Clinical Orthopaedics and Related Research®

, Volume 468, Issue 1, pp 266–275 | Cite as

Q-angle and J-sign: Indicative of Maltracking Subgroups in Patellofemoral Pain

  • Frances T. SheehanEmail author
  • Aditya Derasari
  • Kenneth M. Fine
  • Timothy J. Brindle
  • Katharine E. Alter
Original Article


Mechanical factors related to patellofemoral pain syndrome and maltracking are poorly understood. Clinically, the Q-angle, J-sign, and lateral hypermobility commonly are used to evaluate patellar maltracking. However, these measures have yet to be correlated to specific three-dimensional patellofemoral displacements and rotations. Thus, we tested the hypotheses that increased Q-angle, lateral hypermobility, and J-sign correlate with three-dimensional patellofemoral displacements and rotations. We also determined whether multiple maltracking patterns can be discriminated, based on patellofemoral displacements and rotations. Three-dimensional patellofemoral motion data were acquired during active extension-flexion using dynamic MRI in 30 knees diagnosed with patellofemoral pain and at least one clinical sign of patellar maltracking (Q-angle, lateral hypermobility, or J-sign) and in 37 asymptomatic knees. Although the Q-angle is assumed to indicate lateral patellar subluxation, our data supported a correlation between the Q-angle and medial, not lateral, patellar displacement. We identified two distinct maltracking groups based on patellofemoral lateral-medial displacement, but the same groups could not be discriminated based on standard clinical measures (eg, Q-angle, lateral hypermobility, and J-sign). A more precise definition of abnormal three-dimensional patellofemoral motion, including identifying subgroups in the patellofemoral pain population, may allow more targeted and effective treatments.


Anterior Knee Pain Knee Angle Lateral Patellar Patellofemoral Pain Lateral Tilt 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.



We thank Ching-yi Shieh, PhD, and Elizabeth K. Rasch, PT, PhD, for support on the statistical analysis and Steven Stanhope, PhD, for guidance throughout the project. We also thank Bonnie Damaska, Jamie Fraunhaffer, Jere McLucas, Dr. Barry Boden, and the Diagnostic Radiology Department at the National Institutes of Health for their support and research time.


