Modified Mankin Score Research Articles

A novel Osteoarthritis scoring system to separate typical OA joint degeneration from non-typical lesions in male Sprague Dawley rats

ObjectiveTo develop a novel scoring system to characterize osteoarthritis-related degeneration distinct from spontaneous subchondral bone lesions observed in the tibia and femur of male Sprague Dawley rats. MethodKnee joints from male rats following 12 weeks of a diet-induced obesity model of osteoarthritis (OA) were assessed. OA histopathological changes (OAHC) were assessed in the knee joints. All scores were evaluated using a modified Mankin score and a modified Osteoarthritis Research Society International histological score. OAHC were divided into 3 categories: (I) Typical OA score evaluating the changes in cartilage structure, cellularity, proteoglycan depletion, and tidemark integrity, (II) A novel Non-typical OA score evaluating cartilage integrity, and the size of local thickening, fragmentation and degeneration along the tidemark and the size and severity of the subchondral bone lesion, and (III) Total OA score comprised of both, the Typical and the Non-typical scores. ResultsRats exposed to a high fat/high sucrose diet had higher Typical OA score compared to a control group (Chow). Non-typical and Total OA scores revealed no differences in the severity of the lesions between the HFS and the Chow group animals. All scoring systems had excellent intra- and inter-examiner reliability. ConclusionThe spontaneous bone lesions observed in male Sprague Dawley rats can obscure the effect of the diet-induced obesity if the classical scoring system is used to assess joint degeneration. The newly proposed scoring method provides a reliable method to distinguish classical OA joint degeneration from spontaneous Non-typical lesions occurring in these rats.

The Hounsfield Unit Values of Talar Subchondral Bone Predict Articular Cartilage Degeneration in Patients With Ankle Osteoarthritis.

Therapeutic strategies for ankle osteoarthritis (OA) are determined based on OA staging, alignment, and articular cartilage conditions. However, it is difficult to evaluate the degeneration of the remaining cartilage using imaging modalities. Subchondral bone plays a crucial role in maintaining cartilage homeostasis. Measurement of local Hounsfield unit (HU) values allows for the quantitative assessment of small changes in the subchondral bone. This study aimed to evaluate a relationship between the HU values of the subchondral bone and the histologic findings of articular cartilage in ankle OA. The talar articular surface was harvested from 14 ankles during arthroplasty. The talus was divided into anterior, middle, and posterior parts, and histologic specimens were prepared. Safranin O staining was performed and histologic findings were evaluated using the modified Mankin score. The regions of interest (ROIs) were set in the medial, central, and lateral regions of the specimens and computed tomography (CT) images, and the relationship between the HU values and histologic findings was analyzed. As OA progressed, cartilage defects increased. In conjunction with cartilage degeneration, the subchondral bone plate thickened, and the HU values increased. The HU value significantly and positively correlated with the modified Mankin score (r = 0.756), subchondral bone thickness (r = 0.674, P < .01), and trabecular bone area (r = 0.637). The cutoff HU values were 594 (sensitivity, 0.813; specificity, 0.944) for 3 points and 727 (sensitivity, 0.929; specificity, 0.782) for 11 points on the modified Mankin score. Significant correlations between HU values and cartilage degeneration in ankle OA were noted. Measuring HU values on CT images can be useful for evaluating the joint surface condition, including histologic findings of the remaining cartilage.

Micro-Computed Tomography Analysis of the Knee in Aged Dunkin-Hartley Guinea Pigs after Intra Articular Injection.

The purpose of this protocol is to guide researchers in performing a palpation-guided technique of intra-articular knee injection in guinea pigs and assessment using micro-computed tomography. Dunkin-Hartley guinea pigs are robust models for osteoarthritis research as they spontaneously develop osteoarthritis in their knees. Intra-articular drug delivery is a common method to study the effects of an investigational drug in vivo. In humans, therapeutic agents administered via intra-articular injection can offer pain relief and delay further progression of osteoarthritis. As with any species, the introduction of a needle into a joint space has the potential to cause injury, which can result in pain, lameness, or infection. Such adverse events can compromise animal welfare, confound study results, and necessitate additional animals to achieve study objectives. As such, it is imperative to develop proper injection techniques to prevent complications, especially in longitudinal studies that require multiple, repeated intra-articular injections. Using the presented methodology, five guinea pigs received bilateral knee injections under general anesthesia. Seven days after injection, animals were humanely euthanized for analysis of osteoarthritis severity. No adverse events occurred following anesthesia or knee injections, including limping, pain, or infection. X-ray micro-computed tomography analysis of the knee can detect pathologic changes associated with osteoarthritis. Micro-computed tomography data indicates osteoarthritis is more severe in older animals, as indicated by increased bone mineral density and trabecular thickness with age. These results are consistent with histologic changes and Modified Mankin scores, an established and widely used scoring system to assess arthritis severity in these same animals. This protocol can be utilized to refine intra-articular injections in guinea pigs.

