【作者】 张帅；

【导师】 王刚；

【作者基本信息】 吉林大学 ， 外科学（专业学位）， 2020， 硕士

【摘要】 背景:目前胫骨平台骨折被普遍接受的分型为Schatzker分型,然而对胫骨平台骨折的有限元受力分析多集中于后外侧骨折等胫骨平台特定部位的骨折,而对于Schatzker某种分型的骨折有限元分析研究较少。此外SchatzkerⅥ型胫骨平台骨折临床治疗中无确切的统一治疗方式,主要的治疗方式有单独内侧钢板、单独外侧钢板和内外侧钢板联合使用三种治疗方式,至于哪种治疗方式固定效果最好,目前一对一的临床对照研究较多,而通过有限元方法进行生物力学模拟效果的研究较少。目前只有关于SchatzkerⅥ型胫骨平台骨折内侧钢板和外侧钢板两种治疗方式的有限元对比研究,而三种治疗方式之间的有限元对比尚未见报道。目的:采用三维有限元分析方法对SchatzkerⅥ型胫骨平台骨折在单独内侧钢板、单独外侧钢板和内外侧钢板联合三种不同固定方式下,分别模拟其在不同运动状态即不同载荷下的生物力学,得出骨折块和内固定物的受力情况,从而根据研究结果的优劣为临床治疗提供生物力学方面的参考。方法:使用相关三维建模软件分别构建SchatzkerⅥ型胫骨平台骨折模型,然后根据实验设计及内固定原则装配单独内侧钢板、单独外侧钢板和内外侧钢板联合三种内固定模型,最后分别给与各组模型相应的约束和载荷(双足站立时的250N、单足站立时的500N、慢步时的1000N、快跑时的1500N和其他剧烈活动时的2000N),模拟人体胫骨平台骨折术后在不同运动方式下的受力及位移,然后把得到的数据与相应的实验数据结果标准进行统计学比较和检验后得出相应的统计学结论。实验结果骨质应力大于120Mpa可导致骨质应力性吸收;内固定物应力大于450MPa可导致内固定物不可逆性形变;内固定物应力大于600MPa可导致内固定物断裂;骨折移位大于1mm不利于骨折愈合,而骨折移位大于2mm则可使创伤性关节炎的发生率增加。结果:三组固定方式在不同运动方式即250N、500N、1000N、1500和2000N载荷下外侧骨折块最大移位均少于0.8mm,内侧骨折块最大移位也均少于0.9mm,外侧骨折块最大应力均少于55Mpa,内侧骨折块最大应力均少于28 Mpa,内固定物应力均小于152 Mpa。其统计学结果(1)外侧骨折块移位:Kruskal-Wallis检验结果为:H=0.860,P>0.05(调整后P=0.651),按照α=0.05的检验标准,保留H0,则认为三种固定方式在外侧骨折块移位方面无差别。(2)内侧骨折块移位:Kruskal-Wallis检验结果为:H=0.816,P>0.05(调整后P=0.665),按照α=0.05的检验标准,保留H0,则认为三种固定方式在内侧骨折块移位方面无差别。(3)外侧骨折块应力:Kruskal-Wallis检验结果为:H=12.5,P<0.05(调整后P=0.002),按照α=0.05的检验标准,拒绝H0,则认为三种固定方式在外侧骨折块应力方面有差异。经过两两比较,内钢板组与双钢板组在外侧骨块应力方面无差别(调整后P=0.231);内钢板组与外钢板组在外侧骨块应力方面有差别(P<0.05,调整后P=0.001);双钢板组与外钢板组在外侧骨块应力方面无差别(调整后P=0.231)。因此,内侧钢板固定后外侧骨折块应力较小,且具有统计学意义。(4)内侧骨折块应力:Kruskal-Wallis检验结果为:H=12.522,P<0.05(调整后P=0.002),按照α=0.05的检验标准,拒绝H0,则认为三种固定方式在内侧骨折块应力方面有差异。经过两两比较,内钢板组与双钢板组在内侧骨块应力方面无差别(调整后P=0.231);内钢板组与外钢板组在内侧骨块应力方面有差别(P<0.05,调整后P=0.001);双钢板组与外钢板组在内侧骨块应力方面无差别(调整后P=0.231)。因此,外侧钢板固定后内侧骨折块应力较小,且具有统计学意义。(5)内固定物应力:Kruskal-Wallis检验结果为:H=10.889,P<0.05(调整后P=0.004),按照α=0.05的检验标准,拒绝H0,则认为三种固定方式在内固定物应力方面有差异。经过两两比较,内钢板组与外钢板组在内固定物应力方面无差别(调整后P=0.840);内钢板组与双钢板组在内固定物应力方面有差别(P<0.05,调整后P=0.004);双钢板组与外钢板组在内固定物应力方面无差别(调整后P=0.092)。结论:三种治疗方式在不同载荷下的内外侧骨折块均无明显移位,移位均小于0.9mm,未达到1mm和2mm的设置标准值。并且统计学上来说,三种固定方式在骨折块移位方面无明显差异,均可取得较满意的手术效果。三种不同固定方式均未造成内侧和外侧骨块的最大应力大于胫骨的屈服应力,均可取得较稳定的固定。根据统计学结果,内侧钢板固定后外侧骨折块应力较小,外侧钢板固定后内侧骨折块应力较小;但因外侧骨块较小、骨折线角度较大且与主骨无有效接触和支撑,所以因应力集中造成的螺钉松动而导致的骨块移位风险更大;相对来说内侧骨块较大,从骨折线来看内侧骨块与主骨接触面积大且骨折线角度较小,相对不容易因内固定不稳后发生移位而导致固定失败,因此相对来说应选择外侧骨块应力小的固定方式进行固定,即内侧钢板固定结果更可取。内侧钢板、外侧钢板和双钢板固定骨折后内固定物最大应力均未达到变形和断裂的屈服应力,可取得较稳定和安全的固定,统计学结果:内侧钢板固定后内固定物应力较小,且具有统计学意义。综上所述:三种内固定方式均可取得较满意的固定效果,而相对来说,内侧钢板固定更具有优势,且对患者损伤较小。更多还原

【Abstract】 Background:Currently,the commonly accepted classification of tibial plateau fractures is Schatzker classification.However,the finite element analysis of tibial plateau fractures is mostly focused on the fractures of specific parts of the tibial plateau,such as posterolateral fractures,while the finite element analysis of Schatzker fractures of a certain classification is rarely studied.In addition Schatzker type Ⅵ tibial plateau fractures in clinical treatment,no specific treatment,primary treatment has a separate medial plate,single plate for outside and inside and outside,use a combination of three treatments as to what kind of treatment effect is best,at present there are only some one-on-one controlled clinical studies,and through the finite element method(fem)biomechanical simulation research,there is no effect.Objective:The three-dimensional finite element analysis method is adopted to Schatzker type Ⅵ tibial plateau fractures in a