MR imaging evaluation of knee collateral ligaments and related injuries: Comparison of T1-weighted,T2-weighted,and fat-saturated T2-weighted sequences—correlation with clinical findings

The objectives of this study were to compare the ability of T1-weighted (T1W), proton density/T2-weighted (PD/T2W), and fat saturation (FS) PD/T2W magnetic resonance (MR) sequences for depiction of the knee collateral ligaments and related injuries, and to compare MR findings with clinical findings. Ten subjects with normal knee ligaments and 64 patients with suspected collateral ligament injuries underwent coronal T1W, PD/T2W, and FS PD/T2W imaging. Abnormalities ranged from edema surrounding the collateral ligaments (grade I) to complete disruption of ligamentous fibers (grade III). FS PD/T2W images improved definition of the medial collateral ligament (MCL) and lateral collateral ligament (LCL) compared with other sequences in 78% and 81% of patients, respectively. While the apparent grade of collateral ligament injury was similar with all pulse sequences in most patients, depiction of such injury was usually most conspicuous on FS PD/T2W images (MCL, 92% of patients; LCL, 38% of patients). In no patients were clinically diagnosed collateral ligament injuries undetected or understaged with MR imaging. MR findings indicated higher-grade MCL and LCL injuries than did clinical examination in 24 and 15 patients, respectively.     

半月板的血供及其临床意义

通过动脉灌注,对56侧儿童和成人尸体的半月板血供进行了研究。成人半月板外1/5为血管区,内4/5为无血管区。半月板的撕裂常发生于无血管区或无血管区与血管区的连接处。半月板的退化和磨损位于无血管区。     

滑膜间充质干细胞分离纯化后的生物学特性

背景：大量的研究报道证明滑膜间充质干细胞在细胞形态、免疫表型、集落形成能力和分化潜能等方面与骨髓间充质干细胞相似,但在向软骨分化的能力上,滑膜间充质干细胞明显优于骨髓间充质干细胞。目的：探讨滑膜间充质干细胞作为半月板软骨组织工程种子细胞的可行性。方法：通过有限稀释单克隆培养法将滑膜间充质干细胞从兔滑膜组织中分离出来并加以纯化,在体外培养条件下对其形态学、超微结构、分子表型、增殖动力学、核型以及致瘤性等进行分析。结果与结论：从兔滑膜细胞中分离纯化出滑膜间充质干细胞,体外单层培养具有极强的增殖能力,在第6天时达到生长的最高峰,倍增时间为（30．2±2．4）h。流式细胞术检测滑膜间充质干细胞表达间充质干细胞一些分子标记CD44、CD90。DNA含量检测、染色体核型分析、荷瘤实验结果表明,分离纯化的滑膜间充质干细胞是正常的二倍体细胞,无致瘤性,因此可作为半月板组织工程的种子细胞。     

Magnetic resonance imaging of anterior cruciate ligament tears: reevaluation of quantitative parameters and imaging findings including a simplified method for measuring the anterior cruciate ligament angle

We evaluated the diagnostic utility of magnetic resonance imaging (MRI) for predicting anterior cruciate ligament (ACL) tears using both quantitative parameters and nonquantitative imaging findings. MRI examinations were retrospectively evaluated in a group of patients with arthroscopically confirmed complete ACL tear and in a control group with arthroscopically confirmed intact ACL. We evaluated multiple MRI features to compare their sensitivity and specificity for detecting ACL tears. Particular emphasis is put on the evaluation of three different quantitative parameters, including a simplified method for measuring the ACL angle. With a threshold value of 45° the ACL angle reached a sensitivity and specificity of 100% for detecting ACL tears. With a threshold value of 0° the Blumensaat angle had a sensitivity of 90% and a specificity of 98%. Finally, a threshold value of 115° gave the posterior cruciate ligament angle a sensitivity of 70% and a specificity of 82%. Discontinuity was found to be the most useful of the ACL abnormalities. Of the secondary findings anterior tibial displacement was the best predictor of ligamentous injury. However, ACL abnormalities and secondary findings, alone or combined, failed to surpass the diagnostic value of the ACL angle for predicting ACL tears. Quantitative parameters are thus good predictors of ACL tears and may increase the overall sensitivity and specificity of MRI. The ACL angle may be confidently measured in a single MRI section and can be considered to be the most reliable quantitative parameter for detecting ACL tears.     