CHONDROCYTE-SPECIFIC KNOCKOUT OF PIEZO ION CHANNELS PROTECTS AGAINST POST-TRAUMATIC OSTEOARTHRITIS

Osteoarthritis (OA) is the leading cause of pain and disability worldwide and is characterized by the degenerative changes of articular cartilage. Joint loading is required for cartilage maintenance; however, hyper-physiologic loading is a risk factor for OA. Mechanosensitive ion channels Piezo1 and Piezo2 synergistically transduce hyper-physiologic compression of chondrocytes, leading to chondrocyte death and onset of OA. This injury response is inhibited by Piezo channel loss of function, however the mechanistic role of Piezo channels in vivo is unknown. We examined the hypothesis that deletion of Piezo in chondrocytes will protect mice from joint damage and pain-related behaviors following a surgical destabilization of the medial meniscus (DMM), investigating a key mechanistic and mechanobiological role of these channels in the pathogenesis of OA.Aggrecan-Cre Piezo1 and Piezo1/2 knockout mice ((Agc)1-CREERT2;Piezo1fl/flPiezo2fl/fl) were generated and given a 5-day Tamoxifen regimen at 12-weeks of age (n=6–12/group/sex). Cre-negative mice served as controls. At 16-weeks, mice received DMM surgery on the left knee. 12-weeks following DMM prior to sacrifice, activity and hyperalgesia were measured using spontaneous running wheels and a small animal algometer. Structural changes in bone, cartilage, and synovium were characterized using microCT, histology, and Modified Mankin Score criteria.Knockout of Piezo1/2 channels was chondroprotective in both sexes following DMM surgery as demonstrated by reduced Modified Mankin Score compared to control animals. Piezo1 KO was chondroprotective in only female mice, indicating a sexually dimorphic response. Piezo1 and Piezo1/2 KO was protective against pain in male mice, while females displayed no differences compared to controls. No changes were observed in bone morphology.Chondrocyte-specific Piezo1/2 knockout protects the knee joint from structural damage, hyperalgesia and functional deficits in a surgical model of PTOA in male and female mice, illustrating the importance of Piezo channels in response to injury in vivo. Future work aims to interrogate potential sexually dimorphic responses to cartilage damage and investigating Piezo2 KO mice.

Deep Learning Augmented Osteoarthritis Grading Standardization.

Manual grading of cartilage histology images for investigating the extent and severity of osteoarthritis (OA) involves critical examination of the cell characteristics, which makes this task tiresome, tedious, and error prone. This results in wide interobserver variation, causing ambiguities in OA grade prediction. Such drawbacks of manual assessment can be overcome by implementing artificial intelligence-based automated image classification techniques such as deep learning (DL). Hence, we present the feasibility of training a deep neural network with cartilage histology images, which can grade the extent and severity of knee OA based on modified Mankin scoring system. The grading system used here for automating OA grading was simplified and modified based on the microscopic observations from the histology images, where three parameters (Safranin-O staining intensity, chondrocyte distribution and arrangement, and morphology) were considered for evaluating the OA progression. The histology images were tiled, labeled, and grouped together based on the developed grading system (Grade 0-3). Four different DL architectures were tried for image classification and the best performing model was selected by fivefold validation method. With a validation accuracy of ∼84%, 0.632 Cohen's kappa score, and an excellent receiver operating characteristic (ROC)-area under the ROC curve ranging between 0.89 and 0.99, DenseNet121 was selected among the four models as the best performing model, and was used for inferencing on new data. Final grades obtained from the models were in accordance with the grades provided by the medical experts. We hereby demonstrate that a DL architecture can be taught to interpret the degree of cartilage degradation, with excellent discriminatory ability across all four classes of OA severity. Unlike other works where radiographic images have been considered for grading of OA, we have considered histology images, which is a fundamental approach for grading OA extent and severity. This would bring a paradigm shift in histology-based assessment of OA, making this automated approach to be explored as an option for OA grading standardization. Ethical approval number-IAH-BMR-018/10-19.

