extended in front of them. In more serious cases, pain may become constant, there may be subtle swelling around the kneecap, or the patient may sense instability. In cases of malalignment, the kneecap may actually dislocate with activities involving sudden rotation.

• How is the PFS treated

The backbone of long term treatment is quadriceps strengthening to “unload” the initial stress on the patella. This results in reduced pressure behind the patella and improved tracking. Details of quadriceps strengthening are discussed later. Other than exercise, additional treatments include medication, physical therapy, and bracing. Until acute symptoms subside, the patient is advised to avoid or modify those activities which bring on or exacerbate their symptoms. This means no bicycling for a period of time, avoiding frequent usage of steps, and avoiding activities which require squatting or kneeling. It is also recommended that the patient reduce or eliminate running for a period of days to weeks.

• Whar are the spesific of the exercises program  

 
Initially the patient should strengthen his quadriceps isometrically, progressing to isotonic strengthening. Sometimes isokinetic exercise is necessary as well. (Details follow below.) In some patients, electrical stimulation or biofeedback may supplement and enhance the exercise program. Electrical stimulation involves application of electrodes to the thigh and an electrical current, which assures that the contraction of the muscle will be full and result in strengthening. Biofeedback involves application of electrodes with a sound (auditory) or light (visual) signal which indicates to the patient how complete the contraction is.

The patient can then monitor and adjust their effort to gain fuller control over the muscle contraction. These complex techniques are reserved for more difficult cases. One should always avoid exercising through a painful “arc” of the range of motion. This is usually in the part of the arc where the patello-femoral pressure is highest, through mid-flexion.

• Isometric Strengthening
Lie flat on back, face up. Contract quadriceps and imagine “pushing knee down” into mattress with maximal force. These should be virtually no motion at the knee.


• Straight Leg Raise (Isometric)
Lie flat on back with weight on ankle. Lift foot approximately 12" off bed keeping knee completely straight. Hold for 3-5 seconds. Count out loud. Lower leg to bed again, slowly. Repeat 15 times, 3 sets. The amount of weight on the ankle should be increased slowly from 0-20 lbs.


• Isotonic Strengthening
Once isometric exercises can be done with 15-20 lbs. comfortably, limited-range isotonic strengthening should be begun.


• Terminal Extension
Sitting up on a table or a high chair, with feet dangling, weight around ankle, straighten (extend) the knee to full extension. The knee should then be bent up to 30 degrees of flexion slowly and straightened again. Each flexion-extension arc is one repetition. Perform 15 repetitions, 3 sets. This exercise should be begun with approximately 5-10 lbs. And gradually increased to 20 lbs. over several days to weeks.


• Multiple Small Arc Isometrics/Isotonics
If feasible, multiple similar contractions should be performed at different angles of flexion. These should be begun isometrically and progressed to small arcs of isotonic flexion/extension.


• Once #1 and #2 can be done comfortably
Vradually increase to full-range isotonic strengthening. This means sitting with leg extended, and flexing all the way and extending all the way. This is not for everyone!


• Isokinetic Strengthening
People with more strenuous activities, typically athletes, sometimes need to go beyond isotonic strengthening to isokinetic strengthening. This involves usage of isokinetic machinery, such as BIODEX, where not only the strength of the muscle contraction is trained but the “speed” of contraction as well. The rate of development of force in the muscle is known as “torque”. Training to recruit the fullest possible force in the muscles in the shortest time results in reduced patellar pressure and decreased symptoms.
 
• what medication are useful in the patellofemoral syndrome

Non-steroidal anti-inflammatory drugs (NSAID’s), taken in full anti-inflammatory doses, reduce inflammation in the patellofemoral joint. These include aspirin, ibuprofen (Advil), and numerous other prescription drugs (Disalcid, Naprosyn, Feldene, Clinoril, Dolobid, etc.).

These medications reduce the inflammatory process by inhibiting prostaglandin synthesis. Prostaglandins are responsible for much of the pain, swelling, and destruction of cartilage. These medications are often quite effective. However, there is a risk of heartburn, gastritis, fluid retention, and other less common side effects. Therefore, these should not be taken without advice of a physician.

• what role does physical therapy play

The most common use of physical therapy is in initiating and advancing an exercise program, the backbone of treatment for the patellofemoral syndrome. In addition, in the acute stage, modalities such as ultrasound and electricity can reduce adhesions behind the patella. Mobilization techniques, often helpful as well, involve the therapist manually “freeing up” the patella so that patellar tracking is improved and symptoms reduced. The use of electrical stimulation and biofeedback has already been discussed. In addition, when other predisposing factors such as malalignment are identified, often the physical therapist can do things to help the patient compensate for the predisposing factors.

• what role do orthotics play

Orthotics are appliances which support, unload, or redistribute forces. In the case of the patellofemoral syndrome, it is often effective to use an elastic knee support with a patellar cut-out (with a horseshoe pad). This knee support results in better distribution of pressure at the patella and in better patellar tracking. This is often a temporary measure until quadriceps strength is sufficient to reduce symptoms.

In addition, there is a role for shoe orthotics (inserts). This is primarily useful in people with malalignment. For example, if the patient has flat feet with a consequent increased “Q” angle, orthotics with arch support can reduce the Q angle and, therefore, result in decreased symptoms. Sometimes, taping techniques can be used to reduce symptoms related to patellar tracking.

• what is the prognosis in the patellofemoral syndrome

Eighty to eighty-five percent of the people with patello-femoral syndrome are successfully treated with the above measures. Careful evaluation of predisposing factors and a diligent exercise program results in even better statistical success.

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