ABSTRACT
Purpose The purpose of this study was to compare complication rates following inpatient versus outpatient distal radius fracture ORIF and identify specific complications that occur at increased rates among inpatients. Methods Using the 2005-2013 ACS-NSQIP, we collected patient demographics, comorbidities, surgical characteristics, and 30-day postoperative complications following isolated ORIF of distal radius fractures. A propensity score matched design using an 8-to-1 "greedy" matching algorithm in a 1:4 ratio of inpatients to outpatients was utilized. Rates of minor, major, and total complications were compared. A multinomial logistic regression model was then used to assess the odds of complications following inpatient surgery. Results Total 4,016 patients were identified, 776 (19.3%) of whom underwent inpatient surgery and 3,240 (80.3%) underwent outpatient surgery. The propensity score matching algorithm yielded a cohort of 629 inpatients who were matched with 2,516 outpatients (1:4 ratio). After propensity score matching, inpatient treatment was associated with increased rates of major and total complications but not with minor complications. There was an increased odds of major complications and total complications following inpatient surgery compared with outpatient surgery. There was no difference in odds of minor complications between groups. Conclusion Inpatient operative treatment of distal radius fractures is associated with significantly increased rates of major and total complications compared with operative treatment as an outpatient. Odds of a major complication are six times higher and odds of total complications are two and a half times higher following inpatient distal radius ORIF compared with outpatient. Quality improvement measures should be specifically targeted to patients undergoing distal radius fracture ORIF in the inpatient setting.
ABSTRACT
Expression of the Pho regulon in Escherichia coli is induced in response to low levels of environmental phosphate (P(i)). Under these conditions, the high-affinity PstSCAB(2) protein (i.e., with two PstB proteins) is the primary P(i) transporter. Expression from the pstSCAB-phoU operon is regulated by the PhoB/PhoR two-component regulatory system. PhoU is a negative regulator of the Pho regulon; however, the mechanism by which PhoU accomplishes this is currently unknown. Genetic studies of phoU have proven to be difficult because deletion of the phoU gene leads to a severe growth defect and creates strong selection for compensatory mutations resulting in confounding data. To overcome the instability of phoU deletions, we employed a promoter-swapping technique that places expression of the phoBR two-component system under control of the P(tac) promoter and the lacO(ID) regulatory module. This technique may be generally applicable for controlling expression of other chromosomal genes in E. coli. Here we utilized P(phoB)::P(tac) and P(pstS)::P(tac) strains to characterize phenotypes resulting from various DeltaphoU mutations. Our results indicate that PhoU controls the activity of the PstSCAB(2) transporter, as well as its abundance within the cell. In addition, we used the P(phoB)::P(tac) DeltaphoU strain as a platform to begin characterizing new phoU mutations in plasmids.
