STUDY DESIGN: A case report and review of previous literature. OBJECTIVES: To describe the diagnosis and successful treatment of an intraspinal retro-odontoid cyst associated with an os odontoideum. SUMMARY OF BACKGROUND DATA: Retro-odontoid cysts associated with atlantoaxial instability are extremely rare. Direct excision of the cysts has commonly been performed for the surgical treatment of myelopathy. METHODS: A retro-odontoid cyst in a 58-year-old woman with os odontoideum was treated surgically by posterior fixation between C1 and C3 without resection of the retro-odontoid mass. The patient's history, clinical examination, imaging findings, and treatment are reported. RESULTS: The patient experienced walking difficulty, numbness in the upper and lower limbs, and hypesthesia in both hands. Congenital C2/3 fusion and atlantoaxial instability associated with an os odontoideum were found in the radiographs. Magnetic resonance imaging detected a round retro-odontoid mass, which compressed the spinal cord. The mass showed uniform low intensity on T1-weighted images and uniform high signal intensity on T2-weighted images. Gadolinium-diethylenetriaminepenta-acetic acid-enhanced T1-weighted images showed rim enhancement of the mass with no internal enhancement. Three months after the operation, the mass was no longer visible in a magnetic resonance imaging examination and the patient completely recovered motor function in her extremities. CONCLUSIONS: Posterior fixation without resection was successfully used to eliminate a retro-odontoid cyst associated with atlantoaxial instability.
STUDY DESIGN: A case report and review of previous literature. OBJECTIVES: To describe the diagnosis and successful treatment of an intraspinal retro-odontoid cyst associated with an os odontoideum. SUMMARY OF BACKGROUND DATA: Retro-odontoid cysts associated with atlantoaxial instability are extremely rare. Direct excision of the cysts has commonly been performed for the surgical treatment of myelopathy. METHODS: A retro-odontoid cyst in a 58-year-old woman with os odontoideum was treated surgically by posterior fixation between C1 and C3 without resection of the retro-odontoid mass. The patient's history, clinical examination, imaging findings, and treatment are reported. RESULTS: The patient experienced walking difficulty, numbness in the upper and lower limbs, and hypesthesia in both hands. Congenital C2/3 fusion and atlantoaxial instability associated with an os odontoideum were found in the radiographs. Magnetic resonance imaging detected a round retro-odontoid mass, which compressed the spinal cord. The mass showed uniform low intensity on T1-weighted images and uniform high signal intensity on T2-weighted images. Gadolinium-diethylenetriaminepenta-acetic acid-enhanced T1-weighted images showed rim enhancement of the mass with no internal enhancement. Three months after the operation, the mass was no longer visible in a magnetic resonance imaging examination and the patient completely recovered motor function in her extremities. CONCLUSIONS: Posterior fixation without resection was successfully used to eliminate a retro-odontoid cyst associated with atlantoaxial instability.
Authors: Giuseppe M V Barbagallo; Francesco Certo; Massimiliano Visocchi; Stefano Palmucci; Giovanni Sciacca; Vincenzo Albanese Journal: Eur Spine J Date: 2013-09-19 Impact factor: 3.134