EULAR recommendations for the non-pharmacological core management of hip and knee osteoarthritis: 2023 update

Noisy knees - knee crepitus prevalence and association with structural pathology: a systematic review and meta-analysis

OBJECTIVE

Knee crepitus, the audible crackling or grinding noise during knee movement, can be experienced across the lifespan and create concern for underlying pathology. Our systematic review aims to provide a summary estimate of knee crepitus prevalence and its association with structural pathology among the general population and across knee conditions.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

Medline, Embase, CENTRAL, Web of Science, SPORTDiscus and CINAHL.

ELIGIBILITY CRITERIA

Studies evaluating knee crepitus prevalence.

RESULTS

103 studies involving 36 439 participants (42 816 knees) were included. Based on very low certainty evidence, the pooled prevalence of knee crepitus in the general population was 41% (7609 knees; 95% CI 36% to 45%; I2=92.6%); in pain-free persons 36% (852 knees; 95% CI 23% to 50%; I2=91.9%), and in those with osteoarthritis (OA) 81% (18 821 knees; 95% CI 75% to 87%; I2=97.9%). Across other musculoskeletal knee conditions, the pooled prevalence of knee crepitus ranged from 35% (ligament injury; 2740 knees; 95% CI 27% to 44%; I2=95.6%) to 61% (cartilage pathology; 1445 knees; 95% CI 40% to 81%; I2=98.2%). There was low to very low certainty evidence of an association between knee crepitus and radiographic OA (OR 3.79, 95% CI 1.99 to 7.24; 1725 knees; I2=53.0%) and several OA-related features on magnetic resonance imaging (MRI).

CONCLUSION

In this review, knee crepitus was prevalent in the general population, pain-free persons, those with knee OA and other musculoskeletal knee conditions. Knee crepitus was associated with a more than threefold increased odds of radiographic OA diagnosis and several OA-related MRI features. The low to very low certainty of evidence informing our aggregated prevalence estimates and association outcomes suggest that results should be interpreted with caution.

Semi-invasive therapies for pain in knee osteoarthritis: A systematic review and network meta-analysis

BACKGROUND

The increasing number of semi-invasive pain therapies in knee osteoarthritis poses challenges in decision-making. This review aimed to simultaneously compare established intra-articular therapies with newer peri-articular therapies and explore effect modifiers.

METHODS

Randomized controlled trials were searched from five electronic databases without date or language restrictions. Study selection and data extraction of reports, retrieved up to May 2024, were performed independently by paired assessors. The primary outcome was 6-month pain score. Nine treatments were included. The effect size (ES) for each treatment, relative to placebo, was estimated using standardized means difference and expressed with 95% confidence intervals (CI). The rigor of results was evaluated with subgroup/sensitivity analyses.

RESULTS

A total of 111 studies (14,695 participants) were included, with intra-articular hyaluronic acid having the greatest number of participants. Neuroablation demonstrated the greatest ES (1.08, 95% CI: 0.07, 2.10). While platelet-rich plasma (PRP) ranked second (ES: 0.75, 95% CI: 0.28, 1.22), it was the only intervention demonstrating statistically significant effect at 3, 6, and 12 months. However, this statistical significance was lost in some sensitivity analyses. Larger estimates for biologics and PRP compared with prolotherapy, steroid, and hyaluronic acid injections were consistently observed across different timepoints and in multiple sensitivity analyses. Generally, no statistically significant difference was found between the nine types of therapies.

CONCLUSION

Although there is robust evidence suggesting greater efficacy of PRP, potentially including biologics, over other interventions, future research is needed to identify the phenotype or patient subgroup that would benefit most from PRP.

Do Existing MRI Definitions of Knee Osteoarthritis Identify Knees That Will Develop Clinically Significant Disease Over Up To 11 Years of Follow-Up?

OBJECTIVE

In individuals without radiographic knee osteoarthritis (OA), we investigated whether magnetic resonance imaging (MRI)-defined knee OA at baseline was associated with incident radiographic and symptomatic disease during up to 11 years of follow-up.

