| Part one:Association Study between DSCAM and CNTNAP2 Gene Polymorphisms and Adolescent Idiopathic Scoliosis Susceptibility in a Chinese Han PopulationObjective:To explore whether single nucleotide polymorphisms (SNPs) of DSCAM (rs2222973) and CNTNAP2 (rs11770843) genes are associated with the susceptibility and curve severity of AIS in a Chinese Han population.Methods:A total of 648 AIS patients and 573 age- and sex-matched healthy adolescents in rs2222973 were recruited, and in rs11770843 there were 100 AIS patients and 100 age-and sex-matched healthy adolescents included in present study. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis was repeatedly carried out in a Chinese Han population to verify the linkage of AIS with SNPs rs2222973 in the DSCAM gene and rs11770843 in the CNTNAP2 gene. Case-control and case-only studies were respectively performed to define the contribution of the DSCAM gene polymorphisms to predisposition and disease severity of AIS. Statistical analysis of genotype and allele frequencies was performed by the Chi-squaretest and Power analysis in rs2222973 was performed with PASS.Results:Association analysis of the DSCAM SNP rs2222973 with AIS revealed no significant differences both in genotype frequency (cases vs. controls; T/T:50.0% vs. 46.9%, C/T:40.1% vs.44.5%, and C/C:9.9% vs.8.6%, p=0.280) and allelic frequency (cases vs. controls; T:70.1% vs.69.2%, C:29.9% vs.30.8%, p=0.643). The CNTNAP2 SNP rs 11770843 (C/T) was not found in either the AIS or control group; all 100 AIS patients and 100 normal controls had the T/T genotype. Among skeletally matured AIS patients, the average maximal Cobb angles were also comparable within different DSCAM genotypes.Conclusion:Our study did not repeatedly confirm the association of the DSCAM SNP C/T rs2222973 or the CNTNAP2 SNP C/T rs11770843 with AIS in a Chinese Han population. Considering the statistical power of the present study (99%) which would have sufficient power to detect the possible association and the limitations of the previous report, we concluded that the associations of rs2222973 with AIS predisposition and curve severity are negative in a Chinese Han population.Part two:Correlation between curve patterns and severity and SRS-22 questionnaire scores in female adolescents with idiopathic scoliosisObjectives:To investigate the relationship between SRS-22 questionnaire scores and curve patterns and curve severity in girls with adolescent idiopathic scoliosis (AIS).Methods:From June 2010 to July 2011,272 untreated female AIS patients without any treatment who completed a simplified Chinese edition of SRS-22 questionnaire were recruited in current study. All girls were divided into two groups:small Cobb angle (20°-39°) group (Group A) and large Cobb angle (40°-75°) group (Group B). In addition, according to the curve pattern, each group was further divided into four subgroups:main thoracic curve (T), thoracolumbar curve (TL)/lumbar(L), double major curve (DM) and double thoracic curve (DT). Statistical analysis among different subgroups in the same group and the same subgroups in different groups was performed using nonparametric test with Kruskal-Wallis.Results:In the Group A, the function/activity domain scores, self-image domain scores, and mental health domain scores in patients with T curve and TL/L curve were obviously higher than those in the Group B (P<0.05), and the function/activity domain scores and total sub-scores of DT curve patients were significantly better than those in the Group B (P<0.05). Furthermore, the function/activity domain scores in T curve patients were notably higher when compared with those in TL/L and DM curve patients (P<0.05). However, in the self-image domain scores, DT curve patients were significantly worse than those in T and TL/L curve patients (P<0.05). In the Group B, the pain domain scores in DM curve patients were significantly lower than those in T curve patients (P<0.05); and the self-image domain scores in DT curve patients were the lowest among all curve patterns (P<0.05).Conclutions:In mild to moderate AIS patients, the different curve severity and curve patterns, to a certain extent, may have an effect on the SRS-22 questionnaire scores,especially the AIS patients with DT curve have significantly lower self-image scores.Part three:Pedicle screw insertion with free-hand technique and power-driving technique:which is safer in thoracic scoliosis?Objectives. To assess and compare the accuracy and safety of two different techniques of pedicle screw channel preparation in patients with thoracic scoliosis.Methods. From April 2008 to October 2011, a total of 248 patients undergoing corrective surgery were included in this study. The medical records of all the patients were reviewed including gender, age at the time of surgery, pre-operative Cobb angle of main thoracic curve and complications associated with screw-insertion. According to the methods of screw channel preparation, all patients were divided into two groups:the free-hand group (Group A) and power-driving group (Group B). Pedicle perforation was measured on postoperative CT scans, and was classified into 3 types: medial, lateral/anterior-lateral and anterior perforation. Each type was further categorized into four grades based on the perforation distance (d):Grade 1 (d?2 mm), Grade 2 (d:2.1-4.0 mm), Grade 3 (d:4.1-6.0 mm), Grade 4(d?6 mm), respectively. Analyze of screw malpositioning was performed based on spinal level and side of deformities (convex or concave side), and was compared between two groups, respectively.Results:130 patients had screw insertion with the technique of manual drilling (1319 screws), and that of power drilling was 118 patients (1242 screws). The average of preoperative Cobb angle showed no significant difference between the two groups. Incidence of pedicle penetration was comparable between group A (17.6%) and group B (17.8%) (P=0.89). Both in Group A and Group B, T5 exhibited the highest perforation rate, whereas the lowest breach rate was detected at the T12 level. Breach occurred more frequently in the concave side than the convex side both in the Group A (P=0.03) and Group B (P=0.00). No significant difference of convex or concave cortical perforation was found between two groups (convex side/concave side P=0.78/0.67). In the present study, no screw-related vascular or neurological complications were found in all patients.Conclusion:The power-driving technique, as well as the free-hand technique, is safe and accurate for preparation of pedicle screw channel in corrective surgery of thoracic scoliosis. Therefore, surgeons should choose the way of pedicle screw channel preparation and insertion according to their own experience and preference. |
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