Effects of a viscosupplementation therapy on rabbit menisci in an anterior cruciate ligament transection model of osteoarthritis

The aim of this study was to evaluate the morphological, microstructural, and mechanical effects of a viscosupplementation therapy on rabbit menisci at an early stage of osteoarthritis (OA). Anterior cruciate ligament transection (ACLT) was performed in twelve male New-Zealand White rabbits on the right knee joint. Six of these twelve rabbits received a mono intra-articular injection of high molecular weight hyaluronic acid (HA) two weeks after ACLT. Six additional healthy rabbits served as controls. Medial menisci were removed from all right knees (n = 18) six weeks after ACLT and were graded macroscopically. Indentation-relaxation tests were performed in the anterior and posterior regions of the menisci. Collagen fiber organization and glycosaminoglycan (GAG) content were assessed by biphotonic confocal microscopy and histology, respectively. Viscosupplementation significantly (p = 0.002) improved the surface integrity of the medial menisci compared to the operated non-treated group. Moreover, the injection seems to have an effect on the GAG distribution in the anterior region of the menisci. However, the viscoelastic properties of both operated groups were similar and significantly lower than those of the healthy group, which was explained by their modified collagen fiber organization. They displayed disruption of the tie fibers due to structural alterations of the superficial layers from which they emanate, leading to modifications in the deep zone. To conclude, the viscosupplementation therapy prevents macroscopic lesions of the menisci, but it fails to restore their collagen fiber organization and their viscoelastic properties. This finding supports the role of this treatment in improving the lubrication over the knee.     

关节镜下半月板部分切除术与理疗治疗不稳定半月板撕裂的前瞻性对照研究

目的：评估针对不稳定半月板撕裂,关节镜下半月板部分切除术（APM）是否优于单纯理疗。方法：纳入36 例经磁共振确诊 为不稳定半月板撕裂的患者,平均年龄35 岁,其中9 例伴轻度骨关节炎。所有患者于前8 周,每周行3 次物理治疗,包括股四头 肌功能锻炼和神经-肌肉功能锻炼。完成康复训练后1 周行关节镜下半月板部分切除术。在治疗前、理疗结束后以及术后第4 周 随访时行VAS 评分进行疼痛评估并行Lysholm 评分进行功能评估。结果：36 例患者的VAS 评分由治疗前的5.66± 1.10,改善为 理疗结束后的4.39± 0.95（P＜0.05）,行APM 术后则达到1.82± 0.77（P＜0.05）,并且理疗对VAS 的改善不如APM 明显（P＜ 0.05）。治疗前,伴骨关节炎患者的疼痛症状更为明显,而APM 术后则与不伴骨关节炎的患者无明显差异（P＞0.05）。患者 Lysholm 评分理疗结束后由58.11± 8.06 提高到62.11± 8.34（P＜0.05）,APM术后则达到86.78± 5.50（P＜0.05）。相对于骨关节炎 患者,不伴骨关节炎患者的Lysholm 评分更高（P＜0.05）。结论：物理治疗能有效减轻疼痛和肿胀症状,但是对关节活动受限等改 善不明显。APM相对于理疗能有效缓解症状,改善膝关节功能。     

半月板组织工程天然支架材料研究进展

当今社会半月板损伤十分常见。近些年,伴随生命科学和生物工程学不断发展,用组织工程原理和技术修复损伤的半月板成为热点。许多支架材料也应运而生并取得良好效果,而天然半月板支架材料起着重要的作用,如何选取理想的天然支架材料已成为这一课题的关键,其材料包含种类繁多,可分为可注射类半月板支架材料,不可注射类半月板材料。每种材料都有其独特的优势及缺陷,根据不同的需要来选择合适的材料。迄今为止,运用组织工程技术还不能完全模拟半月板组织,没有一种材料达到最理想的水平。本文着重介绍半月板组织工程天然支架材料。并对未来半月板组织工程支架材料的研究提出展望。     

Involvement of dynamin-2 in formation of discoid vesicles in urinary bladder umbrella cells

Umbrella cells (UCs) of the epithelium of the urinary bladder have the capacity to control bladder volume by regulating exocytosis/endocytosis of their intracellular discoid vesicles (DVs). Dynamin (Dyn) is a GTPase that promotes endocytic processes through scission of cell membranes. We have examined whether Dyn2, the most abundant Dyn form, is expressed in UCs and contributes to their endocytic actions. A specific antibody against Dyn2 was used to localize Dyn2 in human and rodent UCs by immunohistochemistry. To clarify the functional roles of Dyn2, mouse bladders were treated with a Dyn-GTPase inhibitor, dynasore, and its effects on their UC structure were assessed. Since uropathogenic Escherichia coli can be encased into UCs during infection, we used immunohistochemistry to determine whether bacteria-encasing compartments in the infected UCs were also enriched with Dyn2. Light microscopy showed that Dyn2 was abundantly expressed in UCs, especially near the apical cytoplasmic regions. By immunoelectron microscopy, Dyn2 was found on and around DV membranes in UCs. Ultrastructural analysis with a quick-freezing and deep-etching method confirmed these findings and revealed the existence of distinct Dyn2-bound microfilaments in close association with DV membranes. Dynasore treatment of bladders markedly reduced the number of DVs in UCs. In infected UCs, E. coli was encased in compartments enriched in Dyn2. Therefore, Dyn2 is highly enriched in UCs and mostly associated with membranes of DVs and microfilaments in the UCs. Pretreatment of bladders with dynasore inhibits E. coli invasion of UCs. Dyn2 thus contributes to the structural integrity of DVs and to the endocytic activity of UCs.     

