One hundred outpatients (45 males, 55 females, age from 50 to 85 years old, mean age of 58.5 years old) who have done 3D-CT scans (GE Light Speed VCT 64-Slice CT, scan slice of 0.625 mm) of L1-L5 were collected from May 1, 2015 to December 20, 2015. Inclusion criteria were as follows: patients experienced lower back pain that could be determined with CT scans available; images must be clear with a CT scan slice of 0.625 mm. Exclusion criteria: a history of lumbar surgery vertebral abnormalities and developmental abnormalities. The distance between the entry point and the midline of the vertebral body (DEM), the puncture inclination angle (PIA), the range of the safe puncture angle (RSA), and the success rate (SR) of puncture (Fig. 1) were measured and recorded according to previous studies[21 (link),24 (link)] on the Aquarius iNtuition workstation. Measurement software: Aquarius iNtuition workstation was used to perform measurements with a length precision of 0.1 mm and an angles precision of 0.1°. Two spinal surgeons have measured and collected the data, and the average values were considered as the final measurement values. This study was approved by the ethics committee of General Hospital of Northern Theater Command of Chinese PLA.