The Experimental And Clinical Studies On Kyphoplasty For Vertebral Compression Fractures

Objective: To discuss the difference of the leaning inside angle between the percutaneous balloon kyphoplasty and pedicle screw insertion to provide the reference of exactly puncturing in kyphoplasty for osteoporotic vertebral compression fractures.Methods: 120 CT images from normal thoracolumbar vertebra (T8~L5), including six sets normal adult thoracolumbar spinal specimens were scanned by Computed Tomography and the others from CT images from normal adult thoracolumbar vertebrae, were selected and measured their sagittal diameter, the middle transverse diameter, the lateral distance in quarter, the pedicle lateral distance, and the leaning inside angle of pedicle axis, kyphoplasty and pedicle screw by the Computer Dynamic Measure which was created by the Geometer's SketchPad version 4.06 (GSP 4.06), and analyzed their relationship to discuss the difference of the leaning inside angle between the percutaneous balloon kyphoplasty and pedicle screw insertion. Results There is multilinear relationship between the leaning inside pedicle angle and the vertebral level, vertebral diameter and pedicle lateral distance, and there is significant difference between the two sides regression equation (P<0.0001). It is the positive correlation between the leaning inside angle and the pedicle lateral distance and level, with the level increased the pedicle lateral distance increased and the leaning inside angle also increased, so it is the highest in L5. The width and the symmetry of anterior wall also affect the puncture direction through the pedicle approach and there is negative correlation between the parameter lateral distance in quarter and the angle. The kyphoplasty angle is more (13.27±0.16)°than pedicle axis, and the angle of pedicle screw is more (6.87±0.09)°than pedicle axis, but the kyphoplasty angle is more (6.40±0.07)°than pedicle screw.