Regression of retroodontoid pseudotumors following C-1 laminoplasty

Abstract

<jats:p>✓The authors report a new technique for C-1 laminoplasty without fusion in the treatment of cervical myelopathy associated with a retroodontoid pseudotumor (also known as a phantom tumor).</jats:p> <jats:p>The authors review the cases of three patients who underwent C-1 laminoplasty in which hydroxyapatite was used and fusion was not performed. All patients suffered from severe progressive myelopathy before surgery. Magnetic resonance imaging revealed a retroodontoid pseudotumor compressing the spinal cord at the C-1 level in all cases. Computed tomography was performed to examine the extent of bone erosion at the atlantoaxial joint and dens. Clinical parameters included neurological function, measured using the Japanese Orthopaedic Association score, and neck pain. Imaging parameters included pre- and postoperative atlas–dens intervals; the space available for the spinal cord; instability of the atlantoaxial joints; osteoarthritic changes of the atlantoaxial joint; postoperative changes in T<jats:sub>2</jats:sub> high-intensity signal; and postoperative alteration in the size of the pseudotumor.</jats:p> <jats:p>Magnetic resonance imaging demonstrated complete disappearance of the pseudotumor in two cases and partial reduction in one case. In all three cases sufficient neurological recovery was observed. The mean recovery rate was 87.0%.</jats:p> <jats:p>This new technique is less invasive than standard procedures, preserves the cervical range of motion, and avoids the morbidity of obtaining a bone graft and placing instrumentation. The authors conclude that C-1 laminoplasty without fusion is an option in the surgical management of cervical myelopathy associated with a retroodontoid pseudotumor, either without C1–2 instability or with slight, but reducible, C1–2 instability.</jats:p>

Retro-odontoid pseudotumor without atlantoaxial subluxation

“…[1][2][3]6,7 The recommended surgical management of ROP is a combination of laminectomy and posterior C1-C2 fixation with transarticular screws, without removal of the ROP. 3,4,9,10 The ROP gradually reduces within 1 year after surgery, as observed in our patient. [3][4][5]11 Differentiation of the retro-odontoid mass is often difficult.…”

C1 laminectomy for retro-odontoid pseudotumor without atlantoaxial subluxation: review of seven consecutive cases

“…In contrast, Suetsuna et al [14] reported that two of three retro-odontoid pseudotumor patients had spontaneous regression after C1 laminoplasty using hydroxyapatite. In terms of reduction rate, the authors considered that C1 laminectomy seemed inferior to posterior fusion.…”

“…Furthermore, spontaneous regression of pseudotumors following posterior fusion has been reported [10,13]. On the other hand, Suetsuna et al [14] reported spontaneous regression of retro-odontoid pseudotumors following C1 laminoplasty. The etiology of retro-odontoid pseudotumor remains controversial and the appropriate surgical procedure to treat it has not yet been established.…”

Spontaneous anterior arch fracture of the atlas following C1 laminectomy without fusion: A report of three cases and finite element analysis

“…Some authors have suggested C1-ring osteosynthesis using C1 lateral mass screws as a surgical intervention for atlas fractures [25,26]. Additionally, Suetsuna et al suggested the effectiveness of C1 laminoplasty as a less invasive surgical procedure without fusion for retro-odontoid pseudotumor [17]. These procedures, which not only preserve the motion segment but also augment disruption of the circular morphology, may be a prophylactic surgical intervention for anterior arch fracture, especially in cases that involve severe bone fragility.…”