【作者】 何川；

【导师】 李彦林； 赵学凌； 龚跃昆； 王兵；

【作者基本信息】 昆明医科大学 ， 外科学， 2014， 博士

【摘要】 背景在膝关节韧带损伤中,前交叉韧带(Anterior cruciate ligament, ACL)损伤最为常见,关节镜下ACL重建术是ACL损伤后的常规治疗方法。虽然该治疗方法疗效确切,但仍存在10%-15%的失败和返修率,严重影响患者的膝关节功能。该手术成败的关键在于股骨和胫骨隧道的精确定位。近年兴起的计算机辅助外科(Computer Assisted Surgery, CAS)技术可以改善ACL隧道的精确性和手术效果,应用计算机辅助系统辅助实施ACL重建手术,有望获得比传统手术更好的疗效,降低ACL移植物的撞击率,从而降低手术失败率。ACL重建后,患者仍然存在较高的膝关节骨性关节炎的发生比例,可能原因为ACL重建后的膝关节软骨和半月板受到了超出正常范围的过大应力而发生过早的退变、磨损,从而产生骨性关节炎的临床症状,并大大影响患者生活质量。因此,选择术后最能恢复正常膝关节软骨和半月板生物力学的ACL重建方案显得尤为重要,准确评价ACL重建术后膝关节软骨和半月板的应力特点可以帮助医师筛选最佳的手术方案。膝关节三维有限元模型可以模拟术后ACL、软骨和半月板在不同运动和受力情况下的应力大小和分布特点,从而有效、便捷地地分析膝关节内各结构的生物力学特性并推测其损伤机制,还可以探索不同ACL重建方法对关节软骨和半月板应力的影响,筛选最佳的ACL重建方案,并为完善术后的康复训练、支具的设计等方案提供详细的数据。目的1.根据健康志愿者的双膝关节的CT和MRI资料,探索自主研发的计算机辅助ACL虚拟重建系统的可行性,该系统可虚拟设计出ACL重建方案。2.将自主研发的计算机辅助ACL重建系统-ACL detector设计出的虚拟ACL重建方案应用于临床,与传统ACL虚拟重建手术的临床疗效和术后移植物撞击率作对比,探讨计算机辅助ACL虚拟重建系统在ACL损伤治疗方面的临床可行性和优越性。3.建立健康志愿者及ACL损伤患者重建术后膝关节的三维有限元模型,分析不同研究对象的膝关节有限元模型在不同运动状态和受力情况下时,正常膝关节、计算机辅助和传统重建术后膝关节ACL、关节软骨、半月板所受应力大小和分布特点,以探索ACL重建术后发生骨性关节炎可能的原因及计算机辅助ACL重建手术对膝关节软骨、半月板应力的影响,并探寻最佳ACL重建方案。方法1.在前期成功建立50例健康志愿者精确的膝关节三维模型的基础上,随机选择其中一名健康志愿者为研究对象,采用1.5TMRI设备对研究对象伸直位双膝关节进行扫描,并用256排CT对其屈曲位双膝进行扫描,基于以上影像学资料,利用MIMICS14.11、Geomagic Studio2012软件进行双膝关节三维重建,并将三维重建模型导入自主研发的计算机辅助ACL虚拟重建系统-ACL detector中,设计出虚拟的ACL重建方案,包括ACL移植隧道的位置、角度、在股骨和胫骨上的出入口和附着点的面积。2.为进一步验证计算机辅助ACL虚拟重建系统-ACL detector的临床可行性和有效性,本研究于2009年3月-2012年10月期间共完成80例ACL单束重建手术,其中以ACL detector辅助指导ACL重建病例作为计算机辅助组(Computer Assisted Surgery group,CAS group),共40例,采用经典ACL单束重建病例作为传统手术对照组(Traditional Surgery group, TS group),共40例,术前均由查体和MRI检查确诊为ACL损伤,所有CAS组患者均接受双膝关节MRI及CT扫描,根据患者双膝关节的影像学资料,利用ACL detector设计出虚拟ACL重建方案,结合定位工具在术中按虚拟ACL重建方案进行重建,TS组患者接受经典传统ACL重建手术,术后对所有患者进行平均18个月的随访,对比两组患者的膝关节稳定性、关节功能主观评分如Lysholm评分和IKDC评分、ACL移植物撞击率,结果行统计学分析,手术前后及组间的膝关节评分比较采用t检验,两组患者膝关节稳定性和撞击率比较采用卡方检验,以α=0.05为检验标准。3.随机选取18名研究对象进行膝关节三维有限元研究,其中健康志愿者6例,作为正常对照组,CAS组术后患者6例,TS组术后患者6例,使用1.5TMRI设备对正常志愿者双膝关节、CAS组和TS组患者手术后的患侧膝关节伸直位进行扫描,利用MIMICS14.11、Geomagic Studio2012和ABAQUS6.10软件建立膝关节三维有限元模型；在屈曲0°、30°、60°、90°时,对所有模型股骨分别加载股骨后向134N和垂直350N的力,分析出ACL、股骨髁软骨、胫骨平台、半月板的应力分布和大小,将应力分布结果与其他膝关节生物力学研究相比较,以验证有限元模型的有效性,并对比分析各组ACL、股骨髁、胫骨平台软骨和半月板的应力分布及大小变化情况,结果采用方差分析,以α=0.05为检验标准。结果1.成功研发出国内先进的计算机辅助ACL虚拟重建系统-ACL detector,该系统可根据患者的膝关节影像学资料,设计出虚拟的ACL重建方案,包括ACL骨隧道的位置、角度、在股骨和胫骨上的出入口和ACL附着点的面积。2.将ACL detector成功应用于临床,并将CAS组患者与TS组患者进行对比,两组患者均获随访,随访时间12-24个月,平均18个月,术后切口均Ⅰ期愈合,无并发症发生,两组间术后Lachman试验阴性率无显著差异(P>0.05),轴移试验阴性率无显著差异(P>0.05)；CAS组的Lysholm评分由术前(47.83±5.14)分提高到术后(93.28±3.34)分,P<0.05;IKDC评分由术前(42.25±4.46)分提高到术后(89.13±3.45)分,P<0.05；TS组的Lysholm评分由术前(46.85±7.23)分提高到术后(92.05±3.22)分,P<0.05; IKDC评分由术前(42.73±4.82)分提高到术后(88.03±3.25)分,P<0.05,两组组间术后的Lysholm和IKDC评分无统计学差异,P>0.05；成功重建出患者术后膝关节的三维数字化模型,可以从各角度观测ACL移植物的形态、角度及位置,并评估ACL移植物与髁间窝的撞击情况,三维模型上的ACL移植物撞击测量发现CAS组1例(2.50%)发生撞击,TS组8例(20.00%)发生撞击,两组间撞击率存在统计学差异(P<0.05)。3.成功建立正常人、计算机辅助ACL重建组和传统手术重建组术后的膝关节三维有限元模型,模型包括股骨、胫骨、软骨、半月板、ACL、PCL、MCL、LCL,各结构空间位置准确,在验证以上有限元模型的有效性后,在膝关节屈曲0°、30°、60°、90°情况下,对三维有限元模型施加股骨后向的134N力之后,各组ACL应力无统计学差异(P>0.05)；施加350N的垂直力后,TS组患者的关节软骨和半月板的应力在各屈曲角度下均高于正常组及CAS组患者的的应力,差异具有统计学意义(P<0.05)：而CAS组与正常对照组各部分的软骨应力在各屈曲角度及受力情况下差异均无统计学意义(P>0.05)。