Diacerein protects against iodoacetate-induced osteoarthritis in the femorotibial joints of rats

The present study was undertaken to investigate the effect of diacerein on the histopathology of articular cartilage and subchondral bone of the femorotibial joint in rats. Osteoarthritis was induced in rats after single intra-articular injection of sodium iodoacetate. Rats were sacrificed 1, 2, 4, and 8 weeks post intra-articular injection to evaluate the progression of histopathogenesis of osteoarthritis. Diacerein was orally administered (15 mg/kg) once daily post 1 and 2 weeks of iodoacetate injection in two groups, respectively, for up to 12 weeks. Articular cartilage and subchondral bone of the rats of both groups were examined after 8 and 12 weeks, respectively. Quantitative histological analyses were performed by scoring these sections as per the OARSI system. Chondroitin sulfate was also estimated in articular cartilage by decrease in absorbance of methylene blue on complexation with chondroitin sulfate using a spectrophotometer. Intra-articular injection of iodoacetate induced loss of articular cartilage with progressive subchondral bone sclerosis and degeneration. Based on histopathological and biochemical findings, diacerein treatment showed chondroprotective effect. Furthermore, the chondroprotective effect of diacerein was found to be more pronounced after 12 weeks as compared to 8 weeks in both cases (i.e., post 1 and 2 weeks of iodoacetate injection). Similar results were observed by investigation of chondroitin sulfate during biochemical study, showing the chondroprotective effect. In conclusion, diacerein exhibits chondroprotective effect in rats with late onset of action.     

A cadaveric investigation into the links between macroscopic and microscopic osteoarthritic changes at the hip

Our objective was to investigate the frequency and distribution of osteoarthritic changes at the hip, including the relationship between osteoarthritic lesions on the femoral head surface and histological changes in articular cartilage, in 12 cadavers. Twelve embalmed cadavers (five males and seven females) were dissected, and the femoral head was removed from both sides (24 femoral heads). Any gross osteoarthritic changes were noted and graded (on a scale of 1-3). A circular disc was then removed from the equator of the femoral head and divided into nine regions. Out of 192 segments, 54 underwent sectioning and staining with haematoxylin and eosin to assess histological changes in cartilage. Osteoarthritis of the hip was present in all cadavers, with all males having bilateral OA and 50% having grade 2 or higher lesions (50% were grade 1), and four of the seven female specimens having bilateral OA and only 7% with grade 2 lesions (with 71% grade 1 and 21% normal). Chondrocyte clustering was most commonly observed in the deep layer of cartilage followed by the intermediate and superficial layers respectively, as the grade of the macroscopic lesion increased. Cartilage injury at the histological level precedes any visible denudation of the femoral head articular cartilage. This study supports the hypothesis that early osteoarthritic changes occur in the deep layer of cartilage near the tide mark and progress superficially concomitant with an overall increase in the osteoarthritic lesion size on the femoral head surface.     

The bovine patella as a model of early osteoarthritis

The bovine patella model has been used extensively for studying important structure–function aspects of articular cartilage, including its degeneration. However, the degeneration seen in this model has, to our knowledge, never been adequately compared with human osteoarthritis (OA). In this study, bovine patellae displaying normal to severely degenerate states were compared with human tissue displaying intact cartilage to severe OA. Comparisons of normal and OA features were made with histological scoring, morphometric measurements, and qualitative observations. Differential interference contrast microscopy was used to image early OA changes in the articular cartilage matrix and to investigate whether this method provided comparable quality of visualisation of key structural features with standard histology. The intact bovine cartilage was found to be similar to healthy human cartilage and the degenerate bovine cartilage resembled the human OA tissues with regard to structural disruption, cellularity changes, and staining loss. The extent of degeneration in the bovine tissues matched the mild to moderate range of human OA tissues; however, no bovine samples exhibited late‐stage OA. Additionally, in both bovine and human tissues, cartilage degeneration was accompanied by calcified cartilage thickening, tidemark duplication, and the advancement of the cement line by protrusions of bony spicules into the calcified cartilage. This comparison of degeneration in the bovine and human tissues suggests a common pathway for the progression of OA and thus the bovine patella is proposed to be an appropriate model for investigating the structural changes associated with early OA.     

