Volume 15, Issue 1 , Page 34, March 2012
Re: Groin pain in sacral insufficiency fracture. Avoiding delayed diagnosis
Article Outline
Dear Editor,
We read with interest the case study by Ungaro et al.,1 which was published in the latest edition of the IJOM.
The authors’ highlight important issues with regard to the consideration of alternative and potentially serious diagnoses should a patient fail to respond in a timely manner to osteopathic treatment. This serves as a reminder to us all to be on guard continually during our encounters with patients, and to be prepared to re-evaluate a diagnosis when a patient is not improving or worsening. In particular, it is not infrequent in the emergency department to see elderly women who have had pain after apparently innocuous injuries (or indeed there may be no history of antecedent trauma at all), who turn out to have insufficiency fractures.
With regard to the radiological aspects the authors rightfully comment that conventional radiographs may fail to reveal the presence of a sacral insufficiency fracture. This is frequently due to overlying loops of bowel and because the underlying bone is already osteopaenic. However, subtle signs of insufficiency fracture can be picked up on close inspection of a plain radiograph including; disruption in one or more of the three arcuate lines that border the sacral foramina and the presence of linear sclerotic lines in the sacral ala. In this particular case, the fractures were clearly displayed on CT and MR imaging. The T1 weighted MR image displayed in Fig. 3 shows low signal within the sacrum which represents marrow oedema. A fat suppressed MR study (e.g. short tau inversion recovery (STIR) image) however may be more accurate in terms of interpretation and possibly would have made more sense to the reader who may not be versed with all the intricacies of MR imaging.
On a further note, from the text it implies that CT and MR are the only measures with regard to the radiological diagnosis of sacral insufficiency fractures. Nuclear medicine studies, following the injection of Technetium 99m-MDP are very sensitive with this regard and demonstrate increased radiotracer uptake in a characteristic ‘H’ pattern which has been termed the “Honda sign” after the carmaker’s insignia.2 The characteristic appearance is that of fracture lines running vertically through both the left and right sacral ala, medial to the SI joints, and a transverse fracture just below the level of the SI joints.
References
PII: S1746-0689(11)00128-3
doi:10.1016/j.ijosm.2011.11.006
© 2011 Published by Elsevier Inc.
Refers to article:
- Groin pain in sacral insufficiency fracture. Avoiding delayed diagnosis , 13 October 2011
Volume 15, Issue 1 , Page 34, March 2012