METHODS

Osteoarthritis Initiative participants without tibiofemoral radiographic knee OA at baseline were assessed for MRI-based tibiofemoral cartilage damage, osteophyte presence, bone marrow lesions, and meniscal damage/extrusion. We defined MRI knee OA using alternative, reported definitions (Def A and Def B). Kellgren-Lawrence (KL) grade, joint space narrowing (JSN), and frequent knee symptoms (Sx) were assessed at baseline, 1-, 2-, 3-, 4-, 6-, 8-, and 10/11-year follow-up visits. Incident tibiofemoral radiographic knee OA (outcome) was defined as (1) KL ≥2, (2) KL ≥2 and JSN, or (3) KL ≥2 and Sx. Adjusted Cox proportional hazards regression models examined associations of baseline MRI-defined knee OA (Def A and Def B) with incident outcomes during up to 11 years of follow-up.

RESULTS

Among 1,621 participants (mean age ± SD 58.8 ± 9.0 years, mean body mass index ± SD 27.2 ± 4.5 kg/m2, 59.5% women), 17% had MRI-defined knee OA by Def A and 24% by Def B. Baseline MRI-defined knee OA was associated with incident KL ≥2 (odds ratio 2.94 [95% confidence interval (95% CI) 2.34-3.68] for Def A and 2.44 [95% CI 1.97-3.03] for Def B). However, a substantial proportion of individuals with baseline MRI-defined knee OA did not develop incident KL ≥2 during follow-up (59% for Def A and 64% for Def B). Findings were similar for the other two outcomes.

CONCLUSION

Current MRI definitions of knee OA do not adequately identify knees that will develop radiographic and symptomatic disease.

Knee Osteoarthritis

Knee osteoarthritis (OA) typically presents with joint pain that is exacerbated by use and alleviated with rest. There is relatively brief, self-limited morning stiffness and absence of constitutional symptoms. Overweight and obesity are the most important modifiable risk factors. Although pharmacologic and nonpharmacologic interventions are generally effective at alleviating pain and improving physical function, they do not fundamentally reverse the pathologic and radiographic process of knee OA. As the severity of disease increases, the magnitude of pain and functional impairment intensifies. Surgical intervention should be pursued to relieve pain and restore functionality only when nonpharmacologic approaches and pharmacologic agents fail to control pain.

A Review of Current Approaches to Pain Management in Knee Osteoarthritis with a Focus on Italian Clinical Landscape

The global cases of knee osteoarthritis (KOA) are projected to increase by 74.9% by 2050. Currently, over half of patients remain dissatisfied with their pain relief. This review addresses unmet needs for moderate-to-severe KOA pain; it offers evidence and insights for improved management. Italian experts from the fields of rheumatology, physical medicine and rehabilitation, orthopedics, primary care, and pain therapy have identified several key issues. They emphasized the need for standardized care protocols to address inconsistencies in patient management across different specialties. Early diagnosis is crucial, as cartilage responds better to early protective and structural therapies. Faster access to physiatrist evaluation and reimbursement for physical, rehabilitative, and pharmacological treatments, including intra-articular (IA) therapy, could reduce access disparities. Concerns surround the adverse effects of oral pharmacological treatments, highlighting the need for safer alternatives. Patient satisfaction with corticosteroids and hyaluronic acid-based IA therapies reduces over time and there is no consensus on the optimal IA therapy protocol. Surgery should be reserved for severe symptoms and radiographic KOA evidence, as chronic pain post-surgery poses significant societal and economic burdens. The experts advocate for a multidisciplinary approach, promoting interaction and collaboration between specialists and general practitioners, to enhance KOA care and treatment consistency in Italy.

