A mimics study on pedicle measurement and simulation of pedicle screw trajectory

English Keywords:Pedicle axis  Screw trajectory  Materialise′s interactive medical image control system

English Abstract:

  【Abstract】 Objective：To investigate the best pedicle screw trajectory of the 3rd lumbar vertebra（L3） by mimics method.Method：CT data of 50 lumbar from normal adults（including 30 males and 20 females） were enrolled，and simulating vertebral models were established using materialise′s interactive medical image control system（MIMICS）.Point M was defined as the center of the smallest cross-section of L3 pedicle.Simulating the screw trajectory（T1 and T2） connecting entrance point M and point N1 and N2 respectively.The screw channel and orientation were analyzed which were used in preoperative surgical plan 8 cases who sustained lumbar spine fracture.Result：The L3 pedicle cross-sectional diameter was （9.57±0.98）mm，and the sagittal diameter was （14.89±0.78）mm.The horizontal and sagittal angle of T1 channel was 1.5°±1.0° and 12.0°±1.5° respectively，while those for T2 channel was 3.0°±1.0° and 10°±1.5° respectively.8 patients had screws placed under the guide of MIMICS，and good screw position was noted radiographically.Conclusion：The MIMICS can simulate pedicle profile accurately，which can be used in clinical practice.