Role Of Sympathetic Nervous System In The Development And Progression Of Scoliosis And Comparison Of Osteogenic Activities Of Osteoblasts Derived From Different Locations In Patients With Adolescent Idiopathic Scoliosis And Its Associated Clinical Brace S

Chapter1The Effect of Sympathectomy on the Development and Progression of Scoliosis in Bipedal Mice ModelObjective:Sympathetic nervous system may contribute importantly to the etiopathogenesis of scoliosis, via its hypothalamic neuroendocrine control of puberty, menarche and skeletal growth. The aim of the study was to investigate whether the incidence of scoliosis or the magnitude of curves can be changed by pharmacological sympathectomy in bipedal C57BL/6J mice model.Method:Sixty female3-week-old C57BL/6J mice were purchased and underwent amputations of both forelimbs and tails. After operation, they were randomly divided into three groups:Group1(Control group) received daily intraperitoneal injection of0.9%saline (5ml/kg/day); while Group2and3(Sympathectomized groups) were pharmacologically sympathectomized by daily intraperitoneal injection of propranolol and guanethidine sulfate, respectively (propranolol20mg/kg/day, guanethidine sulfate40mg/kg/day). Posteroanterior X-rays of the mice were obtained after20weeks under anesthesia. Curvature of the spine were evaluated by using Cobb method on each film. Scoliosis was defined as a Cobb angle of more than10°. Incidence of scoliosis and magnitude of curves were recorded and compared among the three groups.Results:A total of17(85%) mice presented scoliosis in Group1; whereas11(55%) and10(50%) mice were found to have scoliosis in Group2and3, respectively. The incidence of scoliosis was found to be significantly higher in Group1than in Group2and3, however the statistical P value was just marginal significant (P=0.046). As for the magnitude of curves, the mean Cobb angle was found to be20.5°±9.2°in Group1,10.2°±6.8°in Group2, and11.7°±7.9°in Group3, respectively. The mean Cobb angle of Group1was significantly greater than those of Group2and3(P<0.01); meanwhile no difference was found between Group2and3in the magnitude of curves.Conclusion:Sympathetic nervous system might be involved and play an important role in the development and progression of scoliosis in bipedal C57BL/6J mice model. The incidence of scoliosis did not seem to be dramatically decreased by pharmacological sympathectomy in the bipedal mice model, which indicated that bipedalism itself might be one of the causes leading to the onset of scoliosis in this animal model. Chapter2Comparison of Proliferation and Differentiation of Osteoblasts Derived from Different Locations in Patients with Adolescent Idiopathic ScoliosisObjective:To investigate and compare the proliferation and differentiation abilities of osteoblasts derived from different bone graft locations in patients with adolescent idiopathic scoliosis (AIS) underwent posterior surgery and thoracoplasty.Methods:From January2011to May2012, a total of16AIS patients were recruited in the study. There were14females and2males with age ranging from11to17years old. All patients received posterior surgery for scoliosis, as well as thoracoplasty for severe rib hump deformity. During surgery, trabecular bone chips from ribs, lamina and iliac crest were harvested in each patient for osteoblast culture. Cells were passaged to P2generation and used for the following experiments. Proliferation ability of osteoblasts was evaluated by using MTT method and differentiation ability by alkaline phosphatase (ALP) activity, respectively. The proliferation and differentiation abilities were subsequently compared among osteoblasts derived from different bone graft locations (ribs, lamina and iliac crest).Results:MTT results showed that the proliferation of lamina osteoblast was slightly lower than that of ilium osteoblast; whereas rib osteoblast was slightly higher in the proliferation ability than ilium osteoblast. However, no statistical difference was found between these3types of osteoblasts (P>0.05). ALP activity results showed that the differentiation ability of both lamina and rib osteoblasts were slightly higher than that of ilium osteoblast, but without statistical significance (P>0.05).Conclusion:There was no significant difference in the proliferation and differentiation abilities between osteoblasts derived from rib, spinal lamina and iliac crest in patients with AIS. The results of the current study indicated that local and rib bones harvested during surgery may be good enough and of comparable osteogenic ability for grafting and spinal fusion for AIS patients undergoing thoracoplasty, which could potentially eliminate the need for harvesting autologous iliac bone. Chapter3(section1) Influence of Spinopelvic Morphology on the Effectiveness of Milwaukee Bracing for Adolescent Thoracic Idiopathic ScoliosisObjective:Previous studies had demonstrated that sagittal spinal alignment and pelvic morphology may be associated with the development and progression of adolescent idiopathic scoliosis (AIS). However, the predictive value of initial spinopelvic morphology on the curve