Asssociation Between Leptin Receptor Gene Polymorphism And Susceptibility Of Adolescent Idiopathic Scoliosis And Clinical Radiographic Evaluation Of Idiopathic Scoliosis

Chapter1Asssociation between leptin receptor gene polymorphism and susceptibility of adolescent idiopathic scoliosisObjective To explore whether the LEPR gene polymorphisms are associated with the susceptibility, abnormal growth pattern of adolescent idiopathic scoliosis (AIS).Methods570AIS patients aged10to18years old were enrolled, and570age-matched healthy subjects were recruited as controls. The diagnosis was confirmed clinically and radio logically. Only patients who had Cobb angleslarger than20°ere included in this study. Anthropometric parameters including body weight, height and body mass index (BMI) were measured for AIS patients.6SNPs (rs1137101, rs1137100, rs4655555, rs2767485, rs1751492and rs8179183) of LEPR gene selected on the basis of the earlier literatures. Genotyping using the PC R-based Invader assay. Case-control study and case only study were performed to define the contribution of the6SNPs to predisposition of AIS. One-way ANOVA test was used to compare the mean Cobb angles and BMI of different genotypes in case-only analyses. Statistically significance was set at P<0.05.Results Both the genotype and allele frequencies of SNP rs2767485were significantly different between AIS and control groups. No significant difference of allele frequencies was found in other5SNPs between the AIS patients and the normal controls. Both the mean maximum Cobb angles and BMI of different genotypes were similar with each other for all the6SNPs (P>0.05).Conclusion Polymorphism of rs2767485in LEPR gene is associated with the occurrence of AIS, suggesting LEPR is a predisposition gene. All the selected6SNPs were not modifying locus. Chapter2(sectionl) MR imaging may serve as a valid alternative to standing radiography in evaluating the sagittal alignment of the upper thoracic spineObjective. To compare supine MR imaging versus standing X-ray film in the evaluation of the sagittal alignment of the upper thoracic spine.Methods. Ninety-six adolescents with idiopathic thoracolumbar/lumbar scoliosis were enrolled. The visibility of upper thoracic spine landmarks from C7to T6in the lateral standing X-ray films was graded firstly. For patients with moderate or good clarity for landmarks of each vertebra from C7to T6on X-ray films, the vertebral sagittal angles from T1to T5and the angle of T2-T5kyphosis were measured by3observers on standing X-ray films and supine MR images, respectively. Intraclass correlation coefficients were used to determine the intraobserver, interobserver and method reliability. Paired t test was performed to compare the measurements between the two methods.Results. The visibility of upper thoracic region in X-ray films was generally unsatisfactory, especially for T1and T2, whereas all the vertebrae were clear in MR images. Only50patients’ X-ray films were graded as moderate or good visibility in the upper thoracic spine. Measurements on MR images gave excellent intra-and inter-observer reliability (0.914-0.924and0.838-0.920, respectively), which were better than that on X-ray films (0.767-0.891and0.713-0.883, respectively). No significant difference was found between the two modalities in terms of sagittal angles of T3, T4and T5(P=0.680,0.595and0.239, respectively) and T2-T5kyphosis (P=0.105).Conclusions. With excellent measurement reproducibility, supine MR image may serve as a valid alternative to standing X-ray film for the measurement for T3, T4and T5sagittal angles as well as the evaluation of upper thoracic kyphosis. Chapter2(section2) Comparision of the pelvic morphology in adult idiopathic scoliosis with age-matched healthy adults in Chinese Han populationObject. To determine whether the pelvic morphology in adult idiopathic scoliosis (IS) differ with age-matched healthy adults in Chinese Han population.Methods.151adult patients with idiopathic scoliosis (IS) and65healthy age-matched adults were recruited consecutively. The sagittal parameters measured including thoracic kyphosis (TK), lumbar lordosis (LL), pelvic incidence (PI), sacrum slope (SS), and pelvic tilt (PT). The parameters were compared between adult IS and healthy adults. Analysis of variance was used to compare the sagittal parameters between single thoracic scoliosis (STS) group, lumbar scoliosis (LS) group and healthy adults group. The associations between all parameters were also analyzed.Results. Adult IS patients in Chinese have similar PI and LL with healthy adults. Smaller TK and SS but larger PT were demonstrated in adult IS patients than that in healthy adults. The patients in STS group and LS group have similar pelvic morphology and TK value, while the LL of STS group was larger than that in LS group. The TK was found to be correlated with LL in STS group, LS group and the healthy adults group. The LL was found to be associated with SS and PI in STS group, LS group and the healthy adults group. The PT was correlated with TK and LL in the STS group and LS group, but not in the healthy adults group. The TK (19.7°±12.9°), PT (6.4°±8.2°), and PI (46.3°±10.6°) were found to be significantly lower in Chinese patients with adult IS than the values reported in the historical cohorts of adult IS. The PI in the current adult IS cohort was extremely smaller than that in whites and blacks with IS.Conclusion. Adult idiopathic scoliosis patients in