ABSTRACT
Objective To investigate the biomechanical stability of 5 kinds of internal fixation for acetabular T-shaped fractures using finite element analysis.Methods After a three-dimensional model of normal pelvis was reconstructed using Mimics software,the model of acetabular T-shaped fracture was divided by Solidworks software.Models of acetabular T-shaped fracture fixated by 5 methods were reconstructed:(A) a reconstruction plate for anterior column + lag screws for posterior column,(B) lag screws for anterior column + a reconstruction plate for posterior column,(C) a reconstruction plate for anterior column + a medial ilioischial plate for posterior column (combination plating),(D) retrograde lag screws for 2 columns,and (E) a reconstruction plate for anterior column + and a posterior ilioischial plate for posterior column.Valuation was conducted with software Ansys to simulate 600 N loading on the terminal plate of S1 vertebral body at standing and sitting positions.The biomechanical stabilities were compared between the 5 models of internal fixation.Results At standing and sitting positions,the displacements of anterior column in modelA (0.522±0.121 mmand0.762±0.181 mm),modelC (0.512±0.207mmand0.730±0.181mm) and model E (0.513 ± 0.184 mm and 0.733 ± 0.166 mm) were significantly smaller than those in model B (0.622±0.224 mmand 1.328±0.537 mm) and in modelD (0.655±0.174mm and 1.591± 0.270 mm) (P ＜ 0.05).However,there were no statistically significant differences in anterior column displacements between models A,C and E or between models B and D (P ＞ 0.05).At standing and sitting positions,the displacements of posterior column in model B (0.631 ± 0.151 mm and 0.572 ± 0.693 mm),in model C (0.621 ± 0.195 mm and 0.538 ± 0.075 mm) and in model E (0.625 ± 0.192 mm and 0.544 ± 0.063 mm) were significantly smaller than those in model A (0.742 ±0.140 mm and 0.715 ±0.072 mm)and in modelD (0.754±0.247 mm and 0.717 ± 0.071 mm) (P ＜0.05).However,there were no statistically significant differences in posterior column displacements between models B,C and E or between models A and D (P ＞ 0.05).Conclusions In the treatment of acetabular T-shaped fractures,reconstruction plating has better stability than screwing.Reconstructive plating shows the best stability for anterior and posterior columns,followed by combination plating which is the best choice for reducing surgical injury.
ABSTRACT
Objective To explore the application and analysis of E-PASS scoring system for orthopaedic senile hip surgery risk assessment. Methods Retrospectively analyzed the data of 188 cases of elderly hip fracture patients with anesthesia and surgery, postoperative complications. Useing E-PASS scoring system to evaluate the mortality of patients with surgical risk. Results Postoperative complications mainly was respiratory system diseases, the rate of complication was 25.88%(22/85), accounting for total cases rate was 11.70% (22/188). Secondly for cardiovascular diseased and urinary system diseases. E-PASS scoring system showed that the scores of surgery risk assessment in patients with complication was significantly higher than that without complication:(0.27±0.23) scores vs. (0.17±0.16) scores, t=3.728, P<0.05. Ninety-one patients were evaluated to occur complications by E-PASS grading system, 85 patients occurred practically,the rate of actual value/forecast was 0.93.Six patients were evaluated to die, 2 patients occurred practically, the rate of actual value/forecast was 0.33, there were no significant differences ( P=0.056,0.124). Conclusion E-PASS scoring system for orthopaedic senile hip surgery risk assessment can predict the risk of complication and death effectively,it is value of interventing the preoperative risk factors and has great clinical application value.