Skeletal Radiology

, Volume 39, Issue 7, pp 645–654

Herniation pits and cystic-appearing lesions at the anterior femoral neck: an anatomical study by MSCT and µCT

  • Stephanie Panzer
  • Ulrich Esch
  • Ahmed Nabil Abdulazim
  • Peter Augat
Scientific Article

DOI: 10.1007/s00256-009-0792-9

Cite this article as:
Panzer, S., Esch, U., Abdulazim, A.N. et al. Skeletal Radiol (2010) 39: 645. doi:10.1007/s00256-009-0792-9
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Abstract

Objective

To determine distinguishing features between herniation pits (HPs) and other cystic-appearing lesions at the anterior femoral neck in multi-slice computed tomography (MSCT) and micro-computed tomography (microCT) examinations.

Materials and methods

Institutional review board approval was obtained to examine 37 proximal femora of 23 cadaveric specimens (mean age available in 19 cadavers, 83 years; range 68–100 years; 9 female, 8 male, 6 unknown). All 37 femora were investigated by MSCT. 23 femora, which revealed cystic-appearing lesions at the anterior femoral neck in MSCT examinations, were additionally examined by microCT. Cystic-appearing lesions were categorized by their location, sclerotic margin, demarcation and shape in MSCT with assessment of inter-observer agreement. Detailed cortical and trabecular properties were evaluated in microCT examinations.

Results

There were seven HPs in three femora. There were a number of abnormalities potentially imitating HPs, including focal osteoporosis (13 in 13 femora), degenerative changes (5 in 4 femora) and trabecular restructuring (5 in 4 femora) at the anterior femoral neck. HPs were differentiated on the basis of their subchondral/subcortical location, completely surrounding sclerosis, clear demarcation and round-to-oval shape in MSCT. Because of their location and their microscopic appearance, HPs seem to resemble intra-osseous ganglia at the anterior femoral neck.

Conclusion

HPs have to be differentiated from other cystic appearing lesions at the anterior femoral neck to avoid overestimation of their incidence in the context of diagnosis of femoroacetabular impingement.

Keywords

Spiral computed tomographyBone cystsGanglion cystFemur neckHip joint

Copyright information

© ISS 2009

Authors and Affiliations

  • Stephanie Panzer
    • 1
  • Ulrich Esch
    • 1
  • Ahmed Nabil Abdulazim
    • 2
  • Peter Augat
    • 2
  1. 1.Department of RadiologyTrauma Center MurnauMurnauGermany
  2. 2.Biomechanics LaboratoryParacelsus University Salzburg and Trauma Center MurnauMurnauGermany