[CT imaging measurement of sacral related anatomical parameters]

To investigate the CT measurement of sacral anatomical parameters and understand the safe nail placement channel of DenisⅠ area with a new sacral butterfly plate.

The CT data of 101 normal adult sacrum from January 2020 to June 2020 were retrospectively analyzed, including 49 females and 52 males, aged(49.11±15.02) years old. Firstly, the three-dimensional model of sacrum was reconstruct, the three-dimensional model according to the plane was re segment to be measured, and data measurement and statistical analysis were carried out.

The vertical distance from the lower edge of superior sacral articular process to the lower edge of S₂ posterior sacral foramen was (42.55±4.73) mm;The horizontal distance from the lateral sacral crest of S₁, S₂ and S₃ hole plane to the sacroiliac joint surface was (19.09±3.07) mm, (15.34±2.69) mm and (8.29±2.48) mm respectively;The plane of S1 hole moves forward from the lateral sacral ridge, the inner and outer angles are (7.49±7.49)° and (24.07±4.89)° respectively;The inside and outside angles of S₂ hole plane are (-3.10±8.95)° and (24.95±5.74)° respectively. There were significant differences between different genders except S₁ horizontal distance and S₁ medial angle, and there was no correlation between age and all data.

The new sacral butterfly plate has enough safe nail placement range in DenisⅠ area;There are differences in sacral morphology among adults. The differences are mainly related to gender but not age.