Perioperative comorbidities and complications among patients undergoing primary total knee arthroplasty: a retrospective analysis and prospective survey

• Demographic patterns and comorbidities of patients undergoing total knee arthroplasty have changed over the past 2 decades.
• Perioperative complications are decreased despite increased patient body mass index and comorbidities.
• Anesthesia care has adapted to changing demographic trends.

Study objectiveTo determine the demographic characteristics of patients undergoing primary total knee arthroplasty during the years 1989, 1999, and 2009 at our institution and determine whether their characteristics mirror the changing US demographic characteristics.DesignRetrospective chart review of patients and prospective survey of experienced anesthesia providers in total knee arthroplasty.SettingTertiary care academic medical center.PatientsAll patients 18 years and older who underwent unilateral primary total knee arthroplasty in 1989, 1999, and 2009 were identified through the Mayo Clinic Total Joint Registry. For each year, 200 patients were randomly selected.MeasurementsThe demographic characteristics, comorbidities, perioperative care, and postoperative outcomes of patients, as well as survey responses from experienced anesthesia providers.Main resultsDuring the 3 study years, a total of 591 patients were included for analysis. A statistically significant increase in body mass index (BMI) was observed over time in patients undergoing primary total knee arthroplasty (average BMI, 29.01 in 1989, 31.32 in 1999, and 32.32 in 2009 [P < .001]). Despite the increase in patient comorbidities, the percentage of patients who had postoperative complications decreased over time (P = .003), and postoperative disposition (general medicine ward vs intensive care unit) did not change. Our provider survey received a 76% response rate. In total, 82% of anesthesia providers who responded to the survey perceived that both BMI and the number of comorbidities had increased. Of survey respondents, 67% state that they have modified their perioperative anesthesia care because of changes in body habitus and patient comorbidities.ConclusionsThe number of obese patients with comorbidities who present for total knee arthroplasty at our institution has increased over the past 20 years. Despite this fact, a reduction was detected in postoperative complications.