基于MRI的成人正常膝关节软骨形态学测量

目的：了解正常膝关节软骨分布及股骨髁承重区的软骨厚度特点,为膝关节病变早期诊断和动态观察提供依据。方法：选取100名成人志愿者,男、女各50名,年龄20—30岁,平均25．3岁,膝关节均行MRI扫描。应用MIMICS软件对图像进行处理,在矢状位窗面上测量膝关节各部位软骨最大厚度。选择膝关节正常运动时的承重区,测量承重区域软骨的最大厚度并与其他区域进行比较。基于MRI图像行膝关节软骨三维重建,观察膝关节软骨的三维形态特征。结果：膝关节各部位的最大软骨厚度如下。胫骨外侧平台3．19mm,胫骨内侧平台3．07mm,股骨外侧髁2．93mm,股骨内侧髁3．19mm,股骨滑车软骨3．57mm,髌软骨3．75mm。不同性别与左右侧之间的软骨厚度差异无统计学意义（P〉0．05）。胫股关节承重区软骨厚度大于其他区域,有统计学差异（P〈0．05）。结论：成人正常膝关节各区域软骨厚度不同,胫股关节承重区软骨厚度大于非承重区域。基于MRI可以准确地测量膝关节各部软骨的厚度及重建膝关节软骨的三维形态。     

人体膝关节有限元动力学分析模型的建立与验证

根据乘员碰撞事故中人体膝关节的生物力学响应特性,应用有限元(FE)方法和碰撞模拟技术,构建了一个人体膝关节模型。模型按人体解剖学结构构建,由股骨内、外侧髁,胫骨内、外侧髁,腓骨小头、髌骨、软骨、半月板以及主要韧带构成。通过比较模型仿真和尸体碰撞实验在轴向载荷条件下膝关节受刚性碰撞的响应结果,验证了模型的有效性。该模型为研究人体膝关节损伤机理提供了可靠的基础数据,并可应用于乘员损伤防护装置的设计和开发。     

Osteochondritis dissecans of the weight-bearing surface of the medial femoral condyle in adults

Osteochondritis dissecans (OD) is a syndrome that can be characterized as a non-infectious disturbance of enchondral ossification or as a post-traumatic event. OD occurs in the joint cartilage and physis of long bones, as well as in the talus. The medial femoral condyle is the most commonly affected site. OD of the weight-bearing, inferocentral portion of medial femoral condyle is an uncommon, but still challenging issue in knee surgery. This study reports one surgeon's experience in the treatment of OD of the weight-bearing surface of the medial femoral condyle in adult patients. A total of 29 knees in 28 patients with OD were reviewed as the basis of this study. Four patients were women and 24 were men. The average age was 29.5 years. Patients were observed for an average of 2 years after surgery. Medial joint line tenderness, anterior knee pain, stiffness and locking were the major complaints in 60% of cases. Arthroscopic excision of loose bodies with or without drilling of the crater and fixation of the lesions with 2 K-wires, with or without bone grafting, was undertaken for the patients. In our study, the clinical outcome was excellent in 11 patients, good in 13, fair in four and poor in one. On subjective questioning, all patients reported marked improvement and satisfaction with the surgery.     

Proximal medial tibial biplanar retrotubercle open wedge osteotomy in medial knee arthrosis

The patellar tendon length changes and patella infera occurs in medial open wedge osteotomies. We hypothesized that patellar tendon length in the sagittal plane would not change in a proximal medial tibial biplanar retrotubercle open wedge osteotomy. Proximal medial tibial biplanar retrotubercle open wedge osteotomies were conducted on 23 knees of 22 patients; the mean patient age was 59 ± 7 years (range, 53-69 years). The surgical procedure used had some technical distinctions from those used in literature. The mean follow-up was 37 ± 11 months (range, 19-58 months). Preoperative and postoperative Hospital for Special Surgery Scoring System (HSS) scores, radiological tibial slope, Insall-Salvati, Blackburne-Peel, and Caton indices, femoro-tibial anatomical axis angle, the angle between the femoral condyle and tibial plateau, and the angle between the tibial plateau and tibial axis were measured and compared statistically. Postoperative HSS scores were statistically higher than the preoperative HSS scores. The femoro-tibial axis angle, the angle between the femoral condyle and tibial plateau, and the angle between the tibial plateau and tibial axes decreased significantly. No statistical difference was observed between the preoperative and postoperative Insall-Salvati, Blackburne-Peel, or Caton indices. When we performed proximal medial tibial biplanar retrotubercle open wedge osteotomy, clinical and radiological recovery was observed but patellar height did not change.     

