Os Odontoideum: an unusual association of compressive synovial cyst. Case report and review of the literature
Bibliographic record
Abstract
Background: Os odontoideum is a rare cervical abnormality that harbours a potential risk for atlantoaxial instability. In rare circumstances, synovial cysts may develop and compromise the spinal cord. Therefore, cyst excision has been suggested as part of the surgical management. However, in recent reports, it has been shown that atlantoaxial stabilization alone is sufficient for synovial cyst regression. Methodology: 48-year-old woman presented with symptoms and signs of cervical myelopathy secondary to os odontoideum with atlantoaxial instability. A large synovial cyst was diagnosed with significant spinal cord compression. In addition, her spinal and cranial imaging was suggestive of multiple sclerosis which was confirmed clinically thereafter with one episode of MS flare up and positive cerebrospinal fluid analysis. Results: After she had recovered from her MS flare up, posterior atlantoaxial instrumentation and fusion was performed without synovial cyst resection. Postoperatively, her clinical condition improved substantially and complete regression of the synovial cyst was noted on cervical MRI. Interestingly, she has not had any MS recurrent episodes after the surgery. Conclusion: Degenerative changes in os odontoideum are consequences of atlantoaxial instability. Compressive synovial cysts may develop with associated cord compression. We recommend posterior atlantoaxial stabilization alone in such conditions while preserving cyst fenestration or excision for persistent symptoms related to unresolved synovial cysts.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.002 |
| Meta-epidemiology (narrow) | 0.003 | 0.001 |
| Meta-epidemiology (broad) | 0.002 | 0.001 |
| Bibliometrics | 0.006 | 0.004 |
| Science and technology studies | 0.002 | 0.002 |
| Scholarly communication | 0.002 | 0.003 |
| Open science | 0.002 | 0.002 |
| Research integrity | 0.004 | 0.002 |
| Insufficient payload (model declined to judge) | 0.003 | 0.002 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".