Characteristics and time points to inhibit ferroptosis in human osteoarthritis

Ferroptosis is a form of cell death that is triggered by iron-dependent lipid peroxidation and is closely associated with osteoarthritis. The primary interventions for inhibiting ferroptosis in osteoarthritis are anti-lipid peroxidation and iron chelation. The objective of our study is to investigate the characteristics of ferroptosis in osteoarthritis and identify the optimal time points for inhibiting ferroptosis to alleviate disease progression. Ferroptosis-related alterations and markers of OA were analyzed in paired intact and damaged cartilages from OA patients by immunofluorescence, qRT-PCR, mitochondrial membrane potential and immunohistochemistry. We also compared Ferroptosis-related alterations in cartilage of mild, moderate, and severe OA (according to the modified Mankin score). In addition, we compared the effect of Fer-1 on ferroptosis and the protection of chondrocytes by detecting markers of both ferroptosis and OA by immunofluorescence, CCK8 and qRT-PCR. Ferroptosis-related alterations (GPX4 downregulation, ACSL4 upregulation, MDA, LPO accumulation, Mitochondrial membrane potential decreased) in the damaged area cartilage were more severe than those in the intact area and increased with the progression of OA. Compared with mild OA group, the activity of chondrocytes treated with Fer-1 (a ferroptosis inhibitor) was increased, mitochondrial function was improved, and ferroptosis was reduced (GPX4 upregulation, SLC7A11 upregulation, ACSL4 downregulation,), and promoted the expression of COL2A1 and inhibited the expression of MMP13. However, these changes were not observed in moderate and severe OA chondrocytes. Ferroptosis occurs in a region-specific manner and is exacerbated with the progression of human OA cartilage degeneration. Inhibition of ferroptosis might had a therapeutic effect on chondrocytes with mild OA but had no significant therapeutic effect on chondrocytes with moderate to severe OA.

Correlation of expression of silencing information regulator 2 related enzyme 1 and tumor necrosis factor-like weak inducer of apoptosis in articular effusion and knee osteoarthritis

To analyze the correlation between the expression of silencing information regulator 2 related enzyme 1 (SIRT1), tumor necrosis factor like weak inducer of apoptosis (TWEAK) and knee osteoarthritis. Total of 103 patients with knee joint (knee osteoarthritis group) from February 2019 to August 2021 were selected including 40 males and 63 females with an average age of (62.02±6.09) years;according to the modified Mankin score, 103 patients were divided into mild group (Mankin score 1-4 points, 31 cases) and moderate group (Mankin score 5-8 points, 40 cases) and severe group (Mankin score ≥9, 32 cases). Another 105 physical examination volunteers were selected as the control group including 46 males and 59 females with an average age of (62.11±6.34) years old. The levels of SIRT1 and TWEAK in articular effusion and serum were detected in the knee osteoarthritis group, while serum SIRT1 and TWEAK were detected in the control group only. The relationship between SIRT1, TWEAK and the occurrence and disease of knee osteoarthritis were analyzed. Articular cavity fluid TWEAK, serum TWEAK, CRP, IL-6, IL-1β, white blood cell count and ESR were higher than those in the control group(P<0.05), articular cavity fluid SIRT1 and serum SIRT1 were lower than those in the control group(P<0.05). TWEAK level in the severe group was higher than that in the moderate and mild groups(P<0.05), SIRT1 was lower than that in the moderate and mild groups (P<0.05). The level of SIRT1 in articular cavity effusion was positively correlated with the serum level of SIRT1 (P<0.05), and negatively correlated with CRP, IL-6, IL-1β, white blood cell count, modified Mankin score and ESR (P<0.05). TWEAK level in articular cavity fluid was positively correlated with serum TWEAK level (P<0.05), C-reactive protein(CRP), interleukin(IL)-6, IL-1β, white blood cell count, modified Mankin score and erythrocyte sedimentation rate(ESR) (P<0.05). Body mass index, undertaking heavy physical work, and articular cavity fluid TWEAK were risk factors for the occurrence of knee osteoarthritis(P<0.05), and articular cavity fluid SIRT1 was a protective factor for the occurrence of knee arthritis (P<0.05). The area under curve(AUC) of SIRT1 and TWEAK for knee osteoarthritis was 0.641 and 0.653, and the AUC of SIRT1 and TWEAK for knee osteoarthritis was 0.879, which was higher than SIRT1 and TWEAK alone (z=6.105 and 6.225, P<0.05). The level of SIRT1 in articular fluid in patients with knee arthritis is decreased and the level of TWEAK is increased. Low SIRT1 and high TWEAK are associated with the onset and exacerbation of knee osteoarthritis.

