BACKGROUND: Exploring the research status and development trend of femomacetabular impingement, and finding out the research direction and hot spot of femomacetabular impingement are helpful for domestic scholars to grasp the latest information in this field and explore the most cutting-edge treatment direction. OBJECTIVE: To explore the research status and the development trend of femoroacetabular impingement in the world. METHODS: The science citation index of Wed of Science core collection was used to retrieve English literature on femoroacetabular impingement from January 1, 2005 to February 20, 2020. The bibliometric methods were used to conduct data statistics and analysis. Meanwhile, VOS viewer software was used for visualization conversion to analyze the research status and the development trend of femoroacetabular impingement. RESULTS AND CONCLUSION: (1) Totally 3 158 literatures were included. The literatures concerning global scientific research of femoroacetabular impingement are increasing year by year. The number of the United States published is largest. The United States makes the greatest contribution in the world, ranking the top (1 659 papers), whose number of the citations (37 019 papers) and H index (87 papers) are the highest. The number of literatures is 43 in China. It ranks 14 and the citations are 301; H index is 9. (2) ARTHROSCOPY-THE JOURNAL OF ARTHROSCOPIC AND RELATED SURGERY who contributed the largest number of relevant literatures (426 papers) is more than of the second magazine (287 papers) named AMERICAN JOURNAL OF SPORTS MEDICINE. UNIV BERN (University of Bern) and HOSP SPECIAL SURG (Hospital for Special Surgery) are two institutions which have the largest amount of research publications. (3) Currently, the research topics on femoroacetabular impingement are focusing on five areas, including epidemiology, disease progression, diagnosis, treatment and prognosis. In recent years, the primary field of research is treatment and the hip arthroscopic operation becomes a research hotspot. (4) From the analysis on the current development trend of femoroacetabular impingement, there is still very big exploration space in this area and the number of published literatures continuous increases. The United States remains a leader in this field. The further study is required in China. In recent years, the research direction focuses on the aspect of treatment of femoroacetabular impingement. Hip arthroscopic operation is research focus on femoroacetabular impingement.

BACKGROUND:Overactive osteoclasts disrupt bone homeostasis and play a bad role in the pathological mechanisms of related skeletal diseases,such as osteoporosis,fragility fractures,and osteoarthritis.Studies have confirmed that ellagic acid and ellagtannin have the potential to inhibit osteoclast differentiation.As their natural metabolites,urolithin A has antioxidant,anti-inflammatory,anti-proliferative and anti-cancer effects,but its effect on osteoclast differentiation and its underlying molecular mechanisms remain unclear. OBJECTIVE:To explore the effect of urolithin A on osteoclast differentiation induced by receptor activator for nuclear factor-κB ligand and its mechanism. METHODS:Mouse mononuclear macrophage leukemia cells(RAW264.7)that grew stably were cultured in vitro.Toxicity of urolithin A(0,0.1,0.5,1.5,2.5 μmol/L)to RAW264.7 cells were detected by cytotoxic MTS assay to screen out the safe concentration.Different concentrations of urolithin A were used again to intervene with receptor activator for nuclear factor-κB ligand-induced differentiation of RAW264.7 cells in vitro.Then,tartrate-resistant acid phosphatase staining and F-actin ring and nucleus staining were performed to observe its effect on the formation and function of osteoclasts.Finally,the expressions of urolithin A on upstream and downstream genes and proteins in the MAPK signaling pathway were observed by western blot and RT-qPCR assays. RESULTS AND CONCLUSION:Urolithin A inhibited osteoclast differentiation and F-actin ring formation in a concentration-dependent manner and 2.5 μmol/L had the strongest inhibitory effect.Urolithin A inhibited the mRNA expression of Nfatc1,Ctsk,Mmp9 and Atp6v0d2 and the protein synthesis of Nfatc1 and Ctsk,related to osteoclast formation and bone resorption.Urolithin A inhibited the activity of osteoclasts by downregulating the phosphorylation of p38 protein to inhibit the mitogen-activated protein kinase signaling pathway.