progression during brace treatment is unknown. The objective of this study was to evaluate the relation between initial spinopelvic morphology and the risk of curve progression in AIS patients with Milwaukee brace treatment.Methods:From2002to2007, a total of60AIS girls (single thoracic curve with apex at or above T8) was treated with the Milwaukee brace in our hospital. Initial standing, full-length lateral radiographs were obtained with subjects in relaxed standard position. Seven sagittal spinopelvic radiographic parameters were measured on each X-ray film:thoracic kyphosis (TK), lumbar lordosis (LL), T1-spinopelvic inclination (T1-SPI), T9-spinopelvic inclination(T9-SPI), pelvic incidence (PI), pelvic tilt (PT), and sacral slope (SS). All patients had regular follow-ups until skeletal maturity or progression of Cobb angle>45°. The progression of scoliosis was defined as an increase of Cobb angle>6°at the latest follow-up compared with the initial radiograph, or progression of Cobb angle beyond45°with surgery recommended or undergone during the brace treatment.Results:A total of45patients (75.0%) had successful control of curve progression versus15patients (25.0%) who presented curve progression. Patients who had favorable bracing outcomes were found to be initially significantly more skeletally mature (higher mean Risser sign) than those who progressed. No difference was found in the initial mean Cobb angle between the stable and progressed groups. Stable group had significantly greater mean PT, T1-SPI and T9-SPI than the progressed group, and these three angles were found to be independent predictors for curve progression during the Milwaukee brace treatment. No significant difference was found in initial mean PI, SS, TK or LL between the stable and progressed groups. In addition, pre-bracing PT≤-0.5°was found to be strongly predictive, and Tl-SPI<3.5°was moderately predictive, of curve progression during the Milwaukee brace treatment.Conclusion:Initial pelvic tilt and spinopelvic inclination may have prognostic value in predicting the curve progression and treatment outcome of Milwaukee brace for AIS patients. Special attention and particular consultation should be given to the patients who have a lower PT (≤-0.5°) or T1-SPI (≤3.5°) at presentation before and during the Milwaukee brace treatment. Chapter3(section) A Prospective Randomized Controlled Study on SpineCor Brace versus Rigid Brace for Treatment of Adolescent Idiopathic Scoliosis Using the Scoliosis Research Society Standardized CriteriaObjective:SpineCor is a relatively new bracing system for non-operative treatment of adolescent idiopathic scoliosis (AIS). However, the effectiveness of SpineCor still remains controversial. The objective of the current study was to use standardized Scoliosis Research Society (SRS) criteria for AIS brace study to compare the treatment outcomes of SpineCor brace versus that of rigid brace.Methods:Female AIS patients (aged10to14years old) with Cobb angle between20°and30°were recruited. Subjects were randomly allocated into2groups undergoing treatment with SpineCor (S Group, n=20) or rigid braces (R Group, n=18). Custom made bracing with follow-up assessment and adjustments were done in a special clinic. During SpineCor treatment, patients who had curve progression of>5°were required to switch back to rigid bracing due to ethical consideration. The effectiveness of the2brace treatments was evaluated by using the following SRS standardized criteria:1) Percentage of patients who had more than5°progression at skeletal maturity;2) Percentage of patients who had surgery recommended or undergone before skeletal maturity;3) Percentage of patients who progressed beyond45°;4) A minimum2-year follow-up beyond skeletal maturity to determine the percentage of patients who subsequently progressed or required surgery.Results:Before skeletal maturity, a total of7(35.0%) patients in the S Group and1(5.6%) patient in the R Group presented curve progression of more than5°(P=0.026). At skeletal maturity,5out of the7(71.4%) patients who failed with SpineCor bracing showed control from further progression by changing to rigid bracing. At the latest follow-up (mean45.1m after skeletal maturity),29.4%of patients who were successfully treated by rigid brace showed further curve progression beyond skeletal maturity, versus38.5%of patients in the SpineCor group (P>0.05). For both groups, the primary curves were found to be slightly improved at the time of brace weaning, but with deterioration noted at the latest follow-up at a rate of1.5°per year at the post-maturity period.Conclusion:Curve progression rate was found to be significantly higher in the SpineCor group when compared with the rigid brace group during treatment. Changing to rigid bracing could control further curve progression for majority of patients who progressed with SpineCor bracing. For both SpineCor and rigid brace treatments,30%to40%of patients who were originally successfully treated by bracing would exhibit curve progression of>5°after skeletal maturity. The post-maturity progression rate was found to be1.5°per year in the current study.