Background The 2013 American Academy of Orthopaedic Surgeons (AAOS) guidelines made strong recommendations against intraarticular hyaluronic acid (IAHA) for patients with knee osteoarthritis (OA), as evidence supporting improvements in pain did not meet the minimal clinically important improvement (MCII) threshold. However, there may be important distinctions based on IAHA molecular weight (MW). Hence our objective was to evaluate the efficacy of IAHAs in knee OA based on molecular weight. Methods Randomized controlled trials were searched within MEDLINE, Embase, and CENTRAL and selected based on AAOS criteria. A pain measure hierarchy and longest follow-up were used to select one effect size from each trial. Mean differences between interventions were converted to standardized mean differences (SMDs) and incorporated into a random-effects Bayesian network meta-analysis. High MW (HMW) was defined as ≥6000 kDa, and low MW (LMW) as < 750 kDa. Results HMW IAHA was associated with a statistically significant and possibly clinically significant improvement in pain (SMD − 0.57 (95% credible interval [Crl]: − 1.04, − 0.11), exceeding the − 0.50 MCII threshold. LMW IAHA had a lesser, non-significant improvement (− 0.23, 95% Crl: − 0.67, 0.20). Back-transforming SMDs to the WOMAC pain scale indicated a 14.65 (95% CI: 13.93, 15.62) point improvement over IA placebo, substantially better than the 8.3 AAOS MCII threshold. Conclusions Unlike LMW IAHA, HMW IAHA exceeded the MCII threshold for pain relief, suggesting that improvements can be subjectively perceived by the treated patient. Amalgamation of LMW and HMW may have blurred the benefits of IAHA in the past, leading to negative recommendations. Differentiation according to MW offers refined insight for treatment with IAHA.

The aim of this study was to evaluate the long-term efficacy and safety of single or 1–3 weekly injections of hylan G-F 20 at 1 year following the first injection for knee osteoarthritis (OA). Searches were conducted in PubMed/MEDLINE, Embase, and CENTRAL and included relevant conference proceedings (January 1, 1995–August 17, 2020). Randomized controlled trials (RCTs), non-randomized trials, and observational studies investigating 1-year efficacy and safety of 1–3 weekly injections or single hylan G-F 20 injection for knee OA were included. Primary outcomes were WOMAC pain, physical function, and stiffness. Meta-analyses of RCTs and non-randomized studies were conducted separately. Our search identified 24 eligible studies. Hylan G-F 20, in the meta-analyses of RCTs, showed statistically significant improvement in WOMAC pain (SMCC − 0.98, 95% CI − 1.50, − 0.46), physical function (SMCC − 1.05, 95% CI − 1.28, − 0.83), and stiffness (SMCC − 1.07, 95% CI −1.28, −0.86). Improvement was also seen for VAS pain, SF-36 MCS (mental component summary), and SF-36 PCS (physical component summary). Analyses of non-randomized studies showed similar efficacy estimates. There were no significant differences in efficacy based on injection schedule, nor between RCT and non-randomized studies. Rates of adverse events (AEs) were low for most types of AEs. Hylan G-F 20 (either as single or 1–3 weekly injections) showed improvement in 1-year efficacy outcomes in comparison to baseline and was generally well tolerated. While further research will inform the medical field regarding viscosupplementation treatment options for knee OA, these findings show that hylan G-F 20 at both frequencies/dosages are efficacious and generally well tolerated for long-term use.

Objective Concerns have been raised about severe acute localized reactions (SALR) following intra-articular (IA) hyaluronic acid (HA) injections for knee osteoarthritis (OA). We compared surrogate SALR measures between hylan G-F 20 and non-hylan G-F 20 HA patients and evaluated corresponding SALR risk factors for hylan G-F 20 patients. Design Knee OA patients were identified from the Optum Clinformatics dataset (January 2006 to June 2016), stratified into hylan G-F 20 and non-hylan G-F 20 HA users. Occurrences of surrogate SALR measures including inflammation/infection, intra-articular corticosteroid (CS) injections, arthrocentesis/aspiration, and office visits were evaluated within 3 days of HA use. Risk factors were evaluated using logistic regression. Results The cohort involved 748,428 HA patients (23.2% in the hylan G-F 20 group). Inflammation/infection rate was 0.001% for hylan G-F 20 and 0.002% for non-hylan G-F 20 HA groups. Risk of CS injection (any diagnosis) was greater for hylan G-F 20 patients by 28% ( P < 0.001). Combined rates of CS injection and arthrocentesis/aspiration (any diagnosis) were comparable for both groups (hylan G-F 20, 2.2%; non-hylan G-F 20 HA, 2.6%). The risk of any visit or studied responses was lower for the hylan G-F 20 cohort by 12% ( P < 0.001). Clinical characteristics, such as CS injections within 1 week before HA and fluoroscopic imaging, were associated with the outcomes. Conclusions The diagnosis of inflammations or infections within 3 days of the HA injection was extremely rare. The overall risk of surrogate SALR measures was similar for hylan G-F 20 and non-hylan G-F 20 HA patients.