separate medial plate,single lateral steel plate and inside and outside steel joint under three different fixed way,respectively under different motion state namely load simulation of biomechanics,it is concluded that the stress of the blocks and internal fixation of fracture,and according to the results of biomechanical aspects of reference for clinical treatment.Methods:Use the three-dimensional modeling software build respectively Schatzker type Ⅵ tibial plateau fracture model,then according to the experiment design and principles of internal fixation of the medial plate alone,alone the lateral steel plate and the lateral steel plate joint model,three kinds of internal fixation and finally give each model respectively corresponding constraint and load(250 n,feet when standing on one foot when 1000 n,500 n,walk when run at 1500 n and other violent activities of 2000 n),simulate human tibial plateau fracture in different movement modes of stress and displacement.Then the obtained data were compared and tested by statistical methods and the corresponding conclusions were obtained.The results showed that the bone stress greater than 120 Mpa could lead to the bone stress absorption.The stress of internal fixator greater than 450 MPa can lead to irreversible deformation of internal fixator.The stress of the internal fixator is more than 600 MPa,which can lead to the fracture of the internal fixator.Fracture displacement greater than 1mm is not conducive to fracture healing,while fracture displacement greater than 2mm increases the incidence of traumatic arthritis.Results:Under the loads of 250 N,500N,1000 N,1500 and 2000 N,the maximum displacement of the lateral fracture mass was less than 0.8mm,the maximum displacement of the medial fracture mass was less than 0.9mm,the maximum stress of the lateral fracture mass was less than 55 Mpa,the maximum stress of the medial fracture mass was less than 28 Mpa,and the stress of the internal fixation mass was less than 152 Mpa.The results of the kruskal-wallis test were as follows: H=0.860,P > 0.05(adjusted P=0.651).According to the test standard of alpha =0.05,H0 was retained.Therefore,no difference was found between the three fixation methods in the displacement of the lateral fracture block.(2)displacement of medial fracture block: kruskal-wallis test results: H=0.816,P > 0.05(adjusted P=0.665).According to the test criteria of alpha =0.05,H0 was retained.It was considered that there was no difference in displacement of medial fracture block between the three fixation methods.The results of kruskal-wallis test showed that H=12.5,P < 0.05(P=0.002 after adjustment).According to the test standard of alpha =0.05,H0 was rejected,and the three fixation methods were considered to be different in stress of the lateral fracture block.After pintwo comparison,there was no difference in the stress of the lateral bone mass between the internal plate group and the double-plate group(P=0.231 after adjustment).There was a difference in the stress of the lateral bone mass between the inner plate group and the outer plate group(P < 0.05,P=0.001 after adjustment).There was no difference in the stress of the lateral bone mass between the two groups(P=0.231 after adjustment).Therefore,the stress of posterior lateral fracture block fixation with medial plate is small and statistically significant.