[Association of matrix metalloproteinase 9 polymorphisms with adolescent idiopathic scoliosis in Chinese Han female].

OBJECTIVE: To determine whether the matrix metalloproteinase 9 gene (MMP9) polymorphism is associated with the onset or progression of adolescent idiopathic scoliosis (AIS) in Chinese Han female. METHODS: Three single nucleotide polymorphisms (SNPs) (rs17576, rs2250889, rs1805088) were genotyped through TaqMan-based real-time PCR assay in 190 AIS patients and 190 controls, all of whom were females from Chinese Han population with matched age. Analyses performed included Hardy Weinberg equilibrium test, Pearson chi-square test, Logistic regression analysis, linkage disequilibrium analysis and haplotype analysis. The mean maximum Cobb angles with different genotypes in case-only dataset were also compared. RESULTS: All 3 SNPs have reached Hardy-Weinberg equilibrium in the controls. Genotype and allele frequencies of all SNPs were found similar between cases and controls by Pearson chi-square test and Logistic regression. Genotype-phenotype analysis showed that patients with CC genotype in rs2250889 featured larger maximum Cobb angles. CONCLUSION: MMP9 may not be a predisposition gene of AIS in Han female. However, homozygous mutation in rs2250889 can render scoliosis more severe, implying that MMP9 defect may result in deterioration of AIS.

[A survey on adolescent scoliosis in Guangzhou].

OBJECTIVE: To investigate the prevalence of adolescent scoliosis in Guangzhou for development of effective prevention and treatment program to the disease. METHODS: From November 2007 to July 2009, 30 142 students between 7 to 20 years old in primary and junior middle schools received physical check-up for detection of scoliosis through physical and radiographic examination. RESULTS: 211 cases were diagnosed as scoliosis (Cobb angle ≥ 10°), with the prevalence rate as 0.70%. 192 patients with idiopathic scoliosis (IS) were detected, accounting for 91.00%. There were 19 cases of congenital scoliosis, accounting for 9.00%. Sex ratio of scoliosis was 180/31. The prevalence of scoliosis was significantly lower in boys than that in girls (χ(2) = 112.332, P < 0.001). CONCLUSION: The crude prevalence of adolescent scoliosis was 0.70% in Guangzhou with majority of idiopathic scoliosis. Investigation on scoliosis among school-age population seemed to be important for the purposes of early diagnosis, selection of effective prevention and treatment.

[Association of single nucleotide polymorphisms of IL-1b with lumbar disc disease].

This study was to explore the relationships between (-511)T>C and (+3954)C>T single nucleotide polymorphisms(SNP) in IL-1beta gene with lumbar intervertebral disc disease. We analyzed (-511)T>C and (+3954)C>T SNP in IL-1beta gene by the polymerase chain reaction-restriction fragment length polymorphism and electrophoresis methods respectively in 81 cases with lumbar disc disease and 101 healthy controls. The relationship between (-511)T>C and (+3954)C>T SNP in IL-1beta gene and lumbar disc disease in two groups was measured, so does the relationship between (-511)T>C and (+3954)C>T SNP in IL-1beta gene and intervertebral disc degeneration in those younger than 45-year-old. The results showed there were (-511)T>C and (+3954)C>T SNP in IL-1beta gene. There was a significant difference in the distribution of TT, TC and CC genotype or T, C genotype of (-511)T>C of IL-1beta in two groups. And there was no significant difference in the distribution of (+3954)C>T SNP in IL-1beta gene in two groups. There was no significant difference between the distribution of (-511)T>C and (+3954)C>T SNP in IL-1beta gene and intervertebral disc degeneration in those younger than 45-year-old. It suggested (-511)T>C SNP in IL-1beta gene be one of the susceptible alleles for Lumbar disc disease.

[The vitamin D receptor gene Tru I polymorphisms and its effect on the detection of Bsm I polymorphisms in Han nationality].