Bucket-handle tear of medial plica

Plicae are synovial folds, classified according to their anatomical relationship to the patella. The medial patellar plica is normally asymptomatic, but it may cause symptoms when it becomes thickened and fibrotic. We describe three cases of bucket-handle tear of the medial patellar plica. They all suffered from anterior knee pain and clicking. Our cases' symptoms began when they incurred twisting injuries to the knee; therefore, we think that they had an asymptomatic plica first. Pain and clicking began because of the bucket-handle portion rubbed over the medial femoral condyle with knee flexion, and they improved after resection of the bucket-handle portion. Consequently, we think that medial patellar plica can be symptomatic not only when it becomes thickened or fibrotic but also when a bucket handle tear occurs.     

Comparison of medial and lateral posterior femoral condyle articular cartilage wear patterns

Background

While degenerative changes to the articular cartilage of the anterior and distal portions of the femoral condyles have been well studied in the literature, the changes that occur on the posterior femoral condyle are not as clear. The purpose of this study was to assess the difference in articular cartilage thickness between the medial and lateral posterior femoral condyles in knees undergoing unicompartmental knee arthroplasty.

Robotic-assisted unicompartmental knee arthroplasty in a patient with combined medial compartment arthritis and subchondral defect of the medial femoral condyle

Subchondral defects, or severe osteoarthritic changes, of the medial compartment may complicate component positioning and require proper planning and exact placement to ensure adequate and stable fixation and proper postoperative kinematics. This is a case report on our experience with a CT-based robotic tactile guidance system for unicompartmental knee replacement in a patient with combined medial compartment degenerative joint disease and subchondral defect of the medial femoral condyle. Using the TGS in this case, an exact burring process of the femoral cavity adjacent to the subchondral defect resulted in accurate burring of the cavity depth and width, while preservation of the surrounding supporting bony boundary was possible.     

基于定量动态负荷下膝关节骨性关节炎软骨MRIT2时间表现研究

目的通过比较膝关节骨性关节炎（OA）病人定量动态负荷前后膝关节软骨T2时间变化情况,分析MRIT2mapping序列反映软骨基质生物力学变化的灵敏度．并验证高磁场条件下人体关节负荷装置的有效性。方法10例膝关节OA病人,其中男性3例．女性7例：年龄4l～66岁．平均年龄57-3岁。依托人体下肢关节力学负荷装置,对其施加膝关节动态负荷。负荷前后行膝关节MRIT2maDping成像,将膝关节轴向负荷区软骨分为4个部位：胫骨平台内、外侧软骨区及股骨内、外侧髁软骨区．分别测量各部位软骨负荷前后的T,时间。对负荷前膝关节内、外侧软骨分级评估进行卡方检验,对同一软骨区动态负荷前后的T2时间进行配对t检验。结果负荷前膝关节内外侧软骨分级差异无统计学意义（P〉0．05）。OA病人负荷前后T2值,胫骨平台内侧软骨区分别为（39．59±4．17）ms、（40．14±4．49）ms（f=0．426,P=0．680）;胫骨平台外侧软骨区（38．85±6．72）ms、（41．25±6．54）ms（t=1．704,P=0．123）：股骨内侧髁软骨区（36．44±5．72）ms、（40．63±4．90）ms（t=1．783,P=0．108）;股骨外侧髁软骨区（39．30±5．78）ms、（46．14±5．03）ms（t=2．826,P=0．020）。结论OA病人负荷后膝关节局部区域软骨区T2时间延长．自行设计的动态加压装置适合在高磁场条件下完成加压及MRI检查,有一定推广意义。     

Arthroscopic repair of medial patellofemoral ligament avulsion in acute patellar dislocation in skeletally immature patient - A case report

Acute patellar dislocation is a severe injury to the knee and usually manifests with symptoms such as giving way, a sensation of lateral displacement of the patella accompanied by hemarthrosis and tenderness over the medial epicondylar region to palpation. Spontaneous reduction of the patella makes the diagnosis more difficult in initial evaluation. Radiographs often show a small bony avulsion at the medial border of the patella, which may represent an injury to the medial restraints. Magnetic resonance imaging may show a bone bruise on the medial patella, and/or on the lateral femoral condyle. The medial patellofemoral ligament (MPFL) may be avulsed distally, proximally or sustain in interstitial tear. Arthroscopic findings include hematoma and chondral or osteochondral lesions located on the central or medial facet of the patella or on the anterior lateral femoral condyle. We report a case of a patellar avulsion of medial patellofemoral ligament in a skeletally immature patient.     