(4)internal fracture block stress: kruskalwallis test results are: H=12.522,P < 0.05(P=0.002 after adjustment),according to the alpha =0.05 test standard,rejected H0,it is considered that the three fixation methods in the internal fracture block stress difference.After pin-two comparison,there was no difference in the stress of the medial bone mass between the internal plate group and the double-plate group(P=0.231 after adjustment).There was a difference in the stress of medial bone mass between the inner plate group and the outer plate group(P < 0.05,P=0.001 after adjustment).There was no difference in stress between the two groups(P=0.231 after adjustment).Therefore,the stress of posterior medial fracture block fixed by lateral plate is small and statistically significant.(5)internal fixation stress: kruskalwallis test results were: H=10.889,P < 0.05(adjusted P=0.004).According to the test standard of alpha =0.05,H0 was rejected,and the three fixation methods were considered different in terms of internal fixation stress.After pin-two comparison,there was no difference in the stress of the internal fixator between the inner steel group and the outer steel group(P=0.840 after adjustment).There was a difference in internal fixation stress between the internal plate group and the double-plate group(P < 0.05,P=0.004 after adjustment).There was no difference in internal fixation stress between the two groups(P=0.092 after adjustment).Conclusion:There was no obvious displacement of the medial and lateral fracture blocks under different loading in the three treatment methods,the displacement was all less than 0.9mm,and did not reach the standard values of 1mm and 2mm.Statistically,there was no significant difference between the three fixation methods in fracture block displacement,and all of them could achieve satisfactory surgical results.The three different fixation methods did not cause the maximum stress of the medial and lateral bone mass less than the yield stress of the tibia.According to the statistical results,the stress of posterior lateral fracture block fixed by medial plate was lower than that of posterior lateral fracture block fixed by lateral plate.However,because the lateral bone mass is smaller,it is more likely to be displaced after the instability of internal fixation,which leads to the failure of fixation.The medial bone mass is relatively large.From the perspective of fracture line,the contact area between the medial bone mass and the main bone is large and the Angle of fracture line is small,which is relatively less likely to cause the failure of fixation due to displacement after the instability of internal fixation.Therefore,the result of medial plate fixation is preferable.The maximum stress of internal fixation after internal fixation with medial plate,lateral plate and double plate did not reach the yield stress of deformation and fracture,which could achieve relatively stable and safe fixation.Statistical results: the stress of internal fixation after internal fixation with medial plate was small and statistically significant.In conclusion,all three internal fixation methods can achieve satisfactory results,and compared with other methods,medial plate fixation has more advantages and less damage to patients.更多还原