Related Experiment Video
Updated: Apr 24, 2026
Author Spotlight: Double Posteromedial Approach for Treating Posterior Cruciate Ligament Cysts
Published on: October 20, 2023
Retro-odontoid synovial cyst resected via an anterolateral approach without fusion
Yu-Ichiro Ohnishi1, Koichi Iwatsuki, Shigenori Taketsuna
1Department of Neurosurgery, Osaka University Medical School, 2-2 Yamadaoka, Suita, Osaka, 565-0871, Japan, ohnishi@nsurg.med.osaka-u.ac.jp.
Purpose:
Retro-odontoid synovial cysts are rare and attributable to degenerative changes in the atlantoaxial joints. An anterolateral approach facilitates access to lesions located anterior to the craniocervical junction without harming the atlantoaxial joints, and can also treat small lesions in the ventral mid-portion of the craniocervical junction without compression of spinal cord.
Methods:
We present herein the case of a 70-year-old man with a retro-odontoid synovial cyst. A ventral midsection mass was present at the level of the atlantoaxial joint. The compressed anterior medulla led to neurological deficits. Slight atlantoaxial instability was radiologically present. An intradural cyst resection without fusion was performed via the anterolateral approach. The diagnosis of a synovial cyst was histologically confirmed.
Results:
The patient was followed up for 3 years and exhibited improvements in the neurological deficits. There were no recurrence and postoperative deterioration of atlantoaxial instability.
Conclusions:
The anterolateral approach for the retro-odontoid synovial cyst had little effect on C1-2 instability and yielded neurological improvements.
