Abstract
Compared with nonelective total knee arthroplasties (TKAs), elective procedures have
more time for preoperative planning, which allows for potentially improved patient
optimization, risk factor modification, and patient education. The purpose of this
study was to (1) determine nationwide trends in operative times and (2) evaluate associations
between surgery type, elective or nonelective, with respect to (a) operative times,
(b) length of stay (LOS), (c) discharge dispositions, (d) 30-day postoperative complications,
(e) reoperations, and (f) readmissions. The American College of Surgeons National
Surgical Quality Improvement Program (ACS-NSQIP) database was queried for all primary
TKAs performed between 2011 and 2016. This yielded 209,178 cases which were stratified
into elective and nonelective cases. Elective cases were those in which patients were
brought from their normal living environment for scheduled procedures. One-way ANOVA
(analysis of variance) was used to evaluate associations between operative times and
year of surgery. Multivariate linear and logistic regression models adjusted for surgery
year and patient factors (age, sex, BMI [body mass index], and ASA [American Society
of Anesthesiologists] score) were used to evaluate associations of surgery type with
peri- and postoperative outcomes. A significant inverse correlation between operative
times and operative year was observed (p < 0.001). Mean operative times and LOS were significantly shorter in elective cases
compared with nonelective cases (93 vs. 112 minutes, p < 0.005; 3 vs. 5 days, p < 0.001). Multivariate analysis showed these associations remained significant even
after adjusting for potential confounders (p < 0.001). Compared with the nonelective cohort, patients in the elective cohort were
more likely to be discharged home (74 vs. 69%, p < 0.001). Nonelective patients had higher rates of pneumonia (0.7 vs. 0.3%, p = 0.005), organ-space surgical site infections (SSI; 0.4 vs. 0.2%, p = 0.004), transfusions (10.9 vs. 6.5%, p < 0.001), sepsis (0.6 vs. 0.2%, p = 0.001), and septic shock (0.2 vs. 0.1%, p = 0.005) compared with elective patients. These associations remained significant
with multivariate logistic regression. This study demonstrated that preoperative planning
can help shorten operative times and LOS as well as reduce complication and reoperation
rates. Alongside the direct advantages identified in this study, potential greater
effects include superior patient outcomes and reduced health care costs.
Keywords
preoperative planning - elective - nonelective - TKA - outcomes
