Comparison of ultra-congruent mobile- and fixed-bearing navigation-assisted total knee arthroplasty with minimum 5-year follow-up

Purpose

The purpose of this study was to compare the midterm outcomes between fixed and mobile ultra-congruent (UC) bearings in total knee arthroplasty (TKA).

Methods

This is a retrospective matched-pairs case–control study of patients who underwent primary navigation-assisted TKA with a minimum 5-year follow-up. A total of 182 cases involved the fixed UC bearing system as Group 1 and 101 cases involved mobile UC bearing system group as Group 2. After 1:1 matching, 73 knees in each group were enrolled. Clinical and radiographic outcomes were evaluated.

Results

The overall survival was 143 of 146 cases (97.9 %) at final follow-up, and 72 of 73 cases (96.3 %) in Group 1 and 71 of 73 cases (95.8 %) in Group 2 at final follow-up based on an endpoint of revision surgery. The reasons of revision TKA were periprosthetic fracture in Group 1, infection and bearing dislocation in Group 2. There was no statistical difference in Hospital for Special Surgery (HSS) scores, Knee Society Scores (KSS), WOMAC index score evaluations between groups.

Conclusions

This study demonstrated that the fixed-bearing UC prosthesis could provide satisfactory performance compared with that of the mobile-bearing UC prosthesis with minimum 5-year follow-up. The fixed-bearing UC prosthesis could be considered in navigation-assisted TKA with theoretical advantages of UC design.

Level of evidence

IV.

     

Small area variations in low birth weight and small size of births in India

The states and districts are the primary focal points for policy formulation and programme intervention in India. The within‐districts variation of key health indicators is not well understood and consequently underemphasised. This study aims to partition geographic variation in low birthweight (LBW) and small birth size (SBS) in India and geovisualize the distribution of small area estimates. Applying a four‐level logistic regression model to the latest round of the National Family Health Survey (2015–2016) covering 640 districts within 36 states and union territories of India, the variance partitioning coefficient and precision‐weighted prevalence of LBW (<2.5 kg) and SBS (mother''s self‐report) were estimated. For each outcome, the spatial distribution by districts of mean prevalence and small area variation (as measured by standard deviation) and the correlation between them were computed. Of the total valid sample, 17.6% (out of 193,345 children) had LBW and 12.4% (out of 253,213 children) had SBS. The small areas contributed the highest share of total geographic variance in LBW (52%) and SBS (78%). The variance of LBW attributed to small areas was unevenly distributed across the regions of India. While a strong correlation between district‐wide percent and within‐district standard deviation was identified in both LBW (r = 0.88) and SBS (r = 0.87), they were not necessarily concentrated in the aspirational districts. We find the necessity of precise policy attention specifically to the small areas in the districts of India with a high prevalence of LBW and SBS in programme formulation and intervention that may be beneficial to improve childbirth outcomes.     

Impact of timing of renal replacement therapy initiation on outcome of septic acute kidney injury

Introduction

Sepsis is the leading cause of acute kidney injury (AKI) in critical patients. The optimal timing of initiating renal replacement therapy (RRT) in septic AKI patients remains controversial. The objective of this study is to determine the impact of early or late initiation of RRT, as defined using the simplified RIFLE (risk, injury, failure, loss of kidney function, and end-stage renal failure) classification (sRIFLE), on hospital mortality among septic AKI patients.

Methods

Patient with sepsis and AKI requiring RRT in surgical intensive care units were enrolled between January 2002 and October 2009. The patients were divided into early (sRIFLE-0 or -Risk) or late (sRIFLE-Injury or -Failure) initiation of RRT by sRIFLE criteria. Cox proportional hazard ratios for in hospital mortality were determined to assess the impact of timing of RRT.

Results

Among the 370 patients, 192 (51.9%) underwent early RRT and 259 (70.0%) died during hospitalization. The mortality rate in early and late RRT groups were 70.8% and 69.7% respectively (P > 0.05). Early dialysis did not relate to hospital mortality by Cox proportional hazard model (P > 0.05). Patients with heart failure, male gender, higher admission creatinine, and operation were more likely to be in the late RRT group. Cox proportional hazard model, after adjustment with propensity score including all patients based on the probability of late RRT, showed early dialysis was not related to hospital mortality. Further model matched patients by 1:1 fashion according to each patient's propensity to late RRT showed no differences in hospital mortality according to head-to-head comparison of demographic data (P > 0.05).

Conclusions

Use of sRIFLE classification as a marker poorly predicted the benefits of early or late RRT in the context of septic AKI. In the future, more physiologically meaningful markers with which to determine the optimal timing of RRT initiation should be identified.     

