Ilizarov method and its combined methods in the treatment of long bone defects of the lower extremity: systematic review and meta-analysis.

BACKGROUND: Ilizarov method has become one of primary methods for treating bone defects. Currently, there is growing trend in the application of modified Ilizarov methods (e.g., applying unilateral external fixators or with flap tissue) and its combined methods (e.g., Ilizarov method with antibiotic spacer or internal fixation) to manage bone defects. However, there is a lack of studies with systematical evaluation of the clinical effects of these evolving methods. This study aimed to conduct a systematic review and meta-analysis for overall evaluating the clinical effects on long bone defects of lower extremity in Ilizarov methods and its combined methods. METHODS: Studies were identified in three electronic databases (Pubmed, Embase and Cochrane Library) from the earliest indexing year through November 01, 2022, and relevant data were extracted subsequently. The total number of participants, number of participants with bone unions, bone result or functional result, and related complications including pin infection, pin loosening, pain, refracture, limb discrepancy, malalignment, joint stiffness, recurrent infection, and amputation were extracted in this study. Then, union rate (defined as the proportion of patients who achieved bone unions) and specific complication incidence rate (defined as the proportion of patients who experienced specific complication) were pooled estimated respectively. Relative risk (RR) was used for comparing the clinical effects among various Ilizarov technique. RESULTS: Sixty-eight case series studies, 29 comparative studies, and 3 randomized clinical trials were finally included. The union rate of Ilizarov methods was 99.29% (95% CI: 98.67% ~ 99.86%) in tibial defects and 98.81% (95% CI: 98.81% ~ 100.00%) in femoral defects. The union rate of Ilizarov method with antibiotic spacer and intramedullary nail in tibial defects was 99.58% (95% CI: 98.05% ~ 100.00%) and 95.02% (95% CI: 87.28% ~ 100.00%), respectively. Compared to the Ilizarov methods, the union rate of the Ilizarov method with antibiotic spacer in tibial defects increased slightly (RR = 1.02, 95% CI: 1.01 ~ 1.04). Meanwhile, compared to Ilizarov methods, we found lower excellent rate in bone result in Ilizarov method with antibiotic spacer, with the moderate to high heterogeneity. Compared to the Ilizarov method, lower rate of pin infection, higher rate of recurrent infection and amputation were observed in Ilizarov method with intramedullary nail, however, the findings about the comparison of pin infection and recurrent infection between the two groups were presented with high degree of statistical heterogeneity. CONCLUSION: Our study confirmed the reliable treatment of Ilizarov methods and its combined technique on long bone defects, and founded there were significant differences on some complications rate between Ilizarov methods and its combined technique. However, the findings need to be confirmed by further studies.

Association of 25-Hydroxyvitamin D with Preterm Birth and Premature Rupture of Membranes: A Mendelian Randomization Study.

Low vitamin D (VitD) level is a risk factor for preterm birth (PTB), but the results of previous studies remained inconsistent, which may be influenced by the confounding factors and different types of PTB. We performed Mendelian randomization (MR) to uncover the association of 25-hydroxyvitamin D (25(OH)D) with PTB, premature rupture of membranes (PROM), and preterm premature rupture of membranes (PPROM). This study was conducted in Zhoushan Maternal and Child Health Hospital, Zhejiang, from August 2011 to March 2022. Plasma 25(OH)D levels in three trimesters of pregnancy were measured. We conducted an MR analysis utilizing a genetic risk score (GRS) approach, which was based on VitD-associated single-nucleotide polymorphisms. The prospective cohort study included 3923 pregnant women. The prevalence of PTB, PROM, and PPROM were 6.09%, 13.18%, and 1.33%, respectively. Compared to those without vitamin D deficiency (VDD), only vaginally delivering pregnant women with VDD had a 2.69 (1.08-6.68) times risk of PTB. However, MR analysis did not support the association. One-unit higher GRS was not associated with an increased risk of PTB, regardless of the trimesters (OR [95% CI]: 1.01 [0.93-1.10], 1.06 [0.96-1.18], and 0.95 [0.82-1.10], respectively). When further taking PROM and PPROM as the outcomes, the MR analysis also showed no consistent evidence of a causal effect of VitD levels on the risk of them. Our MR analyses did not support a causal effect of 25(OH)D concentrations in the three trimesters on PTB, PROM, and PPROM.

