Morphologic classiifcation of thoracic pedicles in the patients with scoliosis secondary to neuroifbromatosis type 1

ZHU Cheng-yue; ZHU Ze-zhang; WANG Shou-feng; LIU Zhen; ZHU Feng; JIANG Long; QIU Yong

doi:10.3969/j.issn.2095-252X.2014.02.009

Abstract：Objective To investigate the features of morphologic classiifcation of thoracic pedicles in the patients with scoliosis secondary to neurofibromatosis type 1 ( NF1-S ). Methods Successive spiral CT thoracic vertebrae scans of 100 patients with NF1-S who were adopted from July 2005 to March 2012 were obtained. The morphology of thoracic pedicles was classiifed based on the Lenke classiifcation system. There were type A ( normal type ), type B ( stenotic type ), type C ( isthmic type ), type D ( complete sclerosis type ) and type E ( pedicle absent type ). The numbers of thoracic pedicles of type A, B, C, D and E among the 100 patients with NF1-S were 911, 561, 334, 422 and 172 respectively, and 2400 in all. According to the above classiifcation standard, all the patients’ transverse pedicle diameters of the thoracic vertebrae were measured and classiifed based on the clearest images with the software of picture archiving and communication system ( PACS ). The incidence of different types of thoracic pedicles in the patients with NF1-S was recorded respectively, and the malformation rate was analyzed statistically. Results The malformation rate ( type B-E ) was 62%in the 100 patients with NF1-S. Nondystrophic scoliosis was found in 15 patients whose malformation rate of thoracic pedicles ( MRTP ) was 41.1%and dystrophic scoliosis was found in 85 patients whose MRTP was 65.7%. The MRTP in the dystrophic group was obviously higher than that in the nondystrophic group (χ2=78.8, P<0.001 ). The MRTP was decreased in turn in the concavity group, the neutral vertebrae group and the convexity group ( 80.8%>66.8%>47.9%, P<0.001 ). The MRTP was increased in turn in the ( 40°-59° ) group, ( 60°-79° ) group and≥80° group (50.7%<59.6%<69.2%, P<0.001 ). The MRTP of the patients equal to or more than 18 years old ( 55.3% ) was lower than that of the patients less than 18 years old ( 63.5% ) ( P=0.001 ). In addition, there were no signiifcant differences between males ( 63.4%) and females ( 60.4%) in terms of the MRTP ( P=0.13 ). Conclusions The MRTP in the patients with NF1-S is 62%. The MRTP is obviously higher in the dystrophic scoliosis group than in the nondystrophic scoliosis group. The MRTP is obviously lower in the convexity group than in the concavity group. The MRTP is signiifcantly increased as the Cobb’s angle is increased. The MRTP is obviously lower in adults than in adolescents. The MRTP is not affected by the sex.