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Knee Surgery, Sports Traumatology, Arthroscopy

, Volume 26, Issue 12, pp 3593–3600 | Cite as

Patellar tracking should be taken into account when measuring radiographic parameters for recurrent patellar instability

  • Si Heng Sharon Tan
  • Mazen M. Ibrahim
  • Zhaojie Joel Lee
  • Yen Kit Michael Chee
  • James H. Hui
Knee

Abstract

Purpose

To date, many radiographic parameters on patellar instability have their measurements taken statically, and have not been studied in various degrees of flexion according to the patellar tracking. There are also limited data regarding the use of these parameters in predicting recurrent patellar dislocation. The current study aims to review the radiographic parameters of the patellofemoral joint in different degrees of knee flexion and to correlate them with the presence of recurrent instability.

Methods

A 10-year retrospective study was conducted on all patients who had computed tomography patellar-tracking scan done for patellar instability when aged 18 years or younger. The computed tomography patellar-tracking scans were performed with the knee in extension, 10° flexion, and 20° flexion. The axial radiographic parameters were evaluated at the patellar equator, roman arch, and distal patellar pole. Sagittal and coronal parameters were noted. Radiographic parameters were then correlated with recurrent patellar instability.

Results

The femoral sulcus angle and trochlear groove depth at the distal patellar pole in 10° knee flexion (p value 0.04 and 0.03, respectively) and patellar equator in 20° knee flexion (p value 0.02 and 0.03, respectively) had the most significant clinical correlations with recurrent instability on multivariate analysis. Other radiographic parameters found to have significant clinical correlation on univariate analysis include the patellar tilt angle, congruence angle, femoral sulcus angle, trochlear groove depth, and Wiberg’s classification.

Conclusions

As per the knee dynamics, axial radiographic parameters had the most significant correlation with recurrent patellar instability when measured at the distal patellar pole in 10° knee flexion and at the patellar equator in 20° knee flexion. Future axial radiographic evaluation of patellofemoral instability should then be performed at these degrees of knee flexion and axial cuts. Trochlear dysplasia, as measured by the femoral sulcus angle and trochlear groove depth, was the most significant predictor of recurrent patellar instability in the skeletally immature. Wiberg’s classification was also a novel factor found to have clinical correlation with patellofemoral instability.

Level of evidence

III.

Keywords

Recurrent patellar instability Patellar dislocation Patellar tracking Patellar kinematics 

Notes

Author contributions

TSHS, MMI, and HHP were involved in the design of the study. TSHS, MMI, LZJ, and CYK were involved in the data acquisition and drafting of the manuscript. All authors read and approved the final manuscript.

Compliance with ethical standards

Conflict of interest

The authors declare that they have no conflicts of interest.

Funding

The authors received no financial support for the research, authorship and/or publication of this article.

Ethical approval

The study was approved by the Ethical committee of the institution.

Informed consent

Informed consent was obtained and research approved by the Institutional Review Board.