  1. 1.
    Aglietti P, Insall JN, Cerulli G. Patellar pain and incongruence. I: Measurements of incongruence. Clin Orthop Relat Res. 1983;176:217–224.PubMedGoogle Scholar
  2. 2.
    Amis AA, Oguz C, Bull AM, Senavongse W, Dejour D. The effect of trochleoplasty on patellar stability and kinematics: a biomechanical study in vitro. J Bone Joint Surg Br. 2008;90:864–869.CrossRefPubMedGoogle Scholar
  3. 3.
    Biedert RM, Warnke K. Correlation between the Q angle and the patella position: a clinical and axial computed tomography evaluation. Arch Orthop Trauma Surg. 2001;121:346–349.CrossRefPubMedGoogle Scholar
  4. 4.
    Bourne MH, Hazel WA Jr, Scott SG, Sim FH. Anterior knee pain. Mayo Clin Proc. 1988;63:482–491.PubMedGoogle Scholar
  5. 5.
    Brossmann J, Muhle C, Schroder C, Melchert UH, Bull CC, Spielmann RP, Heller M. Patellar tracking patterns during active and passive knee extension: evaluation with motion-triggered cine MR imaging. Radiology. 1993;187:205–212.PubMedGoogle Scholar
  6. 6.
    Carrillon Y, Abidi H, Dejour D, Fantino O, Moyen B, Tran-Minh VA. Patellar instability: assessment on MR images by measuring the lateral trochlear inclination-initial experience. Radiology. 2000;216:582–585.PubMedGoogle Scholar
  7. 7.
    Cutbill JW, Ladly KO, Bray RC, Thorne P, Verhoef M. Anterior knee pain: a review. Clin J Sport Med. 1997;7:40–45.CrossRefPubMedGoogle Scholar
  8. 8.
    Dejour H, Walch G, Nove-Josserand L, Guier C. Factors of patellar instability: an anatomic radiographic study. Knee Surg Sports Traumatol Arthrosc. 1994;2:19–26.CrossRefPubMedGoogle Scholar
  9. 9.
    Emami MJ, Ghahramani MH, Abdinejad F, Namazi H. Q-angle: an invaluable parameter for evaluation of anterior knee pain. Arch Iran Med. 2007;10:24–26.PubMedGoogle Scholar
  10. 10.
    Fredericson M, Yoon K. Physical examination and patellofemoral pain syndrome. Am J Phys Med Rehabil. 2006;85:234–243.CrossRefPubMedGoogle Scholar
  11. 11.
    Fulkerson JP, Arendt EA. Anterior knee pain in females. Clin Orthop Relat Res. 2000;372:69–73.CrossRefPubMedGoogle Scholar
  12. 12.
    Greene CC, Edwards TB, Wade MR, Carson EW. Reliability of the quadriceps angle measurement. Am J Knee Surg. 2001;14:97–103.PubMedGoogle Scholar
  13. 13.
    Grelsamer RP, Dubey A, Weinstein CH. Men and women have similar Q angles: a clinical and trigonometric evaluation. J Bone Joint Surg Br. 2005;87:1498–1501.PubMedGoogle Scholar
  14. 14.
    Grelsamer RP, Meadows S. The modified Insall-Salvati ratio for assessment of patellar height. Clin Orthop Relat Res. 1992;282:170–176.PubMedGoogle Scholar
  15. 15.
    Grelsamer RP, Weinstein CH, Gould J, Dubey A. Patellar tilt: the physical examination correlates with MR imaging. Knee. 2008;15:3–8.CrossRefPubMedGoogle Scholar
  16. 16.
    Haim A, Yaniv M, Dekel S, Amir H. Patellofemoral pain syndrome: validity of clinical and radiological features. Clin Orthop Relat Res. 2006;451:223–228.CrossRefPubMedGoogle Scholar
  17. 17.
    Herrington L, Nester C. Q-angle undervalued? The relationship between Q-angle and medio-lateral position of the patella. Clin Biomech (Bristol, Avon). 2004;19:1070–1073.CrossRefGoogle Scholar
  18. 18.
    Inoue M, Shino K, Hirose H, Horibe S, Ono K. Subluxation of the patella: computed tomography analysis of patellofemoral congruence. J Bone Joint Surg Am. 1988;70:1331–1337.PubMedGoogle Scholar
  19. 19.
    Johnson LL, van Dyk GE, Green JR, III, Pittsley AW, Bays B, Gully SM, Phillips JM. Clinical assessment of asymptomatic knees: comparison of men and women. Arthroscopy. 1998;14:347–359.PubMedCrossRefGoogle Scholar
  20. 20.
    Jones HE, Ohlssen DI, Spiegelhalter DJ. Use of the false discovery rate when comparing multiple health care providers. J Clin Epidemiol. 2008;61:232–240.CrossRefPubMedGoogle Scholar
  21. 21.
    Kane TR, Likins PW, Levinson DA. Spacecraft Dynamics. New York, NY: McGraw-Hill Book Co; 1983.Google Scholar
  22. 22.
    Kobayashi T, Fujikawa K, Nemoto K, Yamazaki M, Obara M, Sato S. Evaluation of patello-femoral alignment using MRI. Knee. 2005;12:447–453.CrossRefPubMedGoogle Scholar
  23. 23.
    Kujala UM, Jaakkola LH, Koskinen SK, Taimela S, Hurme M, Nelimarkka O. Scoring of patellofemoral disorders. Arthroscopy. 1993;9:159–163.PubMedGoogle Scholar
  24. 24.
    Laurin CA, Dussault R, Levesque HP. The tangential x-ray investigation of the patellofemoral joint: x-ray technique, diagnostic criteria and their interpretation. Clin Orthop Relat Res. 1979;144:16–26.PubMedGoogle Scholar
  25. 25.
    MacIntyre NJ, Hill NA, Fellows RA, Ellis RE, Wilson DR. Patellofemoral joint kinematics in individuals with and without patellofemoral pain syndrome. J Bone Joint Surg Am. 2006;88:2596–2605.CrossRefPubMedGoogle Scholar
  26. 26.
    Merchant AC, Mercer RL, Jacobsen RH, Cool CR. Roentgenographic analysis of patellofemoral congruence. J Bone Joint Surg Am. 1974;56:1391–1396.PubMedGoogle Scholar
  27. 27.
    Mizuno Y, Kumagai M, Mattessich SM, Elias JJ, Ramrattan N, Cosgarea AJ, Chao EY. Q-angle influences tibiofemoral and patellofemoral kinematics. J Orthop Res. 2001;19:834–840.CrossRefPubMedGoogle Scholar
  28. 28.