The effects of NOS1 gene on asthma and total IgE levels in Taiwanese children,and the interactions with environmental factors

Wang T‐N, Tseng H‐I, Kao C‐C, Chu Y‐T, Chen W‐Y, Wu P‐F, Lee C‐H, Ko Y‐C. The effects of NOS1 gene on asthma and total IgE levels in Taiwanese children, and the interactions with environmental factors.
Pediatr Allergy Immunol 2010: 21: 1064–1071.
© 2010 John Wiley & Sons A/S Asthma is a complex disorder, which is known to be affected by interactions between genetic and environmental factors. The aim of this study was to investigate the three microsatellite polymorphisms of GT repeats in intron 2, AAT repeats in intron 20, and CA repeats in exon 29 of the NOS1 gene in 155 asthmatic children and 301 control children, and the interaction with environmental factors in southern Taiwan. Total serum IgE, phadiatop test and genetic polymorphisms were measured. The genotype frequency of 14/14‐AAT repeats of the NOS1 gene was significantly higher in the asthmatic group (p = 0.01). Total IgE concentrations were higher in asthmatic children (p = 0.015) carrying the NOS1 14/14‐AAT genotype than in subjects with other polymorphisms. The gene and environmental interaction effects were 3.83‐fold, 6.86‐fold, and 8.04‐fold (all corrected p‐values <0.001) between subjects carrying at least one NOS1 14‐AAT allele and exposure to cockroaches, high levels of total IgE, and positive response against the phadiatop test in asthmatic children. The findings of this study provide strong evidence that NOS1 gene with 14‐AAT tandem repeats has a significant effect in asthmatic children. Environmental factors and atopic status will enhance the asthmatic risk for children who carry NOS1 susceptible allele.     

Contribution of B7RP‐1/ICOS co‐stimulation to lethal acute GVHD

Fujimura J, Takeda K, Kaduka Y, Saito M, Akiba H, Yagita H, Yamashiro Y, Shimizu T, Okumura K. Contribution of B7RP‐1/ICOS co‐stimulation to lethal acute GVHD.
Pediatr Transplantation 2010: 14:540–548. © 2010 John Wiley & Sons A/S. Abstract: Co‐stimulatory molecules expressed on T cells critically regulate donor T‐cell activation and are implicated in acute GVHD after allogeneic BMT. We here investigated the role of interaction between B7‐related protein‐1 (B7RP‐1) and ICOS in murine acute GVHD model that received T cell‐depleted BM cells and splenocytes. Administration of blocking anti‐B7RP‐1 mAb significantly reduced the lethality and symptoms in acute GVHD. A significant hypo‐responsiveness of splenocytes to host alloantigen was observed in the recipient mice treated with anti‐B7RP‐1 mAb. Moreover, acute GVHD was significantly reduced in the recipients of T cells composed of ICOS‐deficient CD8 T cells and WT CD4 T cells compared with that in the recipients of T cells composed of WT CD8 T cells and ICOS‐deficient CD4 T cells. These results suggested that B7RP‐1/ICOS co‐stimulatory signal plays a role in the activation of alloantigen‐reactive donor T cells, particularly in CD8 T cells, in murine acute GVHD model, and that the blockade of B7RP‐1/ICOS interaction may be useful for selectively manipulating allo‐reactive T cells in the recipients with acute GVHD.     

Revision of a furosemide-loading vestibular-evoked myogenic potential protocol for detecting endolymphatic hydrops

Objective: The presence of endolymphatic hydrops can be suggested by improving the amplitude of vestibular-evoked myogenic potential (VEMP) after furosemide administration (furosemide loading VEMP [FVEMP]). The authors aimed to determine a stimulation frequency and judgment criteria to ascertain whether a revised FVEMP protocol can be applied to clinical settings.

Methods: The study included 25 individuals with unilateral Meniere’s disease (MD) and 11 normal healthy volunteers. Normalized amplitude of VEMP, using a tone burst sound at 250, 500, 700, 1000, 1500 and 2000?Hz, was measured before and after furosemide administration in the two groups. Improvement ratio (IR) of amplitude was calculated at each frequency.

Results: There were no significant differences in IR between the control group and the MD group at each frequency, except at 500?Hz. Receiver operating characteristic curve analysis revealed an IR cut-off value of 14.2% at 500?Hz, with a sensitivity of 0.706 and a specificity of 0.810.

Conclusions: The revised FVEMP protocol using a 500?Hz tone burst stimulus and normalized amplitudes was defined as positive when IR exceeded 14.2% or when a biphasic wave could be detected after furosemide administration in cases without a detectable biphasic wave before administration.     

Do local anesthetics interact preferentially with membrane lipid rafts? Comparative interactivities with raft-like membranes

Membranous lipid bilayers have been reconsidered as the site of action of local anesthetics (LAs). Recent understanding of biomembranes indicates the existence of lipid raft microdomains enriched in cholesterol and sphingolipids as potential platforms for channels and receptors. Based on the hypothesis that LAs may interact preferentially with lipid rafts over non-raft membranes, we compared their effects on raft model membranes and cardiolipin-containing biomimetic membranes. Liposomes were prepared with phospholipids, sphingomyelin, cerebroside, and cholesterol to have compositions corresponding to lipid rafts and cardiomyocyte mitochondrial membranes. After reacting LAs (50–200 μM) with the membrane preparations, their interactivities were determined by measuring fluorescence polarization with 1,6-diphenyl-1,3,5-hexatriene. Although bupivacaine and lidocaine acted on different raft-like liquid-ordered membranes to reduce polarization values, their effects on biomimetic less ordered membranes were much greater. LAs interacted with biomimetic membranes with the potency being R(+)-bupivacaine > racemic bupivacaine > S(−)-bupivacaine > ropivacaine > lidocaine > prilocaine, which is consistent with the rank order of pharmacotoxicological potency. However, raft model membranes showed neither structure-dependence nor stereoselectivity. The relevance of membrane lipid rafts to LAs is questionable at least in their effects on raft-like liquid-ordered membranes.