Increased Mortality with the Use of Cementless Fixation for Femoral Neck Fractures: Analysis of 5883 Hip Arthroplasty Cases.

BACKGROUND: The use of cemented fixation for hip arthroplasty for femoral neck fractures has been advocated to limit the postoperative and intraoperative risk of periprosthetic fractures. However, there are concerns with the potential effects of cementing on patient mortality, particularly at the time of cementation. METHODS: This study examined the mortality rates of cemented compared to cementless hip arthroplasty fixation in a group of 5883 femoral neck fracture patients from 2001 to 2017. The data were derived from large administrative databases and census data. Confounders were identified and controlled with a multivariate analysis. The data were also stratified into 2 time frames, 2001-2008 and 2009-2017, to determine if there was an effect of more recent improvements in patient care or implant technology. RESULTS: Cemented fixation had a statistically significant reduction in mortality rates at 30, 90, and 365 days after surgery. There was no difference in mortality in 0, 1, or ≤7 days after discharge or during the admission. The mortality rate decreased but was still significantly increased with cementless fixation when the subjects were grouped from 2001 to 2008 and 2009 to 2017. CONCLUSION: Based on this evidence, the cemented fixation of hip arthroplasty should be considered for patients with femoral neck fractures.

Total cost of surgical site infection in the two years following primary knee replacement surgery.

OBJECTIVE: The disease burden of surgical site infection (SSI) following total knee (TKA) replacement is considerable and is expected to grow with increased demand for the procedure. Diagnosing and treating SSI utilizes both inpatient and outpatient services, and the timing of diagnosis can affect health service requirements. The purpose of this study was to estimate the health system costs of infection and to compare them across time-to-diagnosis categories. METHODS: Administrative data from 2005-2016 were used to identify cases diagnosed with SSI up to 1 year following primary TKA. Uninfected controls were selected matched on age, sex and comorbidities. Costs and utilization were measured over the 2-year period following surgery using hospital and out-of-hospital data. Costs and utilization were compared for those diagnosed within 30, 90, 180, and 365 days. A subsample of cases and controls without comorbidities were also compared. RESULTS: We identified 238 SSI cases over the study period. On average, SSI cases cost 8 times more than noninfected controls over the 2-year follow-up period (CaD$41,938 [US$29,965] vs CaD$5,158 [US$3,685]) for a net difference of CaD$36,780 (US$26,279). The case-to-control ratio for costs was lowest for those diagnosed within 30 days compared to those diagnosed later. When only patients without comorbidities were included, costs were >7 times higher. CONCLUSION: Our results suggest that considerable costs result from SSI following TKA and that those costs vary depending on the time of diagnosis. A 2-year follow-up period provided a more complete estimate of cost and utilization.

Measuring Surgical Site Infection From Linked Administrative Data Following Hip and Knee Replacement.

BACKGROUND: Surgical site infections (SSIs) in hip and knee arthroplasty are increasing internationally. Current trends in SSI monitoring use single source administrative databases with data collection points commonly at 30 or 90 days. We hypothesize that SSI rates are being under-reported due to methodological biases. METHODS: Data from multiple administrative data sets were contrasted and compared to look at the 90-day SSI rates for hip and knee arthroplasty in a single province from 2001 to 2015. SSI rates were calculated over time by year, and the differences in infection rates between single and multiple administrative data sets were calculated as an estimate of under reporting rates of SSIs. Days until diagnosis was measured for those diagnosed with an infection within 1 year. RESULTS: Combining administrative data sets indicates that hospital-based data underestimate SSI rates by 0.44 (P < .0001) of a percentage point over all years, a clinically significant result given the overall infection rate of 2.2% over the period. Less than 50% of hip and knee arthroplasty was recorded as infected by 30 days and approximately 75% of cases were recorded as infected by 90 days. CONCLUSION: Single source administrative data sets and short follow-up periods underestimate SSI rates. Administrative data sets should be combined and a minimum follow-up period of 90 days should be used to more accurately track SSI rates in hip and knee arthroplasty.

Chronic poverty and childhood asthma in the Maritimes versus the rest of Canada.

OBJECTIVE: To examine the role of higher long-term poverty rates in the Maritimes as an explanation for higher rates of asthma among children 2-7 years of age. METHODS: Using longitudinal data from the National Longitudinal Survey of Children and Youth (NLSCY), logistic regressions examine associations between poverty duration and the probability of a child having been diagnosed with asthma, having a current asthma attack or experiencing wheezing in the past 12 months, controlling for other known determinants. RESULTS: NLSCY data indicate that 15.9% of Maritime children have been diagnosed with asthma, 8.7% have recently had an attack and 24.1% experienced wheezing, statistically higher levels than in the rest of Canada. Children in chronic poverty show rates that are over 30% higher than the Canadian averages. Although 19.9% of Maritime children have been chronically poor compared to 11.7% elsewhere, and although poverty is associated with a higher probability of asthma/wheezing, controlling for poverty status does not eliminate the regional difference in asthma rates. Including other controls with poverty status again does not fully explain the difference. CONCLUSION: While these findings do not completely explain why asthma prevalence rates are higher for Maritime children, they do indicate important pathways from poverty to childhood asthma. For example, chronically poor children are more likely to have had low birthweights and are less likely to have been breastfed, both of which are correlates of asthma. Such information can be useful for policy-makers. Pollutants and other environmental factors associated with asthma not included in the study may help further explain regional differences.