Comparison Of Bone Mineral Density In Different Anatomical Locations Of Ankylosing Spondylitis Patients And Its Clinical Significance

Part one:Sagittal Spinopelvic Alignment in Various Curve Patterns in Adolescent Idiopathic ScoliosisObjective:To compare the sagittal spinal alignment of adolescent idiopathic scoliosis (AIS) patients with various curve patterns.Methods:In this study,161 patients with AIS were recruited and classified into Lenke type 1,2 and 5 curve groups (group A, B and C, respectively). Sagittal spinal and pelvic parameters were measured from the standing lateral radiograph, including cervical sagittal angle (CSA), thoracic kyphosis (TK), lumbar lordosis (LL), pelvic incidence (PI), sacrum slope (SS), and pelvic tilt (PT). Analysis of variance was used in the comparison of each dependent variable between the 3 groups. The relations between all parameters were determined via Pearson correlation coefficient (r).Results:The mean Cobb angle of major curve were 51.2°±8.7°,53.7°±5.2° and 48.9°±4.8° for the group A, B and C, respectively. No significant difference in the magnitude of Cobb angle was observed between the 3 groups. The CSA and TK were found to be significantly lower in the group A compared with the group B and C (P<0.05) but were not significantly different between the latter 2 groups (P>0.05). The CSA was strongly correlated with TK in the all groups (group A:r=0.73; group B: r=0.29; group C:r=0.60). The TK was found to be correlated with LL only in group C (r=0.40).Conclusion:In AIS patients with various curve patterns, CSA is related to TK, but has little correlation with global spinopelvic alignment. Patients with Lenke type 1 curves tend to have a more severe cervical hyperlodosis and thoracic hyperkyphosis. Only in Lenke type 2 patients, thoracic alignment may be related to lumbar spine.Part two:The outcome of three-dimensional correction on Lenke 5C adolescent idiopathic scoliosis by uniplanar pedicle screw combined with vertebral derotation techniqueObjectives To evaluate the outcome of three-dimensional correction by uniplanar pedicle screw combined with vertebral derotation technique for the treatment of Lenke 5C adolescent idiopathic scoliosis (AIS).Methods A retrospective review was conducted on patients with Lenke 5C AIS between February 2012 and August 2013. A total of 49 patients treated with posterior selective fusion by uniplanar or conventional pedicle screw were enrolled. Of these patients,26 cases were included in the control group with an average age of 13.7 years old and the other 23 cases were included in the uniplanar pedicle screw (UPS) group with an average age of 13.2 years old. Patients were evaluated before surgery, after surgery and at the final follow-up in radiographic changes in lumbar and thoracic curve magnitude, thoracic kyphosis (TK), lumbar lordosis (LL) were evaluated in both groups. Apical vertebral rotation (AVR) were measured pre-and post-operatively by CT scans.Results After surgery, the average correction of the main curve was 75.9% and 77.5% in the control and UPS groups, respectively. No difference in the correction of the main curve magnitude between the two groups was observed. Corrections of AVR were 40.6%±16.5% in the control group and 57.4%±13.8% in the UPS group, showing a significant difference. No difference in the TK and LL was observed between the two groups. Patients were followed up for an average of 14.5 months in the control group and 13.6 months in the group UPS, showing no significant loss of correction.Conclusion Uniplanar pedicle screw provided a significantly better axial vertebral derotation as well as it can manage coronal misalignment and recover spine sagittal alignment effectively.Part three:Morphological Differences in the Vertebrae of Scoliosis Secondary to Neurofibromatosis Type 1 with and without Paraspinal NeurofibromasObjective:To investigate morphological differences in the vertebrae of scoliosis secondary to neurofibromatosis type 1 (NF1-S) with and without paraspinal neurofibromas and to identify the relationship between paraspinal neurofibromas and vertebral deformity.Methods:One hundred and fourteen NF1-S patients were classified into spinal tumor (ST) group and non-tumor (NT) group with respect to the presence of paraspinal neurofibromas. The curve pattern, curve magnitude, the shape and location of paraspinal neurofibromas and various kinds of morphological changes of vertebrae were evaluated by complete radiographs were compared between the two groups to determine whether the presence of paraspinal neurofibromas could be associated with a more severe vertebral deformity.Results:The ST and NT groups included 54 patients (age,16.8±5.5 years) and 60 patients (age,17.3±4.2 years), respectively. The Cobb angles of the main curve were 72.3°±20.6° and 65.4°±19.4° for the ST and NT groups respectively. No significant differences were observed between the two groups in age, sex ratio and Cobb angle. There were significant differences between the ST and NT groups in apical vertebral rotation (36.8°±7.2°vs.27.5°±6.8°; P< 0.001) and the prevalence of rotatory subluxation (66.1% versus 35.0%; P=0.04). Most of the paraspinal neurofibromas (70.4%) developed within the apical region, with the majority (29/38) located on the concave side.Conclusion:The NF1-S patients with paraspinal neurofibromas had significantly higher prevalence of morphological changes of vertebrae. The paraspinal neurofibromas, most of which were located on the concave side of the apical region, could be associated with more severe vertebral deformities.