[Digital modeling and analysis of the applicability of backward rotation method in lumbar kyphoplasty with unilateral puncture].

Objective: The 3D model of lumbar spine was established by using Mimics software. To observe the applicability and needling parameters of lumbar vertebral kyphoplasty with unilateral puncture by backward rotation method using simulated puncture.

Methods: Twenty-four patients (12 males and 12 females) with osteoporotic thoracic fracture in the first time and no signs of lumbar misalignment and bone destruction were scanned by spiral CT on the lumbar spine. The original DICOM file was modeled in 3D with Mimics software, and the vertebral bodies were separated. After being imported into 3-matic software, the posterior wall of the vertebral body was restrained for standardized measurement. A sketch perpendicular to the mid-section of the pedicle and the posterior wall of the vertebral body was drawn. The simulated puncture was performed on the sketch. The angle and distance parameters of the range of motion of the puncture needle were recorded, and the puncture needle was recorded at the top. The crossing points of the anterior, middle and posterior zones of the tangential line of the vertebral body were located at the high extraversion angle, and the results were compared and analyzed.

Results: All the data in the left and right sides had no significantly differences(>0.05). Data of different segments in different gender were significantly differences(<0.05). The maximal extraversion angle in lumbar spine increased gradually from (33.41±1.31) degree to (56.53±4.71) degree in males, as same as in females from(28.58±2.55) to (53.86±2.68) degree. There was no crossing point in area A, 3.3% of males and 26.67% of females in area B, rest in area C. The distribution areas on gender showed statistically significance (<0.05).

Conclusions: Backward rotation method can theoretically meet the requirements of puncture point for vertebral compression fracture, especially for males and lower lumbar spine. The determination of the maximum inclination angle is of guiding significance to the backward rotation method.