Short Posterior Screw Fixation Treatment Of Sacroiliac Joint Fracture Dislocation

Posterior Short Screws Fixation Stabilize Sacroiliac Joint Dislocation Abstract Objective: To explore the safety and efficacy of the treatment of sacroiliac joint dislocation by posterior fixation with short screws. Methods: Applicable anatomy of saerum and biomechanic test of pelvic fractrue model were studied. Operative methods and efficacies of I I cases were analysed. Results: Applicable anatomy (1) In 86.6% of the cases, inferior border of auricalar surface is below the one third of posterior sacral forament of 52 and 53. (2) The lateral column of S2 and S3 is trapzoid. its superior border is right angle with the posterior lamina of sacrum and its inferior border is an acute angle. The distance between the anterior and the posterior of the lateral column is 28.3?1.7mm (52) ,21.4?1.5mm (median, S3), 8.4?1.1mm (one third of median-inferior, S3). (3) The distance between median sacral crest and auricalar surface is 26.7?.6mm (S2), 27.2?.8mm (53). The distance between each posterior saeral forament is 17.4?1.6mm (S1-2) 176?.1mm (S2-3). Biomechanic: (1) Fixation used two screws can limit the shift of sacroiliac joint. It抯 longitudinal firmness has not significant difference with normal. (2) Fixation in both posterior and anterior can increase the Degrees of stiffness and firmness. Significantly as well as load tangent motion. (3) Both normal pelvis and pelvis after diffrent internal ftxators can not load torsion effectively. Conclusion: The posterior fixation with screws through the superior-median of sacral lateral column, without exceeding the link of sacral foramen , not only can attain a stable fixation but also can avoid effectively nervous injury. The efficacies of sacroiliac joint抯 bone graft and arthrodesis is well observing in the long term.