Mesenchymal Stem Cell-Derived Exosomes as a Treatment Option for Osteoarthritis

Osteoarthritis (OA) is a leading cause of pain and disability worldwide in elderly people. There is a critical need to develop novel therapeutic strategies that can effectively manage pain and disability to improve the quality of life for older people. Mesenchymal stem cells (MSCs) have emerged as a promising cell-based therapy for age-related disorders due to their multilineage differentiation and strong paracrine effects. Notably, MSC-derived exosomes (MSC-Exos) have gained significant attention because they can recapitulate MSCs into therapeutic benefits without causing any associated risks compared with direct cell transplantation. These exosomes help in the transport of bioactive molecules such as proteins, lipids, and nucleic acids, which can influence various cellular processes related to tissue repair, regeneration, and immune regulation. In this review, we have provided an overview of MSC-Exos as a considerable treatment option for osteoarthritis. This review will go over the underlying mechanisms by which MSC-Exos may alleviate the pathological hallmarks of OA, such as cartilage degradation, synovial inflammation, and subchondral bone changes. Furthermore, we have summarized the current preclinical evidence and highlighted promising results from in vitro and in vivo studies, as well as progress in clinical trials using MSC-Exos to treat OA.

Efficacy of Eggshell Membrane in Knee Osteoarthritis: A Systematic Review and Meta-Analysis

Osteoarthritis (OA) is a prevalent, degenerative joint disease, with knee OA being particularly common and impactful. This systematic review and meta-analysis aimed to assess the efficacy of eggshell membrane (ESM) supplementation in improving joint functionality and reducing pain in individuals with knee OA. A comprehensive search was conducted across PubMed, Scopus, Web of Science, and Cochrane Database up to July 2024, following PRISMA guidelines. Seven randomized controlled trials (RCTs) met the inclusion criteria, with five included in the meta-analysis. The studies compared ESM to a placebo, evaluating outcomes based on assessment tools such as the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Visual Analogue Scale (VAS), and Knee Injury and Osteoarthritis Outcome Score (KOOS). Results indicated that ESM significantly reduced pain and improved functionality, with notable improvements in total WOMAC score (effect size -0.34; 95% CI: -0.56 to -0.13; p < 0.001) and pain subscale (SMD -0.23; 95% CI: -0.42 to -0.04; p < 0.02). The findings support ESM as a promising adjunctive treatment for knee OA, offering a safe, natural supplement to enhance quality of life. Further high-quality RCTs are needed to confirm these results and explore the long-term effects and mechanisms of ESM.

Osteoarthritis Year In Review 2024: Rehabilitation and outcomes

This Year in Review presents key highlights from recent research relating to osteoarthritis rehabilitation and its outcomes, defined as any non-pharmacological and non-surgical treatment that aims to improve osteoarthritis symptoms at any joint. Three databases (Medline, Embase, and CINAHL Plus) were searched between 1 March 2023 to 12 March 2024. Relevant studies were chosen based on the predefined inclusion/exclusion criteria, perceived clinical importance, quality, controversy in the field, or personal interest, and organised into four overarching themes (with 1-5 sub-themes each). The first theme related to uncertainties regarding exercise benefits. New work has challenged the clinical effectiveness of exercise on symptoms, as well as highlighted uncertainty around our understanding of both mechanisms of effects, how to enhance effectiveness and adherence, and which subgroups of people are more or less likely to improve with exercise. However, we also highlight new work confirming the role of exercise as a first-line management strategy. The second theme related to digital modes of service delivery. There was new evidence to support its effectiveness in improving symptoms and clear potential for creating and evaluating new mobile apps. New work also highlighted the potential future role artificial intelligence can have in providing treatment information and recommendations. The third theme related to patient education, and the call for change to the impairment-based narrative that prevails in osteoarthritis information. The fourth theme is related to weight loss. New work compared the effectiveness of different weight loss diets and explored alternative models of weight loss delivery.

