Osteoporosis International

, Volume 23, Issue 12, pp 2893–2896

Atypical fractures do not have a thicker cortex

Short Scientific Communication

DOI: 10.1007/s00198-012-2173-9

Cite this article as:
Koeppen, V.A., Schilcher, J. & Aspenberg, P. Osteoporos Int (2012) 23: 2893. doi:10.1007/s00198-012-2173-9



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.


BisphosphonatesFemoral fractureFractures stressOsteoporosis

Supplementary material

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

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