结论1.自主研制出国内先进的计算机辅助ACL重建系统-ACL detector,将其成功应用于临床后发现,该计算机辅助系统在改善膝关节功能方面与传统ACL重建手术相比无明显差异,但可以降低ACL术后撞击率,显示出较好的临床疗效,值得进一步推广应用。2.成功建立健康正常人和ACL重建术后患者的膝关节三维有限元模型,该模型可模拟膝关节不同运动状态下的受力情况,并可有效地分析膝关节ACL重建术后ACL、软骨、半月板等结构的在不同屈曲角度下的生物力学特性。3.计算机辅助和传统ACL重建术后受到股骨后向134N的力后,ACL移植物的生物力学特性无显著差异,且与正常对照组膝关节的ACL生物力学特性相似,在受到股骨垂直350N的力后,计算机辅助组患者的膝关节软骨及半月板的生物力学特性最接近正常对照组膝关节,但传统重建组的关节软骨和半月板应力高于正常组和计算机辅助组,提示计算机辅助技术有可能降低术后膝关节软骨和半月板的损伤风险,值得进一步深入研究。更多还原

【Abstract】 BackgroundAnterior cruciate ligament (ACL) injury is the most common ligament injury in knee joint. After injury, the ACL reconstruction under arthroscopy is the most common treatment. Although the treatment was applied widely, the rate of failure and revision after surgery was still high as10-15%. The accuracy of position for ACL tunnel affected the clinical result. Compare with traditional treatment, the computer assisted surgery (CAS) for ACL reconstruction which developed these years could improved the accuracy of tunnel, reduced the impingement rate of ACL graft and get better clinic effect.After ACL reconstruction, there is still high occurence rate of osteoarthritis in these patients, the probable cause is the abnormal stress on cartilage which exceed the normal range of stress in cartilage of knee joint, and may resulted in the degeneration or even wear or destroy of cartilage and meniscus. So, it is important to choose the best project of ACL reconstruction which can result in the most proper stress of cartilage after surgery. The3-dimensional finite element model of knee joint can simulate the different conditions of motion and force in knee joint, analyzed the biomechanical property of the ligament and cartilage in knee joint with different conditions precisvely. It is helpful for fully understanding the causes of the osteoarthritis and the biomechanical property and injury mechanics of major ligaments and cartilage in knee, and helpful for exploring the most proper method of ACL reconstruction, diagnosis and assessment method on related disorders injuries of ligaments and cartilage and surgical procedures of ACL reconstruction.Objective1. Based on the CT and MRI data of a healthy subject’s bilateral knees, to invent the innovated CAS system which was advanced domestically for ACL reconstruction, it could design the virtual plan of ACL reconstruction.2. Applied the innovated CAS system-ACL detector in clinic for ACL reconstruction, compare with traditional ACL reconstruction, to explore the effect and advantage of CAS system for ACL reconstruction, establish the3D model of knee joint after ACL reconstruction and analyzed the position and impingement of ACL graft.3.In order to explore the causes of osteoarthritis after ACL reconstruction and find the optimal ACL reconstruction method which can result in the most suitable biomechanical condition of cartilage, it is neccerary to establish