Objective: Case reports of severe acute localized reactions (SALR) following intraarticular (IA) hyaluronic acid (HA) injections for knee osteoarthritis (OA) have been described. We compared surrogate SALR measures between patients using hylan G-F 20 and specific non-hylan G-F 20 HA products. Design: Knee OA patients were identified from the Optum Clinformatics dataset (January 2006 to June 2016), stratified into hylan G-F 20 and non-hylan G-F 20 HA users, matched by single or multiple injection products. Occurrences of surrogate SALR measures including inflammation/infection, intraarticular corticosteroid (CS) injections, arthrocentesis/aspiration, arthrotomy/incision and drainage, and arthroscopy were evaluated within 3 days post-HA. Results: Based on 694,404 HA injections, inflammation/infection rate was rare within 3 days of HA (up to 0.03%), with no statistical differences between hylan G-F 20 and non-hylan G-F 20 groups (matched by single or multiple injection products). The risk of knee arthrotomy/incision and drainage, arthroscopy, or arthrocentesis for hylan G-F 20 (2 mL) 3 weekly injection patients was lower than Hyalgan/Supartz and Orthovisc patients, but greater than Euflexxa patients. Overall, we found that Hylan G-F 20 (2 mL) 3 weekly injection had lower SALR rates compared to Hyalgan/Supartz and Orthovisc. However, Hylan G-F 20 (2 mL) 3 weekly injection had slightly higher rates of SALR when compared to Euflexxa. Among the single injection products, Hylan G-F 20 (6 mL) single injection had lower rates of SALR than Monovisc and Gel-One. Conclusions: This study shows no clear correlation between avian-derived or cross-linked products and SALR and provides evidence against avian-derived products or crosslinking as a source for these reactions.

Aims: The objective of this review was to examine the relationship between osteoarthritis (OA) and mobility-related comorbidities, specifically diabetes mellitus (DM) and cardiovascular disease (CVD). It also investigated the relationship between OA and mortality. Methods: An overview of meta-analyses was conducted by performing two targeted searches from inception to June 2020. The association between OA and (i) DM or CVD ( via PubMed and Embase); and (ii) mortality ( via PubMed) was investigated. Meta-analyses were selected if they included studies that examined adults with OA at any site and reported associations between OA and DM, CVD, or mortality. Evidence was synthesized qualitatively. Results: Six meta-analyses met inclusion criteria. One meta-analysis of 20 studies demonstrated a statistically significant association between OA and DM, with pooled odds ratio of 1.41 (95% confidence interval: 1.21, 1.65; n = 1,040,175 patients). One meta-analysis of 15 studies demonstrated significantly increased risk of CVD among OA patients, with a pooled risk ratio of 1.24 (1.12, 1.37, n = 358,944 patients). Stratified by type of CVD, OA was shown to be associated with increased heart failure (HF) and ischemic heart disease (IHD) and reduced transient ischemic attack (TIA). There was no association reported for stroke or myocardial infarction (MI). Three meta-analyses did not find a significant association between OA (any site) and all-cause mortality. However, OA was found to be significantly associated with cardiovascular-related death across two meta-analyses. Conclusion: The identified meta-analyses reported significantly increased risk of both DM and CVD (particularly, HF and IHD) among OA patients. It was not possible to confirm consistent directional or causal relationships. OA was found to be associated with increased mortality, but mostly in relation to CVD-related mortality, suggesting that further study is warranted in this area.