|
Year |
2007 |
|---|---|
|
Question Number |
243 |
|
Category |
Spine |
Question
Figures 92a and 92b show the MRI scans of a 24-year-old man who reports right upper extremity weakness that has been worsening for the past 7 days. He is an active IV drug abuser. Blood cultures are positive for Staphylococcus aureus. What is the next most appropriate step in management
1- Parenteral antibiotics for 6 weeks
2- IV steroids for 48 hours and oral antibiotics
3- Posterior laminectomy of C3-C7
4- Anterior decompression and fusion
5- Posterior laminectomy of C5 and C8
Figures
Answer (click for answer)
The correct answer is 4- Anterior decompression and fusion
Some general rules for spine surgery:
(1) approach the pathology from the most accessible side (pathology anterior? anterior approach; pathology posterior? posterior approach); this makes sense as one would not want to traverse the spinal canal to get to anterior pathology via a posterior approach and vice versa
(2) immediate intervention is necessary in the setting of a changing neuro exam (e.g., new onset weakness/numbness)
The above vignette paints the picture of a questionably healthy younger IV drug-abusing patient with a hematogenously disseminated infection (i.e., Staphylococcus aureus, per the blood cultures). He has a progressing neurologic deficit (i.e., increasing weakness of his RUE) over the past week. Furthermore an axial and sagittal MRI section of the spine show a fluid collection with some element of rim enhancement (suggestive of abscess) at the C4-5 level residing within the anterior and predominantly right side of the canal. This collection is encroaching upon the canal space and is impinging on the spinal cord itself. There are also increased signal changes within the endplates and bodies of the C4 and C5 vertebral bodies and of the disk space at C4-5. Furthermore, the soft tissues anterior to C3-5 are with increased signal changes suggestive of contained edema.
The above area contains an abscess (an immune-privileged site effectively) that will not be responsive to IV antibiotics (eliminating answer choice 1). Furthermore, this is an aggressive infectious process that is ongoing (with resultant cord compression, damage to the C4 and C5 vertebral bodies and the intervertebral C4-5 disk space) and needs to be addressed via surgical means urgently/emergently. So administering IV steroids x48 hours and sending out on PO antibiotics is absolutely the wrong thing to do as the infectious process would only be potentiated and not responsive to this even weaker form of antibiosis. Surgery is the answer here. Now, should an anterior or posterior approach be utilized? The pathology lies anterior so there is no reason to approach posteriorly (eliminating answer choices 3 and 5). The correct answer is 4—anterior decompression and fusion. By approaching anteriorly, the abscess can be decompressed, the surrounding affected tissues can be irrigated and debrided and given the instability that would result from the infection and surgery itself, the C4-5 level should be fused.
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