Whether a gut-joint axis exists to regulate osteoarthritis is unknown. In two independent cohorts, we identified altered microbial bile acid metabolism with reduced glycoursodeoxycholic acid (GUDCA) in osteoarthritis. Suppressing farnesoid X receptor (FXR)—the receptor of GUDCA—alleviated osteoarthritis through intestine-secreted glucagon-like peptide 1 (GLP-1) in mice. GLP-1 receptor blockade attenuated these effects, whereas GLP-1 receptor activation mitigated osteoarthritis. Osteoarthritis patients exhibited a lower relative abundance of Clostridium bolteae , which promoted the formation of ursodeoxycholic acid (UDCA), a precursor of GUDCA. Treatment with C. bolteae and Food and Drug Administration–approved UDCA alleviated osteoarthritis through the gut FXR–joint GLP-1 axis in mice. UDCA use was associated with lower risk of osteoarthritis-related joint replacement in humans. These findings suggest that orchestrating the gut microbiota–GUDCA–intestinal FXR–GLP-1–joint pathway offers a potential strategy for osteoarthritis treatment.

Objective To investigate the efficacy and safety of the pulsed electromagnetic field (PEMF) therapy in treating osteoarthritis (OA). Design Meta-analysis. Data sources PubMed, Embase, the Cochrane Library and Web of Science were searched through 13 October 2017. Eligibility criteria for selecting studies Randomised controlled trials compared the efficacy of PEMF therapy with sham control in patients with OA. Data extraction and synthesis Pain, function, adverse effects and characteristics of participants were extracted. RevMan V.5.2 was used to perform statistical analyses. Results Twelve trials were included, among which ten trials involved knee OA, two involved cervical OA and one involved hand OA. The PEMF group showed more significant pain alleviation than the sham group in knee OA (standardised mean differences (SMD)=−0.54, 95% CI −1.04 to –0.04, p=0.03) and hand OA (SMD=−2.85, 95% CI −3.65 to –2.04, p<0.00001), but not in cervical OA. Similarly, comparing with the sham–control treatment, significant function improvement was observed in the PEMF group in both knee and hand OA patients (SMD=−0.34, 95% CI −0.53 to –0.14, p=0.0006, and SMD=−1.49, 95% CI −2.12 to –0.86, p<0.00001, respectively), but not in patients with cervical OA. Sensitivity analyses suggested that the exposure duration <=30 min per session exhibited better effects compared with the exposure duration >30 min per session. Three trials reported adverse events, and the combined results showed that there was no significant difference between PEMF and the sham group. Conclusions PEMF could alleviate pain and improve physical function for patients with knee and hand OA, but not for patients with cervical OA. Meanwhile, a short PEMF treatment duration (within 30 min) may achieve more favourable efficacy. However, given the limited number of study available in hand and cervical OA, the implication of this conclusion should be cautious for hand and cervical OA.

Background: Limited studies have examined the benefits of early arthroplasty within 48 h from admission to surgery for femoral neck fractures (FNFs). Using the national inpatient database, the authors aimed to investigate the trends in early arthroplasty within 48 h for FNFs in China and to assess its effect on in-hospital complications and 30-day readmission patterns. Materials and methods: This was a retrospective cohort study. Patients receiving primary total hip arthroplasty (THA) or hemiarthroplasty (HA) for FNFs in the Hospital Quality Monitoring System between 2013 and 2019 were included. After adjusting for potential confounders with propensity score matching, a logistic regression model was performed to compare the differences in in-hospital complications [i.e. in-hospital death, pulmonary embolism, deep vein thrombosis (DVT), wound infection, and blood transfusion], rates and causes of 30-day readmission between early and delayed arthroplasty. Results: During the study period, the rate of early THA increased from 18.0 to 19.9%, and the rate of early HA increased from 14.7 to 18.4% (P<0.001). After matching, 11 731 pairs receiving THA and 13 568 pairs receiving HA were included. Compared with delayed THA, early THA was associated with a lower risk of pulmonary embolism [odds ratio (OR) 0.51, 95% CI: 0.30–0.88], DVT (OR 0.59, 95% CI: 0.50–0.70), blood transfusion (OR 0.62, 95% CI: 0.55–0.70), 30-day readmission (OR 0.82, 95% CI: 0.70–0.95), and venous thromboembolism-related readmission (OR 0.50, 95% CI: 0.34–0.74). Similarly, early HA was associated with a lower risk of DVT (OR 0.70, 95% CI: 0.61–0.80) and blood transfusion (OR 0.74, 95% CI: 0.68–0.81) than delayed HA. Conclusion: Despite a slight increase, the rate of early arthroplasty remained at a low level in China. Given that early arthroplasty can significantly improve prognosis, more efforts are needed to optimize the procedure and shorten the time to surgery.

