Predicting Femoral Component Rotation in Mechanically Aligned Total Knee Arthroplasty: Can Preoperative Three-Joint Alignment Radiograph Help?

Document Type : RESEARCH PAPER

Authors

Joint Reconstruction Research Center, Tehran University of Medical Sciences, Tehran, Iran -Department of Orthopedic Surgery, Imam Khomeini Hospital Complex, Tehran University of Medical Sciences, Tehran, Iran

10.22038/abjs.2025.83023.3781

Abstract

Objectives: Achieving precise femoral component external rotation (FCER) is crucial in Total Knee Arthroplasty (TKA) to prevent patellofemoral maltracking, implant loosening, pain, and wear. While CT scans and MRIs help determine the rotational profile of the distal femur, their use is limited by concerns about radiation exposure and cost. This study aims to explore the potential role of a preoperative three-joint alignment radiograph in predicting the necessary FCER for mechanically aligned TKA.
Methods: This retrospective cohort study was conducted on 922 patients (1,208 knees) with varus deformity who underwent primary TKA performed by a single knee surgeon between 2018 and 2020. The angular parameters from the three-joint alignment radiograph and FCER were extracted from the JRRC Knee Registry. These angular parameters included the lateral distal femoral angle (LDFA), medial proximal tibial angle (MPTA), joint line congruency angle (JLCA), and varus angle (VA). FCER was determined intraoperatively based on standard anatomical criteria, including Whiteside’s line, the trans-epicondylar line, posterior condylar axis, anteroposterior axis, and the assessment of the proximal tibial cut. Data analysis was performed using SPSS 26.
Results: A total of 922 patients (57.9% female, 42.1% male) with a mean age of 65.39 ± 8.03 years (range: 43-90) were included in the study. The FCER was 0° in 0.33%, 3° in 83.6%, 5° in 15.23%, and 7° in 0.82% of patients. FCER showed no correlation with MPTA, LDFA, or VA, but it was significantly correlated with JLCA/LDFA, JLCA/MPTA, and JLCA/VA, with cut-offs at 0.11, 0.12, and 0.62, respectively. JLCA/MPTA emerged as the best predictor for FCER in TKA (sensitivity = 48%, specificity = 81%, and accuracy = 0.67).
Conclusion: Preoperative three-joint alignment radiographs can guide the surgeon in determining the required FCER during TKA. If the ratios exceed the established cut-offs, an FCER greater than 3° may be necessary.
        Level of evidence: III

