C1-C2 Pedicle Screw Fixation for Pediatric Atlantoaxial Dislocation: Initial Results and Long-term Follow-up.

BACKGROUND: There are few studies reporting the use of atlantoaxial pedicle screws and the long-term effects of C1-C2 posterior fusion in children. Our study is to investigate the initial results of C1-C2 pedicle screw fixation for pediatric atlantoaxial dislocation (AAD) and assessed spontaneous change of postoperative radiography after a long-term follow-up period. METHODS: Posterior pedicle screw fixations were performed in 21 pediatric patients with AAD. All the patients underwent implant removal 1 year after their initial surgery and had regular follow-up with an average duration of 76.4 months (range, 52 to 117 mo). Clinical and radiographic data were then collected and compared. RESULTS: Frankel Grade was significantly improved at 3 months follow-up compared with pretreatment values. All patients had good bony fusion at a mean of 4.2±0.9 months (range, 3 to 6 mo) after treatment. None of the patients experienced worsening neurological symptoms or injury to the vertebral artery. However, 2 cases experienced minor complications. Following removal of the implants, no spinal deformities or subaxial instabilities were found. The mean angle of sagittal curvature increased from 12.1±2.4 degrees (range, 0 to 22 degrees) immediately postoperatively to 19.1±2.7 degrees (range, 6 to 31 degrees) at the final follow-up (P>0.05). CONCLUSIONS: The results demonstrated that C1-C2 pedicle screw fixation could achieve satisfactory initial results for the management of the pediatric AAD. Moreover, removal of the metal implant after bony fusion did not increase the risk of spinal deformity or subaxial instability at long-term follow-up.

Analysis of sagittal balance using spinopelvic parameters in ankylosing spondylitis patients treated with vertebral column decancellation surgery.

This study was designed to explore the change of spinopelvic parameters after vertebral column decancellation (VCD) for the management of thoracolumbar kyphosis secondary to ankylosing spondylitis (AS). Forty-two AS patients including thirty-six males and six females with thoracolumbar kyphosis, who underwent VCD from April 2005 to June 2012 in our hospital, were retrospectively reviewed. A series of spinopelvic parameters including thoracic kyphosis (TK), lumbar lordosis (LL), sacral slope (SS), pelvic incidence (PI), pelvic tilt (PT) and sagittal vertical axis (SVA) measured on preoperative and postoperative free-standing radiographs were obtained and analyzed. Also clinical assessments were performed with the Oswestry disability index (ODI) and the Bath Ankylosing Spondylitis Activity and Function Index (BASDAI and BASFI) so as to seek correlations between radiological parameters and symptoms. Except for pelvic incidence (PI), significant difference was found in all radiological spinopelvic parameters between the preoperative and follow-up values. Furthermore, there was significant improvement in the clinical assessment parameters ODI, BASDAI and BASFI, which all correlated significantly with the postoperative pelvic tilt (PT). The results of this study show that posterior VCD is an effective option to manage sagittal imbalance in AS. In the current series, patients improving LL and PT were found to achieve good clinical outcomes. Overall, our findings show that it is important to quantify sagittal spinopelvic parameters and promote sagittal balance in the surgery for AS.