gms | German Medical Science

54. Jahrestagung der Norddeutschen Orthopädenvereinigung e. V.

Norddeutsche Orthopädenvereinigung

16.06. bis 18.06.2005, Hamburg

Prevalence of spontaneous osteonecrosis of the medial femoral condyle

Meeting Abstract

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  • corresponding author D. Pape - Universitätskliniken des Saarlandes, Orthopädie, Homburg/Saar
  • R. Seil - Homburg/Saar
  • D. Kohn - Homburg/Saar

Norddeutsche Orthopädenvereinigung. 54. Jahrestagung der Norddeutschen Orthopädenvereinigung e.V.. Hamburg, 16.-18.06.2005. Düsseldorf, Köln: German Medical Science; 2005. Doc05novEP54

The electronic version of this article is the complete one and can be found online at:

Published: June 13, 2005

© 2005 Pape et al.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License ( You are free: to Share – to copy, distribute and transmit the work, provided the original author and source are credited.



Aseptic osteonecrosis (ON) of the medial femoral condyle has been recently described as a complication of arthroscopic surgery. The time interval between the onset of symptoms and pathognomonic MRI changes (diagnostic window) is not known for ON of the knee. Knowing the prevalence of early-stage spontaneous osteonecrosis of the knee (SONK) would be helpful to avoid unnecessary arthroscopy.

To determine the prevalence of early stage SONK, 176 patients were prospectively examined by MRI between May 1998 and December 1999 in a prospective cohort study. All patients met the following criteria: onset of medial knee pain 6 weeks prior to MRI examination, no history of trauma, clinically suspected meniscal lesion, normal or inconclusive findings on conventional radiographs, age equal or older than 50 years.

In 6 (5 female, 1 male, mean age 67 years) of 176 patients, MRI-examination revealed a bone marrow edema pattern and subtle subchondral bone changes in the medial condyle consistent with early stage SONK indicating a prevalence of 3.4%. Fifty-three of the 176 patients were older than 65 years. In this group, the prevalence was as high as 9,4%. In 10 patients (5.7%), the bone and marrow changes on MR imaging either resolved on follow-up MRI and were designated as transient epiphyseal lesions or were considered to be reactive changes due to underlying degenerative articular disease.

The prevalence of early stage SONK in patients older than 65 years with meniscal symptoms without trauma history is 9.4%. Extending the preoperative diagnostic procedure to a MRI examination could avoid missing the diagnosis of avascular necrosis before planning an operative treatment of suspected meniscal tears in elderly patients.