Degraded and osteogenic property of coated magnesium alloy was evaluated for the fracture fixation in rabbits. Magnesium alloy AZ31 with a different coating thickness by microarc oxidation was used, and the bilateral radial fracture model was created by the bite bone clamp. Thirty-six New Zealand white rabbits in weight of 2.5~3.0 kg were randomly divided into A, B, and C groups at four time points and other 3 rabbits as the control group without magnesium alloy. Coated magnesium alloy AZ31 was implanted on the fracture and fixed with silk thread. Indexes such as general observation, histology, X-ray, hematology, and mechanical properties were observed and detected at 2nd, 4th, 8th, and 12th week after implantation. Fracture in each rabbit was healed at 12th week after implantation. Among the three groups, the best results of general observation, histology, and X-ray appeared in A group without coating. However, A group showed the worst results from the perspective of mechanical properties about tensile strength and flexural strength, which failed to reach that of the natural bone at the 12th week. Comprehensive results displayed that C group with 20-μm coating was better than others in mechanical properties, while there is no difference between B and C groups in hematology. Degradation rate is inversely proportional to the coating thickness. And magnesium alloy with a 20-μm coating is more suitable for the fracture fixation.

Among osteoarthritis (OA) subtypes, hand osteoarthritis (HOA) is the fastest-growing by estimated annual percentage change in age-standardized rates and percentage change in case numbers. Yet its burden in adults aged ≥55 years, who are disproportionately affected, has not been systematically quantified. Using Global Burden of Disease 2021 data, we assessed the global burden of HOA in this age group. Trends were analyzed using estimated annual percentage change and percentage change, and future projections were made using an autoregressive integrated moving average model. From 1990 to 2021, incident cases, prevalent cases, and years lived with disability (YLDs) in this age group increased by 3.13 million, 95.32 million, and 2.99 million, accounting for 51.40%, 80.80%, and 79.95% of total increases in the general population, respectively. In 2021, there were 5.13 million incident cases, 154.68 million prevalent cases, and 4.86 million YLDs, representing 49.52%, 79.61%, and 78.77% of the global burden, respectively, with corresponding age-standardized rates of 2.89, 4.71, and 4.66 times those in the general population. China, India, the United States, Japan, Russia, and Brazil together accounted for over 54% of incident cases, prevalent cases, and YLDs. By 2050, incident cases, prevalent cases, and YLDs are projected to reach 8.99 million, 292 million, and 8.96 million, respectively, with corresponding age-standardized rates of 2.57, 5.13, and 5.01 times those in the general population. The growth in HOA burden in this age group over the past 3 decades and through 2050 exceeds that of other osteoarthritis subtypes. The burden of HOA in adults aged ≥55 years is disproportionately high and is increasing faster than any other osteoarthritis subtype, with 6 countries (China, India, the United States, Japan, Russia, and Brazil) bearing the heaviest absolute burden. Thus, HOA in this age group has emerged as a global challenge demanding sufficient attention.