Investigation Of The Correlation Between Bone Mineral Densitv And Osteocalcin & Bone Metabolism Index In Patients With Scoliosis Secondary To Neurofibromatosis Type 1 And The Penetration Of Rib Head Into The Spinal Canal In Patients With Neurofibromatosis

Part one:Investigation of the correlation between bone mineral density and osteocalcin & bone metabolism index in patients with scoliosis secondary to Neurofibromatosis type 1Objective To investigate the relationship between bone mineral density(BMD) and osteocalcin(BGP) & serum levels of bone metabolism indexes in patients with scoliosis secondary to Neurofibromatosis type 1(NF1-S).Materials and Methods From February 2012 to March 2013,17 NF1-S patients who aged 8-18 years old with the Cobb angle ranging from 45°to 143°were recruited as the case group,17 healthy peers whose age ranged 7-19 years old were recruited as the control group. Dual-energy X-ray absorptiometry equipment was used to measure the lumber spine and proximal femur BMD of two groups. The bone metabolism indexes including BGP, serum alkaline phosphatase (ALP), serum calcium, serium phosphorus, urinary calcium, urinary phosphorus, and urinary creatinine were measured by using Electro-Chemiluminescence Immunoassay and an automatic biochemical analyzer. SPSS 16.0 software was used for data analysis. Independent-sample t test was used to analyze the differences of BMD and bone metabolism indexes between two groups, the relationships between lumbar BMD and bone metabolism were accessed by using correlation analysis.Results No differences in terms of age and sex were noticed in two groups (p>0.05). The BMD of the lumber spine and the proximal femur in case group were significantly lower than that of the control group (p<0.05). The level of BGP(135.6ng/ml), serum calcium(2.59mmol/l), serum phosphorus(1.75mmol/l) and urinary calcium/creatinine(U Ca/Cr)(0.10mg/mg) were significantly higher than that of control group(79ng/ml,2.45mmol/l,1.47mmol/l,0.06mg/mg), The level of serum ALP(141.6u/l vs 141.8 u/1, t=0.991, p=3.611) and urinary phosphorus/creatinine ration(U P/Cr)(0.47mg/mg vs 0.46mg/mg, t=0.054, p=0.957) showed no significance between the two groups(p>0.05). The factors, including BGP(r=-0.916, p=0.000) and U Ca/Cr(r=-0.968, p=0.000), were both negatively correlated with BMD.Conclusion The BMD in NF1-S patients were significantly lower than that of the normal control. The levels of BGP, serum Ca, serum P and U Ca/Cr in NF1-S patients were higher than that of the normal control. The measurement of the levels of BGP and U Ca/Cr is a more sensitive way to monitor the situation of BMD in NF1-S patients.Part two:The radiological features of rib head protrusion into the spinal canal in patients with scoliosis secondary to Neurofibromatosis type 1.Objective To investigate the features of the protrusion of the rib head into the spinal canal in patients with scoliosis secondary to Neurofibromatosis type 1 (NF1-S).Methods From August in 1998 to March in 2011,142 patients with NF1-S were included in this study. The images of rib head protrusion into spinal canal were analyzed retrospectively and the features of this phenomenon were concluded.91 thoracic soliosis patients with NF1-S had complete imaging data. Seven boys and four girls with the age ranged 11 to 21 years old were found rib head protruded into the spinal canal. The magnitude of rib head protrusion into the canal, the apex rotation and the ratio of the dislocated rib head width between convex and concave side were measured. The features of this phenomenon were concluded and the cause was analyzed.Results The incidence of this phenomenon was 12.1%. The level of rib head protrusion is from T5 to T11 vertebra. The magnitude of rib head protrusion into the canal was from 11.2% to 50% and the average magnitude was 26.5%. The rib head into the canal behaved sharp and thin. The ratio of the dislocated rib head width between convex and concave side was 0.50 to 0.99 with an average ratio of 0.77. The apex where the rib head protruded into the canal had a significant rotation and the median of this rotation was Ⅲ degrees (Ⅰ to Ⅳ degrees). In the axial imaging in MRI, the spinal cord shifted to the concave side. The spinal cord against the medial wall of spinal pedicle in the concave side closely was found in 5 patients. Paraspinal neurofibromas were found in 4 patients.Conclusion The rib head protrusion into the spinal canal was found in the convex side of apical area in the patients with NF1-S. The sharpness and thinness of rib, rotation and displacement of apex may contribute to this. CT-scan is a necessary examination around apical area before operation.Part three:Security analysis of the preservation of the intraspinal rib head when correcting the spinal deformity in neurologically intact patients with scoliosis secondary to Neurofibromatosis type 1.Objective To observe the safety and efficacy of the posterior spinal instrumentation (PSI) with preserving the intraspinal rib head in neurologically intact patients with scoliosis secondary to Neurofibromatosis type 1.Methods The clinical and radiographic data of nine patients, who underwent PSI from August 1998 to March 2012, were retrospectively investigated. The average age of these patients (4 male,5 female) was 17.2 years (7-33 years). The following parameters, including the magnitude of rib head penetration into the spinal canal (MRPC), the angel between the bilateral rib in the anomaly level (ABR) and the angel between the dislocated rib and the posterior vertebral wall (ARV), the coronal Cobb angle, the sagittal Cobb angle, were statistically analyzed before and after surgery.Results The follow-up period was 0.5 to 4.8 years. The average MRPC decreased from preoperative 32.8%±9.9% to postoperative 16.8%±15.2%(p=0.026), the average ABR decreased from preoperative 83.0±19.5° to postoperative 67.9°±13.3°(P=0.009), the average ARV increased from preoperative 34.7°±16.4° to postoperative 47.8°±17.5°(p=0.001); The average coronal Cobb angle decreased from preoperative 70.7°±17.7° to postoperative 35.4°±17.0° immediately after operation and the average sagittal Cobb angle decreased from preoperative 59.7±17.6° to postoperative 24.7°±10.8° immediately after operation.The coronal and sagittal Cobb angle had no significant change during follow-up period. The neurological status was Frankel grade E immediately after operation and at final follow-up.Conclusion For NF1 scoliosis patients with rib head penetration into the spinal canal without impingement of the spinal cord and neurological deficits, the deformity can be corrected safely and effectively without resecting the intraspinal rib head.