Osteoarthritis in 2014: Changing how we define and treat patients with OA

A Preliminary Study of Quantitative MRI Cartilage Loss Fraction and Its Association With Future Arthroplasty Using the Osteoarthritis Initiative Database

Background and objective  Osteoarthritis (OA) is the most common arthritis in the world. Despite the high disease burden, there is no therapy to prevent, halt, or reverse OA, and many clinical trials relied on radiographic biomarkers for therapy response. It is important to identify patients with early OA who will eventually need arthroplasty, the end-stage treatment for osteoarthritis. This pilot study evaluates a novel MRI biomarker, cartilage loss fraction, for association with future arthroplasty and evaluates its feasibility of use and effect size estimates. Materials and methods Publicly available knee MRIs from the Osteoarthritis Initiative were used. A total of 38 participants with Kellgren-Lawrence (K-L) grade >1 and 38 participants with K-L grade ≤ 1 at enrollment were matched in age, sex, race, and BMI, and assessed for the degree of full-thickness cartilage loss, or cartilage loss fraction. Univariate conditional logistic regression analysis was performed for differences in cartilage loss fractions between groups. Receiver operating characteristic (ROC) curve analysis was performed to assess the association of MRI biomarkers and knee arthroplasty during the eight-year follow-up. Results The medial femoral condyle, medial tibial plateau, total, and two-year progression cartilage loss fractions were significantly higher in participants with K-L grade >1 (p < 0.01 for all) and showed high area under the curve (AUC) values on ROC analysis (812, 0.827, 0.917, and 0.933, respectively). These results were comparable or more strongly associated with other OA grading schemes. Conclusion MRI biomarker cartilage loss fractions are significantly higher in subjects with K-L grade >1 and show a strong association with arthroplasty. After further validation, cartilage loss fracture may be used to predict future arthroplasty.

The Role of Dot1l in Prenatal and Postnatal Murine Chondrocytes and Trabecular Bone

Osteoarthritis and osteoporosis are widely prevalent and have far-reaching public health implications. There is increasing evidence that epigenetics, in particular, histone 3 lysine 79 methyltransferase DOT1L, plays an important role in the cartilage and bone biology. In this study, we evaluated the role of Dot1l in the articular cartilage, growth plate, and trabecular bone utilizing conditional KO mouse models. We generated chondrocyte-specific constitutive and inducible conditional Dot1l KO mouse lines using Col2a1-Cre and Acan-CreER systems. Prenatal deletion of Dot1l in mouse chondrocytes led to perinatal mortality, accelerated ossification, and dysregulation of Col10a1 expression. Postnatal deletion of Dot1l in mouse chondrocytes resulted in trabecular bone loss decreased extracellular matrix production, and disruption of the growth plate. In addition, pharmacological inhibition of DOT1L in a progeria mouse model partially rescued the abnormal osseous phenotype. In conclusion, Dot1l is important in maintaining the growth plate, extracellular matrix production, and trabecular bone. © 2019 The Authors. JBMR Plus published by Wiley Periodicals, Inc. on behalf of American Society for Bone and Mineral Research.

Evidence-Based Cutoff Threshold Values from Receiver Operating Characteristic Curve Analysis for Knee Osteoarthritis in the 50-Year-Old Korean Population: Analysis of Big Data from the National Health Insurance Sharing Service

We aimed to investigate the characteristics of patients with osteoarthritis (OA), using the data of all Koreans registered in the National Health Insurance Sharing Service Database (NHISS DB), and to provide ideal alternative cutoff thresholds for alleviating OA symptoms. Patients with OA (codes M17 and M17.1–M17.9 in the Korean Standard Classification of Disease and Causes of Death) were analyzed using SAS software. Optimal cutoff thresholds were determined using receiver operating characteristic curve analysis. The 50-year age group was the most OA pathogenic group (among 40~70 years, n = 2088). All exercise types affected the change of body mass index (p < 0.05) and the sex difference in blood pressure (BP) (p < 0.01). All types of exercise positively affected the loss of waist circumference and the balance test (standing time on one leg in seconds) (p < 0.01). The cutoff threshold for the time in seconds from standing up from a chair to walking 3 m and returning to the same chair was 8.25 (80% sensitivity and 100% specificity). By using the exercise modalities, categorized multiple variables, and the cutoff threshold, an optimal alternative exercise program can be designed for alleviating OA symptoms in the 50-year age group.

Mud-Bath Therapy in Addition to Usual Care in Bilateral Knee Osteoarthritis: An Economic Evaluation Alongside a Randomized Controlled Trial

OBJECTIVE

To perform a cost-effectiveness analysis of mud-bath therapy (MBT) in addition to usual treatment compared to usual treatment alone in patients with bilateral knee osteoarthritis (OA).

METHODS

An economic evaluation alongside a randomized controlled trial was conducted. Patients were randomly assigned to receive either a 2-week cycle of MBT in addition to their usual treatment or to continue routine care alone. The EuroQol 5-domain questionnaire was administered at baseline, 2 weeks, and at 3, 6, 9, and 12 months. Direct health care resource consumption data up until 12 months were derived from a daily diary given to patients and returned at prescheduled followup visits.

RESULTS

A total of 103 patients were included (n = 53 for MBT patients; n = 50 for controls). Overall, patients in the MBT group accrued mean ± SD 0.835 ± 0.10 quality-adjusted life years (QALYs) compared to 0.753 ± 0.11 in the control group (P < 0.001). Average direct costs per patient (€303 versus €975; P < 0.001) were higher in the control group, primarily because of hospitalization for total knee replacement and use of intraarticular hyaluronic acid. Bootstrapping replications of costs and QALY sample distributions consistently indicated that the MBT therapy combined with standard therapy represents a dominant strategy as compared with standard therapy alone. The probability of MBT being cost-effective at standard cost-effectiveness thresholds (e.g., €20,000/QALY) is 100%.