The Role of MicroRNAs in the Pathophysiology of Osteoarthritis

Worldwide, osteoarthritis (OA) is the most common cause of joint pain in older people. Many factors contribute to osteoarthritis' development and progression, including secondary osteoarthritis' underlying causes. It is important to note that osteoarthritis affects all four tissues: cartilage, bone, joint capsule, and articular apparatus. An increasingly prominent area of research in osteoarthritis regulation is microRNAs (miRNAs), a small, single-stranded RNA molecule that controls gene expression in eukaryotes. We aimed to assess and summarize current knowledge about the mechanisms of the action of miRNAs and their clinical significance. Osteoarthritis (OA) is affected by the interaction between miRNAs and inflammatory processes, as well as cartilage metabolism. MiRNAs also influence cartilage cell apoptosis, contributing to the degradation of the cartilage in OA. Studies have shown that miRNAs may have both an inhibitory and promoting effect on osteoporosis progression through their influence on molecular mechanisms. By identifying these regulators, targeted treatments for osteoarthritis may be developed. In addition, microRNA may also serve as a biomarker for osteoarthritis. By using these biomarkers, the disease could be detected faster, and early intervention can be instituted to prevent mobility loss and slow deterioration.

Management and Rehabilitative Treatment in Osteoarthritis with a Novel Physical Therapy Approach: A Randomized Control Study

Knee osteoarthritis (KOA) is a chronic degenerative disease characterized by progressive joint damage leading to significant disability. Although rehabilitative treatment methods for KOA have been widely implemented, the optimal integrated instrumental physical therapy approach remains unclear. Therefore, this study aimed to analyze the effect of Quantum Molecular Resonance (QMR) on pain reduction as the primary outcome and the functional improvement in activity daily living (ADL) as a secondary outcome. The study was designed as a double-blind, randomized, controlled trial in an outpatient setting. Fifty-four (N = 54) patients were enrolled and then randomized into three groups according to a simple randomization list: Group 1 (intensive protocol, N = 22), Group 2 (extensive protocol, N = 21), and a Sham group (N = 11). Patients were evaluated over time with scales assessing pain and function. Treatment was performed with the QMR model electro-medical device, which generates alternating electric currents characterized by high frequency (4-64 MHz). The results showed that QMR had a positive effect with respect to the Sham group in terms of pain and function (p < 0.01), and intensive treatment was more effective than the extensive treatment in terms of "speed of response" to the treatment (p < 0.05). In conclusion, QMR in KOA could be effective in slowing the progression of clinical symptoms and improving patients' pain and functionality and thus quality of life. Future studies will be necessary to investigate further treatment algorithms and therapeutic associations with rehabilitative exercise.

How can clinicians enhance self-efficacy beliefs in osteoarthritis? An overview of systematic reviews with meta-analysis

This overview of reviews aimed to synthesize the effectiveness of non-pharmacological approaches to enhance self-efficacy in people with osteoarthritis. The CINAHL, Embase, PsycINFO, PubMed, SPORTDiscus, and the Cochrane Library databases were searched from inception to December 2023. We considered systematic reviews with meta-analysis of randomized clinical trials evaluating any non-pharmacological intervention. We used AMSTAR 2 to assess the methodological quality of reviews. The overlap between reviews was calculated. We included eight systematic reviews with meta-analysis evaluating 30 different clinical trials. Overall, mind-body exercises, psychological interventions, and self-management strategies may improve arthritis self-efficacy. Specifically, the meta-analyses showed tai chi exercises, coping skills training, and the arthritis self-management program are more effective than controls to enhance arthritis self-efficacy in people with hip and/or knee osteoarthritis. In addition, inconsistent results were detected across meta-analyses regarding the effectiveness of multidisciplinary interventions. Finally, the degree of overlap between all reviews was moderate (CCA = 6%) and many included reviews reported most of the items of AMSTAR 2. Tai chi exercises, coping skills training, and the arthritis self-management program may be beneficial for enhancing arthritis self-efficacy. Open Science Framework Registration: https://doi.org/10.17605/OSF.IO/VX2T6 .

Metabolic Dysregulation and Its Role in Postoperative Pain among Knee Osteoarthritis Patients

Knee osteoarthritis (KOA) is characterized by low-grade inflammation, loss of articular cartilage, subchondral bone remodeling, synovitis, osteophyte formation, and pain. Strong, continuous pain may indicate the need for joint replacement in patients with end-stage OA, although postoperative pain (POP) of at least a two-month duration persists in 10-40% of patients with OA.