the3D finite element model of normal and postoperative knee joint with different ACL reconstruction methods, simulated the different flexion conditions and forces of knee joint, and analyzed the different stress conditions of ACL, cartilage in femur, tibia and meniscus.Methods1. Based on the successful experiences of establishing the3D model of knee joint at past, a healthy person was selected as a subject, whose bilateral knee received1.5T MRI at extensive position and256row CT scan at flexed position of90°, imported the MRI and CT data into the3D reconstructive software MIMICS14.11and Geomagic Studio2012to established the3D model of bilateral knees, then, imported the3D model of knee into the innovated CAS system-ACL Detector, it could designed the virtual plan of ACL reconstruction.2. In order to explore the feasibility, effect and advantage of innovated CAS system-ACL detector, we applied the CAS system in clinic. From March2009to October2012,80cases of ACL reconstruction surgery were finished. All the cases were diagnosed as ACL injury by physical examination and MRI. All the patients were divided into2groups, Computerized assisted group (CAS group) of patients (40cases) received ACL reconstruction assisted by the viutual plan of ACL detector; Traditional surgery group (TS group) of patients (40cases) with ACL injury received traditional ACL reconstruction. At18months after surgery, the surgical effect of2 groups were evaluated by knee stability test and subjective functional score, the digital3D model of postoperative knees were estabilished based on MRI and CT date and evaluated the position and impingement condition of ACL graft, the results were analyzed statistically.3.6healthy man (Normal group) and12patients (6cases in CAS group and6cases in TS group) were selected as subjects for finite element study, the healthy man’s bilateral knee and the patients’operated knee s were scanned by1.5T MRI, imported MRI data of all subjects into the software such as MIMICS14.11, Geomagic Studio2012and ABAQUS6.10to establish3D finite element model (FEM) of knees, the FEM consisting of two bony structures, articular layers, menisci, and four principal ligaments. After verified the validity of the FEMs by comparing other FEM studies, added134N posterior femoral force and350N vertical force on the3D finite element model respectively at flexed angle of0°,30°,60°,90°, Analyzed the stress of ACL, cartilage and meniscucs of knee joint, Then, Compared the magnitude and distribution of stress in ACL, cartilage and meniscus among3groups. The statistical standard was α=0.05.Results1. The computerized assisted system-ACL detector was invented, it was advanced domesticlly. It could designed the virtual plan of ACL reconstruction based on subjects’MRI and CT date in knee joints, the virtual plan included the reconstruction tunnel’s position, angle of ACL graft, the entrance and exit of virtual tunnel in femur and tibia and the proportion