Enlarging retro-odontoid pseudotumor after expanding cervical laminoplasty in the presence of kyphosis.
BACKGROUND
In cranio-vertebral junction, retro-odontoid pseudotumor without evidence of rheumatoid arthritis is a rare condition.


OBJECTIVE
To discuss the mechanism of enlarging retro-odontoid pseudotumor after expanding cervical laminoplasty as a predictable complication.


METHODS
We report a rare case of an elderly man with non-inflammatory retro-odontoid pseudotumor after cervical expanding laminoplasty.


METHODS
A 76-year-old man presented with progressive quadriparesis of two week's duration caused by enlarging retro-odontoid soft tissue mass after cervical laminoplasty.


METHODS
Pre- and postoperative image, including X-ray and MRI, and the Japanese Orthopaedic Association scores for cervical myelopathy were assessed.


METHODS
The patient subsequently underwent resection of the posterior arch of the atlas and posterior fusion from the occiput to C6 using Olerud system without removal of the retro-odontoid soft tissue mass.


RESULTS
One year after surgery, the Japanese Orthopaedic Association scores for cervical myelopathy improved from 1 to 10 points, and postoperative MRI showed a mild reduction in the size of the retro-odontoid soft tissue mass.


CONCLUSIONS
The kyphotic stability from C3 to C7 after laminoplasty, leading to a compensatory hyperlordosis at the occipitocervical junction, may cause the development of a degenerative osteoarthritic change, resulting in the production of an enlarging mass. Not only posterior compression of spinal cord due to posterior arch of the hyperextended atlas but also anterior compression of spinal cord due to retro-odontoid pseudotumor probably triggered the severe myelopathy. Laminoplasty may be inappropriate in cervical myelopathy with kyphosis.
Matsumoto
Tomoyuki
T
Department of Orthopaedic Surgery, Kobe University Graduate School of Medicine, 7-5-2 Kusunoki-cho, Chuo-ku, Kobe, 650-0017, Japan. matsun@m4.dion.ne.jp
Takada
Shozo
S
Tsujimoto
Kazuo
K
Ozaki
Takuma
T
Ishimoto
Katsuhiko
K
Tsumura
Nobuhiro
N
Shiba
Ryoichi
R
Kurosaka
Masahiro
M
D000368:Aged; D002574:Cervical Vertebrae / Q000473:pathology* / Q000601:surgery; D006801:Humans; D007738:Kyphosis / Q000209:etiology* / Q000601:surgery; D007796:Laminectomy / Q000009:adverse effects*; D008279:Magnetic Resonance Imaging; D008297:Male; D009809:Odontoid Process / Q000473:pathology*; D011183:Postoperative Complications / Q000473:pathology* / Q000601:surgery; D013118:Spinal Cord Diseases / Q000209:etiology / Q000601:surgery; D013122:Spinal Diseases / Q000209:etiology*