Nagamani Peri MD, Presenter: Nothing to Disclose

Efstathios Papavassiliou MD, Abstract Co-Author: Nothing to Disclose

Rafael Rojas MD, Abstract Co-Author: Nothing to Disclose

Rafeeque A. Bhadelia MD, Abstract Co-Author: Nothing to Disclose

To assess (1) the extent of marrow edema and other associated MRI findings in acute odontoid fractures (2) if initial presence or absence of marrow edema correlates with healing on follow up

IRB approved retrospective evaluation of patients with acute odontoid fractures who had concurrent CT and MRI from 1999-2008 was performed. Marrow edema at the fracture site was assessed on sagittal STIR images as: (a) none, (b) linear- limited to the fracture cleft and (c) diffuse. Associated injuries were noted at (1) interspinous ligaments (2) posterior spinous soft tissues (3) spinal cord. Presence and extent of marrow edema at presentation was correlated with healing on follow up.

Eighteen patients (11- type 2; 7- type 3 odontoid fractures) were included in the study. Marrow edema was absent in 4(22%), linear- limited to fracture cleft in 11 (61%), and diffuse in 3(17%). Increased interspinous ligament STIR signal at C1-2 was seen in 78%.; it was seen in all patients with absent or diffuse edema, and in 63% of those with linear edema pattern limited to fracture cleft. Increased posterior spinous soft tissue signal and prevertebral soft tissue swelling were noted in 50%; spinal cord edema in 17% all of whom had type 3 odontoid fractures and other cervical or thoracic bony spine injuries in 28%. 11/18 had follow up imaging 1 month or later using plain radiographs or CT; two of these had no marrow edema-one had near complete healing at 8 month and the other had partial healing at 2 month follow up. However, the extent of healing was variable between those with linear and diffuse types of marrow edema, seen as absent or partial healing.  

In contradistinction to elsewhere in the skeletal system, marrow edema is absent or little in acute odontoid fractures. Hence, it may be necessary to look for additional MR findings to determine the acute nature of these fractures. Increased signal in the interspinous ligaments at C1/2 can be helpful in identifying the acute nature of the odontoid fractures. Though several factors are involved in healing of the fractures, MRI findings at presentation may play a role in speculating healing.  

Identification of acute nature of odontoid fractures and prediction of healing have important therapeutic implications and hence, it is necessary to know the MR findings that address these issues.

Peri, N, Papavassiliou, E, Rojas, R, Bhadelia, R, MRI of Acute Odontoid Fractures: Is Marrow Edema Helpful in Diagnosing “ACUTE” Nature of Fracture and Predicting Healing?.  Radiological Society of North America 2009 Scientific Assembly and Annual Meeting, November 29 - December 4, 2009 ,Chicago IL. http://archive.rsna.org/2009/8013094.html