Do Synovial Inflammation and Meniscal Degeneration Impact Clinical Outcomes of Patients Undergoing Arthroscopic Partial Meniscectomy? A Histological Study

Correlation of meniscus tear type with synovial inflammation and the therapeutic potential of docosapentaenoic acid

BACKGROUND

Synovitis, characterized by inflammation of the synovial membrane, is commonly induced by meniscus tears. However, significant differences in inflammatory responses and the key inflammatory mediators of synovium induced by different types of meniscal tears remain unclear.

METHODS

Magnetic resonance imaging (MRI) was employed to identify the type of meniscus tear, and the quantification of synovial inflammation was assessed through H&E staining assay. Transcription and expression levels of IL-1β and IL-6 were evaluated using bioinformatics, ELISA, RT-qPCR, and IHC of CD68 staining assays. The therapeutic potential of Docosapentaenoic Acid (DPA) was determined through network pharmacology, ELISA, and RT-qPCR assays. The safety of DPA was assessed using colony formation and EdU staining assays.

RESULTS

The results indicate that both IL-1β and IL-6 play pivotal roles in synovitis pathogenesis, with distinct expression levels across various subtypes. Among tested meniscus tears, oblique tear and bucket handle tear induced the most severe inflammation, followed by radial tear and longitudinal tear, while horizontal tear resulted in the least inflammation. Furthermore, in synovial inflammation induced by specific meniscus tears, the anterior medial tissues exhibited significantly higher local inflammation than the anterior lateral and suprapatellar regions, highlighting the clinical relevance and practical guidance of anterior medial tissues' inflammatory levels. Additionally, we identified the essential omega-3 fatty acid DPA as a potential therapeutic agent for synovitis, demonstrating efficacy in blocking the transcription and expression of IL-1β and IL-6 with minimal side effects.

CONCLUSION

These findings provide valuable insights into the nuanced nature of synovial inflammation induced by various meniscal tear classifications and contribute to the development of new adjunctive therapeutic agents in the management of synovitis.

Arthroscopic Linear Chain Fixation for the Treatment of Medial Meniscus Posterior Root Tear: A Case Study

BACKGROUND

The repair and reconstruction of medial meniscus posterior root tears (MMPRTs) is an important issue in the field of orthopedic sports medicine. This study reports the first application of arthroscopic linear chain fixation for the treatment of MMPRTs.

CASE PRESENTATION

A 78-year-old female patient presented with a 1.5-month history of right knee pain accompanied by a locked facet joint. The patient underwent surgery with the new linear chain fixation method. In this method, the suture and the loop part of the buckle-strap titanium plate were combined into a linear chain mechanical complex, and the tension of the posterior root stump was gradually increased by pulling on the two attachment lines at the external mouth of the tibial tunnel. The postoperative Lysholm score was 89, and the visual analogue scale score was 0.9, indicating a significant improvement in knee joint function. At the 7-month and 1-year post-surgery follow-up, physical and MRI examinations confirmed satisfactory healing of the MMPRTs.

CONCLUSION

This surgical approach offers several benefits, including a simplified instrumentation setup, preservation of natural anatomical structures, and reliable residual stump fixation. It has the potential for clinical implementation.

Mechanistic role of quercetin as inhibitor for adenosine deaminase enzyme in rheumatoid arthritis: systematic review

Rheumatoid arthritis (RA) is an autoimmune disease involving T and B lymphocytes. Autoantibodies contribute to joint deterioration and worsening symptoms. Adenosine deaminase (ADA), an enzyme in purine metabolism, influences adenosine levels and joint inflammation. Inhibiting ADA could impact RA progression. Intracellular ATP breakdown generates adenosine, which increases in hypoxic and inflammatory conditions. Lymphocytes with ADA play a role in RA. Inhibiting lymphocytic ADA activity has an immune-regulatory effect. Synovial fluid levels of ADA are closely associated with the disease's systemic activity, making it a useful parameter for evaluating joint inflammation. Flavonoids, such as quercetin (QUE), are natural substances that can inhibit ADA activity. QUE demonstrates immune-regulatory effects and restores T-cell homeostasis, making it a promising candidate for RA therapy. In this review, we will explore the impact of QUE in suppressing ADA and reducing produced the inflammation in RA, including preclinical investigations and clinical trials.