Measurement of knee cartilage thickness using MRI: a reproducibility study in a meniscectomized guinea pig model of osteoarthritis

The in vivo precision (reproducibility) of quantitative MRI is of particular importance in osteoarthritis (OA) progression of small magnitude and response to therapy. In this study, three-dimensional high-resolution MRI performed at 7 T was used to assess the short-term reproducibility of measurements of mean tibial cartilage thickness in a meniscectomized guinea pig model of OA. MR image acquisition was repeated five times in nine controls (SHAM) and 10 osteoarthritic animals 3 months after meniscectomy (MNX), in vivo. The animals were then killed for histomorphometric assessment and correlation with the MRI-based measurements. Medial tibial cartilage thickness was measured on MR images using semi-automatic dedicated 3D software developed in-house. The reproducibility of measurements of cartilage thickness was assessed by five repeated MRI examinations with a short recovery delay between examinations (48 h). The computed coefficients of variation were 8.9% for the SHAM group and 8.2% for the MNX group. The coefficients of variation were compatible with expected thickness variations between normal and pathological animals. A positive agreement and significant partial correlation (Spearman r' = 0.74; P < 0.01) between the MRI and histomorphometric data was established. Three-dimensional high-resolution MRI is a promising non-invasive research tool for in vivo follow-up. This modality could be used for staging and monitoring therapy response in small-animal models of OA.     

Autophagy in osteoarthritis

Osteoarthritis is characterized by continuous degeneration of articular cartilage resulting in disability. The death of chondrocytes and the loss of the extracellular matrix are the central peculiarities in cartilage degeneration during osteoarthritis pathogenesis. Autophagy is an essential cellular homeostasis mechanism whereby cellular organelles and macromolecules are recycled to maintain cellular metabolism. Autophagy is reported to be cytoprotective effects for articular cartilage, and osteoarthritis is associated with decreased autophagy. While autophagy is known to be cytoprotective to chondrocytes, its role may vary with differing stages and models of osteoarthritis. Therefore, more in-depth studies on autophagy are needed to determine its impact on cell survival and death in articular cartilage under various in vitro and in vivo conditions. Application of autophagy on osteoarthritis therapeutics will be possible after a profound understanding is established on the role of autophagy in osteoarthritis pathogenesis.     

Wnt signalling in the articular cartilage: A matter of balance

Degradation of the articular cartilage is a hallmark of osteoarthritis, a progressive and chronic musculoskeletal condition, affecting millions of people worldwide. The activation of several signalling cascades is altered during disease development: among them, the Wnt signalling plays a pivotal role in the maintenance of tissue homeostasis. Increasing evidence is showing that its activation needs to be maintained within a certain range to avoid the triggering of degenerative mechanisms. In this review, we summarise our current knowledge about how a balanced activation of the Wnt signalling is maintained in the articular cartilage, with a particular focus on receptor-mediated mechanisms.     

