The dorsal transverse reconstruction plate fixation for treating sacral fractures:applied anatomy

Objective To study the feasibility of the dorsal transverse reconstruction plate fixation for treating longitudinal or oblique sacral fractures.Methods CT data of pelvis were collected from 60 healthy adults(30 males and 30 females)and then imported into Mimics14.1 for 3D image reconstruction.MedCAD was used to simulate screw placement.Observation was made on the screw position,adjacent vessels and nerves for determining the S1～4 screw entry points.The length of screw trajectory was measured,as well the intersection angle between the screw trajectory and horizontal plane,coronal plane and sagittal plane,respectively.30 cadaveric specimens were dissected to observe the distribution of the vessels and nerves around the screw entry points.Simulated screw placements were performed on 2 adult pelvic specimens,with the results testing by X-ray.Results The length of medial screw trajectory in males was(32.78±2.10)mm for S1,(28.54±2.67)mm for S2,(18.54±1.86)mm for S3,and(12.58±1.18)mm for S4;that in females was(31.18±2.52)mm,(26.00±2.49)mm,(16.79±2.09)mm,and(11.19±1.53)mm respectively.The length of lateral screw trajectory in males was(35.78±1.88)mm for S1,(29.99±2.48)mm for S2,(22.53±2.21)mm for S3 and(13.62±1.58)mm for S4;that in females was(33.03±2.23)mm,(29.3±3.87)mm,(21.00±2.12)mm,and(12.72±1.83)mm respectively.The test results proved satisfactory.Conclusions The dorsal transverse reconstruction plate is capable of fixing longitudinal or oblique sacral fracture with small trauma,satisfactory reduction and marked sturdiness.