of graft’s attachment.2.After applied the ACL detector in clinic, all cases in CAS and TS groups were followed up by12-24months (mean,18months), all the incisions healed well, and no complication was found. The results indicated that there was no significant difference in negative rate of lachman test (P>0.05) and pivot shift test (P>0.05) between two groups after surgery. After surgery, the CAS group’s Lysholm score improved from47.83±5.14to93.28±3.34,(P<0.05), the IKDC score improved from42.25±4.46to89.13±3.45,(P<0.05); The TS group’s Lysholm score improved from46.85±7.23to 92.05±3.27,(P<0.05), the IKDC score improved from42.73±4.82to88.03±3.25,(P <0.05). There was no significant difference in Lysholm and IKDC score after surgery between2group,(P>0.05). The3D models of operated knee were established succsefully and the position, angle and impingement of ACL graft could be observed. The results of ACL graft impingement measurement indicated that there was significant difference in Impingement rate of ACL in3D model,1case (2.50%) in CAS group and8cases (20.00%) in TS group,(P<0.05) between2groups after surgery.3. The3D finite element models (FEM) of healthy and operated knee were established successfully, the models consisting of femur, tibia, articular layers, meniscus, ACL, posterior cruciate ligament (PCL), medial collateral ligament (MCL) and lateral collateral ligament (LCL). After verified the validation of the FEM of each groups, applied posterior femoral134N force on femur at different flexion angle, there was no sigficant difference in stress of ACL among3groups (P>0.05). After applied350N vertical force on femur at different flexion angle, the stresses in most part of cartilage and meniscus of TS group were higher than CAS group and control group (P<0.05). There was no significant difference (P>0.05) in stresses of all parts in knee joint between CAS group and control group.Conclusion1. The innovated computer-assisted surgery system for ACL reconstruction-ACL detector which was advanced domestically was invented. It could designed the viutual plan for ACL reconstruction and could be applied in clinic succesufully. After applied the computer-assisted surgery technology in clinic, it could improve the function of knee, compared with traditional ACL surgery,it could reduce the impingement rate indicated the better effect of CAS technology.2. Established the3D finite element model of normal and operated knee joint after ACL reconstruction successfully, The stress in cartilage of femur, tibia, meniscus and ligaments in knee joint could be effectively analyzed.3. There was no significant difference on stress of ACL among3groups after ACL reconstruction. The stress on cartilage of femur, tibia and meniscus of CAS group were similar to normal group, and lower than some part of cartilage in CS group. Indicated the causes of complications after traditional ACL reconstruction and the advantages of CAS technology..更多还原