Osteoporosis International

, Volume 23, Issue 12, pp 2893–2896 | Cite as

Atypical fractures do not have a thicker cortex

Short Scientific Communication



An association between atypical fractures and general cortical thickness of the femoral shaft is often suggested in the literature. Our radiographic measurements of 59 atypical and 218 ordinary fractures now exclude a difference larger than 10 % in mean femoral cortical thickness (sum of lateral and medial) with 95 % confidence.


An increased general cortical thickness in patients with fatigue fracture of the femoral shaft (atypical fractures) is commonly suggested. However, there are scarce data to support this.


In a published nationwide Swedish study, we identified by radiographic review 59 women with an atypical fracture during 2008. The femoral cortical thickness index (thickness/femoral diameter) of these women was now compared with the 218 ordinary fractures that occurred in the same region of the femur in a case–control design. The cortical thickness index 5 cm below the lesser trochanter was the primary variable.


Patients with atypical fractures were younger. Without correction for age, they had a thicker cortex (i.e., higher index). However, the difference in cortical thickness disappeared after age correction. The 95 % CI excludes a group mean difference exceeding 10 % of total mean thickness. Similarly, there was no significant difference in cortical thickness between patients with or without bisphosphonate treatment or between the ipsi- and contralateral femurs in patients with an atypical fracture.


The concept of a generally increased cortical thickness in patients with atypical fractures should be reconsidered.


Bisphosphonates Femoral fracture Fractures stress Osteoporosis 

Supplementary material

198_2012_2173_MOESM1_ESM.pdf (148 kb)
ESM 1(PDF 147 kb)


  1. 1.
    Lenart BA, Neviaser AS, Lyman S, Chang CC, Edobor-Osula F, Steele B et al (2009) Association of low-energy femoral fractures with prolonged bisphosphonate use: a case control study. Osteoporos Int 20:1353–1362PubMedCrossRefGoogle Scholar
  2. 2.
    Lo JC, Huang SY, Lee GA, Khandewal S, Provus J, Ettinger B et al (2012) Clinical correlates of atypical femoral fracture. Bone 51:181–184PubMedCrossRefGoogle Scholar
  3. 3.
    Shane E, Burr D, Ebeling PR, Abrahamsen B, Adler RA, Brown TD et al (2010) Atypical subtrochanteric and diaphyseal femoral fractures: report of a task force of the American Society for Bone and Mineral Research. J Bone Miner Res 25:2267–2294PubMedCrossRefGoogle Scholar
  4. 4.
    Rizzoli R, Akesson K, Bouxsein M, Kanis JA, Napoli N, Papapoulos SE et al (2011) Subtrochanteric fractures after long-term treatment with bisphosphonates: a European Society on Clinical and Economic Aspects of Osteoporosis and Osteoarthritis, and International Osteoporosis Foundation Working Group Report. Osteoporos Int 22:373–390PubMedCrossRefGoogle Scholar
  5. 5.
    Napoli N, Jin J, Peters K, Wustrack R, Burch S, Chau A et al (2012) Are women with thicker cortices in the femoral shaft at higher risk of subtrochanteric diaphyseal fractures. The study of osteoporotic fractures. J Clin Endocrinol Metab 97:2414–2422PubMedCrossRefGoogle Scholar
  6. 6.
    Giusti A, Hamdy NAT, Dekkers OM, Ramautar SR, Dijkstra S, Papapoulos SE (2011) Atypical fractures and bisphosphonate therapy: a cohort study of patients with femoral fracture with radiographic adjudication of fracture site and features. Bone 48:966–971PubMedCrossRefGoogle Scholar
  7. 7.
    Schilcher J, Michaëlsson K, Aspenberg P (2011) Bisphosphonate use and atypical fractures of the femoral shaft. N Engl J Med 364:1728–1737PubMedCrossRefGoogle Scholar
  8. 8.
    Sah AP, Thornhill TS, Leboff MS, Glowacki J (2007) Correlation of plain radiographic indices of the hip with quantitative bone mineral density. Osteoporos Int 18:1119–1126PubMedCrossRefGoogle Scholar
  9. 9.
    Rizzoli R, Laroche M, Krieg MA, Frieling I, Thomas T, Delmas P, Felsenberg D (2010) Strontium ranelate and alendronate have differing effects on distal tibia bone microstructure in women with osteoporosis. Rheumatol Int 30:1341–1348PubMedCrossRefGoogle Scholar
  10. 10.
    Kwek EBK, Goh SK, Koh JSB, Png MA, Howe TS (2008) An emerging pattern of subtrochanteric stress fractures: a long-term complication of alendronate therapy? Injury 39:224–231PubMedCrossRefGoogle Scholar
  11. 11.
    Odvina CV, Levy S, Rao S, Zerwekh JE, Rao DS (2010) Unusual mid-shaft fractures during long-term bisphosphonate therapy. Clin Endocrinol 72:161–168CrossRefGoogle Scholar

Copyright information

© International Osteoporosis Foundation and National Osteoporosis Foundation 2012

Authors and Affiliations

  1. 1.Orthopedics, Department of Clinical and Experimental Medicine, Faculty of Health ScienceLinköping UniversityLinköpingSweden

Personalised recommendations