The Association of Vitamin D during Pregnancy and mRNA Expression Levels of Inflammatory Factors with Preterm Birth and Prelabor Rupture of Membranes.

The aim of this study was to elucidate the association between vitamin D (VD) and the risk for preterm birth (PTB) and prelabor rupture of membranes (PROM). This study included two parts, with a cohort study and a case-control study. Plasma 25-hydroxyvitamin vitamin D [25(OH)D] levels in three trimesters in the cohort study and maternal 25(OH)D before delivery in the case-control study were measured. Quantitative real-time PCR was used to detect relative mRNA expression levels of the inflammatory factors associated with pyroptosis in peripheral blood mononuclear cell (PBMC), placenta and fetal membranes. Multinomial logistic regression and the Wilcoxon test were applied to analyze the associations. In the cohort study, 6381 pregnant women were included. We found that VD deficiency in T3 (PTB without PROM: OR = 1.90, 95% CI: 1.02-3.55, Term PROM (TPROM): OR = 0.76, 95% CI: 0.59-0.98) and less change of 25(OH)D between T1 and T3 (PTB without PROM: OR = 2.32, 95% CI: 1.07-5.06, TPROM: OR = 0.73, 95% CI: 0.56-0.96) were associated with the increased risk of PTB without PROM, while there was a decreased risk of TPROM. Neither VD, nor the increase of VD during pregnancy was associated with the premature rupture of membranes preterm delivery (PPROM). In the case-control study, there were no associations between VD during delivery and PTB or PROM (TPROM: OR = 1.33, 95% CI: 0.52-3.44); PTB without PROM: OR = 1.66, 95% CI: 0.33-8.19; PPROM: OR = 1.19, 95% CI: 0.42-3.40). The mRNA expression of NLRP1 (NOD-like receptor thermal protein domain associated protein 1) (p = 0.0165) in PBMC in the TPROM group was higher than that in the term group, and IL-18 (p = 0.0064) was lower than that in the term group. Plasma 25(OH)D in T3 and the increase of 25(OH)D between T1 and T3 were associated with a lower risk for PTB without PROM but a higher risk for TPROM. Further studies are warranted to clarify the association between VD and PTB and PROM and its mechanism.

Serial recombination during circulation of type 1 wild-vaccine recombinant polioviruses in China.

Type 1 wild-vaccine recombinant polioviruses sharing a 367-nucleotide (nt) block of Sabin 1-derived sequence spanning the VP1 and 2A genes circulated widely in China from 1991 to 1993. We surveyed the sequence relationships among 34 wild-vaccine recombinants by comparing six genomic intervals: the conserved 5'-untranslated region (5'-UTR) (nt 186 to 639), the hypervariable portion of the 5'-UTR (nt 640 to 742), the VP4 and partial VP2 genes (nt 743 to 1176), the VP1 gene (nt 2480 to 3385), the 2A gene (nt 3386 to 3832), and the partial 3D gene (nt 6011 to 6544). The 5'-UTR, capsid (VP4-VP2 and VP1), and 2A sequence intervals had similar phylogenies. By contrast, the partial 3D sequences could be distributed into five divergent genetic classes. Most (25 of 34) of the wild-vaccine recombinant isolates showed no evidence of additional recombination beyond the initial wild-Sabin recombination event. Eight isolates from 1992 to 1993, however, appear to be derived from three independent additional recombination events, and one 1993 isolate was derived from two consecutive events. Complete genomic sequences of a representative isolate for each 3D sequence class demonstrated that these exchanges had occurred in the 2B, 2C, and 3D genes. The 3D gene sequences were not closely related to those of the Sabin strains or 53 diverse contemporary wild poliovirus isolates from China, but all were related to the 3D genes of species C enteroviruses. The appearance within approximately 2.5 years of five recombinant classes derived from a single ancestral infection illustrates the rapid emergence of new recombinants among circulating wild polioviruses.