Clock gene Per1 regulates rat temporomandibular osteoarthritis through NF-κB pathway: an in vitro and in vivo study

PurposeTemporomandibular joint osteoarthritis (TMJOA) is a common disease that negatively affects the life quality of human beings. Circadian rhythm acts an important role in life activities. However, whether the clock genes are rhythmic expressed in mandibular condylar chondrocytes, or the clock genes have an effect on the progression of TMJOA remains unknown. In this study, we aim to explore expression of clock genes and regulatory mechanism of TMJOA in rat mandibular condylar chondrocytes.MethodsAfter synchronized by dexamethasone, the expression of core clock genes Per1, Per2, Clock, Cry1, Cry2 and Bmal1 and cartilage matrix degrading factor gene Mmp13 were analyzed in mandibular condylar chondrocytes every 4 h with RT-qPCR. The mandibular condylar chondrocytes were stimulated with IL-1β, and expression of Per1, Mmp13, P65 and p-P65 was assessed by RT-qPCR and Western blot. Sh-Per1 lentivirus was used to assess the effect of clock gene Per1 in IL-1β-induced chondrocytes, and expression of Mmp13, P65 and p-P65 was measured. After establishing a rat TMJOA model using unilateral anterior crossbite (UAC), micro-CT, H & E, Alcian Blue & Nuclear Fast Red and Safranin O & Fast Green, cartilage thickness was utilized to assess the damage of cartilage and subchondral bone. Immunohistochemistry of PER1, MMP13 and P65 was performed in condylar sections.ResultsAll core clock genes and Mmp13 were rhythmically expressed. And Mmp13 expression curve was closed in phase and amplitude with Per1. After stimulation with IL-1β, the expression of MMP13, PER1 and P65 and ratio of p-P65/P65 increased in condylar chondrocytes. After Per1 was down-regulated in condylar chondrocytes, the expression of MMP13 and P65 and ratio of p-P65/P65 decreased. Compared with the condyles of Sham group, the bony parameters of UAC group were significantly worse. The thickness of cartilage in UAC group significantly reduced. The modified Mankin scores and the expression of PER1, MMP13 and P65 in cartilage of UAC group significantly increased compared with Sham group.ConclusionCore clock genes and Mmp13 are rhythmic expressed in rat mandibular condylar chondrocytes. PER1 can regulate the expression of MMP13 through NF-κB pathway in IL-1β-induced mandibular condylar chondrocytes.

TLR4 antagonism provides short-term but not long-term clinical benefit in a full-depth cartilage defect mouse model

ABSTRACT Purpose/Aim Cartilage injury and subsequent osteoarthritis (OA) are debilitating conditions affecting millions worldwide. As there are no cures for these ailments, novel therapies are needed to suppress disease pathogenesis. Given that joint injuries are known to produce damage-associated molecular patterns (DAMPs), our central premise is that the Toll-like receptor 4 (TLR4) pathway is a principal driver in the early response to cartilage damage and subsequent pathology. We postulate that TLR4 activation is initiated/perpetuated by DAMPs released following joint damage. Thus, antagonism of the TLR4 pathway immediately after injury may suppress the development of joint surface defects. Materials and Methods Two groups were utilized: (1) 8-week-old, male C57BL6 mice treated systemically with a known TLR4 antagonist and (2) mice injected with vehicle control. A full-depth cartilage lesion on the midline of the patellofemoral groove was created in the right knee of each mouse. The left knee was used as a sham surgery control. Gait changes were evaluated over 4 weeks using a quantitative gait analysis system. At harvest, knee joints were processed for pathologic assessment, Nanostring® transcript expression, and immunohistochemistry (IHC). Results Short-term treatment with a TLR4 antagonist at 14-days significantly improved relevant gait parameters; improved cartilage metrics and modified Mankin scores were also seen. Additionally, mRNA expression and IHC showed reduced expression of inflammatory mediators in animals treated with the TLR4 antagonist. Conclusions Collectively, this work demonstrates that systemic treatment with a TLR4 antagonist is protective to further cartilage damage 14-days post-injury in a murine model of induced disease.

The healing effects of L-carnitine and spongostan on cartilage defect in rat model

PurposeWe aimed to determine the effect of L-carnitine and spongostan on cartilage healing in an experimental animal model with a full-thickness cartilage defect. MethodsIn the study 32 Sprague–Dawley rats were divided into four groups in equal numbers. A cartilage defect with a diameter of 1 mm and a depth of 3 mm was created in the femoral intercondylar region of rats in groups A, B, and C. Group A received no treatment in the defective area. Group B received treatment with spongostan. Group C received treatment with spongostan soaked in L-carnitine. Group D served as the healthy control group. The rats were euthanized 6 weeks after the treatment. Histological evaluation of the condyles was done with the modified Mankin scoring. ResultsIn the histopathological imaging of the cartilage structure, it was observed that in group A, there was complete disorganization and cellular structure was completely absent up to the subchondral bone. In group B, moderate structural improvement, partially intact appearance in border integrity and mostly diffuse hypercellularity were observed. In group C, a near-normal healing, a completely intact appearance in boundary integrities and normal or hypercellularity in cellular structure were observed. The total score of the modified Mankin decreases numerically from A to D. There was no statistically significant difference observed between the A-B (p = 0.176), C-D (p = 0.145), and C-B (p = 0.580) groups, while significant differences were detected between the A–C (p = 0.004), B–D (p = 0.007), and A–D (p = 0.000) groups. ConclusionIt has been known that mitochondrial activity is reduced in the osteoarthritis, and as a result, decrease in cellular activity occurs with ATP synthesis. For this reason, we found that L-carnitine, which we expect to stimulate cell proliferation by stimulating ATP synthesis, makes a positive contribution to cartilage healing, as expected. It has been found that combining spongostan with L-carnitine for the treatment of cartilage healing, instead of applying spongostan alone, provides near-normal healing.