骨性关节炎患者退变软骨及滑膜组织中细胞因子的表达

背景：骨性关节炎的炎症反应是由软骨细胞、滑膜组织分泌的细胞因子所介导的。关节软骨和滑膜组织内含有多种细胞因子,在关节软骨的损伤修复中起着重要的调节作用。 目的：分析软骨细胞、滑膜组织分泌的细胞因子与骨性关节炎发病的关系及影响。 方法：由第一作者应用计算机检索万方数据库(www.wanfangdata.com.cn),PubMed数据库(www.ncbi.nlm.nih.guv/pubmed)检索时间：2005至2010年。检索词为“骨性关节炎,退变,软骨组织,细胞因子”。计算机初检得到146篇文献,阅读标题和摘要进行初筛,排除因研究目的与此文无关的86篇,内容重复性的研究40篇,保留21篇骨性关节炎患者退变软骨及滑膜组织中各种细胞因子作用及影响的相关文献作进一步分析。 结果与结论：细胞因子主要是指活化的免疫细胞和某些基质细胞分泌的一类非特异调节免疫应答和介导炎症反应的小分子蛋白质,包括由淋巴细胞产生的淋巴因子,单核巨噬细胞产生的单核因子及其他细胞因子等。关节滑膜细胞分泌的细胞因子可部分解释骨性关节炎的病理过程,在炎症关节中起着重要的作用。虽然越来越多的学者重视到滑膜细胞、软骨细胞分泌细胞因子的作用,但主要是研究外源性细胞因子对软骨细胞或滑膜细胞的影响,而其内源性细胞因子在骨性关节炎发病中的作用却未广泛开展研究。     

木瓜蛋白酶诱导大鼠膝早期骨关节炎软骨表面的电镜扫描

背景：木瓜蛋白酶注射建立骨性关节炎动物模型是用于骨关节炎防治研究的常用方法之一。 目的：观察木瓜蛋白酶和L-半胱氨酸混合注射诱导大鼠膝早期骨关节炎进程中扫描电镜下软骨表面形态学变化。 方法：2%木瓜蛋白酶和0.03 mol/L左旋半胱氨酸按2∶1比例混匀,取0.15 mL注射至SD大鼠右膝关节腔诱导骨关节炎模型,左膝注射等量生理盐水为对照组,另取2只4膝不做处理为正常对照组,于注射后第2,4,6周后分别使用扫描电镜观察股骨内侧髁关节软骨表面形态学变化。 结果与结论：正常和对照组可见表面分布较均匀的浅坑。木瓜蛋白酶和L-半胱氨酸混合注射2周后大鼠软骨表面出现凹凸不平,皱缩扭曲变形;4周表面变薄,局部出现小裂纹;6周出现深大裂纹,软骨缺损。提示2%木瓜蛋白酶和0.03 mol/L左旋半胱氨酸混合注射诱导的早期骨关节炎模型的时间节点可以定在4-6周。 中国组织工程研究杂志出版内容重点：组织构建;骨细胞;软骨细胞;细胞培养;成纤维细胞;血管内皮细胞;骨质疏松;组织工程全文链接：     

Effects of growth and exercise on composition, structural maturation and appearance of osteoarthritis in articular cartilage of hamsters

Articular cartilage composition and structure are maintained and remodeled by chondrocytes under the influence of loading. Exercise‐induced changes in the composition, structure, mechanical properties and tissue integrity of growing and aging hamster articular cartilage were investigated. Articular cartilage samples (n = 191) were harvested from the proximal tibiae of hamsters aged 1, 3, 6, 12 and 15 months. The hamsters were divided into runners and controls. The runners had free access to a running wheel between 1 and 3 months (runner groups 3‐, 12‐ and 15‐month‐old hamsters) or 1 and 6 months (runner group 6‐month‐old hamsters) of age. Control animals were subjected to a sedentary lifestyle. Mechanical indentation tests and depth‐wise compositional and structural analyses were performed for the cartilage samples. Furthermore, the integrity of articular cartilage was assessed using histological osteoarthritis grading. Exercise affected the collagen network organization after a 5‐month exercise period, especially in the middle and deep zones. However, no effect on the mechanical properties was detected after exercise. Before the age of 12 months, the runners showed less osteoarthritis than the controls, whereas at 15 months of age the situation was reversed. It is concluded that, in hamsters, physical exercise at a young age enhances cartilage maturation and alters the depth‐wise cartilage structure and composition. This may be considered beneficial. However, exercise at a young age demonstrated adverse effects on cartilage at a later age with a significant increase in the incidence of osteoarthritis.     

