Background: Rheumatoid arthritis (RA) is a key health issue worldwide. Due to early identification and effective treatment strategies, the disease pattern of RA has also changed. However, the most comprehensive and up-to-date information about the burden of RA and its trends in subsequent years is lacking. Objective: this study aimed to report the global burden of RA by sex, age, region, and forecast for 2030. Method: Publicly available data from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019 were used in this study. The trends in the prevalence, incidence, and disability-adjusted life years (DALYs) of RA from 1990 to 2019 were reported. The global burden of RA in 2019 was reported by a sex, age, and sociodemographic index (SDI). Finally, the trends in the following years were predicted by Bayesian age-period-cohort (BAPC) models. Results: Globally, the age-standardized prevalence rate increased from 207.46 (95% UI:189.99 to 226.95) in 1990 to 224.25 (95% UI: 204.94 to 245.99) in 2019, with an estimated annual percent change (EAPC) of 0.37% (95% CI: 0.32 to 0.42). Regarding the incidence, the age-standardized incidence rate (ASR) increased from 12.21 (95% UI: 11.13 to 13.38) to 13 (95% UI: 11.83 to 14.27) per 100,000 people from 1990 to 2019, with an EAPC of 0.3% (95% CI: 11.83 to 14.27). The age-standardized DALY rate also increased from 39.12 (95% UI: 30.13 to 48.56) per 100,000 people in 1990 to 39.57 (95% UI: 30.51 to 49.53) in 2019, with an EAPC of 0.12% (95% CI: 0.08% to 0.17%). There was no significant association between the SDI and ASR when the SDI was lower than 0.7, while there was a positive association between the SDI and ASR when the SDI was higher than 0.7 The BAPC analysis showed that the ASR was estimated to be up to 18.23 in females and approximately 8.34 per 100,000 people in males by 2030. Conclusion: RA is still a key public health issue worldwide. The global burden of RA has increased over the past decades and will continue to increase in the coming years, and much more attention should be given to early diagnosis and treatment to reduce the burden of RA.

Background: Adiposity is closely related to osteoarthritis, but the causal effects of different types of adiposity on osteoarthritis are indistinct. This study conducted a Mendelian Randomization (MR) analysis for the causal effects of general adiposity and abdominal adiposity on knee osteoarthritis (KOA) and hip osteoarthritis (HOA). Methods: The general adiposity was assessed by body mass index (BMI), while the abdominal adiposity was evaluated with waist circumference (WC), hip circumference (HC), and waist-to-hip ratio (WHR). The data used in this two-sample MR analysis originated from genome-wide association studies (GWAS). Significant (p < 5 × 10⁻⁸) and independent (r² < 0.01) single-nucleotide polymorphisms were selected as instrumental variables for the MR analysis. Subsequently, this study used the inverse variance weighted, weighted median, and other methods for the causal inference, and the results were presented as odds ratios (OR). Moreover, sensitivity analyses were conducted to assess the stability and reliability of the results. Results: The MR results revealed positive causal effects of BMI on KOA (OR: 1.694; 95% CI: from 1.492 to 1.923; p = 3.96 × 10⁻¹⁶) and HOA (OR: 1.412; 95% CI: from 1.196 to 1.666; p = 4.58 × 10⁻⁵). Additionally, WC and HC both positively and causally related to KOA (WC: OR: 1.827; 95% CI: from 1.564 to 2.134; p = 2.68 × 10⁻¹⁴; HC: OR: 1.610; 95% CI: from 1.357 to 1.912; p = 5.03 × 10⁻⁸) and HOA (WC: OR: 1.491; 95% CI: from 1.254 to 1.772; p = 5.85 × 10⁻⁶; HC: OR: 1.439; 95% CI: from 1.205 to 1.719; p = 5.82 × 10⁻⁵). However, no causal relationship existed between WHR and obesity. These results were robust according to the sensitivity analyses. Conclusions: This study indicated that both general and abdominal obesity had positive causal effects on knee osteoarthritis and hip osteoarthritis.

Background: The relationship between obesity and osteoporosis is an important public health issue. The goal of this study was to investigate whether and to what extent central obesity traits affect bone mineral density (BMD). Methods: We conducted a two-sample Mendelian randomization analysis. Genomewide significant single nucleotide polymorphisms associated with waist circumference, hip circumference, waist-to-hip ratio, waist circumference adjusted by body mass index (WCadjBMI), hip circumference adjusted by BMI (HCadjBMI) and waist-to-hip ratio adjusted by BMI (WHRadjBMI) were obtained from a large-scale database containing 224,459 samples. The BMD summary dataset was obtained from a UK Biobank database including 265,627 participants. Results: The results provided strong evidence that the HCadjBMI trait was causally and negatively associated with BMD (β: − 0.135, 95% CI − 0.216 to − 0.054; P = 0.001), while the WHR trait was causally and positively associated with BMD (β: 0.194, 95% CI 0.062 to 0.325, P = 0.004). No significant effects were observed for other traits on BMD. Conclusions: This study indicates variations in the abilities of different central obesity traits to influence BMD. These results should be considered in further studies and public health measures on obesity and osteoporosis prevention strategies.

