Biomechanical Comparison of Two-Point and Three-Point Fixation for Treating SandersⅢ Calcaneal Fracture / 医用生物力学

Objective To analyze the biomechanical feasibility of two-point fixation by distal radius plate for the treatment of SandersⅢ calcaneal fractures. Methods The three-dimensional (3D) finite element musculoskeletal foot model was established based on CT and MRI images, which comprised bones, muscles, plantar fascia, ligaments and soft tissues. After validation, the SandersⅢ calcaneal fracture models fixed by distal radial plate (two-point fixation) and calcaneal plate (three-point fixation) were established, so as to compare the biomechanical characteristics of two calcaneal models. Results The maximum stress of the two-point fixation and three-point fixation model was 324.70 and 407.90 MPa, respectively. The maximum displacements of the two models were 2.498 and 2.541 mm, respectively. There was no significant difference in the posterior articular surface displacement between the two models. In both models, the Bohler’s angle and Gissane’s angle were within the normal range. Conclusions The two-point fixation by distal radial plate can satisfy the biomechanical stability of calcaneal fracture treatment. Compared with traditional steel plate, the two-point fixation shows the advantage of smaller surgical trauma, more uniform overall stress distribution, early weight-bearing rehabilitation after surgery, which is a novel treatment recommended for treating calcaneal fractures.

Three point fixation is superior to two point fixation technique for zygomatic complex fracture

Background:Isolated zygomatic or malar bone fractures are second most common fracture among facial skeletal injuries. It has been reported that three point fixation is appropriate for isolated zygomaticbone fracture. The objective of current study was to compare the mean difference in terms of malar height outcome by using different fixation techniques (two point and three point)in patients with zygomatic complex fracture.Methods:This randomized controlled trial was conducted at Department of Oral and Maxillofacial Surgery, MMDC, Multan, during a period of six months from 1st June 2017 to 30th November 2017. A total 182 patients of both genders were included in this study. Two point fixation techniques were used in Group-A patients. While 3 point fixation was used in Group-B patients. After 6 weeks follow-up, patients were assessed for malar height. Outcome was measured by comparing the mean difference of pre and postoperative malar height of both techniques. Data were analyzed using computer program SPSS-21. P≤0.05 was taken as significant in all analysis.Results:Among patients in two pointfixation group, the mean malar height was 67.55±2.98 mm and in three pointfixation group, meansmalar height was 71.55±2.36 mm. The difference of malar height among two treatments was highly significant with p<0.01. Conclusions: Using three point fixation results better as compared to two point fixations in terms of malar height outcome