Spatial distribution of elements during osteoarthritis disease progression using synchrotron X-ray fluorescence microscopy

The osteochondral interface is a thin layer that connects hyaline cartilage to subchondral bone. Subcellular elemental distribution can be visualised using synchrotron X-ray fluorescence microscopy (SR-XFM) (1 μm). This study aims to determine the relationship between elemental distribution and osteoarthritis (OA) progression based on disease severity. Using modified Mankin scores, we collected tibia plates from 9 knee OA patients who underwent knee replacement surgery and graded them as intact cartilage (non-OA) or degraded cartilage (OA). We used a tape-assisted system with a silicon nitride sandwich structure to collect fresh-frozen osteochondral sections, and changes in the osteochondral unit were defined using quantified SR-XFM elemental mapping at the Australian synchrotron's XFM beamline. Non-OA osteochondral samples were found to have significantly different zinc (Zn) and calcium (Ca) compositions than OA samples. The tidemark separating noncalcified and calcified cartilage was rich in zinc. Zn levels in OA samples were lower than in non-OA samples (P = 0.0072). In OA samples, the tidemark had less Ca than the calcified cartilage zone and subchondral bone plate (P < 0.0001). The Zn–strontium (Sr) colocalisation index was higher in OA samples than in non-OA samples. The lead, potassium, phosphate, sulphur, and chloride distributions were not significantly different (P > 0.05). In conclusion, SR-XFM analysis revealed spatial elemental distribution at the subcellular level during OA development.

Doxycycline Promotes Graft Healing and Attenuates Posttraumatic Osteoarthritis After Anterior Cruciate Ligament Reconstruction in a Rat Model

Background: Doxycycline (Doxy) has been shown to facilitate tendon healing by reducing on-site matrix metalloproteinase (MMP) activity, but its effect on graft healing after anterior cruciate ligament reconstruction (ACLR) has not been investigated, and the therapeutic effect of Doxy in preventing ACLR-induced posttraumatic osteoarthritis (PTOA) is unclear. Hypothesis: Doxy promotes graft healing and alleviates the progression of PTOA after ACLR. Study Design: Controlled laboratory study. Methods: Sprague Dawley rats (n = 74; age, 12-13 weeks; male) that underwent ACLR were divided into untreated control and Doxy treatment (50 mg/kg/d orally until sacrifice) groups. At 2 and 6 weeks after surgery, graft healing was assessed by biomechanical testing, histology, immunohistochemical staining, and micro–computed tomography (μCT). The progression of PTOA was evaluated at 6 weeks by histology, the Mankin score, and immunofluorescence staining of the tibial plateau, and osteophyte formation was evaluated by μCT. Hindlimb weight distribution was evaluated at 6 weeks, and gait patterns were evaluated at 2 and 6 weeks. Intra-articular MMP activity was evaluated at 6 weeks in vivo using an MMP-activatable near-infrared fluorescent probe. Results: Graft healing was enhanced by Doxy treatment, and the ultimate failure load (P = .002) and stiffness of the graft (P = .007) were significantly higher in the Doxy group at week 2. Bone mineral density and bone volume/total volume for both the tibial and the femoral tunnels at week 6 in the Doxy group were significantly higher compared with in the control group (P < .05). The overall graft healing scores were significantly higher in the Doxy group. Doxy treatment enhanced graft integration, intratunnel graft integrity, and collagen birefringence; more collagen types 1 and 10 and less MMP-13 were found at the graft-bone interface. At week 6, the Doxy group had a lower modified Mankin score (P = .033) and showed fewer MMP 13–positive chondrocytes at the articular cartilage surface (P = .002), indicating moderate joint cartilage damage. μCT revealed less osteophyte formation, and gait analysis revealed more symmetric weightbearing and gait patterns, after Doxy treatment at week 6 (P < .05). In vivo imaging with the near-infrared fluorescent probe identified significantly lower intra-articular MMP activity in the Doxy group at week 6 (P = .016). Conclusion: The oral administration of Doxy was able to synchronously promote graft healing and attenuate PTOA in an ACLR rat model. Clinical Relevance: Our results indicated that Doxy, a widely used drug, is potentially beneficial to patients after ACLR.