Diffuse tibiofemoral cartilage change prior to the development of accelerated knee osteoarthritis: Data from the osteoarthritis initiative

We compared the spatial distribution of tibiofemoral cartilage change between individuals who will develop accelerated knee osteoarthritis (KOA) versus typical onset of KOA prior to the development of radiographic KOA. We conducted a longitudinal case–control analysis of 129 individuals from the Osteoarthritis Initiative. We assessed the percent change in tibiofemoral cartilage on magnetic resonance images at 36 informative locations from 2 to 1 year prior to the development of accelerated (n = 44) versus typical KOA (n = 40). We defined cartilage change in the accelerated and typical KOA groups at 36 informative locations based on thresholds of cartilage percent change in a no KOA group (n = 45). We described the spatial patterns of cartilage change in the accelerated KOA and typical KOA groups and performed a logistic regression to determine if diffuse cartilage change (predictor; at least half of the tibiofemoral regions demonstrating change in multiple informative locations) was associated with KOA group (outcome). There was a non‐significant trend that individuals with diffuse tibiofemoral cartilage change were 2.2 times more likely to develop accelerated knee OA when compared with individuals who develop typical knee OA (OR [95% CI] = 2.2 [0.90–5.14]. Adults with accelerated or typical KOA demonstrate heterogeneity in spatial distribution of cartilage thinning and thickening. These results provide preliminary evidence of a different spatial pattern of cartilage change between individuals who will develop accelerated versus typical KOA. These data suggest there may be different mechanisms driving the early structural disease progression between accelerated versus typical KOA. Clin. Anat. 32:369–378, 2019. © 2018 Wiley Periodicals, Inc.     

A method for quantifying time dependent changes in MR signal intensity of articular cartilage as a function of tissue deformation in intact joints

A method is proposed to determine accurately the signal intensity changes of the articular cartilage from sectional MR images and its related cartilage deformation under compression in an intact joint. Image processing methods are developed to delineate and register the cartilage boundaries in consecutive MR images in order to track corresponding tissue sectors during the loading experiment. Regions of interest can then be defined and traced during the compression, making a spatial and temporal analysis of signal intensity changes possible. In addition, the cartilage deformation is calculated in the respective tissue sectors and is related to the MR signal changes. Using a fat-suppressed FLASH 3D sequence, the preliminary results showed location-dependent slight changes of the signal intensity varying from individual to individual. The quantitative analysis of the signal intensity changes as a function of cartilage deformation with magnetic resonance imaging (MRI) aims to characterize microstructural properties of the articular cartilage that may lead to a better understanding of degenerative joint disease.     

The electron microscope appearance of the subchondral bone plate in the human femoral head in osteoarthritis and osteoporosis

The subchondral bone plate supports the articular cartilage in diarthrodial joints. It has a significant mechanical function in transmitting loads from the cartilage into the underlying cancellous bone and has been implicated in the destruction of cartilage in osteoarthritis (OA) and its sparing in osteoporosis (OP), but little is known of its composition, structure or material properties. This study investigated the microscopic appearance and mineral composition of the subchondral bone plate in femoral heads from patients with OA or OP to determine how these correspond to changes in composition and stiffness found in other studies. Freeze-fractured full-depth samples of the subchondral bone plate from the femoral heads of patients with osteoarthritis, osteoporosis or a matched control group were examined using back scattered and secondary emission scanning electron microscopy. Other samples were embedded and polished and examined using back-scattered electron microscopy and electron probe microanalysis. The appearances of the samples from the normal and osteoporotic patients were very similar, with the subchondral bone plate overlayed by a layer of calcified cartilage. Osteoporotic samples presented a more uniform fracture surface and the relative thicknesses of the layers appeared to be different. In contrast, the OA bone plate appeared to be porous and have a much more textured surface. There were occasional sites of microtrabecular bone formation between the trabeculae of the underlying cancellous bone, which were not seen in the other groups, and more numerous osteoclast resorption pits. The calcified cartilage layer was almost absent and the bone plate was apparently thickened. The appearance of the osteoarthritic subchondral bone plate was, therefore, considerably different from both the normal and the osteoporotic, strongly indicative of abnormal cellular activity.     