STUDY PURPOSE

The inflammation observed in joint tissues is linked to pain caused by the production of proinflammatory cytokines. Since the biosynthesis of cytokines requires energy, their production is supported by extensive metabolic conversions of carbohydrates and fatty acids, which could lead to a disruption in cellular homeostasis. Therefore, this study aimed to investigate the association between POP development and disturbances in energy metabolic conversions, focusing on carbohydrate and fatty acid metabolism.

METHODS

Peripheral blood samples were collected from 26 healthy subjects and 50 patients with end-stage OA before joint replacement surgery. All implants were validated by orthopedic surgeons, and patients with OA demonstrated no inherent abnormalities to cause pain from other reasons than OA disease, such as malalignment, aseptic loosening, or excessive bleeding. Pain levels were assessed before surgery using the visual analogue scale (VAS) and neuropathic pain questionnaires, DN4 and PainDETECT. Functional activity was evaluated using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Three and six months after surgery, pain indices according to a VAS of 30 mm or higher were considered. Total RNA isolated from whole blood was analyzed using quantitative real-time RT-PCR (qRT-PCR) for the expression of genes related to carbohydrate and fatty acid metabolism. Protein levels of the examined genes were measured using an ELISA in the peripheral blood mononuclear cells (PBMCs). We used qRT-PCR because it is the most sensitive and reliable method for gene expression analysis, while an ELISA was used to confirm our qRT-PCR results.

KEY FINDINGS

Among the study cohort, 17 patients who reported POP demonstrated significantly higher (p < 0.05) expressions of the genes PKM2, LDH, SDH, UCP2, CPT1A, and ACLY compared to pain-free patients with KOA. Receiver-operating characteristic (ROC) curve analyses confirmed the association between these gene expressions and pain development post-arthroplasty. A principle component analysis identified the prognostic values of ACLY, CPT1A, AMPK, SDHB, Caspase 3, and IL-1β gene expressions for POP development in the examined subjects.

CONCLUSION

These findings suggest that the disturbances in energy metabolism, as observed in the PBMCs of patients with end-stage KOA before arthroplasty, may contribute to POP development. An understanding of these metabolic processes could provide insights into the pathogenesis of KOA. Additionally, our findings can be used in a clinical setting to predict POP development in end-stage patients with KOA before arthroplasty.

A Comprehensive Review of Current Management Trends in Medial Compartment Arthritis of the Knee Joint

Medial compartment arthritis of the knee joint presents a significant clinical challenge, with diverse management options ranging from nonsurgical interventions to various surgical procedures. This comprehensive review synthesizes current evidence on the management trends in medial compartment arthritis, highlighting both nonsurgical approaches such as physical therapy, pharmacological interventions, and intra-articular injections as well as surgical interventions, including arthroscopic debridement, high tibial osteotomy, and knee arthroplasty. Through a comparative analysis of efficacy, complication rates, and patient outcomes, this review underscores the importance of tailoring treatment strategies to individual patient characteristics and preferences. Furthermore, emerging techniques and technologies promise to advance the field, necessitating ongoing research efforts to refine treatment algorithms and establish standardized guidelines. By adopting a multidisciplinary approach and integrating evidence-based practices, clinicians can optimize the management of medial compartment arthritis and enhance patient care outcomes.

Sex and age differences in the patient-reported outcome measures and adherence to an osteoarthritis digital self-management intervention

Objective

To explore sex and age differences in Patient-Reported Outcomes Measures (PROMs) and adherence to digital osteoarthritis (OA) self-management intervention.