Obesity is a risk factor for total knee arthroplasty (TKA). Wound dehiscence and surgical site infections (SSIs) are the main complications of TKA in patients with obesity. They can profoundly affect patients because they often require readmission, additional surgical interventions, lengthy intravenous antibiotic administration, and delayed rehabilitation. Negative pressure wound therapy (NPWT) exposes the wound site to negative pressure, resulting in the improvement of blood supply, removal of excess fluid, and stimulation of cellular proliferation of granulation tissue. This study aims to assess the incidence of wound dehiscence and SSIs in patients with obesity undergoing TKA after the routine use of NPWT. This sduty enrolled adult patients with obesity who underwent TKA within 8 years. A total of 360 adult patients with obesity (NPWT: 150, non-NPWT: 210) underwent TKA, and the baseline characteristics were similar between the 2 groups. Compared with the non-NPWT group, the NPWT group had a 50% lower incidence of wound dehiscence (3.33% vs 9.52%; P < .05) and a significantly lower incidence of SSIs (11.33% vs 25.24%; P < .05), including prosthetic joint infection (4.0% vs 10.0%; P < .05) and superficial wound infection (7.33% vs 15.24%; P < .05). In addition, the NPWT group had a lower need to return to the operating room for new interventions for any reason (2.67% vs 9.05%; P = .0107) than the non-NPWT group. Conventional incision NPWT can significantly reduce the incidence of wound dehiscence and SSIs in patients with obesity after TKA.

Background: How the hip dysplasia affects the spinopelvic alignment in developmental dysplasia of the hip (DDH) patients is unclear, but it is an essential part for the management of this disease. This study aimed to investigate the coronal and sagittal spinopelvic alignment and the correlations between the spinopelvic parameters and the extent of hip dysplasia or the low back pain in unilateral DDH patients.Methods: From September 2016 to March 2021, 22 unilateral patients were enrolled in the DDH group with an average age of 43.6 years and 20 recruited healthy volunteers were assigned to the control group with an average age of 41.4 years. The Cobb angle, seventh cervical vertebra plumbline–central sacral vertical line (C7PL–CSVL), third lumbar vertebra inclination angle (L3IA), pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS), thoracic kyphosis (TK), thoracolumbar kyphosis (TLK) and lumbar lordosis (LL) were measured on the standing anteroposterior and lateral full-length standing spine radiographs. Additionally, the Oswestry Disability Index (ODI) and Japanese Orthopaedic Association Back Pain Evaluation Questionnaire (JOABPEQ) were used to assess the degree of low back pain.Results: Cobb angle (8.68 ± 6.21° vs. 2.31 ± 0.12°), L3IA (4.80 ± 5.47° vs. 0.83 ± 0.51°), C7PL–CSVL (1.65 ± 1.57 cm vs. 0.48 ± 0.33 cm), PT (15.02 ± 9.55° vs. 9.99 ± 2.97°) and TLK (7.69 ± 6.66° vs. 3.54 ± 1.63°) were significantly larger in DDH patients, whereas LL (37.41 ± 17.17° vs. 48.79 ± 7.75°) was significantly smaller (P < 0.05). No correlation was found between significantly different spinopelvic parameters and the extent of dysplasia. Statistical analysis revealed correlations between ODI and Cobb angle (r = 0.59,P < 0.01), PT (r = 0.49,P = 0.02), TK (r = −0.46, P = 0.03) and TLK (r = 0.44,P = 0.04). Correlations between JOABPQE score and the Cobb angle (r = −0.44,P = 0.04), L3IA (r = −0.53,P = 0.01), PT (r = −0.44,P = 0.04), and TK (r = 0.46,P = 0.03) were also observed.Conclusions: Cobb angle, L3IA, C7PL–CSVL in coronal plane and PT, TLK in sagittal plane increased, while LL decreased in unilateral DDH patients. These significantly different spinopelvic parameters have no correlation with the extent of dysplasia. Changes in coronal and sagittal plane including Cobb angle, L3IA, PT, TK and TLK were associated with the low back pain in the patients with unilateral DDH.