Functional mass spectrometry imaging maps phospholipase-A2 enzyme activity during osteoarthritis progression.

Background: Enzymes are central components of many physiological processes, and changes in enzyme activity are linked to numerous disease states, including osteoarthritis (OA). Assessing changes in enzyme function can be challenging because of difficulties in separating affected tissue areas that result in the homogenisation of healthy and diseased cells. Direct correlation between spatially-resolved enzyme distribution(s) and diseased cells/tissues can thus lead to advances in our understanding of OA pathophysiology. Herein, we present a method that uses mass spectrometry imaging (MSI) to visualise the distribution of lipase enzymes and their downstream lipid products in fresh bone and cartilage tissue sections. Immunohistostaining of adjacent tissue sections was then used to identify OA cells/tissues, which were then statistically correlated with molecular-level images. Methods: MSI was used to image lipase enzymes, their substrates, and their metabolic products to validate enzymatic activity and correlate to OA regions determined by immunohistochemistry (IHC). Based on the modified Mankin score, six non-OA and OA patient-matched osteochondral samples were analysed by matrix-assisted laser desorption/ionisation mass spectrometry imaging (MALDI-MSI). Due to the involvement of phospholipase A2 (PLA2) in inflammatory pathways, explant tissues were treated with IL-1β to mimic inflammation observed in OA. Bovine explant tissues were then subject to MSI methods to observe the spatial distribution of PLA2. Results: Compared with non-OA samples, OA samples showed an elevated level of multiple arachidonic acid (AA)-containing phospholipids (P < 0.001), in which the elevation in the surface and deep layer cartilage of OA tissues is correlated to elevated PLA2 activity (P < 0.001). Bovine explant tissues treated with IL-1β to mimic OA pathophysiology validated these results and displayed elevated PLA2 levels in OA mimic samples relative to the controls (P < 0.001). It was established that the PLA2G2A isoform specifically was responsible for PLA2 enzyme activity changes in OA tissues (P < 0.001). Conclusion: Our results present a reliable method for imaging enzyme dynamics in OA cartilage, which sets up the foundation for future spatial enzyme dynamics in the OA field. We demonstrated that OA patients exhibit increased expression of PLA2G2A at the superficial and deep cartilage zone that degrades cartilage differently at the spatial level. A tissue-specific PLA2G2A precision inhibition may be the potential target for OA.

Alleviation of cartilage degeneration by laser acupuncture: An ultrasound biomicroscopic study of early postmenopausal osteoarthritis in rats

This study aims to evaluate the therapeutic effects of laser acupuncture (LA) on articular cartilage degradation at the early stage of postmenopausal osteoarthritis (PMOA) by an ultrasound biomicroscopic technology. Twenty-one healthy female Sprague-Dawley rats were randomly and evenly divided into three groups - sham, ovariectomized (OVX) and OVX ​+ ​LA groups. Only the peri-ovarian fatty tissue of the sham rats was exteriorized. The animals in the OVX and OVX ​+ ​LA groups underwent bilateral ovariectomy to create a menopause model. On day 8 after the ovariectomy, the 2-week LA therapy at acupoints Guanyuan (CV-4), Sanyinjiao (SP-6), and Zusanli (ST-36) was performed in the OVX ​+ ​LA group, while the sham and OVX groups had a sham treatment. All the animals were sacrificed on day 22. The cartilage tissues in the left knee joint were examined by ultrasound and histology. Compared with the sham group, the significantly degenerate alterations (p ​< ​0.01) in ultrasound roughness index (URI), reflection coefficient (RC1) and cartilage thickness were found in the OVX group, while the values of these parameters were significantly recovered (p ​< ​0.01) in the OVX ​+ ​LA group. The LA treatment enhanced proteoglycans (PGs) content with a significant reduce of the modified Mankin score (p ​< ​0.01). The acoustic assessment strongly correlated with the histologic evaluation. The results showed that LA treatment could alleviate the postmenopause-induced cartilage degradation and promote tissue repair. LA has potential to be a simple and safe non-pharmacological countermeasure against PMOA for geriatric patient population. The ultrasound biomicroscopic technology could be a quantitative evaluation tool of the structural and morphological responses of articular cartilage to LA intervention.

A Combination of Surgical and Chemical Induction in a Rabbit Model for Osteoarthritis of the Knee.