Keywords

Main Subjects

References

  1. Sherafatvaziri A, Salkhori O, Razi M, Sarzaeem MM, Ahadi K, Ebrahimzadeh MH, Jabalameli M, Firoozabadi MA, Mortazavi SJ. Practice Trends in Primary Total Knee Arthroplasty among Members of the Iranian Society of Knee Surgery, Arthroscopy, and Sports Traumatology. Archives of Bone and Joint Surgery. 2025;13(6):359.
  2. Cho Y, Lee MC. Rotational alignment in total knee arthroplasty. Asia-Pacific Journal of Sports Medicine, Arthroscopy, Rehabilitation and Technology. 2014; 1(4):113-118.
  3. Berger RA, Crossett LS, Jacobs JJ, Rubash HE. Malrotation causing patellofemoral complications after total knee arthroplasty. Clin Orthop Relat Res. 1998 :( 356):144-53. doi: 10.1097/00003086-199811000-00021.
  4. Putman S, Boureau F, Girard J, Migaud H, Pasquier G. Patellar complications after total knee arthroplasty. Orthop Traumatol Surg Res. 2019; 105(1S):S43-S51. doi: 10.1016/j.otsr.2018.04.028.
  5. Corona K, Cerciello S, Vasso M, et al. Femoral component malrotation is not correlated with poor clinical outcomes after total knee arthroplasty. Knee Surg Sports Traumatol Arthrosc. 2020; 28(12):3879-3887. doi: 10.1007/s00167-020-05880-2.
  6. Kaseb MH, Mortazavi J, Firoozabadi MA, Toofan H. Comparison between patellar resurfacing and retention in total knee arthroplasty regarding the postoperative satisfaction of patients and patellar crepitus. Archives of Bone and Joint Surgery. 2019 Sep;7(5):441.
  7. Coyle RM, Bas MA, Rodriguez JA, Hepinstall MS. The Effect of femoral cutting jig design on restoration of femoral offset in posterior-referenced total knee arthroplasty. Orthopedics. 2019; 42(6):316-322. doi: 10.3928/01477447-20190906-05.
  8. Wen L, Yu Y, Ma D, Wang Z. Effect of joint line orientation parameters on initial bone resection in mechanically aligned total knee arthroplasty: a retrospective clinicoradiological correlation study. BMC Musculoskelet Disord. 2023; 24(1):222. doi: 10.1186/s12891-023-06299-9.
  9. Firoozabadi MA, Salkhori O, Razzaghof M, Naghizadeh H, Aminizadeh S, Almutawa ZS, Poursalehian M, Mortazavi SM. Can preoperative lower limb alignment angles predict necessary soft tissue release during total knee arthroplasty for varus knees? A retrospective cohort study. International Orthopaedics. 2025 Jul 18:1-9.
  10. Cho BW, Hong HT, Koh YG, Choi J, Park KK, Kang KT. Analysis of gender differences in the rotational alignment of the distal femur in kinematically aligned and mechanically aligned total knee arthroplasty. J Clin Med. 2021; 10(16):3691. doi: 10.3390/jcm10163691.
  11. Nam JH, Koh YG, Kang K, Park JH, Kang KT. The posterior cortical axis as an alternative reference for femoral component placement in total knee arthroplasty. J Orthop Surg Res. 2020; 15(1):603. doi: 10.1186/s13018-020-02146-y.
  12. Grassi A, Pizza N, Lopomo NF, et al. No differences in knee kinematics between active and passive flexion-extension movement: an intra-operative kinematic analysis performed during total knee arthroplasty. J Exp Orthop. 2020; 7(1):12. doi: 10.1186/s40634-020-00229-7.
  13. Bonnin MP, Saffarini M, Nover L, et al. External rotation of the femoral component increases asymmetry of the posterior condyles. Bone Joint J. 2017; 99-B (7):894-903. doi: 10.1302/0301-620X.99B7.BJJ-2016-0717.R1.
  14. Cilengir AH, Dursun S, Sinci KA, Tosun O. Preoperative radiological assessment of the total knee arthroplasty. Forbes Journal of Medicine. 2021; 2(2).
  15. Jabalameli M, Rahbar M, Bagherifard A, et al. Evaluation of distal femoral rotational alignment according to transepicondylar axis and Whiteside’s line: a study in Iranian population. Journal of Research in Orthopedic Science. 2014; 1(3):0-.
  16. Kang K, Koh Y, Son J, et al. Measuring the effect of femoral malrotation on knee joint biomechanics for total knee arthroplasty using computational simulation. Bone Joint Res. 2016; 5(11):552-559. doi: 10.1302/2046-3758.511.BJR-2016-0107.R1.
  17. Seo JG, Choi S-H, Shin S, Lee BH, Chang MJ. Relationship between mechanical axis-derived and anatomic landmark-derived femoral rotation in TKA: a three-dimensional CT study. J Arthroplasty. 2014; 29(12):2314-8. doi: 10.1016/j.arth.2014.07.017.
  18. Robertson EL, Hengherr M, Amsler F, Hirschmann MT, Mathis DT. A comparison of femoral component rotation after total knee arthroplasty in Kanekasu radiographs, axial CT slices and 3D reconstructed images. Skeletal Radiol. 2021; 50(7):1389-1397. doi: 10.1007/s00256-020-03702-7.
  19. Chalmers BP, Kolin DA, Mayman DJ, et al. Three degrees external to the posterior condylar axis has little relevance in femoral component rotation: a computed tomography-based total knee arthroplasty simulation study. J Arthroplasty. 2021; 36(7S):S380-S385. doi: 10.1016/j.arth.2020.12.028.
  20. Hernández-Hermoso JA, Nescolarde L, Yañez-Siller F, Calle-García J, Garcia-Perdomo D, Pérez-Andres R. Combined femoral and tibial component total knee arthroplasty device rotation measurement is reliable and predicts clinical outcome. J Orthop Traumatol. 2023; 24(1):40. doi: 10.1186/s10195-023-00718-2.
  21. Zhu W, Zeng N, Wang N. Sensitivity, specificity, accuracy, associated confidence interval and ROC analysis with practical SAS implementations. InNESUG Proc.: Health Care and Life Sciences 2010 (Vol. 19, pp. p-67).
  22. Di J, Bai J, Zhang J, et al. Regional disparities, age-related changes and sex-related differences in knee osteoarthritis. BMC Musculoskelet Disord. 2024; 25(1):66. doi: 10.1186/s12891-024-07191-w.
  23. Patel AP, Gronbeck C, Chambers M, Harrington MA, Halawi MJ. Gender and total joint arthroplasty: variable outcomes by procedure type. Arthroplast Today. 2020; 6(3):517-520. doi: 10.1016/j.artd.2020.06.012.
  24. Rajabi M, Pourahmadi E, Adel A, Kemmak AR. Economic burden of knee joint replacement in Iran. Cost Eff Resour Alloc. 2024; 22(1):74. doi: 10.1186/s12962-024-00583-8.
  25. Amiresmaili M, Nekoei MM, Goudarzi R, Yazdi FV, Karimi MM,

 

        Jahad SA. Study of total knee arthroplasty in Iran: implications for Health managers and Policy makers; 2021.

  1. Shon HC, Choi ES, Kim YM, et al. Femoral component rotation of total knee arthroplasty in Korean subjects: a study using grand piano sign and computed tomography. Journal of the Korean Orthopaedic Association. 2012; 47(6):432-8.
  2. Kanekasu K, Kondo M, Kadoya Y. Axial radiography of the distal femur to assess rotational alignment in total knee arthroplasty. Clin Orthop Relat Res. 2005 :( 434):193-7. doi: 10.1097/01.blo.0000156819.24866.8b.
  3. Koh Y-G, Nam J-H, Chung H-S, Kim H-J, Lee H-Y, Kang K-T. Gender differences exist in rotational anatomy of the distal femur in osteoarthritic knees using MRI. Knee Surg Sports Traumatol Arthrosc. 2020; 28(9):2990-2997. doi: 10.1007/s00167-019-05730-w.

 

 

 

 

 

The Archives of Bone and Joint Surgery
Volume 13, Issue 12
December 2025
Pages 831-838

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History

  • Receive Date: 13 October 2024
  • Revise Date: 14 January 2025
  • Accept Date: 22 January 2025

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