Applied Anatomical Study Of The Dorsal Transverse Reconstruction Plate Fixation For Sacral Fractures

Objective To study the feasibility of dorsal transverse reconstruction plate fixation forlongitudinal or oblique sacral fractures. Methods CT scanning data of pelvis were collectedclinically from60adults（30males and30females）and then imported into Mimics14.1for3Dimage reconstruction. MedCAD was used to simulate screw placement, and observation wasmade on the screw position together with the adjacent vessels and nerves to determine the S1-S4screw entry points. The screw trajectory lengths were measured, as well as the intersection anglebetween the screw trajectory and horizontal plane, coronal plane and sagittal plane, respectively. Thirty cadaveric specimens were dissected to observe the distribution of the vessels and nervesaround the screw entry points. Simulated screw placements were performed on2adult pelvicspecimens, whose results were tested by X-ray. Results The medial screw entry point S1was themidpoint of the tie-line between the superior articular process and S1posterior sacral foramina,while the medial S2～S4were the midpoints of the tie-line between the adjacent posterior sacralforamina; the lateral screw entry points S1and S2were the intersection points of the horizontalline of medial screw entry points and sacral lateral crest, while the lateral S3and S4were theintersection points of the horizontal line of medial entry points and sacral lateral crest. Themedial screw trajectory length 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）mmfor S1,(26.00±2.49)mm for S2,(16.79±2.09)mm for S3, and (11.19±1.53)mm for S4.Thelateral screw trajectory length 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 forS1,(29.3±3.87)mm for S2,(21.00±2.12)mm for S3, and (12.72±1.83)mm for S4. The testresults proved satisfactory. Conclusions The dorsal transverse reconstruction plate is capable offixing longitudinal or oblique sacral fracture with small trauma, satisfactory reduction and markedsturdiness.