基于CT和MRI膝关节有限元模型建立与不同载荷下生物力学特性分析

基于CT和MRI图像数据建立膝关节有限元模型,采用六面体网格对不同载荷系统下人体膝关节生物力学特性进行研究,并进行有效性验证。建立膝关节有限元模型包括:股骨、胫骨、髌骨、腓骨、股骨软骨、胫骨软骨、腓骨软骨、半月板、前后交叉韧带、内外侧副韧带、髌韧带和股四头肌腱等。对膝关节施加1 kN轴向压缩载荷、134 N后向抽屉力和5、10、15 N[?m内翻力矩和外翻力矩,分析膝关节内软骨和半月板的接触应力和接触面积,股骨内外翻倾角以及位移变化情况。在1 kN压缩载荷和134 N抽屉力作用下,股骨软骨、内外侧半月板和内外侧胫骨软骨的接触应力峰值分别为4.47、3.25、2.83、2.70、2.53 MPa,Von Mises应力峰值分别为2.22、2.44、2.25、2.07、1.64 MPa。股骨相对胫骨前向位移为4.19 mm。施加5、10、15 N[?m内翻和外翻力矩时,股骨内翻和外翻倾角分别为3.49°、4.48°、4.91°和3.22°、3.62°、4.01°。随着力矩的线性增大,膝关节各组成部分的应力呈非线性变化趋势。膝关节软骨、半月板和韧带的研究结果符合其生物力学特性,与前人数值分析和实验研究结果相一致,可为临床膝关节生理病理分析和治疗提供一定的理论依据。     

Matrix-assisted autologous chondrocyte implantation into a 14 cm2 cartilage defect,caused by steroid-induced osteonecrosis

Modern chemotherapy protocols have improved the prognosis for acute lymphoblastic leukaemia (ALL), one of the most common paediatric malignancies, but their high-dose corticosteroids lead to osteonecrosis in up to 9% of ALL patients. A 13.5-year-old female patient developed massive osteonecrosis of the right knee after successful ALL treatment. She presented at the age of 17.5 years as a candidate for knee arthroplasty after conservative treatment had failed. Magnetic Resonance Imaging (MRI) revealed severe osteonecrosis, with the cartilage layer of the medial femoral condyle completely detached from the bone. We preferred to attempt a two-step biological reconstruction in this young patient, with arthroscopy of the right knee joint and removal of the dissected cartilage layer of the medial condyle. Matrix-assisted autologous chondrocyte implantation (MACI) was performed with harvested chondrocytes after imaging had indicated vital bone remodelling. Rehabilitation was according to MACI guidelines and after 5.5 years, the patient shows continuous clinical improvement and is satisfied with the result. The Lysholm score improved from 45 to 99 and Tegner's activity score from 1 to 4. MRI follow-up showed a solid cartilage layer covering the medial condyle as a result of bone and chondral regeneration. Even if this approach had failed, bone remodelling would have still provided better conditions for knee arthroplasty.     

Articular cartilage defects: study of 25,124 knee arthroscopies

This retrospective study aimed to provide data on the prevalence, epidemiology and etiology of the knee articular cartilage lesions and describe and estimate, on the ground of a large database, the number of patients who might benefit from cartilage repair surgery. The analysis of 25,124 knee arthroscopies performed from 1989 to 2004 was conducted. Information concerning cartilage lesion, associated articular lesions and performed procedure were collected. Cartilage lesions were classified in accordance with the Outerbridge classification. Chondral lesions were found in 60% of the patients. Documented cartilage lesions were classified as localized focal osteochondral or chondral lesion in 67%, osteoarthritis in 29%, osteochondritis dissecans in 2% and other types in 1%. Non-isolated cartilage lesions accounted for 70% and isolated lesions accounted for 30%. The patellar articular surface (36%) and the medial femoral condyle (34%) were the most frequent localization of the cartilage lesions. Grade II according to Outerbridge classification was the most frequent grade of the cartilage lesion (42%). The most common associated articular lesions were the medial meniscus tear (37%) and the injury of the anterior crucial ligament (36%). Articular cartilage lesions are a common pathology of the knee joint. The potential candidates for cartilage repair surgery, patients with one to three localized grade III and IV cartilage lesions, under the age of 40 were found in 7% and under the age of 50 years in 9% of all analysed patients. However, because these patients are a heterogeneous group and the natural history of cartilage lesions remains so far unknown, also the total number of patients in our study, who might benefit from cartilage repair, remains unknown precisely.     