OBJECTIVE: To explore the polymorphisms of vitamin D receptor (VDR) gene Tru I polymorphisms and the influence of this variation on Bsm I polymorphisms in Han nationality. METHODS: Venous blood samples from 80 healthy individuals of Han nationality were collected and genomic DNA was extracted, VDR Bsm I and Tru I were tested by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) to analyze the polymorphisms of VDR gene; After using another primers to test VDR Bsm I in the same samples, the consistence of each method was assessed. RESULTS: The frequencies of the VDR Tru I genotype in the groups were: TT 68.7%, Tt 26.3%, tt 5.0%; VDR Bsm I were: BB 6.2%, Bb 52.5%, bb 41.3%; Both polymorphisms were under Hardy-Weinberg equilibrium. After using another pair of primer, the frequencies of Bsm I genotype were BB 20.0%, Bb 26.2%, bb 53.8%, 22 genotype Bb changed to genotype BB or genotype bb in comparison with the result of first detection. CONCLUSION: The VDR Tru I polymorphism is found in the Han nationality, the distribution of this site's polymorphism is different from that of other nationalities. The presence of Tru I variation can result in some allele of Bsm I genotype drop-out in some study.

[The risk factors and preventive strategies of heterotopic ossification after artificial disc replacement in lumbar spine].

OBJECTIVE: To analyze the risk factors of heterotopic (HO) ossification after total lumbar disc replacement and probe the preventive strategies for it. METHODS: The radiographs and clinical data of 78 discs in 65 patients who received artificial lumbar disc replacement (ADR) from April 1998 to December 2003 were analyzed retrospectively by two radiologists and one orthopaedic surgeon and then postoperative HO were graded according to McAfee system. The bony formations in disc spaces, time of HO were found, and range of motion (ROM) of the operated levels were measured on radiographic films. In addition, the risk factors such as preoperative peri-annulus ossification, bony endplates injuries, and subsided or mal-position of the prostheses were also analyzed by Logistic regression analysis. RESULTS: Postoperative HO was found in 10 spaces of 9 cases. Class I of HO were occurred in 7 patients at means 2.1 years postoperatively with normal range of motion preserved. Three of them turned into class II or III with 10 degrees of mean ROM in the following 2.5 years. Another 2 (2/9) cases with preoperative peri-annulus ossification had bridging trabecular bone (class III) between the endplates and 9 degrees of ROM 2 years after surgery, then turned into class IV at 6 years with 0 degrees and 4 degrees of motion in the operated levels. As the risk factors of HO, preoperative annulus ossification (2 cases), bony endplates injuries (5 cases), mal-positioned prostheses (2 cases) and subsided prostheses (2 cases) were found simultaneity with significant positive relation to HO occurred (P < 0.05). CONCLUSIONS: Factors such as preoperative ossification of annulus, endplate injuries, prosthesis subsided and mal-position would have higher risks to have HO occurred after ADR, but ROM of most affected levels are preserved. Strict control indication and avoid all above risk factors can prevent HO occurring effectively.

[Design and experiment of the pedicle aiming device for the cervical spine].

OBJECTIVE: To probe the accuracy and safety of using an aiming device in the transpedicular fixation of cervical spine. METHODS: Eight cervical specimens were obtained. We used the computed tomography (CT) to scan C3 to C7, measured the medial angle of the pedicle, and determined the location of the pedicle projecting on the articular process. Then we took the oblique X-ray film, measured the cephalic/caudal angle of the pedicle, and determined the location of the pedicle projecting on the articular process. All the specimens were equally divided into two groups. Screws of 2.8 mm x 30 mm, were used. Specimens in one group were inserted with the transpedicular screw manually, while specimens in the other one inserted with the transpedicular screw using a self-designed aiming device that can be modulate at the three dimensions according to the angles of the pedicles. RESULTS: The first group totally had 40 screws from C3 to C7. There were 13 screws in the pedicle, 9 violated the walls of the pedicle but not involved the adjunct structure, and 18 injured the important structure such as spinal cord, verteberal artery, or nerve root. In the other group, only 4 screws violated the walls of the pedicle but not involved the adjunct structure, and the others all in the pedicles. The difference was of statistical significance (P < 0.01). CONCLUSION: In the cervical spine, transpedicular fixation using an aiming device can improve the accuracy and safety during operation.