Appropriate animal models of osteoarthritis (OA) are essential to develop new treatment modalities for OA. A combination of surgical and chemical induction could be appropriate for OA models. Rabbit knee OA models developed by surgical induction (anterior cruciate ligament transection [ACLT]), chemical induction (monosodium iodoacetate [MIA] injection), and a combination of both were compared to assess compositional and structural destruction of the knee joint. Twenty-one New Zealand white rabbits were randomly divided into 3 groups to induce OA (group 1: ACLT, n = 3; group 2: MIA [3, 6, 9mg] injection, n = 9; group 3: ACLT + MIA [3, 6, 9mg] injection, n = 9). In all groups, the Modified Mankin score was significantly higher in the osteoarthritis-induced knee than in the control. Modified Mankin scores were compared by category. The ACLT group was observed to score high in cartilage structure. In the MIA group, chondrocytes and matrix staining showed higher scores, and the ACLT+MIA group scored higher in all categories for cartilage structure, chondrocytes, matrix staining, and tidemark integrity. The ACLT + 3 mg MIA showed definite OA characteristics such as cartilage surface destruction and degeneration of cartilage layers, and the ACLT + 6 mg MIA and ACLT + 9 mg MIA showed more prominent OA characteristics such as cartilage surface destruction, matrix disorganization, and osteophyte formation. The combination of MIA injection and ACLT could be an appropriate method for OA induction in rabbit models.

Effects of Joint Immobilization and Treadmill Exercise on Articular Cartilage After ACL Reconstruction in Rats.

Background:The development of osteoarthritis after anterior cruciate ligament (ACL) reconstruction (ACLR) is an important issue. However, the appropriate rehabilitation protocol to prevent cartilage degeneration due to postoperative osteoarthritis is unclear.Purpose:To examine the effects of joint immobilization and treadmill exercise on articular cartilage after ACLR.Study Design:Controlled laboratory study.Methods:A total of 55 rats received unilateral knee ACL transection and reconstruction surgery using tail tendon autografts. After surgery, rats were reared without intervention, with joint immobilization, or with daily treadmill exercise (12 m/minute, 60 minutes/day, 6 days/week). Treadmill exercise was initiated at 3 or 14 days postoperatively. After 2 weeks of immobilization, the fixation device was removed from some of the immobilized rats, and the knee was allowed to move freely for 2 weeks. Untreated, age-matched rats (n = 8) were used as controls. At 2 or 4 weeks after starting the experiment, cartilage degeneration in the medial tibial plateau was histologically assessed using a modified Mankin score, cartilage thickness, chondrocyte density, and immunohistochemistry for cyclooxygenase-2 (COX-2) in the anterior, middle, and posterior regions.Results:After ACLR, cartilage degeneration in the anterior region characterized by increased Mankin score, accompanied with increased COX-2 expression, was detected. Joint immobilization after ACLR facilitated cartilage degeneration, which is detected by histological changes such as reductions in cartilage thickness, chondrocyte density, and high Mankin scores. Enhanced COX-2 expression in all degenerated cartilage regions was also detected. It was found that 2 weeks of remobilization could not restore cartilage degeneration induced by 2 weeks of immobilization after ACLR. Treadmill exercise after ACLR did not affect most articular cartilage parameters, regardless of the timing of exercise.Conclusion:Our results indicated that (1) immobilization after ACLR accelerates cartilage degeneration, even when applied only for 2 weeks, and (2) mild exercise during early phases after ACLR does not facilitate cartilage degeneration.Clinical Relevance:To reduce cartilage degeneration, periods of joint immobilization after ACLR should be minimized. Mild exercise during the early phases after ACLR will not negatively affect articular cartilage.

Dexamethasone-Loaded Radially Mesoporous Silica Nanoparticles for Sustained Anti-Inflammatory Effects in Rheumatoid Arthritis.

Radially mesoporous silica nanoparticles (RMSNs) with protonated amine functionality are proposed to be a dexamethasone (Dex) carrier that could achieve a sustained anti-inflammatory effect in rheumatoid arthritis (RA). High-capacity loading and a sustained release of target drugs were achieved by radially oriented mesopores and surface functionality. The maximum loading efficiency was confirmed to be about 76 wt%, which is about two times greater than that of representative mesopores silica, SBA-15. In addition, Dex-loaded RMSNs allow a sustained-release profile with about 92% of the loaded Dex for 100 h in vitro, resulting in 2.3-fold better delivery efficiency of Dex than that of the SBA-15 over the same period. In vivo evaluation of the inhibitory effects on inflammation in a RA disease rat model showed that, compared with the control groups, the group treated with Dex-loaded RMSNs sustained significant anti-inflammatory effects and recovery of cartilage over a period of 8 weeks. The in vivo effects were confirmed via micro-computed tomography, bone mineral density measurements, and modified Mankin scoring. The proposed Dex-loaded RMSNs prolonged the life of the in vivo concentrations of therapeutic agents and maximized their effect, which should encourage its application.