Effect of sodium hyaluronate on prevention of osteoarthritis

The changes in the surface of articular cartilage of femoral condyle from rabbits were evaluated after degenerative changes were made by the technique advocated by Hulth. The medial collateral and both cruciate ligaments were excised, and a medial menisectomy was done. Then the right knee joint was injected with 1 ml of Na-hyaluronate gel every two weeks. The animals were sacrificed at two, four, six, eight, or sixteen weeks postoperatively. After sacrifice, the medial femoral condyle was excised and prepared for the light microscopic and scanning electron microscopic study. At eight to sixteen weeks, there were chondrocyte clones with clefts to the radial zone and increased loss of the height of articular cartilage on the control side; but, on the experimental side there was a significant delay and lessening of the arthritic response. The biocompatibility and the protective effect of joint degeneration of this device make this material a valuable adjuvant in the treatment of osteoarthritis and the traumatized joints.     

A case of compression fracture of medial tibial plateau and medial femoral condyle combined with posterior cruciate ligament and posterolateral corner injury

We report a case of compression fracture of anterior margin of medial tibial plateau and medial femoral condyle combined with the posterior cruciate ligament and posterolateral corner disruption. A thirty-seven-year old male had undergone the left knee injury 6 months before. The physical examination revealed positive posterior drawer test and tibial dial test, which evidenced the posterior cruciate ligament and posterolateral corner insufficiency. The plain lateral knee radiographs showed a marginal fracture of the anteromedial tibial plateau and a dimpling on the adjacent part of the medial femoral condyle. On arthroscopy, there were no gross tear of the cruciates, but the posterolateral capsule disclosed stigmata of stretching injury with multiple petechiae and scarring. The compression fracture on the anteromedial side and the stretching injury on the posterolateral side altogether support the mechanism of hyperextension pivoting on the anteromedial side of the knee joint. A small bony lesion around the knee joint should be inspected rigorously with an assumed mechanism of injury for it may herald major ligamentous injury.     

膝降血管髌下支蒂股骨内侧髁骨膜瓣逆行转位术的应用解剖

目的　为膝降血管髌下支蒂股骨内侧髁骨膜瓣修复膝关节面缺损提供解剖学基础。 方法　在30侧动脉内灌注红色乳胶的成人下肢标本上,以收肌结节、股骨内侧髁为观测点解剖观测膝降动脉关节支的走行、分支与分布。另在1侧新鲜标本上进行摹拟手术。 结果　膝降血管关节支在距股骨内侧髁下缘上(5.9±1.2) cm处发出两大分支：①骨膜支起始外径（1.3±0.2）mm,在股骨内侧髁面上走行距离为(4.8±1.1) cm;②髌下支起始外径为(1.3±0.2) mm,向下走行距离为(6.6±1.5)cm。 结论　可形成膝降血管髌下支-骨膜支蒂股骨内侧髁骨膜瓣逆行转位修复膝关节面缺损。     

Patellar instability with increased knee flexion due to lateral femoral condyle distal dysplasia: a report of two cases

We present two case reports with clinical and radiological assessment of the anatomical features at the distal lateral end of trochlea and femur in patients with patellar instability in higher knee flexion and how these findings could possibly be involved in the genesis of this rare type of patellar instability. Both patients underwent several (nine and seven) surgical procedures, but the patellar instability could not be successfully eliminated. Our hypothesis was that a short and flattened lateral distal condyle/trochlea may cause lateral patellar instability in higher flexion. We found considerable anatomical variations at the distal lateral femoral condyle and trochlea in both patients. Individually tailored surgical procedures were selected for each patient according to the documented variations and the previous operations. Our surgical interventions consisted of different components, such as osteotomy of the distal lateral femoral condyle/trochlea with lengthening and elevation, balancing of the medial and lateral patellar soft tissue structures, MPFL reconstruction, transposition of the medialised tibial tubercle and the patellar tendon back to lateral to the normal initial anatomical position. With these procedures, lateral patellar instability with increased flexion could be completely eliminated in both patients at the 1- and 2-year follow-up. Our experience of assessment and treatment of these patients let us conclude that variations of the distal lateral femoral condyle/trochlea morphology may be responsible for patellar instability with increased flexion. This is another type of patellar instability caused by distal condyle/trochlea dysplasia compared to the well known and often described types of patellar instability close to extension caused by proximal trochlea dysplasia.     