Mild degenerative changes of hip cartilage in elderly patients: an available sample representative of early osteoarthritis

This study investigated the cellular and molecular changes which occur in cartilage from adults with femoral neck fracture (FNF) and osteoarthritis (OA), and explored the similarities in hip cartilage obtained from elderly patients and patients with early OA. Femoral heads were retrieved from 23 female patients undergoing total hip arthroplasty (THA). This group included 7 healthy patients with FNF (hFNF), 8 elderly adults with FNF (eFNF), and 8 elderly patients with hip OA (OA). After high-field MRI T2 mapping, osteochondral plugs were harvested from the weight-bearing area of femoral heads for subsequent macroscopic, histologic, and immunochemical evaluation. Additionally, the contents of cartilage matrix were analyzed, and gene expression was detected. The surface of cartilage from hFNF and eFNF patients appeared smooth, regular, and elastic, whereas it showed irregularities, thinning, and defects in OA patients. Elevated T2 values and decreased accumulation of glycosaminoglycans (GAGs) were detected in cartilage from eFNF patients. Furthermore, type I collagen accumulation was slightly increased and type X collagen concentration was obviously elevated in eFNF patients; however, type II collagen distribution and the contents and anisotropy of collagen fibrils in eFNF patients showed no significant changes. Consistent with histology and immunohistochemical results, aggrecan was downregulated and type X collagen was upregulated, while collagens types I and II showed no significant changes in eFNF patients. The cellular and molecular characteristics of hip cartilage in eFNF patients who showed no symptoms of OA were similar to those in patients with mild OA. Thus, eFNF cartilage can serve as a comparative specimen for use in studies investigating early OA.     

淫羊藿苷治疗骨性关节炎过程中对关节软骨、软骨下骨、滑膜等影响的机制

文题释义： 淫羊藿苷：为淫羊藿干燥茎叶的提取物,呈淡黄色针状结晶粉末, 相对分子质量为676.65, 属黄铜类化合物,现代药理学研究发现其具有很强的生物活性, 对骨组织、免疫系统、肿瘤组织、神经系统、生殖系统、内分泌系统和心血管系统等具有显著作用。 滑膜：是关节囊的内层。滑膜呈淡红色,平滑闪光,薄而柔润,由疏松结缔组织组成,其功能是制造和调节滑液等。滑膜直接附着于关节软骨的边缘并向内贴附在关节囊内的非关节区域,覆盖在关节囊、关节内韧带、骨与肌腱表面。滑膜分泌滑液,在关节活动中起重要作用。背景：淫羊藿苷是具有补肾强筋健骨功效的淫羊藿的主要有效成分,近年来大量的研究发现淫羊藿苷在治疗骨性关节炎方面有着显著作用。 目的：综述淫羊藿苷治疗骨性关节炎的分子机制研究进展。 方法：第一作者应用计算机以“Icariin、Osteoarthritis、Cartilage、Subchondral bone、Synovial membrane 、Synovium、Inflammation”及“淫羊藿苷、骨关节炎、骨性关节炎、软骨、软骨下骨、滑膜、炎症”作为主题词检索PubMed、中国知网、万方、维普等数据库相关文献,按入选标准及排除标准进行筛选,最终纳入42篇文献进行分析。 结果与结论：淫羊藿苷通过促进骨髓间充质干细胞的成软骨分化及增强软骨细胞和成骨细胞的增殖,抑制软骨细胞外基质的降解、降低破骨细胞的活性和减轻炎症因子所致的滑膜炎症反应来有效的治疗骨性关节炎。但其最佳有效剂量及浓度安全性仍需要大量实验研究,目前绝大部分实验仍停留在动物及组织细胞等基础实验,尚需要大量临床研究,继续完善其具体机制,以期为淫羊藿苷治疗骨关节炎提供循证医学证据。ORCID:0000-0002-2013-743X(余绍涌)中国组织工程研究杂志出版内容重点：组织构建;骨细胞;软骨细胞;细胞培养;成纤维细胞;血管内皮细胞;骨质疏松;组织工程     

