Q: After having a long history of 'patella-femoral syndrome', I asked my doctor what exactly caused it. He said that it was due to an imbalance in the strength of my leg muscles. What does this mean ?
A: In patella-femoral syndrome, the knee-cap (patella) does not slide completely straight in the groove in the leg which was designed for it to slide in. Although a number of things can cause this, it is though that in some people, a weakness of the muscles of the inner thigh (vastus medialis) allows the patella to go too far toward the outside of the leg when the leg is bent, and this may cause symptoms of pain. The 'quadricep' muscles of the upper leg are attached to the patella, and thus may control the direction it slides in.
Q: Help Me! I've had knee pain for several years, and it often cracks and pops while I'm running. I want to continue to run, as I'm training for a marathon, but I can't keep going. Is this Patella-Femoral Syndrome ?
A: Patella femoral syndrome is one of the most common causes of knee pain. It generally includes several of these symptoms:
Pain in the front of one or both knees
Swelling in the knee joint
Cracking/Popping/Noises
Pain after sitting for long periods of time with the knee bent (the Cinema Sign)
Pain increases when going up and down stairs
Q: How can patella-femoral syndrome be treated?
A: Treatment of patella-femoral syndrome is complex. All athletes must have a rehabilitation program that is custom tailored to their own symptoms and anatomy. Patella-femoral pain is thought to be due to one or more of the following factors:
Abnormal Patella-Femoral joint mechanics
Altered lower extremity alignment or motion
Overuse.
Treatment must be individualized based on the above factors.
Treatment of Abnormal Pattellofemoral Alignment:
Bony or structural alignement problems (patella alta, trochlea dysplasia, femeoral anteversion, knee valgus, or laterally displaced tibial tuberosity) may require surgical intervention.
Tightness of Iliotibial band (ITB) may force the patella to track laterally and aggravate symptoms. Since the ITB is dense and fibrous, stretching may not be helpful. Occassionaly deep massage may be of benefit in reducing adhesions.
Decreased Patellar Mobility may be corrected with patellar mobilization techniques. Usually the knee is held at a small amount of flexion (less than 20 degrees) while a therapist mobilized the patella from side-to-side. It is important that the knee is not overly flexed, as this causes the patella to be firmly seated in the trochlear groove.
Quadriceps muscle strengthening can significantly improve patellofemoral symptoms. This should involve open and closed chain kinetic exercises to facilitate leg strength at the full range of motion. Exercises performed while standing on one leg encourage use of the lower abdominals and obliques which must work to stabilize the pelvis.
Strengthening of the Vastus Medialis Obliquus (VMO) has been advocated as a means to improve the medial tracking of the patella. However, there is no conclusive evidence that any exercise will selectively activate the VMO. Likely this falls into general quadricep muscle strengthening.
Patellar Taping may lead to a reduction of symptoms by 50%
Patellar Bracing may also lead to a 50% reduction in symptoms. Interestingly, MRI studies have failed to show an alternation in patellar tracing when the brace is used. This suggests that another mechanism is active-such as increased contact area due to compression, or dispersing of joint forces over a greater area.
Treatment of Altered lower extremitly alignment:
Subtalar Joint Pronation may lead to an increase in Q-angle (the angle formed by lines connecting the anterior iliac spine the center of the patella, and the tibial tuberosity). Increased Q-angle may lead to increased force on the patella, and aggravate patellofemoral symptoms. Orthotics may be useful, however, if the Q-angle is not decrease by at least 5 degrees, their effect is likely to be negligible.
Hip Internal Rotation may cause the patella to ride in a far lateral postion. If this rotation is due to motion about the pelvis, PFD symptoms may improve with strengthening of the external rotators (gluteus maximus, gluteus medius, and the deep rotators). Conversely if the femur is in a constant state of internal rotation secondary to a fixed bony defect (femoral anterversion) only surgery can correct the problem.
Gait Deviations may amplify PFG symptoms, particularly among runners. Reversal of hyperextension or decreased knee flexion during weight bearing may indicate a quadriceps avoidance pattern. Since knee flexion is mandatory for shock absorption, this pattern should be corrected.
Treatment of Overuse. If the physical examination is normal, then PFD is likely due to overuse. The standard pattern of R/I/C/E should be used. In particularly, athletes must avoid training errors such as overly ambitious increases in volume or intensity.