Chinese have similar PI compared with age-matched healthy adults. The pelvic incidence did not differ between the scoliosis groups. These findings suggested that PI may not be the risk factor for the development of idiopathic scoliosis in Chinese Han population. There are significant differences in spinopelvic morphology between adult IS patients in Chinese and the white race, which confirmed that race may influence an individual’s spinopelvic morphology. This variety of spinopelvic morphology should be taken in account in the surgical planning. Chapter2(section3) Influence of demographic factors and radiographic parameters on Scoliosis Research Society-22(SRS-22) performance in adult idiopathic scoliosisObjective To investigate the influence of demographic factors and radiographic parameters on the SRS-22performance in adult idiopathic scoliosis.Methods From January2008to December2012,109adult idiopathic scoliosis patients (17males and92females) without a history of brace treatment or spine surgery completed the simplified Chinese version of SRS-22questionnaire. The average age was24.8years (range,19to40years), and the average Cobb angle was37.3°(range,16°to102°). Spearman correlation analysis was used to evaluate the correlation among SRS-22domains and age, body mass index (BMI), Cobb angle and sagittal vertical axis (SVA). Comparisons were conducted in terms of SRS-22subtotal scores and other domains between patients stratified with age (<30yrs vs.>30yrs), curve magnitude (<40°vs.>40°), curve pattern (thoracic vs. thoracolumbar/lumbar scoliosis) and gender.Results Age was negatively correlated with SRS-22subtotal scores (r=-0.35, P<0.001), pain (r=-0.50, P<0.001), mental (r=-0.31, P=0.001), function (r=-0.21, P=0.026) domains. BMI was negatively correlated with pain domain (r=-0.23, P=0.016). Cobb angle was negatively correlated with SRS-22subtotal scores (r=-0.31, P=0.001), self-image (r=-0.49, P<0.001) and function (r=-0.30, P=0.001) domains. SVA was negatively correlated with function domain (r=-0.26, P=0.007). Older adult patients had lower scores than younger adult patients in SRS-22subtotal scores (P=0.034), pain (P<0.001) and mental (P=0.029) domains. Patients with large curve magnitude had lower SRS-22subtotal scores (P=0.010), self-image (P<0.001) and function (P=0.021) domains than the patients with small curve magnitude. Patients with thoracic scoliosis had lower scores in self-image (P=0.042) and mental (F=0.043) domains as compared to those with thoraco lumbar/lumbar scoliosis. Female patients have lower pain (P=0.008) domain score than male patients, but no difference was found in terms of other domains.Conclusion Adult idiopathic scoliosis patients’responses to SRS-22questionnaire can be influenced by age, Cobb angle, BMI and sagittal balance, in which Cobb angle and age influenced the SRS-22subtotal scores to a great extent. Patients with thoracic scoliosis present with poorer self-image and function than those with thoracolumbar/lumbar scoliosis. Female patients have tower tolerance of pain than male patients. The above characteristics should be taken into account during the treatment for adult idiopathic scoliosis. Chapter3(sectionl) Risk Factors and Revision Strategies for Rod Fracture in Patients with Severe Kyphoscoliosis Following Posterior Vertebral Column ResectionObjective:To investigate the risk factors and revision strategies for rod fracture in patients with severe kyphoscoliosis following posterior vertebral column resection (PVCR).Methods:Between June2003to June2011,7patients (4males and3females) who developed rod fractures following PVCR in our institution were retrospectively reviewed. The average age was24.4yr (range,12-39yrs) at the time of primary surgeries. The occurrence times and locations of the rod fractures were recorded and the risk factors for the fractures were analyzed. Patients who underwent revision surgeries were followed up to evaluate the correction outcomes.Result:The occurrence times of the rod fractures ranged from6-53months, with an average of23.4months.5fractures occurred within2years after the primary surgeries, while the other2occurred more than4years after the primary surgeries. Six (85.7%) fractures occurred at the levels of osteotomies and1occurred1level below the osteotomy. The potential reasons for the rod fractures were listed as follows:(1) residual kyphosis (1case);(2) residual kyphosis in association with unsteady gait (1case);(3) residual kyphosis associated with single rod fixation (1case);(4) residual kyphosis combined with titanium mesh cage malposition (1case);(5) residual kyphosis combined with anterior column defect;(6) injury (2cases). Among these6patients underwent revision surgeries,5patients received one-stage combined anterior-posterior approach surgeries, while1patient received single posterior surgery. These patients underwent follow-up range from12to22months, with an average of18months. At the last follow-up, all the patients obtained satisfying corrections and graft fusion, without internal fixation-related complications.Conclusion:Rod fractures mostly occurred within2years after PVCR at the levels of osteotomies. Residual kyphosis was the main risk factor for the rod fracture. Injury, anterior column defects, unsteady gait, single rod fixation and malposition of titanium mesh cage also increased the risks of rod fractures. One-stage combined anterior-posterior revision surgery can obtain satisfying correction outcome.