Methods

A register-based study with data from an OA digital self-management intervention. PROMs and adherence were collected at baseline and/or 3 ​month follow-up: 'pain intensity' in hip/knee (best/worst: 0-10), 'activity impairments' (best/worst: 0-10), 'overall health' perception (worst/best: 0-10), 'physical function' (30-s chair stand test), 'health-related quality of life' (EQ-5D-5L index score; worst/best: 0.243-0.976), the subscales and total scores of the Knee Injury/Hip Disability and Osteoarthritis Outcome Score (KOOS/HOOS-12; worst/best: 0-100), 'fear of movement' (yes/no), 'walking difficulties' (yes/no), 'programme adherence' (0-100 ​% and ≥80 ​% [yes/no]), 'patient acceptable symptom state' (PASS; yes/no), and 'treatment failure' (those who answered no to PASS question and thought the treatment failed [yes/no]). We used linear/logistic regression to calculate mean/risk differences in the PROMs and adherence levels among sex and age groups at 3-month follow-up. We employed entropy balancing to explore the contributions of baseline characteristics and different covariates to the sex/age differences.

Results

We included 14,610 participants (mean (SD) age: 64.1 (9.1), 75.5 ​% females). Females generally reported better outcomes than males. Participants aged ≥70 had greater activity impairments, lower KOOS/HOOS-pain/function scores, more walking difficulties, less fear of movement and higher adherence than those <70. However, these differences were small and not likely clinically relevant.

Conclusion

No clinically relevant differences in PROMs and adherence were found among sex/age groups in this digital OA programme, suggesting that sex/age seemed not to impact the outcomes of this intervention.

Cemented vs. Cementless Fixation in Primary Knee Replacement: A Narrative Review

Knee osteoarthritis (OA) is one of the leading causes of disability around the globe. Osteoarthritis is mainly considered a disease affecting the elderly. However, more and more studies show that sports overuse, obesity, or congenital disorders can initiate a pathologic cascade that leads to OA changes in the younger population. Nevertheless, OA mostly affects the elderly, and with increasing life expectancy, the disease will develop in more and more individuals. To date, the golden standard in the treatment of the end-stage of the disease is total joint replacement (TJR), which restores painless knee motion and function. One of the weakest elements in TJR is its bonding with the bone, which can be achieved by bonding material, such as poly methyl-methacrylate (PMMA), or by cementless fixation supported by bone ingrowth onto the endoprosthesis surface. Each technique has its advantages; however, the most important factor is the revision rate and survivor time. In the past, numerous articles were published regarding TJR revision rate, but no consensus has been established yet. In this review, we focused on a comparison of cemented and cementless total knee replacement surgeries. We introduced PICO rules, including population, intervention, comparison and outcomes of TJR in a PubMed search. We identified 783 articles published between 2010 and 2023, out of which we included 14 in our review. Our review reveals that there is no universally prescribed approach to fixate knee prostheses. The determination of the most suitable method necessitates an individualized decision-making process involving the active participation and informed consent of each patient.

Pain sensitivity genes as therapeutic targets in knee osteoarthritis: A comprehensive analysis

Pain sensitivity is a significant factor in knee osteoarthritis (KOA), influencing patient outcomes and complicating treatment. Genetic differences, particularly in pain-sensing genes (PSRGs), are known to contribute to the variability in pain experiences among KOA patients. This study aims to systematically analyze PSRGs in KOA to better understand their role and potential as therapeutic targets. We utilized bulk RNA-seq data from the GSE114007 and GSE169077 datasets to identify differentially expressed genes, with 20 genes found to be significantly altered. Key PSRGs, including PENK, NGF, HOXD1, and TRPA1, were identified using LASSO, SVM, and random forest algorithms. Further, KEGG and GO enrichment analyses revealed pathways such as "Neuroactive ligand-receptor interaction" and "ECM-receptor interaction," which were validated through external datasets. Single-cell RNA-seq analysis from GSE152805, GSE133449, and GSE104782 datasets demonstrated the heterogeneity and dynamic expression of PSRGs across different cell subpopulations in synovium, meniscus, and cartilage samples. UMAP and pseudotime analyses were used to visualize spatial distribution and developmental trajectories of these genes. The findings emphasize the critical roles of PSRGs in KOA, highlighting their potential as therapeutic targets and suggesting that integrating genetic information into clinical practice could significantly improve pain management and treatment strategies for KOA.