ABSTRACT
Objective To discuss the characteristics,growth and development of atlantoaxial pedicle in preschool children,and to provide the basic theoretical basis for the design,production and clinical application of pedicle screw technique in the treatment of atlantoaxial disease in preschool children.Methods Excluded patients with atlantoaxial fractures,deformities,tuberculosis and tumor,the clinical data of 60 children aged from 3 to 6 years old with cervical spondylolisthesis were collected.The original CT images were reconstructed in DICOM format and the subjects were reconstructed with Mimics software.The subjects were grouped by age to measure and analyze the atlantoaxial pedicle correlation.Results The pedicle width(PW),pedicle height(PH) and total length of pedicle bone channel (PL) increased gradually with age.The PW/PH ratio of the vertebrae(C1) is greater than 1.0,and that is, the width of the pedicle of the C1 pedicle is greater than the height.The PW/PH ratio of the vertebral (C2) is less than 1.0,which means the width of the pedicle of the C1 pedicle is less than the height.Conclusion The growth and development of spine in preschool children are fast, and the pedicle of atlantoaxial calculus in different age groups has different developmental characteristics.In this study,the diameter of the pedicle of the atlantoaxial pedicle in the 3 to 6 year old children is increasing with age.The pedicle screw with the smallest diameter of 3.5 mm can be implanted into the atlantoaxial pedicle with feasibility in theory.
ABSTRACT
Objective To provide accurate bone tunnel positioning reference for clinical individual anterior cruciate ligament (ACL) reconstruction by three-dimensional (3D) reconstruction of femoral and tibial original footprint of ACL.Methods Forty volunteers were selected for this study,including 20 males and 20 females,and aged 18 to 35 years old.3D CT scanning images of knee data were obtained.3D bone models of knee and footprint of ACL were reconstructed.On the 3D reconstruction models,the shape and position of original footprint of ACL were displayed.Statistical significance was compared for their difference.Results Femoral original footprint of ACL,long axis of footprint,distances to the distal margin of the articular cartilage (DDCM),distances to the posterior margin of the articular cartilage (DPCM),double bundle center distance,and tibial original footprint short axis of ACL were significantly different between genders (P ＜ 0.05).However,no significant difference was found between genders for tibial original footprint long axis of ACL (P ＞ 0.05).Conclusions The insertion mark shape and nature position of footprint of ACL could be observed by 3D reconstruction using CT scan images.