Effectiveness of an aquatic exercise program and low-level laser therapy on articular cartilage in an experimental model of osteoarthritis in rats

Objective: The aim of this study was to evaluate the effects of an aquatic exercise program and low-level laser therapy (LLLT) (associated or not) on degenerative modifications and inflammatory mediators on the articular cartilage using an experimental model of knee OA. Method: Forty male Wistar rats were divided into 4 groups: knee OA – without treatment (OA); OA plus exercise program group (OAE); OA plus LLLT (OAL); OA plus exercise program associated with LLLT (OAEL). Trained rats performed a water-jumping program carrying a load equivalent to 50-80 % of their body mass strapped to their chest. The laser irradiation was used either as the only method or after the exercise training had been performed, at 2 points contact mode (medial and lateral side of the left joint). The treatments started 4 weeks after the surgery, 3 days/week for 8 weeks. Results: The results revealed that all treated groups (irradiated or not) exhibited a better pattern of tissue organization, with less fibrillation and irregularities along the articular surface and improved chondrocytes organization. Also, a lower cellular density and structural damage (OARSI score) and higher thickness values were observed in all treated groups. Additionally, OAE and OAEL showed a reduced expression in IL-1β and caspase-3 as compared with OA. Furthermore, a statistically lower MMP-13 expression was only observed in OAEL as compared with OA. Conclusion: These results suggest that aquatic exercise program and LLLT were effective in preventing cartilage degeneration. Also, physical exercise program presented anti-inflammatory effects in the knees in OA rats.     

吻合静脉外减张法在不缩短指骨、保留远指间关节的断指再植术中的应用

目的 探讨吻合静脉外减张法在不缩短指骨、保留远指间关节的断指再植术中的临床应用价值。方法 系列病例报告。纳入2016年1月—2021年6月徐州仁慈医院手显微外科利器切割致单指远节完全离断患者8例,其中男5例、女3例,年龄3~57岁、平均29.7岁,3例自远侧指间关节平面完全离断、5例为累及远侧指间关节面的远节基底部斜行完全离断,示指2例、中指4例、环指和小指各1例,缺血时间1~10 h。8例患者均行不短缩指骨、保留远指间关节、直接吻合血管的断指再植术,术中采用吻合静脉外减张法降低静脉吻合口的张力。术后观察患者再植指血运及成活情况,术后随访期间观察再植指的外形、饱满度、静态两点辨距觉、关节活动度等,并依据《中华医学会手外科学会上肢部分功能评定试用标准》对其进行功能评价。结果 8例患者断指再植术中,均通过静脉外减张法降低了静脉吻合口的张力,手术均顺利完成。患者术后恢复良好,伤口均一期愈合,未出现血管危象,再植8指均完全成活。7例术后获得6~18个月随访,另1例失访。7例患者末次随访时,见手术瘢痕细小,再植指体饱满,其长度、外形、远侧指间关节活动度均与健侧相似,两点辨距觉为3~5 mm,患侧手功能评价均为优。结论 对于利器切割致远侧指间关节平面离断或累及远侧指间关节面的远节近端离断的断指患者,在行不短缩指骨、保留远侧指间关节、直接吻合血管的断指再植术修复时,采用吻合静脉外减张法可有效降低皮下静脉吻合口的张力、促进静脉血液回流,有利于再植指体的成活以及外形和功能的恢复。     

Early Cartilage Degeneration in a Rat Experimental Model of Developmental Dysplasia of the Hip