Molecular Biology of Meniscal Healing: A Narrative Review

This review provides insights at the molecular level into the current and old methods for treating meniscal injuries. Meniscal injuries have been found to have a substantial impact on the progression of osteoarthritis. In line with the "save the meniscus" approach, meniscectomy is considered a last-resort treatment. Nevertheless, it is important to note that mechanical repair alone may not achieve the complete restoration of the meniscus. A deep understanding of the healing pathways could lead to future improvements in meniscal healing. The inclusion of cytokines and chemokines has the potential to facilitate the process of tear repair or impede the inflammatory catabolic cascade. MicroRNA (miRNA) could serve as a potential biomarker for meniscal degeneration, and RNA injections might promote collagen and growth factor production. The critical aspect of the healing process is angiogenesis within the inner zone of the meniscus. The use of collagen scaffolds and the implantation of autologous meniscus fragments have been successfully integrated into clinical settings. These findings are encouraging and underscore the need for well-designed clinical trials to explore the most effective factors that can enhance the process of meniscal repair.

Using Single Peroneal Longus Tendon Graft for Segmental Meniscus Transplantation and Revision Anterior Cruciate Ligament Combined Anterolateral Reconstruction

This case report describes a new approach to segmental meniscal reconstruction using a peroneal longus autograft in a patient with recurrent traumatic medial meniscus tear and anterior cruciate ligament reconstruction (ACLR) failure. While allograft meniscal transplantation is the preferred method for treating meniscal deficiency, its high cost and various legal regulations have limited its widespread use. Autologous tendon grafts have been proposed as a substitute for allograft meniscus transplantation, but their initial results were poor, leading to little progress in this area. However, recent animal experiments and clinical studies have demonstrated promising results in using autologous tendon grafts for meniscal transplantation, including improvements in pain and quality of life for patients. Further research is needed to evaluate the effectiveness of segmental meniscal reconstruction using autologous tendon grafts, but it could potentially lead to more accessible and cost-effective treatment options for patients with meniscal deficiency.

Biomechanics of Chondrocytes and Chondrons in Healthy Conditions and Osteoarthritis: A Review of the Mechanical Characterisations at the Microscale

Biomechanical studies are expanding across a variety of fields, from biomedicine to biomedical engineering. From the molecular to the system level, mechanical stimuli are crucial regulators of the development of organs and tissues, their growth and related processes such as remodelling, regeneration or disease. When dealing with cell mechanics, various experimental techniques have been developed to analyse the passive response of cells; however, cell variability and the extraction process, complex experimental procedures and different models and assumptions may affect the resulting mechanical properties. For these purposes, this review was aimed at collecting the available literature focused on experimental chondrocyte and chondron biomechanics with direct connection to their biochemical functions and activities, in order to point out important information regarding the planning of an experimental test or a comparison with the available results. In particular, this review highlighted (i) the most common experimental techniques used, (ii) the results and models adopted by different authors, (iii) a critical perspective on features that could affect the results and finally (iv) the quantification of structural and mechanical changes due to a degenerative pathology such as osteoarthritis.

Increased Effusion Synovitis for Those With a Dysregulated Inflammatory Response After an Anterior Cruciate Ligament Injury