References

  1. 1.
    Amis AA, Senavongse W, Bull AM (2006) Patellofemoral kinematics during knee flexion-extension: an in vitro study. J Orthop Res 24(12):2201–2211CrossRefGoogle Scholar
  2. 2.
    Amis AA (2007) Current concepts on anatomy and biomechanics of patellar stability. Sports Med Arthrosc 15(2):48–56CrossRefGoogle Scholar
  3. 3.
    Askenberger M, Janarv PM, Finnbogason T, Arendt EA (2017) Morphology and anatomic patellar instability risk factors in first-time traumatic lateral patellar dislocations. Am J Sports Med 45(1):50–58CrossRefGoogle Scholar
  4. 4.
    Camp CL, Stuart MJ, Krych AJ, Levy BA, Bond JR, Collins MS, Dahm DL (2013) CT and MRI measurements of tibial tubercle–trochlear groove distances are not equivalent in patients with patellar instability. Am J Sports Med 41(8):1835–1840CrossRefGoogle Scholar
  5. 5.
    Colvin AC, West RV (2008) Patellar instability. J Bone Joint Surg Am 90(12):2751–2762CrossRefGoogle Scholar
  6. 6.
    Dejour D, Saggin P (2010) The sulcus deepening trochleoplasty-the Lyon’s procedure. Int Orthop 34(2):311–316CrossRefGoogle Scholar
  7. 7.
    Dejour D, Le Coultre B (2007) Osteotomies in patello-femoral instabilities. Sports Med Arthrosc 15(1):39–46CrossRefGoogle Scholar
  8. 8.
    Dejour DH (2013) The patellofemoral joint and its historical roots: the Lyon school of knee surgery. Knee Surg Sports Traumatol Arthrosc 21(7):1482–1494CrossRefGoogle Scholar
  9. 9.
    Dejour H, Walch G, Nove-Josserand L, Guier C (1994) Factors of patellar instability: an anatomic radiographic study. Knee Surg Sports Traumatol Arthrosc 2(1):19–26CrossRefGoogle Scholar
  10. 10.
    Demehri S, Thawait GK, Williams AA, Kompel A, Elias JJ, Carrino JA, Cosgarea AJ (2014) Imaging characteristics of contralateral asymptomatic patellofemoral joints in patients with unilateral instability. Radiology 273(3):821–830CrossRefGoogle Scholar
  11. 11.
    Dickschas J, Harrer J, Bayer T, Schwitulla J, Strecker W (2016) Correlation of the tibial tuberosity-trochlear groove distance with the Q-angle. Knee Surg Sports Traumatol Arthrosc 24(3):915–920CrossRefGoogle Scholar
  12. 12.
    Fithian DC, Paxton EW, Stone ML, Silva P, Davis DK, Elias DA, White LM (2004) Epidemiology and natural history of acute patellar dislocation. Am J Sports Med 32:1114–1121CrossRefGoogle Scholar
  13. 13.
    Hinckel BB, Gobbi RG, Filho EN, Pécora JR, Camanho GL, Rodrigues MB, Demange MK (2015) Are the osseous and tendinous-cartilaginous tibial tuberosity-trochlear groove distances the same on CT and MRI? Skeletal Radiol 44(8):1085–1093CrossRefGoogle Scholar
  14. 14.
    Inoue M, Shino K, Hirose H, Horibe S, Ono K (1988) Subluxation of the patella: computed tomography analysis of patellofemoral congruence. J Bone Joint Surg Am 70(9):1331–1337CrossRefGoogle Scholar
  15. 15.
    Insall J, Goldberg V, Salvati E (1972) Recurrent dislocation and the high-riding patella. Clin Orthop Relat Res 88:67–69CrossRefGoogle Scholar
  16. 16.
    Iranpour F, Merican AM, Baena FR, Cobb JP, Amis AA (2010) Patellofemoral joint kinematics: the circular path of the patella around the trochlear axis. J Orthop Res 28(5):589–594PubMedGoogle Scholar
  17. 17.
    Jaquith BP, Parikh SN (2017) Predictors of recurrent patellar instability in children and adolescents after first-time dislocation. J Pediatr Orthop 37(7):484–490CrossRefGoogle Scholar
  18. 18.
    Lewallen LW, McIntosh AL, Dahn DL (2013) Predictors of recurrent instability after acute patellofemoral dislocation in pediatric and adolescent patients. Am J Sports Med 41(3):575–581CrossRefGoogle Scholar
  19. 19.