Osteoarthritis (OA) is a common long-term complication of developmental dysplasia of the hip (DDH) that is associated with a higher incidence of OA. In addition, the age of onset of OA in DDH patients is significantly younger than in the general population. In order to investigate the early degeneration in DDH cartilage, we used a rat DDH model that was established by the straight-leg swaddling position. The hips were isolated from the DDH model rats and an untreated control group at postnatal weeks 2, 4, 6, and 8. Histology and proteoglycan levels were observed in articular cartilage using Safranin O staining. Biomarkers of cartilage degeneration, including type X collagen and matrix metalloproteinase (MMP)-13, were assessed using immunohistochemistry and quantitative real-time polymerase chain reaction. In addition, expressions of ADAMTS-4 and ADAMTS-5 were studied using quantitative real-time polymerase chain reaction at different ages. DDH rats showed decreased proteoglycans and derangement of chondrocytes when compared with the control group. Collagen X and MMP-13 expressions were higher in the superficial zone of DDH rats than in that of controls (p < 0.05), and the increase was age-dependent. mRNA expression of Collagen X and MMP-13 showed similar results (p < 0.05). A significant increase in mRNA expression of ADAMTS-5 was found in the DDH model cartilage at 8 weeks (p < 0.05). However, no change was observed in ADAMTS-4 expression. This study shows that degenerative cartilage changes occur at an early stage in the rat DDH model and become aggravated with age.     

Development of a microcomputed tomography scoring system to characterize disease progression in the Hartley guinea pig model of spontaneous osteoarthritis

Aim: There is potential discrepancy between human and laboratory animal studies of osteoarthritis (OA), as radiographic assessment is the hallmark of the former and histopathology the standard for the latter. This suggests a need to evaluate OA in animal models in a manner similar to that utilized in people. Our study aimed to develop a whole joint grading scheme for microcomputed tomography (microCT) images in Hartley guinea pigs, a strain that recapitulates joint changes highlighted in human spontaneous OA. Materials and Methods: Knees from animals aged 2, 3, 5, 9, and 15 months were evaluated via whole joint microCT and standard histologic scoring. Quantitative microCT parameters, such as bone volume/total volume were also collected. Results: Both whole joint microCT and histologic scores increased with advancing age and showed strong correlation (r = 0.89. p < 0.0001). Histologic scores, which focus on cartilage changes, increased progressively with age. Whole joint microCT scores, which characterize bony changes, followed a stepwise pattern: scores increased between 3 and 5 months of age, stayed consistent between 5 and 9 months, and worsened again between 9 and 15 months. Conclusions: This work provides data that advocates the use of a whole joint microCT scoring system in guinea pig studies of OA, as it provides important information regarding bony changes that occur at a different rate than articular cartilage changes. This grading scheme, in conjunction with histology and quantitative microCT measurements, may enhance the translational value of this animal model as it pertains to human work.     

A cadaveric study of the structural anatomy of the sternoclavicular joint

Pathologies of the sternoclavicular (SC) joint are infrequent and effective management is often hindered by a limited understanding of the anatomy. In this study, we did macroscopic evaluations of the ligaments, the intra‐articular disc, and the articulating surfaces of 25 SC joints. After removal of the joint capsule, the articulating surfaces of the sternal end of clavicle and the sternum were evaluated and the intra‐articular disc was macroscopically examined. The anterior SC ligament covered the intra‐articular disc, which divided the joint into a clavicular and a sternal part. A thin capsule, relatively lateral and medial from the anterior SC ligament, covered the two intra‐articular parts. This means that the anterior SC ligament can be used as a landmark to enter into clavicular or sternal part of the SC joint. Posteriorly, there was a thick capsule without soft‐spot or clear posterior SC ligament. Only the antero‐inferior surface of the sternal end of every clavicle was covered by cartilage. Of the intra‐articular discs 56% were incomplete. All of these incomplete discs displayed a central hole with signs of degeneration and fraying. This was associated with increased cartilage degeneration at the clavicular side. By experimental design (past and present), it would seem reasonable to assume that the incomplete types are caused by degeneration and are not developmental. Clin. Anat. 25:903–910, 2012. © 2012 Wiley Periodicals, Inc.