Biomechanical comparison of three different plate fixation methods for acetabular posterior column fractures in standing and sitting positions / 中国组织工程研究

ABSTRACT

BACKGROUND: Studies have shown that there are differences in the biomechanics of different internal fixation methods to fix the acetabular posterior column fracture. OBJECTIVE: To simulate the acetabular posterior column fracture and evaluate the stability of the acetabular posterior column with three fixation methods. METHODS: Thirty-six cadaveric hemipelvic specimens were collected to establish models of acetabular posterior column fracture. The models were randomly divided into three groups, and were fixed by three different fixation methods: (short iliosciatic plate in group A, traditional posterior plate in group B, and long iliosciatic plate in group C; n=12 per group). Mechanical loads were applied vertically in standing and sitting positions. The fracture ends displacement and biomechanical stability were evaluated by using image displacement method. RESULTS AND CONCLUSION: (1) In the standing position, the relative displacement of the fracture ends of the three groups was positively correlated with the load; there was no statistically significant difference in the displacement of the fracture ends under the same load in the three groups (P > 0.05). When loaded with a load of 1 800 N, the relative displacement of each group of models did not exceed 3 mm. (2) In the sitting position, the relative displacement of the fracture end was positively correlated with the size of the load; the relative displacement of the three groups under the same load was significantly different (P < 0.05). Under the same load, the relative displacement of group B was greater than that of groups A and C; the relative displacement of group A under 100-500 N load was greater than that of group C, and the relative displacement under 600 N load was smaller than that of group C. (3) The results suggested that the iliosciatic plate fixation of the acetabular posterior column fracture can provide the same biomechanical stability as the traditional posterior column steel plate, and the rigidity of the fixed structure is high, which can meet the postoperative rehabilitation needs.