    Lippacher S, Dejour D, Elsharkawi M, Dornacher D, Ring C, Dreyhaupt J, Reichel H, Nelitz M (2012) Observer agreement on the Dejour trochlear dysplasia classification A comparison of true lateral radiographs and axial magnetic resonance images. Am J Sports Med 40(4):837–843CrossRefGoogle Scholar
  20. 20.
    Merchant AC, Mercer RL, Jacobsen RH, Cool CR (1974) Roentgenographic analysis of patellofemoral congruence. J Bone Joint Surg Am; 56(7):1391–1396CrossRefGoogle Scholar
  21. 21.
    Pfirrmann CW, Zanetti M, Romero J, Hodler J (2000) Femoral trochlear dysplasia: MR findings. Radiology 216(3):858–864CrossRefGoogle Scholar
  22. 22.
    Redziniak DE, Diduch DR, Mihalko WM, Fulkerson JP, Novicoff WM, Sheibani-Rad S, Saleh KJ (2009) Patellar instability. J Bone Joint Surg Am 91(9):2264–2275PubMedGoogle Scholar
  23. 23.
    Salzmann GM, Weber TS, Spang JT, Imhoff AB, Schottle PB (2010) Comparison of native axial radiographs with axial MR imaging for determination of the trochlear morphology in patients with trochlear dysplasia. Arch Orthop Trauma Surg 130(3):335–340CrossRefGoogle Scholar
  24. 24.
    Schoettle PB, Zanetti M, Seifert B, Pfirrmann CW, Fucentese SF, Romero J (2006) The tibial tuberosity–trochlear groove distance: a comparative study between CT and MRI scanning. Knee 13(1):26–31CrossRefGoogle Scholar
  25. 25.
    Schutzer SF, Ramsby GR, Fulkerson JP (1986) The evaluation of patellofemoral pain using computerised tomography: a preliminary study. Clin Orthop Relat Res 204:286–293Google Scholar
  26. 26.
    Smith TO, Davies L, Toms AP, Hing CB, Donell ST (2011) The reliability and validity of radiological assessment for patellar instability: a systematic review and meta-analysis. Skeletal Radiol 40(4):399–414CrossRefGoogle Scholar
  27. 27.
    Solomon L, Warwick D, Nayagam S (2010) Apley’s system of orthopaedics and fractures (international student edition: 9th edn). Holder Arnold, UK, pp 562–564CrossRefGoogle Scholar
  28. 28.
    Stepanovich M, Bomar JD, Pennock AT (2016) Are the current classifications and radiographic measurements for trochlear dysplasia appropriate in the skeletally immature patient? Orthop J Sports Med 4(10):2325967116669490CrossRefGoogle Scholar
  29. 29.
    Tecklenburg K, Dejour D, Hoser C, Fink C (2006) Bony and cartilaginous anatomy of the patellofemoral joint. Knee Surg Sports Traumatol Arthrosc 14(3):235–240CrossRefGoogle Scholar
  30. 30.
    Thakkar RS, Del Grande F, Wadhwa V, Chalian M, Andreisek G, Carrino JA, Eng J, Chhabra A (2016) Patellar instability: CT and MRI measurements and their correlation with internal derangement findings. Knee Surg Sports Traumatol Arthrosc; 24(9):3021–3028CrossRefGoogle Scholar
  31. 31.
    Toms AP, Cahir J, Swift L, Donell ST (2009) Imaging the femoral sulcus with ultrasound, CT, and MRI: reliability and generalizability in patients with patellar instability. Skeletal Radiol 38(4):329–338CrossRefGoogle Scholar
  32. 32.
    Tscholl PM, Wanivenhaus F, Fucentese SF (2017) Conventional radiographs and magnetic resonance imaging for the analysis of trochlear dysplasia. Am J Sports Med 45(5):1059–1065CrossRefGoogle Scholar
  33. 33.
    Wiberg G (1941) Roentgenographic and anatomic studies on the femoropatellar joint. Acta Orthop Scand 12(1–4):319–410Google Scholar

Copyright information

© European Society of Sports Traumatology, Knee Surgery, Arthroscopy (ESSKA) 2017

Authors and Affiliations

  • Si Heng Sharon Tan
    • 1
  • Mazen M. Ibrahim
    • 1
    • 2
  • Zhaojie Joel Lee
    • 1
  • Yen Kit Michael Chee
    • 1
  • James H. Hui
    • 1
  1. 1.Department of Orthopaedic Surgery, University Orthopaedic, Hand and Reconstructive Microsurgery ClusterNational University Health System (NUHS)SingaporeSingapore
  2. 2.Department of Orthopaedic SurgeryHelwan UniversityCairoEgypt

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