Introduction The progression to posttraumatic osteoarthritis (PTOA) after an anterior cruciate ligament (ACL) injury is likely multifactorial, involving biological, mechanical, and psychosocial factors. Following acute joint trauma, there appears to be a subset of patients that demonstrate a dysregulated inflammatory response. This pro-inflammatory phenotype, or "Inflamma-type," is characterized by an amplified pro-inflammatory response combined with a lack of attendant anti-inflammatory response and has been observed following both an ACL injury and an intra-articular fracture. The aims of this study were to: 1) compare magnetic resonance imaging (MRI)-measured effusion synovitis between those with vs. without a dysregulated inflammatory response, and 2) assess the correlations between effusion synovitis and synovial fluid concentrations of proinflammatory cytokines, degradative enzymes, and synovial fluid biomarkers of cartilage degradation. Methods A cluster analysis was previously performed with synovial fluid concentrations of biomarkers of inflammation and cartilage degradation from 35 patients with acute ACL injuries. Patients were then categorized into two groups: a pro-inflammatory phenotype ("Inflamma-type") and those with a more normal inflammatory response to injury (NORM). Effusion synovitis measured from each patient's preoperative clinical MRI scan was compared between the Inflamma-type and NORM groups using an independent, two-tailed t-test. In addition, Spearman's rho non-parametric correlations were calculated to evaluate the relationship between effusion synovitis and each of the synovial fluid concentrations of pro-inflammatory cytokines, degradative enzymes, and biomarkers of cartilage degradation and bony remodeling. Results Effusion synovitis was significantly greater for the Inflamma-type (10.9±3.8 mm) than the NORM group (7.4±4.4 mm, p=0.04, Cohen's d=0.82). Effusion synovitis significantly correlated with matrix metalloproteinase-3 (rho=0.63, p<0.001), matrix metalloproteinase-1 (rho=0.50, p=0.003), and sulfated glycosaminoglycan (rho=0.42, p=0.01). No other significant correlations were present. Conclusion Effusion synovitis was significantly greater for those that demonstrated a dysregulated inflammatory response after acute ACL injury than those with a more normal response to injury. Effusion synovitis was also found to significantly correlate with synovial fluid concentrations of degradative enzymes and a biomarker of early cartilage degradation. Future work is needed to determine if non-invasive methods, such as MRI or ultrasound, may accurately identify patients within this pro-inflammatory phenotype and whether this subset is more prone to more rapid PTOA changes after injury.

Human Cartilage Biomechanics: Experimental and Theoretical Approaches towards the Identification of Mechanical Properties in Healthy and Osteoarthritic Conditions

Articular cartilage is a complex connective tissue with the fundamental functions of load bearing, shock absorption and lubrication in joints. However, traumatic events, aging and degenerative pathologies may affect its structural integrity and function, causing pain and long-term disability. Osteoarthritis represents a health issue, which concerns an increasing number of people worldwide. Moreover, it has been observed that this pathology also affects the mechanical behavior of the articular cartilage. To better understand this correlation, the here proposed review analyzes the physiological aspects that influence cartilage microstructure and biomechanics, with a special focus on the pathological changes caused by osteoarthritis. Particularly, the experimental data on human articular cartilage are presented with reference to different techniques adopted for mechanical testing and the related theoretical mechanical models usually applied to articular cartilage are briefly discussed.

Macroscopic Synovial Inflammation Correlates with Symptoms and Cartilage Lesions in Patients Undergoing Arthroscopic Partial Meniscectomy: A Clinical Study

Background: The aim of the study was to examine the relationship among patients’ characteristics, intraoperative pathology and pre/post-operative symptoms in a cohort of patients undergoing arthroscopic partial meniscectomy for symptomatic meniscal tears. Methods: Clinical data were collected (age, sex, body mass index, time to surgery, trauma). Intraoperative cartilage pathology was assessed with Outerbridge score. Meniscal tears were graded with the ISAKOS classification. Synovial inflammation was scored using the Macro-score. Patient symptoms were assessed pre/post-operatively using the KOOS instrument. Results: In the series of 109 patients (median age 47 years), 50% of the meniscal tears were traumatic; 85% of patients showed mild to moderate synovitis; 52 (47.7%) patients had multiple cartilage defects and 31 (28.4%) exhibited a single focal chondral lesion. Outerbridge scores significantly correlated with patient age, BMI and synovial inflammation. There was a correlation between severity of chondral pathology and high-grade synovial hyperplasia. Pre-operative KOOS correlated with BMI, meniscal degenerative changes and symptom duration. Obesity, time to surgery, presence of high-grade synovial hyperplasia and high-grade cartilage lesions were independent predictors of worse post-operative pain and function. Conclusion: We demonstrated that pre-operative symptoms and post-operative outcomes correlate with synovitis severity and cartilage pathology, particularly in old and obese patients that underwent arthroscopic partial meniscectomy. Importantly, patients with a degenerative meniscal pattern and with longer time to surgery experienced more severe cartilage damage and, consequentially, pain and dysfunction. These findings are fundamental to identify patients suitable for earlier interventions.