Upper Cervical Compression Myelopathy Caused by the Retro-Odontoid Pseudotumor With Degenerative Osteoarthritis and Calcium Pyrophosphate Dihydrate Disease: A Case Report and Literature Review

Prevalence of likely retro-odontoid pseudotumor in patients receiving dental CBCT examinations

OBJECTIVES

We calculated the prevalence of unsuspected retro-odontoid pseudotumor (ROP) as detected in cone beam computed tomography (CBCT) examinations. Additionally, we examined patient age, sex, and presence and severity of cervical osteoarthritis (OA) as potential risk factors for ROP.

STUDY DESIGN

We retrospectively analyzed de-identified CBCT scans of 455 patients from the Division of Oral and Maxillofacial Radiology at the University of Connecticut School of Dental Medicine. Identification of likely ROP was completed through a likelihood scoring scale (1-4) due to the lack of magnetic resonance images. Severity of cervical OA was determined using 5 osteoarthritic features. An ordinal logistic regression model was used to link potential risk factors to ROP.

RESULTS

In total, 18 patients (3.9%) were classified with probable (11 patients [2.4%]) or definite (7 patients [1.5%]) likely ROP. Older age and the presence and severity of OA were significantly associated with higher ROP scores (P < .001). There was no significant association of ROP likelihood and patient sex (P = .637). An increase of 1 year of age increased the chance of a patient having a higher ROP likelihood score (P < .001). The age-adjusted chance of having a more severe ROP increased with moderate to severe OA (P ≤ .017).

CONCLUSIONS

Prevalence of likely ROP increases with age and OA but is not associated with sex. Individuals with moderate or severe OA are more likely to have ROP.

Crystal Diseases of the Spine

Gout, calcium pyrophosphate deposition disease, and apatite calcifications, the three main crystal disorders, may involve the spine. These disorders can be completely asymptomatic or associated with various clinical symptoms, such as acute flares and more chronic manifestations. This article presents the typical and more unusual imaging features encountered in these disorders.

Operative Technique for Resection of a Ventral Trans-Dural Retro-Odontoid Pannus: A 2-Dimensional Operative Video

Retro-odontoid pseudotumors are rare inflammatory complications of atlantoaxial instability often associated with cervical degenerative disease and rheumatoid arthritis. While propagation of these lesions has been shown to cause spinal cord compression and cervical myelopathy, intradural extension has rarely been reported. In this manuscript and two-dimensional illustrative intra-operative video, we demonstrate cervical decompression, removal of the intradural component, and stabilization with C1-2 instrumentation utilizing a posterior approach. A 71 year old patient presented with progressive cervical myelopathy. Preoperative imaging demonstrated a large retro-odontoid pannus causing severe spinal cord compression and an associated contrast-enhancing intradural lesion, in the absence of obvious C1-2 instability or fractures on CT scan. C1-2 posterior decompression and fusion were performed with maximally safe intradural pannus resection and ventral dural reconstruction. Postoperatively, the patient experienced significant improvement in myelopathic symptoms. Imaging demonstrated good spinal cord decompression with complete intradural pannus resection and debulking of the extradural component. Our outcome in this rare complication suggests a posterior approach may be effective in treating similar patients.