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Association of atypical femoral fracture location and lower limb mechanical axis: a computed tomography-based finite element analysis

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Abstract

Summary

Atypical femoral fractures (AFFs) are categorized as low-energy fractures of the femoral shaft or subtrochanteric region. The use of computed tomography-based finite element analysis demonstrated that the femoral weakest point against tensile stress coincided with AFF location, which was determined by the lower limb axis and femoral bowing.

Introduction

This study aimed to assess the relationship between the femoral weakest point against tensile stress and the lower limb axis and geometry, including femoral bowing, using a computed tomography (CT)-based finite element analysis (FEA) model.

Methods

We retrospectively reviewed 19 patients with AFFs and analyzed their CT images of the contralateral intact femur. We performed FEA to find the maximum principal stress (MPS) and maximal tensile stress loading area (femoral weakest point, FWP) of each patient and matched the FWP with the real location of AFF. We applied mechanical axes differently, as neutral, varus, and valgus, in the FEA model, when we analyzed the change in MPS and FWP based on lower limb alignment. We compared the degree of agreement between the real fracture location and FWP before and after knee mechanical axis adjustment.

Results

The average participant age was 75.9 (range, 61–87) years, and all participants were women. In the 19 patients included, we observed 20 and 7 shaft and subtrochanteric AFFs, respectively. The average mechanical axis at the knee joint level was 22.6 mm (range, 0–70 mm) of the varus. All the patients showed an increasing trend of MPS and a distal movement of FWP when the mechanical axis of the knee was applied from the valgus to varus alignment. The root mean square errors between the FWP and real fracture location were 14.58% and 10.87% before and after adjustment, respectively, implying that the degree of agreement was better in patients who underwent mechanical adjustment.

Conclusion

The use of CT/FEA demonstrated that the FWP against tensile stress coincided with AFF location, which was determined by the lower limb axis and femoral bowing.

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Data availability

Data cannot be shared publicly because it contains potentially identifying information of each patient. Data are available from the Asan Medical Center Institutional Data Access/Ethics Committee (contact via Asan Medical Center Institutional Review Board, Convergence Innovation Bldg. 88, Olympic-ro 43-gil, Songpa-gu, Seoul, Republic of Korea. Website link, http://eirb.amc.seoul.kr/; E-mail, irb@amc.seoul.kr; Phone, + 82–2-3010–7165) for researchers who meet the criteria for access to confidential data.

Code availability

Not applicable.

References

  1. Shane E, Burr D, Abrahamsen B et al (2014) Atypical subtrochanteric and diaphyseal femoral fractures: second report of a task force of the American Society for Bone and Mineral Research. J Bone Miner Res 29:1–23

    Article  Google Scholar 

  2. Odvina CV, Zerwekh JE, Rao DS, Maalouf N, Gottschalk FA, Pak CY (2005) Severely suppressed bone turnover: a potential complication of alendronate therapy. J Clin Endocrinol Metab 90:1294–1301

    Article  CAS  Google Scholar 

  3. Haider IT, Schneider PS, Edwards WB (2019) The role of lower-limb geometry in the pathophysiology of atypical femoral fracture. Curr Osteoporos Rep 17:281–290

    Article  Google Scholar 

  4. Kim K-k, Park Y-w, Kim T-h, Seo K-d (2020) Atypical femoral neck fracture after prolonged bisphosphonate therapy. J Pathol Translat Med 54:346–350

    Article  Google Scholar 

  5. Buitendijk SKC, van de Laarschot DM, Smits AAA, Koromani F, Rivadeneira F, Beck TJ, Zillikens MC (2019) Trabecular bone score and hip structural analysis in patients with atypical femur fractures. J Clin Densitom 22:257–265

    Article  Google Scholar 

  6. Lim SJ, Yeo I, Yoon PW, Yoo JJ, Rhyu KH, Han SB, Lee WS, Song JH, Min BW, Park YS (2018) Incidence, risk factors, and fracture healing of atypical femoral fractures: a multicenter case-control study. Osteoporos Int 29:2427–2435

    Article  CAS  Google Scholar 

  7. Morin SN, Wall M, Belzile EL, Godbout B, Moser TP, Michou L, Ste-Marie LG, de Guise JA, Rahme E, Brown JP (2016) Assessment of femur geometrical parameters using EOS imaging technology in patients with atypical femur fractures; preliminary results. Bone 83:184–189

    Article  Google Scholar 

  8. Oh Y, Wakabayashi Y, Kurosa Y, Ishizuki M, Okawa A (2014) Stress fracture of the bowed femoral shaft is another cause of atypical femoral fracture in elderly Japanese: a case series. J Orthop Sci 19:579–586

    Article  Google Scholar 

  9. Sasaki S, Miyakoshi N, Hongo M, Kasukawa Y, Shimada Y (2012) Low-energy diaphyseal femoral fractures associated with bisphosphonate use and severe curved femur: a case series. J Bone Miner Metab 30:561–567

    Article  Google Scholar 

  10. Haider IT, Schneider P, Michalski A, Edwards WB (2018) Influence of geometry on proximal femoral shaft strains: implications for atypical femoral fracture. Bone 110:295–303

    Article  Google Scholar 

  11. Oh Y, Fujita K, Wakabayashi Y, Kurosa Y, Okawa A (2017) Location of atypical femoral fracture can be determined by tensile stress distribution influenced by femoral bowing and neck-shaft angle: a CT-based nonlinear finite element analysis model for the assessment of femoral shaft loading stress. Injury 48:2736–2743