关节镜下缝合治疗63例半月板撕裂疗效分析

[背景]观察关节镜下半月板撕裂缝合的治疗效果.[病例报告]给63例经膝关节镜检查确诊的多种类型半月板撕裂伤患者,采用3种不同的缝合方法进行缝合治疗,随访6个月~2年,行Lysholm-Ⅱ评分,评定膝关节功能及运动水平.结果见术前Lysholm-Ⅱ评分平均为48.6分,术后为90.5分,疗效满意.[讨论]采用1种或多种缝合方法,可缩短半月板撕裂手术时间,提高疗效.     

Prevalence of abnormal findings in magnetic resonance images of asymptomatic knees

 One hundred fifteen asymptomatic Japanese volunteers aged from 13 to 76 years were examined by magnetic resonance imaging (MRI) to evaluate age-related meniscal degeneration and to determine the prevalence of discoid menisci. Each meniscus was graded in the anterior and posterior portions according to intrameniscal MRI signals. Discoid meniscus was diagnosed if a bow-tie configuration was noted on three or more contiguous sagittal sections. Meniscal abnormalities on MRI became more prevalent with age in both men and women. The posterior horn of the medial meniscus showed a significantly higher prevalence of degeneration than other parts of the meniscus. Discoid menisci were noted in 15 subjects (13% prevalence), always representing the lateral meniscus. Subchondral changes were observed in 13 subjects more than 40 years old, mostly women, and were located in the medial compartment. These abnormalities were not correlated with severity of degeneration in the posterior portion of the medial meniscus. This study demonstrates considerable prevalence of meniscal abnormalities in asymptomatic Japanese subjects. Received: January 15, 2001 / Accepted: December 13, 2001     

The effect of meniscus compression on the biomechanical properties of repaired meniscal lesions

Introduction The objective of the present study was to investigate the influence of meniscus compression, as it occurs with weight-bearing, on the biomechanical behavior of different repair types.Materials and methods Young human meniscal tissue specimens were fitted with a single Bionx Arrow, a Innovasive Meniscal Screw, or a vertical suture (Ethibond 2–0) according to standard clinical practice. Test specimens then underwent repetitive loading with 10 N under 1 N pretension up to a maximum of 1182 cycles and were finally loaded to failure. Half of the cases in each group were additionally subjected to synchronized intermittent compression during the test. The main variables investigated were the number of cycles survived and ultimate failure load. To reduce the complexity, investigations were limited to the peripheral repair site.Results The number of cycles survived was significantly affected by compression and the type of repair. Arrows and Screws survived 311 and 52 cycles, respectively, without compression, while 983 and 1182 cycles were survived with added compression. In the suture group, no premature failure occurred either with or without compression. Both compression and the type of repair had a significant effect on the ultimate failure load. It increased about twofold in the Arrow and Screw group, while the suture group was not affected.Conclusions Compression of the meniscus can substantially increase the pullout resistance of meniscal repair implants and thus seems not to be a factor negatively influencing the stability of the repair.     

关节镜下套管针缝合在军事训练致半月板损伤中的应用

目的评价膝关节镜下半月板缝合术在军事训练致半月板损伤中的应用效果。方法应用膝关节镜及套管针对45例半月板损伤患者关节镜下行半月板缝合术。结果45例均在关节镜下顺利完成缝合修复手术,平均手术时间60min。随访6-24个月。按Ikeuchi膝关节评分标准评定疗效：优30例,良9例,中6例,优良率86.6%。结论关节镜下套管针缝合术是治疗半月板损伤理想的方法。