Patellofemoral pain syndrome

Patellofemoral pain syndrome (PFPS) is a syndrome characterized by pain or discomfort seemingly originating from the contact of the posterior surface of the patella (back of the kneecap) with the femur (thigh bone). It is the most frequently encountered diagnosis in sports medicine clinics.

Mechanism

The cause of pain and dysfunction often results from either abnormal forces (e.g. increased pull of the lateral quadricep retinaculum with acute or chronic lateral PF subluxation/dislocation) or prolonged repetitive compressive or shearing forces (running or jumping) on the PF joint. The result is thinning and softening (chondromalacia) of the articular cartilage under the patella and/or on the medial or lateral femoral condyles, synovial irritation and inflammation and subchondral bony changes in the distal femur or patella known as "bone bruises". Secondary causes of PF Syndrome are fractures, internal knee derangement, OA of the knee and bony tumors in or around the knee.^[1]

Specific populations at high risk of primary Patellofemoral Syndrome include runners, basketball players, young athletes and females especially those who have an increased angle of genu valgus (aka "Q-Angle" or commonly referred to as "knock-knees"). Typically patients will complain of localized anterior knee pain which is exacerbated by sports, walking, sitting for a long time, or stair climbing. Descending stairs may be worse than ascending. Unless there is an underlying pathology in the knee, swelling is usually mild to nil. Palpation, as well, is usually unremarkable.

Treatment

Exercises

Quadriceps strengthening is commonly suggested because the quadricep muscles help to stabilize the patella. Proper form is very important. Inflexibility has often been cited as a source of patellofemoral pain syndrome. Stretching of the hip, hamstring, calf, and iliotibial band may help restore proper biomechanics.^{[2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18]} Furthermore, the use of a foam roller may help to add flexibility and relieve pain from sore or stiff muscles in the leg.

Rest

Patellofemoral pain syndrome may also result from overuse or overload of the PF joint. For this reason, knee activity should be reduced until the pain is resolved.^[4][5] Those with pain originating from sitting too long should straighten the leg or walk periodically. Those who engage in high impact activity such as running should consider a nonimpact activity such as swimming or aerobics on an elliptical machine.

Ice and medication

To reduce inflammation, ice can be applied to the PF joint after an activity. The ice should be kept in place for 10 to 15 minutes. Additionally anti-inflammatory drugs such NSAIDs can also be taken immediately after an activity.

Taping and braces

In addition to physical therapy, external devices such as braces and tape could be used to stabilize the knee. These devices will not correct the underlying source but may prevent further injury. For this reason, they should be used in conjunction with and not in lieu of physical therapy. The technique of McConnell taping has been helpful in some studies.^[19][20][21]

Arch support

Low arches can cause overpronation or the feet to roll inward too much increasing the Q angle and genu valgus. Poor lower extremity biomechanics may cause stress on the knees and ultimately patellofemoral pain syndrome. Stability or motion control shoes are designed for people with pronation issues. Arch supports and custom orthotics may also help to improve lower extremity biomechanics.^[22][23]

See also

• Knee
• Knee pain
• Chondromalacia patellae
• Plica syndrome
• Iliotibial band syndrome

References

1. ^ Tom Plamondon. Special tests in the clinical examination of patellofemoral syndrome. Doctors Lounge Website. Available at: http://www.doctorslounge.com/index.php/articles/page/287. Accessed October 07 2010.
2. ^ Reid DC. Sports injury assessment and rehabilitation. New York: Churchill Livingstone, 1992:345-98.
3. ^ Brukner P, Khan K. Clinical sports medicine. Sydney, Australia: McGraw-Hill, 1993:372-91.
4. ^ ^{a b} Thomee R, Renstrom P, Karlsson J, Grimby G. Patellofemoral pain syndrome in young women. I. A clinical analysis of alignment, pain parameters, common symptoms and functional activity level. Scand J Med Sci Sports 1995;5:237-44.
5. ^ ^{a b} Tria AJ Jr, Palumbo RC, Alicea JA. Conservative care for patellofemoral pain. Orthop Clin North Am 1992;23:545-54.
6. ^ Kannus P, Niittymaki S. Which factors predict outcome in the nonoperative treatment of patellofemoral pain syndrome? A prospective follow-up study. Med Sci Sports Exerc 1994;26:289-96.
7. ^ Natri A, Kannus P, Jarvinen M. Which factors predict the long-term outcome in chronic patellofemoral pain syndrome? A 7-yr prospective follow-up study. Med Sci Sports Exerc 1998;30:1572-7.
8. ^ Zappala FG, Taffel CB, Scuderi GR. Rehabilitation of patellofemoral joint disorders. Orthop Clin North Am 1992;23:555-66.
9. ^ Callaghan MJ, Oldham JA. The role of quadriceps exercise in the treatment of patellofemoral pain syndrome. Sports Med 1996;21:384-91.
10. ^ Doucette SA, Goble EM. The effect of exercise on patellar tracking in lateral patellar compression syndrome. Am J Sports Med 1992;20:434-40.
11. ^ LaBrier K, O'Neill DB. Patellofemoral stress syndrome. Current concepts. Sports Med 1993;16: 449-59.
12. ^ O'Neill DB, Micheli LI, Warner JP. Patellofemoral stress. A prospective analysis of exercise treatment in adolescents and adults. Am J Sports Med 1992; 20:151-6.
13. ^ Cerny K. Vastus medialis oblique/vastus lateralis muscle activity ratios for selected exercises in persons with and without patellofemoral pain syndrome. Phys Ther 1995;75:672-83.
14. ^ Powers CM, Landel R, Perry J. Timing and intensity of vastus muscle activity during functional activities in subjects with and without patellofemoral pain. Phys Ther 1996;76:946-55.
15. ^ Laprade J, Culham E, Brouwer B. Comparison of five isometric exercises in the recruitment of the vastus medialis oblique in persons with and without patellofemoral pain syndrome. J Orthop Sports Phys Ther 1998;27:197-204.
16. ^ Mirzabeigi E, Jordan C, Gronley JK, Rockowitz NL, Perry J. Isolation of the vastus medialis oblique muscle during exercise. Am J Sports Med 1999; 27:50-3.
17. ^ Puniello MS. Iliotibial band tightness and medial patellar glide in patients with patellofemoral dysfunction. J Orthop Sports Phys Ther 1993;17: 144-8.
18. ^ Winslow J, Yoder E. Patellofemoral pain in female ballet dancers: correlation with iliotibial band tightness and tibial external rotation. J Orthop Sports Phys Ther 1995;22:18-2
19. ^ Bockrath K, Wooden C, Worrell T, Ingersoll CD, Farr J. Effects of patella taping on patella position and perceived pain. Med Sci Sports Exerc 1993;25:989-92.
20. ^ McConnell JS. The management of chondromalacia patellae: a long-term solution. Aust J Physiotherapy 1986;32:215-23.
21. ^ Powers CM, Landel R, Sosnick T, Kirby J, Mengel K, Cheney A, et al. The effects of patellar taping on stride characteristics and joint motion in subjects with patellofemoral pain. J Orthop Sports Phys Ther 1997;26:286-91.
22. ^ Gross ML, Davlin LB, Evanski PM. Effectiveness of orthotic shoe inserts in the long-distance runner. Am J Sports Med 1991;19:409-12.
23. ^ Eng JJ, Pierrynowski MR. Evaluation of soft foot orthotics in the treatment of patellofemoral pain syndrome. Phys Ther 1993;73:62-70 [Published erratum in Phys Ther 1993;73:330].

External links

• Patient handout for patellofemoral pain syndrome by the American Academy of Family Physicians