CONCLUSION

The results of this cost-effectiveness analysis support the use of MBT as midterm complementary therapy in the management of knee OA.

Pharmacotherapies in Geriatric Chronic Pain Management

Pharmacologic management of chronic pain in older adults is one component of the multimodal, interdisciplinary management of this complex condition. In this article, we summarize several of the key barriers to effective pharmacologic management in older adults and review the existing (albeit limited) evidence for its effectiveness and safety, especially in a medically complex population with multimorbidity. This review covers topical formulations, acetaminophen, oral nonsteroidal antiinflammatory drugs, and adjuvant therapies. The article concludes with a suggested approach to managing chronic pain in the older patient, incorporating goals and expectations for treatment as well as careful monitoring of medication adjustments.

Effects of Electroacupuncture for Knee Osteoarthritis: A Systematic Review and Meta-Analysis

Purpose. This study aims to verify the effects of electroacupuncture treatment on osteoarthritis of the knee. Methods. MEDLINE/PubMed, EMBASE, CENTRAL, AMED, CNKI, and five Korean databases were searched by predefined search strategies to screen eligible randomized controlled studies meeting established criteria. Any risk of bias in the included studies was assessed with the Cochrane Collaboration's tool. Meta-analysis was conducted using RevMan version 5.3 software. Results. Thirty-one randomized controlled studies of 3,187 participants were included in this systematic review. Meta-analysis was conducted with eight studies including a total of 1,220 participants. The electroacupuncture treatment group showed more significant improvement in pain due to knee osteoarthritis than the control group (SMD −1.86, 95% CI −2.33 to −1.39, I² 75%) and in total WOMAC score than the control group (SMD −1.34, CI 95% −1.85 to −0.83, I² 73%). Compared to the control group, the electroacupuncture treatment group showed more significant improvement on the quality of life scale. Conclusion. Electroacupuncture treatment can relieve the pain of osteoarthritis of the knees and improve comprehensive aspects of knee osteoarthritis and the quality of life of patients with knee osteoarthritis.

MicroRNA-99a regulates early chondrogenic differentiation of rat mesenchymal stem cells by targeting the BMPR2 gene

Mesenchymal stem cells (MSCs) are candidates for the regeneration of articular cartilage as they possess the potential for chondrogenic differentiation. MSCs are easily obtained and expanded in vitro. Specific microRNAs (miRNAs) that regulate chondrogenesis have yet to be identified and the mechanisms involved remain to be defined. The miRNAs regulate biological processes by binding target mRNA to reduce protein synthesis. In this study, we show that expression of miR-99a and miR-125b-3p were increased during early chondrogenic differentiation of MSCs (rMSCs) derived from the Norwegian brown rat (Rattus norvegicus). MiR-99a knockdown promoted proteoglycan deposition and increased the expression of ACAN and COL2A1 during early chondrogenic differentiation. MiR-99a knockdown promoted early chondrogenic differentiation of rMSCs. A dual-luciferase reporter gene assay showed that miR-99a targeted a putative binding site in the 3'-UTR of bone morphogenetic protein (BMP) receptor type 2 (BMPR2). Overexpression of miR-99a reduced the expression levels of BMPR2 protein. The expression of total p38 and p-p38 increased at 7 and 14 days during early chondrogenic differentiation of rMSCs. Reduction in levels of total p38 and p-p38 protein followed miR-99a overexpression during early chondrogenic differentiation of rMSCs. BMPR2 silencing reversed the effects of miR-99a inhibition on proteoglycan deposition and protein expression of ACAN, COL2A1, total p38 and p-p38 during early chondrogenic differentiation of rMSCs. In conclusion, the findings of these in vitro studies in rat MSCs support a role for miR-99a as a negative regulator of early chondrogenic differentiation by directly targeting the BMPR2 gene at an early stage.

Plasma-Derived Fibronectin Stimulates Chondrogenic Differentiation of Human Subchondral Cortico-Spongious Progenitor Cells in Late-Stage Osteoarthritis

Migration and chondrogenesis of human subchondral cortico-spongious progenitor cells (SPCs) are the key steps in the repair of microfracture-induced articular cartilage defects. The aim of this study was to evaluate the effect of human plasma-derived fibronectin (Fn) on the chondrogenic differentiation of SPCs, which was isolated from subchondrol cortico-spongious bone of late-stage osteoarthritis (OA) patients. SPCs were isolated and cultured for three passages. Stem cell surface antigens of SPCs were analyzed by flow cytometry. The osteogenic, chondrogenic and adipogenic differentiation potential were detected by histological staining. The chondrogenesis potential of SPCs with or without stimulation of either Fn or BMP-2 were studied by immunochemical staining and gene expression analysis. Cells isolated from subchondral bone presented to be positive for CD44, CD73, CD90, and CD166, and showed high capacity of osteogenic, adipogenic and chondrogenic differentiation, which suggested this cell population to be MSC-like cells. Stimulating with Fn increased the expression of SOX-9, aggrecan, collagen II while decreased the formation of collagen I by immunochemical staining. Gene expression analysis showed similar results. These results suggest that plasma-derived Fn can increase the chondrogenic differentiation of SPCs isolated from late-stage OA and improve cartilage repair after microfracture.