    Morton R, Hebel J, McCarter R, eds. Correlations. A Study Guide to Epidemiology and Biostatistics. Ed 4. Gaithersburg, MD: Aspen Publishers, Inc; 2008:92.Google Scholar
  29. 29.
    Muhle C, Brossmann J, Heller M. Kinematic CT and MR imaging of the patellofemoral joint. Eur Radiol. 1999;9:508–518.CrossRefPubMedGoogle Scholar
  30. 30.
    Mulford JS, Wakeley CJ, Eldridge JD. Assessment and management of chronic patellofemoral instability. J Bone Joint Surg Br. 2007;89:709–716.CrossRefPubMedGoogle Scholar
  31. 31.
    Murray TF, Dupont JY, Fulkerson JP. Axial and lateral radiographs in evaluating patellofemoral malalignment. Am J Sports Med. 1999;27:580–584.PubMedGoogle Scholar
  32. 32.
    Naslund J, Naslund UB, Odenbring S, Lundeberg T. Comparison of symptoms and clinical findings in subgroups of individuals with patellofemoral pain. Physiother Theory Pract. 2006;22:105–118.CrossRefPubMedGoogle Scholar
  33. 33.
    Pfirrmann CW, Zanetti M, Romero J, Hodler J. Femoral trochlear dysplasia: MR findings. Radiology. 2000;216:858–864.PubMedGoogle Scholar
  34. 34.
    Piva SR, Fitzgerald K, Irrgang JJ, Jones S, Hando BR, Browder DA, Childs JD. Reliability of measures of impairments associated with patellofemoral pain syndrome. BMC Musculoskelet Disord. 2006;7:33–46.CrossRefPubMedGoogle Scholar
  35. 35.
    Post WR. Clinical evaluation of patients with patellofemoral disorders. Arthroscopy. 1999;15:841–851.PubMedGoogle Scholar
  36. 36.
    Rebmann AJ, Sheehan FT. Precise 3D skeletal kinematics using fast phase contrast magnetic resonance imaging. J Magn Reson Imaging. 2003;17:206–213.CrossRefPubMedGoogle Scholar
  37. 37.
    Schutzer SF, Ramsby GR, Fulkerson JP. Computed tomographic classification of patellofemoral pain patients. Orthop Clin North Am. 1986;17:235–248.PubMedGoogle Scholar
  38. 38.
    Seisler AR, Sheehan FT. Normative three-dimensional patellofemoral and tibiofemoral kinematics: a dynamic, in vivo study. IEEE Trans Biomed Eng. 2007;54:1333–1341.CrossRefPubMedGoogle Scholar
  39. 39.
    Sheehan FT, Derasari A, Brindle TJ, Alter KE. Understanding patellofemoral pain with maltracking in the presence of joint laxity: complete 3D in vivo patellofemoral and tibiofemoral kinematics. J Orthop Res. 2009;27:561–570.CrossRefPubMedGoogle Scholar
  40. 40.
    Sheehan FT, Drace JE. Quantitative MR measures of three-dimensional patellar kinematics as a research and diagnostic tool. Med Sci Sports Exerc. 1999;31:1399–1405.CrossRefPubMedGoogle Scholar
  41. 41.
    Sheehan FT, Drace JE. Human patellar tendon strain (a non-invasive, in vivo study). Clin Orthop Relat Res. 2000;370:201–207.CrossRefPubMedGoogle Scholar
  42. 42.
    Sheehan FT, Zajac FE, Drace JE. Using cine phase contrast magnetic resonance imaging to non-invasively study in vivo knee dynamics. J Biomech. 1998;31:21–26.CrossRefPubMedGoogle Scholar
  43. 43.
    Sheehan FT, Zajac FE, Drace JE. In vivo tracking of the human patella using cine phase contrast magnetic resonance imaging. J Biomed Eng. 1999;121:1–7.Google Scholar
  44. 44.
    Shih YF, Bull AM, Amis AA. The cartilaginous and osseous geometry of the femoral trochlear groove. Knee Surg Sports Traumatol Arthrosc. 2004;12:300–306.CrossRefPubMedGoogle Scholar
  45. 45.
    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;5:237–244.PubMedGoogle Scholar
  46. 46.
    Tomsich DA, Nitz AJ, Threlkeld AJ, Shapiro R. Patellofemoral alignment: reliability. J Orthop Sports Phys Ther. 1996;23:200–208.PubMedGoogle Scholar
  47. 47.
    Ward SR, Terk MR, Powers CM. Patella alta: association with patellofemoral alignment and changes in contact area during weight-bearing. J Bone Joint Surg Am. 2007;89:1749–1755.CrossRefPubMedGoogle Scholar
  48. 48.
    Wilson NA, Press JM, Koh JL, Hendrix RW, Zhang LQ. In vivo and noninvasive evaluation of abnormal patellar tracking during squatting in patellofemoral pain. J Bone Joint Surg Am. 2009;91:558–566.CrossRefPubMedGoogle Scholar
  49. 49.
    Wilson T. The measurement of patellar alignment in patellofemoral pain syndrome: are we confusing assumptions with evidence? J Orthop Sports Phys Ther. 2007;37:330–341.PubMedGoogle Scholar
  50. 50.
    Witonski D, Goraj B. Patellar motion analyzed by kinematic and dynamic axial magnetic resonance imaging in patients with anterior knee pain syndrome. Arch Orthop Trauma Surg. 1999;119:46–49.CrossRefPubMedGoogle Scholar
  51. 51.
    Zhu Y, Drangova M, Pelc NJ. Fourier tracking of myocardial motion using cine-PC data. Magn Reson Med. 1996;35:471–480.PubMedGoogle Scholar

Copyright information

© The Association of Bone and Joint Surgeons® 2009

Authors and Affiliations

  • Frances T. Sheehan
    • 1
    Email author
  • Aditya Derasari
    • 2
  • Kenneth M. Fine
    • 3
  • Timothy J. Brindle
    • 4
    • 5
  • Katharine E. Alter
    • 4
    • 6
  1. 1.National Institutes of HealthBethesdaUSA
  2. 2.Department of OrthopaedicsUniversity of MiamiMiamiUSA
  3. 3.The Orthopaedic CenterRockvilleUSA
  4. 4.Rehabilitation Medicine DepartmentNational Institutes of HealthBethesdaUSA
  5. 5.Walter Reed Army Medical CenterWashingtonUSA
  6. 6.Mt Washington Pediatric HospitalBaltimoreUSA

Personalised recommendations