Cervical myelopathy caused by invaginated laminae of the axis associated with occipitalizaion of the atlas

RATIONALE In previous studies, few cases of cervical myelopathy caused by invaginated anomalous laminae of the axis have been reported, and none of them was combined with occipitalization of the atlas. PATIENT CONCERNS A 28-year-old male was brought to our hospital with motor and sensory impairments of the extremities after a car accident. DIAGNOSES MRI showed the spinal cord was markedly compressed at the C2/3 level. Reconstructed CT scans revealed an invaginated laminae of axis into the spinal canal as well as atlas assimilation. INTERVENTIONS The patient was successfully managed with surgical treatment by removal of the anomalous osseous structure as well as fixation and fusion. OUTCOMES The patient had a rapid recovery after the operation. He regained the normal strength of his 4 extremities and the numbness of his extremities disappeared. He returned to his normal work 3 months after the surgery without any symptoms. LESSONS Invaginated laminae of axis combined with occipitalization of the atlas is a rare deformity. MRI and reconstructed CT scans are useful for both diagnosing and surgical planning of this case. Surgical removal of the laminae results in a satisfactory outcome. The pathogenesis of this anomaly could be the fusion sequence error of the 4 chondrification centers in the embryological term.