Biomechanical research on anterior double-plate fixation for vertically unstable sacroiliac dislocations.

OBJECTIVE: To determine the best method for anterior internal fixation by comparing the biomechanical characteristics of various anterior fixation methods for vertically unstable sacroiliac dislocations. METHODS: Eight pelves with Tile C fracture with vertical loading were measured separately. Three- and two-hole anterior double plates were fixed at different angles and compared with sacroiliac screws. RESULTS: For two-hole anterior double plates, with increasing angle, axial stability increases while lateral stability decreases. For three-hole plates with an angle of 60°, axial stability is clearly better when placed horizontally, while lateral stability shows no obvious differences. CONCLUSION: For fixing sacroiliac dislocations, three-hole anterior double plates placed at about 60° produce excellent stability, which would be greatly increased if screws were added on the iliac side.