Prevalence of lumbopelvic pain during pregnancy: A systematic review and meta-analysis of cross-sectional studies.

INTRODUCTION: Lumbopelvic pain (LPP) is common in pregnant women and has a significant negative effect on physical and psychological health. In this study, for the first time, we conduct a meta-analysis to estimate the overall prevalence of LPP among pregnant women and clarify the reasons for the differences in the estimated results. MATERIAL AND METHODS: A systematic search of four databases (PubMed, Embase, Web of Science and Cochrane Central Register of Controlled Trials) was conducted from inception until October 2022. Two reviewers conducted a methodological quality assessment. Random-effects model analysis was used to estimate the pooled prevalence and the 95% confidence interval. Chi-square tests and I2 -values were used to assess the heterogeneity. Subgroup analysis (according to the participants' continent, age, body mass index [BMI], gestational age and study risk of bias), sensitivity analysis and random-effects meta-regression were used to explore the the sources of heterogeneity. RESULTS: Of the 1661 unique citations, 38 studies (21 533 pregnant participants) were included in this systematic review and meta-analysis. The overall pooled prevalence of LPP during pregnancy was 63% (95% CI: 0.57 to 0.69), with significant heterogeneity (I2 = 99.1%, P < 0.001). The prevalence differed by participants' continents, 71% (North America), 74% (South America), 63% (Asia), 64% (Europe), 59% (Africa) and 45% (Oceania). The prevalence differed by BMI, 64% (BMI <25), 64% (25 ≤ BMI ≤ 28), and 71% (BMI >28). The prevalence differed by age, 72% (age <25 years), 58% (25 ≤ age ≤ 30 years), and 69% (age >30 years). The prevalence were the same differed by study risk of bias, 63% (both low and moderate risk of bias studies). The prevalence were similar by gestational age, 62% (second trimester) and 63% (third trimester). CONCLUSIONS: Lumbopelvic pain during pregnancy is common; about three-fifths of pregnant women experience LPP. More prevention and intervention research for lumbopelvic should be conducted in pregnant women with different clinical characteristics.

Comparative Study on Pore Characteristics and Mechanical Properties of Solid and Sheet TPMS Models / 医用生物力学

Objective To analyze and compare pore characteristics and mechanical properties of models with solid and sheet triply periodic minimal surface (TPMS) structures, and build a porous structure with high specific surface area, low stiffness and high strength. Methods The solid TPMS and sheet TPMS models of D, G, and P units with the same porosity were established, and pore characteristics of the model such as pore diameter, rod diameter and specific surface area were compared; mechanical properties of the model were analyzed by finite element method. The porous titanium samples were made by additive manufacturing technology, pore characteristics of porous titanium were observed by microscope and scanning electron microscope, and mechanical properties of porous titanium were detected by compression test. Results The specific surface area of the sheet structure with the same unit was significantly higher than that of the solid structure; mechanical properties of the sheet structure with the same were significantly better than those of the solid structure. Among them, the D unit sheet TPMS model had the most significant advantages, with the specific surface area of 13.00 mm-1, and the elastic modulus, yield strength and compressive strength of the sheet porous titanium sample were (5.65±0.08) GPa, (181.03±1.30) MPa and (239.83±0.45) MPa, respectively, which were 43.87%, 55.08% and 67.21% higher than those of the solid porous titanium sample. Conclusions While retaining low rigidity of the porous structure, the sheet TPMS model of the same unit has a larger specific surface area, which is beneficial for cell adhesion and growth, and its low stiffness and high strength mechanical properties can effectively reduce stress shielding and provide sufficient mechanical support. It is an ideal pore structure model for bone defect repair substitutes.