电针治疗膝骨性关节炎患者上下楼梯的三维有限元分析

针对电针治疗膝骨性关节炎患者上下楼梯运动生物力学特性改变进行有限元仿真研究,对比分析膝关节生物力学行为改变与电针治疗疗效的相关性.基于CT和MRI图像数据,结合Mimics和Geomagic医学图像处理软件,建立人体膝关节下楼梯屈曲15°和上楼梯屈曲50°时的三维有限元模型,模型包括股骨、胫骨、腓骨、内外侧半月板、股骨...     

膝关节损伤修复后的生物力学分析

背景：对膝关节及膝关节韧带进行生物力学分析是防止膝关节损伤和治疗膝关节疾病的基础。 目的：总结膝关节损伤重建术中修复材料的应用进展及其修复后膝关节的生物力学特征。 方法：以“膝关节、韧带、半月板、生物材料、生物力学”为中文关键词,以“ tissue enginneering,articular cartilage,scaffold material,biomechanics” 为英文关键词,采用计算机检索中国期刊全文数据库、PubMed数据库相关文章。重点对修复后膝关节的生物力学特征进行了讨论。 结果与结论：生物力学研究证明膝关节后外侧结构在限制膝关节内翻,胫骨外旋、前移、后移有着重要作用。膝关节内韧带部分或完全断裂对股骨内髁生物力学特性均有不良影响,膝关节每条韧带又与其他韧带和组织协同完成某些方面的功能达到力学平衡,其中一条韧带断裂,平衡就会遭到破坏,各条韧带的应力分布将发生改变。膝关节的损伤类型与部位各有不同,修复与重建的材料与重建手段也各有不同,最终其生物力学表现特征各有不同。修复材料生物力学性能研究对于移植后膝关节生物塑形、愈合过程以及功能恢复都有很重要的作用。           

膝关节软骨负荷运动前后磁共振T_2时间与容积变化研究

目的通过比较分析负荷运动前后膝关节软骨磁共振T2时间和软骨容积变化,探讨利用T2时间和容积变化反映负荷作用下软骨形态变化的可行性。方法选择20例健康志愿者,其中男性16例,女性4例;年龄为20.1~30.4岁,平均年龄25.7岁。在同等运动负荷前后进行软骨T2mapping序列成像,测量股骨内外侧髁、胫骨平台和髌软骨T2时间;以三维脂肪抑制快速扰相梯度回波(3D-FS-SPGR)序列扫描并采用最大信号强度投影法(MIP)重建后测量髌软骨及股骨髁软骨容积。比较负荷前后软骨T2时间变化、软骨容积差异,并分析软骨容积与T2时间变化间的相关性。结果运动前与运动后髌软骨T2时间最长,胫骨外侧平台最短;运动后不同部位软骨T2时间均降低(P=0.000),股骨内侧髁软骨下降幅度最大(t=-27.96,P=0.000);运动后膝关节软骨容积减小(P=0.000),股骨髁软骨容积变化程度(t=-86.71,P=0.000)大于髌软骨(t=-9.42,P=0.000);软骨容积与T2时间变化间无线性相关性(P0.05)。结论运动后膝关节软骨各部位T2时间和局部软骨容积均减少,但软骨容积与T2时间变化间无相关性;软骨T2mapping和软骨容积变化磁共振成像技术对评价负荷作用下软骨形态变化有一定的意义。     

Comparative biomechanical analysis of human and caprine knee articular cartilage

BackgroundThe goat is one of the most commonly used preclinical models for focal defect repair and regeneration. While the biomechanics of the human knee has been studied extensively, less is known about the biomechanics of the caprine knee. Differences between human and caprine knees have not been quantified and their significance is largely unknown.MethodsWe conducted a biomechanical analysis of the differences in goat and human knees to assess the validity of these preclinical in vivo models.ResultsCT and MRI scans revealed several differences in articular geometry: the caprine tibial plateaux were more convex and the menisci were significantly thicker and covered a larger proportion of the tibial articular surface. Caprine cartilage thickness was consistently thinner, while elastic modulus on indentation testing was consistently stiffer than human cartilage measured at eight different articular locations. Contact area and pressure were measured with electronic pressure sensors under loads normalized by multiples of body weight and at knee flexion angles reported for walking. The highest peaks in contact pressure were measured in the patellofemoral joint in goat and human knees. Peak contact pressure measured at 2 times body weight at the goat tibiofemoral joint at 70° flexion was significantly higher than for any other condition at the human tibiofemoral joint.ConclusionThese differences in contact conditions might explain the lower quality of local repair reported for caprine femoral condylar defects relative to trochlear defects. Further comparative analysis, including biologic response, is necessary to determine the extent to which the goat knee reproduces clinical conditions.