Objective To examine the analgesic efficacy and safety of ketamine after total knee or hip arthroplasty. Design Systematic review and meta-analysis. Data sources PubMed, EMBASE and Cochrane Library from inception to 22 May 2019. Eligibility criteria for selecting studies Randomised controlled trials comparing the efficacy and safety of ketamine with placebo for postoperative pain relief in patients undergoing total knee or hip arthroplasty. Data extraction and synthesis Data (ie, pain intensity, morphine consumption, gastrointestinal and psychotic adverse effects) were extracted by two reviewers independently. The Cochrane Collaboration’s recommended tool was used to determine the methodological quality of included studies. Results A total of 10 studies were included. One of them was rated as low quality. Compared with placebo, intravenous ketamine was effective for pain relief during 0–8-hour (weighted mean difference (WMD) −1.21, 95% CI −1.45 to −0.98, p<0.001; three studies, 149 participants) but not during 8–24-hour postoperative periods, and effective for reduction of cumulative morphine consumption during both 0–24-hour (WMD −17.76, 95% CI −31.25 to −4.27, p=0.01; five studies, 366 participants) and 0–48-hour (WMD −21.79, 95% CI −25.46 to −18.11, p<0.001; four studies, 252 participants) postoperative periods, without increasing risks of gastrointestinal or psychotic adverse effects. The limited data available for intra-articular (WMD −0.49, 95% CI −0.70 to −0.29, p<0.001; two studies, 83 participants) and epidural (WMD −2.10, 95% CI −3.30 to −0.90, p<0.001; one study, 20 participants) ketamine pointed to a significant reduction in pain intensity during 8–24-hour postoperative period. Conclusions Intravenous administration of ketamine is effective and safe for postoperative pain relief in patients undergoing total knee or hip arthroplasty. Nevertheless, the analgesic efficacy and safety of ketamine in such patients seem to vary by different administration routes and still warrant further studies to explore.

Background: We aimed to evaluate the efficacy and safety of biologic agents targeting three main cytokines, that is, nerve growth factor (NGF), interleukin-1 (IL-1), and tumor necrosis factor-α (TNF-α), for osteoarthritis (OA) treatment. Methods: Databases (PubMed, Embase, and Cochrane Library) and ClinicalTrials.gov were systematically searched for randomized placebo-controlled trials (RCTs) of biologic agents from inception to November 15, 2020. The outcomes were the mean change in pain, function scores, and the risk of adverse effects (AEs). Results: Out of the 28 studies with 29 RCTs (8555 individuals) included, biologic agents were superior to placebo in pain relief (standardized mean difference [SMD] = 0.28, 95% confidence interval [CI] = 0.17–0.38, p < 0.001) and function improvement (SMD = 0.30, 95% CI = 0.18–0.43, p < 0.001). The incidence of any AEs (risk ratio [RR] = 1.09, 95% CI = 1.05–1.14, p < 0.001) and discontinuations due to AEs (RR = 1.39, 95% CI = 1.05–1.83, p = 0.021) were higher following treatment with biologic agents while no significant difference was found in serious AEs. Subgroup analyses showed that NGF inhibitors provided superior pain relief (SMD = 0.36, 95% CI = 0.26–0.47, p < 0.001) and function improvement (SMD = 0.41, 95% CI = 0.30–0.51, p < 0.001), whereas IL-1 inhibitors and TNF-α inhibitors did not. Meanwhile, NGF inhibitors increased the incidence of any AEs (RR = 1.12, 95% CI = 1.07–1.17, p < 0.001) and discontinuations due to AEs (RR = 1.48, 95% CI = 1.07–2.06, p = 0.018). IL-1 inhibitors and TNF-α inhibitors showed no difference in safety compared with placebo. Conclusions: The efficacy and safety of biologic agents vary by mechanism of action. NGF inhibitors can relieve OA-related pain and improve function but involve safety concerns. IL-1 inhibitors and TNF-α inhibitors are relatively safe options but with limited efficacy.