Pathological, Morphometric and Correlation Analysis of the Modified Mankin Score, Tidemark Roughness and Calcified Cartilage Thickness in Rat Knee Osteoarthritis after Extracorporeal Shockwave Therapy.

The paper displayed the pathological changes and relationships of the modified Mankin score, tidemark roughness and calcified cartilage (CC) thickness by extracorporeal shockwave therapy (ESWT) (0.25 mJ/ mm2 with 800 impulses) on different positions of the medial and lateral rat knee OA joint. After the experiments, the articular cartilage was assessed using histomorphometry, image analysis and statistical method. In the micro-CT analysis, ESWT on medial groups were better than lateral groups in the trabecular volume and trabecular number. The data showed a strong negative correlation between the modified Mankin score and tidemark roughness (r = -0.941; P < 0.001). In terms of the relationship of tidemark roughness with CC thickness, the medial and Sham groups showed a significant negative correlation (r = -0.788, P = 0.022). Additionally, the Euclidean distance derived from 3D scatter plot analysis was an indicator of chondropathic conditions, exhibiting a strong correlation with OA stage in the articular cartilage of the femur (r = 0.911, P < 0.001) and tibia (r = 0.890, P < 0.001) after ESWT. Principle component analysis (PCA) further demonstrated that ESWT applied to medial locations had a better outcome than treatment at lateral locations for knee OA by comparing with Sham and OA groups, and CC thickness was the most important factor affecting hyaline cartilage repair after ESWT.

EVALUATION OF CHONDROPROTECTIVE EFFECTS OF HYALURONIC ACID IN A RAT MODEL OF OSTEOARTHRITIS

Objective: To evaluate the chondroprotective effects of hyaluronic acid in a rat model of osteoarthritis.&#x0D; Study Design: Laboratory based experimental study.&#x0D; Place and Duration of Study: Department of Pharmacology, Army Medical College, Rawalpindi, in alliance with National Institute of health, Islamabad and Department of Pathology, Army Medical College Rawalpindi, from Apr to Jun 2019.&#x0D; Methodology: Sixteen (16) rats of Sprague Dawley breed were procured in this study. Osteoarthritis was induced in right knee joint of rats by surgical resection of medial meniscus and anterior cruciate ligament. They were allocated into two (02) groups with eight (08) rats in both groups. Group-I was control group that was treated with 0.2 ml intra articular saline once weekly for four weeks. While group-II was treatment group that was intra particularly administered with 0.2ml hyaluronic acid once weekly for four weeks. One week after the last dosage, gait pattern of the animals was scored. Then animals were sacrificed and a part of proximal tibia was obtained for histopathologic analysis.&#x0D; Results: Mean gait score of control group and treatment group was 3.25 ± 0.707 and 1.00 ± 0.756 respectively with a statistically significant p-value of &lt;0.001, while mean histopathological Modified Mankin score of control and treatment group was 11.5 ± 1.195 and 5.50 ± 1.195 respectively with a significant p-value of &lt;0.001.&#x0D; Conclusion: Intra articular viscosupplementation of hyaluronic acid in rat model of osteoarthritis resulted in improved gait pattern and histopathology.

Ultrasound-Based Quantification of Cartilage Damage After In Vivo Articulation With Metal Implants.

ObjectiveThis study aims to evaluate the applicability of the ultrasound roughness index (URI) for quantitative assessment of cartilage quality ex vivo (post-mortem), after 6 months of in vivo articulation with a Focal Knee Resurfacing Implant (FKRI).DesignGoats received a metal FKRI (n = 8) or sham surgery (n = 8) in the medial femoral condyles. After 6 months animals were sacrificed, tibial plateaus were stained with Indian ink, and macroscopic scoring of the plateaus was performed based on the ink staining. The URI was calculated from high-frequency ultrasound images at several sections, covering both areas that articulated with the implant and non-articulating areas. Cartilage quality at the most damaged medial location was evaluated with a Modified Mankin Score (MMS).ResultsThe URI was significantly higher in the FKRI-articulating than in the sham plateaus at medial articulating sections, but not at sections that were not in direct contact with the implant, for example, under the meniscus. The mean macroscopic score and MMS were significantly higher in the FKRI-articulating group than in the sham group (, , respectively). Correlation coefficients between URI and macroscopic score were significant in medial areas that articulated with the implant. A significant correlation between URI and MMS was found at the most damaged medial location ().ConclusionsThis study demonstrates the potential of URI to evaluate cartilage roughness and altered surface morphology after in vivo articulation with a metal FKRI, rendering it a promising future tool for quantitative follow-up assessment of cartilage quality.