    Article  Google Scholar 

  12. Oh Y, Wakabayashi Y, Kurosa Y, Fujita K, Okawa A (2014) Potential pathogenic mechanism for stress fractures of the bowed femoral shaft in the elderly: mechanical analysis by the CT-based finite element method. Injury 45:1764–1771

    Article  Google Scholar 

  13. Park YC, Song HK, Zheng XL, Yang KH (2017) Intramedullary nailing for atypical femoral fracture with excessive anterolateral bowing. J Bone Joint Surg Am 99:726–735

    Article  Google Scholar 

  14. Mosleh H, Rouhi G, Ghouchani A, Bagheri N (2020) Prediction of fracture risk of a distal femur reconstructed with bone cement: QCSRA, FEA, and in-vitro cadaver tests. Phys Engineer Sci Med 43:269–277

    Article  Google Scholar 

  15. Heiner AD (2008) Structural properties of fourth-generation composite femurs and tibias. J Biomech 41:3282–3284

    Article  Google Scholar 

  16. Lee S-J, Lee H-J, Kim J-I, Oh K-J (2011) Measurement of the weight-bearing standing coronal and sagittal axial alignment of lower extremity in young Korean adults. J Korean Orthop Assoc 46:191–199

    Article  Google Scholar 

  17. Polgár K, Gill HS, Viceconti M, Murray DW, O’Connor JJ (2003) Strain distribution within the human femur due to physiological and simplified loading: finite element analysis using the muscle standardized femur model. Proc Inst Mech Engineer H 217:173–189

    Article  Google Scholar 

  18. Ha S, Lee JJ (2018) A comparison of the accuracy of different single plasma sample methods for measuring glomerular filtration rate using 51Cr-EDTA in children. Nucl Med Molec Imag 52:293–302

    Article  CAS  Google Scholar 

  19. Kim JW, Kim JJ, Byun YS, Shon OJ, Oh HK, Park KC, Kim JW, Oh CW (2017) Factors affecting fracture location in atypical femoral fractures: a cross-sectional study with 147 patients. Injury 48:1570–1574

    Article  Google Scholar 

  20. Hyodo K, Nishino T, Kamada H, Nozawa D, Mishima H, Yamazaki M (2017) Location of fractures and the characteristics of patients with atypical femoral fractures: analyses of 38 Japanese cases. J Bone Miner Metab 35:209–214

    Article  Google Scholar 

  21. Chen LP, Chang TK, Huang TY, Kwok TG, Lu YC (2014) The correlation between lateral bowing angle of the femur and the location of atypical femur fractures. Calcif Tissue Int 95:240–247

    Article  CAS  Google Scholar 

  22. Saita Y, Ishijima M, Mogami A et al (2014) The fracture sites of atypical femoral fractures are associated with the weight-bearing lower limb alignment. Bone 66:105–110

    Article  Google Scholar 

  23. Jung IJ, Choi EJ, Lee BG, Kim JW (2021) Population-based, three-dimensional analysis of age- and sex-related femur shaft geometry differences. Osteopor Intl. Online ahead of print.

  24. Kim JW, Kim H, Oh CW, et al. (2017) Surgical outcomes of intramedullary nailing for diaphyseal atypical femur fractures: is it safe to modify a nail entry in bowed femur? Arch Orthop Trauma Surg

  25. Shon OJ, Yoon JY, Kim JW (2020) Clinical outcomes of using contralateral-side laterally bent intramedullary nails in atypical femur fractures with femoral bowing. Arch Orthop Trauma Surg 141:1291–1296

    Article  Google Scholar 

  26. McKenna MJ, McKiernan FE, McGowan B, Silke C, Bennett K, van der Kamp S, Ward P, Hurson C, Heffernan E (2017) Identifying incomplete atypical femoral fractures with single-energy absorptiometry: declining prevalence. J Endocr Soc 1:211–220

    PubMed  PubMed Central  Google Scholar 

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Funding

This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) (2021R1A2C1012972).

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Author notes

  1. Donghwan Hwang and Chul-Ho Kim contributed equally to this work as the first authors.

Authors and Affiliations

  1. Medical Device Development Center, Daegu-Gyeongbuk Medical Innovation Foundation, Daegu, Republic of Korea

    Donghwan Hwang

  2. Department of Orthopaedic Surgery, Chung-Ang University Hospital, Chung-Ang University College of Medicine, Seoul, Republic of Korea

    Chul-Ho Kim

  3. Korea Institute of Machinery and Materials, Daegu, Republic of Korea

    Yongkoo Lee

  4. Department of Orthopedic Surgery, Asan Medical Center, University of Ulsan College of Medicine, 88 Olympic-ro 43-gil, Songpa-gu, Seoul, Republic of Korea

    Ji Wan Kim

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  1. Donghwan Hwang
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Corresponding author

Correspondence to Ji Wan Kim.

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Ethics approval

This study was approved by the Institutional Review Board of Asan Medical Center and waiver was received for the need to provide written informed consent (IRB No. 2019–1568).

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Hwang, D., Kim, CH., Lee, Y. et al. Association of atypical femoral fracture location and lower limb mechanical axis: a computed tomography-based finite element analysis. Osteoporos Int 33, 1285–1293 (2022). https://doi.org/10.1007/s00198-021-06173-1

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  • DOI: https://doi.org/10.1007/s00198-021-06173-1

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