Comparison of biomechanical characteristics of superior and inferior pubic ramus fractures fixed with different internal fixation methods
- VernacularTitle:不同内植物固定耻骨上下支骨折生物力学特征的比较
- Author:
Xin RAO
1
;
Daixiang JIANG
;
Hui LU
;
Yangxing LUO
;
Meng LI
;
Dingxi LIU
;
Qimei WU
;
Rong LIU
Author Information
- Publication Type:Journal Article
- Keywords: fracture of upper and lower rami of pubis; percutaneous reverse hollow screw; minimally invasive percutaneous plate; retrograde intramedullary nail in superior rami of pubis; finite element analysis; biomechanics
- From: Chinese Journal of Tissue Engineering Research 2025;29(27):5757-5764
- CountryChina
- Language:Chinese
- Abstract: BACKGROUND:Percutaneous retrograde screws and minimally invasive percutaneous plates are extensively used in the treatment of unilateral pubic ramus fractures.However,the above internal fixations have the disadvantages of mistakenly penetrating the hip joint and damaging the medial pelvic trophoblastic artery.A new type of retrograde superior pubic ramus intramedullary nail offers advantages,such as fewer radiographic exposures and shorter surgery times,but the validation of the biomechanical properties of the three endoprostheses is lacking.OBJECTIVE:To compare the biomechanical differences post-treatment of upper and lower pubic ramus fractures using percutaneous retrograde screws,minimally invasive percutaneous plates,and retrograde superior pubic ramus intramedullary nail under various conditions through finite element analysis.METHODS:Pelvic CT data were collected from one volunteer and imported into Mimics 20,Geomagic Wrap 2021,and SolidWorks 2019 to create geometric models of three types of internal fixation for treating unilateral pubic ramus fractures:hollow screw group,plate group,and intramedullary nail group.Each model was imported into Ansys 2022 software,where it was set up in vertical,book-opening,and shear conditions for preprocessing and calculation to compare and analyze the mechanical stability of the implants.RESULTS AND CONCLUSION:(1)In vertical conditions,the biomechanical stability of the hollow screw treatment for unilateral pubic fractures was superior to that of the steel plate and intramedullary nail,with the smallest peak stress in the implant,which was four times lower compared to the other two groups.(2)In book-opening conditions,the steel plate treatment for unilateral pubic fractures showed better biomechanical stability,particularly in reducing stress at the fracture ends of the upper pubic branch,with stress values five times higher in the other two groups.(3)In shear conditions,the intramedullary nail treatment for unilateral pubic fractures exhibited good biomechanical stability,maintaining the best pelvic displacement,with a 25％greater displacement observed in the other two groups.(4)These findings reveal the biomechanical differences of different implants:the peak stress of implants is the smallest under vertical working conditions with percutaneous retrograde screws.Minimally invasive percutaneous plates reduce the stress at the broken end of superior pubic branch under open-book working condition.Retrograde superior pubic ramus intramedullary nail of superior pubic branch maintains pelvic displacement under shear working condition.The surgeon can combine the biomechanical differences of the implants with the actual situation of pubic injury in clinical practice to make the best implant treatment.
