Morphometric analysis of lumbar pedicles in patients with spinal dysraphism.

BACKGROUND: In patients with open neural tube defects, the incidence of scoliosis and requirement for spinal fusions are increased. Historically, there has been no standardized measurement of vertebral morphometry in these patients. However, anecdotally, patients with open neural tube defects have a more medially oriented lumbar pedicle trajectory than the average population. METHODS: A single-institution retrospective review of patients with open neural tube defects was conducted. The demographic parameters and functional and anatomical levels of the defects were noted. CT and MRI scans of the lumbar spine were analyzed; the pedicles from L 1 to S 1 were measured for width (W), length (L) and midline angle (α). The measurements were compared bilaterally, at each level, and with data from previously published reports. RESULTS: 16 scans of pediatric patients (mean = 3.0 ・} 4.3; age range = 7 days to 14.4 years; 7 males, 9 females) with a diagnosis of either myelomeningocele or lipomyelomeningocele were assessed. Most defects occurred in the lumbar region, with L 2 and L 5 accounting for 37.5% each. All angles demonstrated a quadratic increase from L 1 to S 1 (means: L 1 = 28.3 ・} 5.24° ; L 2 = 29.1 ・} 6.2°; L 3 = 33.2 ・} 6.0°; L 4 = 36.8 ・} 5.6°; L 5 = 43.8 ・} 5.9°; S 1 = 52.0 ・} 3.6°) and were more medially angulated than those reported previously; no significant difference existed between right and left measurements (W = 0.65 ≤ p ≤ 0.94; L = 0.91 ≤ p ≤ 1; α = 0.24 ≤p ≤0.86). CONCLUSIONS: Patients with open neural tube defects had more medially angled pedicle trajectories in the lumbar spine when compared to previously reported values.

Pediatric iatrogenic thoracic kyphosis and tension myelopathy treated with a thoracic pedicle subtraction osteotomy: a case report and review of the literature.

PURPOSE: Pediatric kyphotic deformity is an uncommon clinical entity that can occur following posterior spinal operations and has significant complexity in its treatment. Tension myelopathy in a pediatric patient with a thoracic kyphotic deformity has not been reported in the literature. CASE REPORT: We present a 17-year-old boy with a progressive thoracic kyphosis and tension myelopathy 4 years after he underwent a thoracic laminoplasty at an outside institution for the treatment of a dorsal spinal arachnoid cyst. At our institution, he was treated with a pedicle subtraction osteotomy as well as thoracic Ponte osteotomies for sagittal plane correction to relieve the tension myelopathy. CONCLUSIONS: Both clinical and radiographic improvements were observed after surgery. We review the literature on pediatric thoracic kyphosis and tension myelopathy and the treatment of these pathologies.