Utility of the lateral meniscal notch in distinguishing hominin taxa

In humans, a notch marking the posterior attachment of the lateral meniscus is often visible on the posterior, lateral plateau of the tibia, adjacent to the intercondylar eminence. In theory, the presence or absence of this notch in dry bone can be used to differentiate the fossil remains of Australopithecus from those of the genus Homo. In a small-scale study, however, we found examples of modern human tibiae that appear not to have such a notch. In other cases, the morphology of the surrounding bone made it difficult to determine whether or not the notch was present. Although based on a small sample, this study questions: 1) the theoretical postulate that the lateral meniscal notch can be used to differentiate between hominin taxa, and 2) the practical reliability of determining the absence or presence of the notch in fossil remains.     

低场MRI对膝关节半月板损伤诊断的临床价值

目的探讨低场MRI在膝关节半月板损伤中的诊断价值。材料和方法搜集我院2007年2月-6月间,进行MRI检查的141例151个膝关节,进行半月板损伤诊断的回顾性分析。检查序列包括冠状面FSET2WI、矢状面SET1WI、FSET2WI及STIRE。结果低场MRI显示正常半月板内可以见似三角型或片状高信号,不延伸至关节面或游离缘,临床症状不明显;损伤半月板除信号改变外,其形态可全部或局部不规则,常同时伴关节组成骨及关节软骨、滑膜囊、软组织等的异常信号,临床症状明显。本组资料中,MRI诊断半月板损伤130个,14个膝关节外院行关节镜检查,12个证实有半月板撕裂。低场MRI对半月板撕裂的诊断率85．7％。结论低场MRI能较好的显示膝关节半月板损伤,能对其进行损伤分级,显示损伤的特点和严重程度,为临床选择合适的治疗方案提供依据。     

Relationships among element contents in the medial meniscus

To elucidate compositional changes of elements in the meniscus with aging, the authors investigated the relationships among elements in the medial meniscus by inductively coupled plasma-atomic emission spectrometry. The subjects consisted of 16 men and 7 women, ranging in age from 65 to 93 yr. In the left medial meniscus, extremely significant correlations were found both between calcium and phosphorus contents and between sulfur and magnesium contents, whereas significant correlations were found between calcium and either iron or zinc contents, between phosphorus and either iron or zinc contents, and between iron and zinc contents. On the other hand, in the right medial meniscus, there were only an extremely significant correlation between calcium and phosphorus contents and a significant correlation between sulfur and magnesium contents. The common finding between the left and right medial menisci was an extremely significant correlation between calcium and phosphorus contents and a significant correlation between sulfur and magnesium contents.     

Confocal laser scanning microscopy in orthopaedic research

Confocal laser scanning microscopy (CLSM) is a type of high-resolution fluorescence microscopy that overcomes the limitations of conventional widefield microscopy and facilitates the generation of high-resolution 3D images from relatively thick sections of tissue. As a comparatively non-destructive imaging technique, CLSM facilitates the in situ characterization of tissue microstructure. Images generated by CLSM have been utilized for the study of articular cartilage, bone, muscle, tendon, ligament and menisci by the foremost research groups in the field of orthopaedics including those teams headed by Bush, Errington, Guilak, Hall, Hunziker, Knight, Mow, Poole, Ratcliffe and White. Recent evolutions in techniques and technologies have facilitated a relatively widespread adoption of this imaging modality, with increased "user friendliness" and flexibility. Applications of CLSM also exist in the rapidly advancing field of orthopaedic implants and in the investigation of joint lubrication.     

Poisson's ratio of bovine meniscus determined combining unconfined and confined compression

Poisson's ratio has not been experimentally measured earlier for meniscus in compression. It is however an important intrinsic material property needed in biomechanical analysis and computational models. In this study, equilibrium Poisson's ratio of bovine meniscus (n = 6) was determined experimentally by combining stress-relaxation measurements in unconfined and confined compression geometries. The average Young's modulus, aggregate modulus and Poisson's ratio were 0.182 ± 0.086 MPa, 0.252 ± 0.089 MPa and 0.316 ± 0.040, respectively. These moduli are consistent with previously determined values, but the Poisson’s ratio is higher than determined earlier for meniscus in compression through biomechanical modelling analysis. This new experimentally determined Poisson’s ratio value could be used in the analysis of biomechanical data as well as in computational finite element analysis when the Poisson’s ratio is needed as an input for the analysis.     

关节镜治疗膝关节盘状半月板损伤的疗效及术后疼痛的影响因素研究

目的:探讨关节镜治疗膝关节盘状半月板损伤的疗效以及患者术后疼痛的原因、影响因素。方法:选取2011年7月至2013年7月我院收治的46例膝关节盘状半月板损伤的患者作为研究对象,运用统计学方法分析关节镜的手术疗效。结果:根据Lkeuchi评分标准进行评分:优29例(63.04%),良12例(26.09%),中3例(6.52%),差2例(4.35%),优良率为89.13%。两组患者性别、BMI(体质指数)之间无差异,但是疼痛与年龄、负重早晚、关节软骨损伤、术后是否冷敷均有关系,且差异具有统计学意义(P0.05)。结论:关节镜治疗膝关节盘状半月板损伤具有确切的疗效,术后疼痛与多种因素有关。