Impact of Chronic Obstructive Pulmonary Disease on Complications and Readmissions Following Total Knee Arthroplasty: A Retrospective Matched Cohort Study.

Abstract

Chronic obstructive pulmonary disease (COPD) is a common comorbidity among patients undergoing total knee arthroplasty (TKA). We compared preoperative characteristics, perioperative management methods, postoperative complications, and readmissions after TKA in patients who did and did not have COPD. We performed a retrospective matched cohort study of primary, elective TKAs at an urban academic center (August 2012 to December 2020). We identified 785 patients who had COPD and matched them 1:3 to 2,274 patients who did not have COPD by age, sex, and body mass index (BMI). Groups were compared using univariate analyses. Multivariable regressions evaluated the independent associations of COPD with complications and 30-day readmissions. Temporal trends in complications and readmissions were assessed across the study period. Compared with non-COPD patients, those who had COPD had modest, but consistently higher prevalence of several cardiopulmonary and medical comorbidities, reflecting a higher overall comorbidity burden at baseline. Intraoperatively, COPD patients more often received general anesthesia (10.1 versus 7.6%, P = 0.037) and carried higher American Society of Anesthesiologists (ASA) classifications (Class III or IV: 51.1 versus 30.3%, P < 0.001). Univariate analyses showed higher rates of postoperative anemia (3.6 versus 2.1%, P = 0.033), any complication (11.7 versus 8.1%, P = 0.003), and 30-day readmission (5.2 versus 3.2%, P = 0.014) among COPD patients. However, in multivariable models, COPD was not independently associated with increased complications or readmissions. Complication rates among COPD patients declined markedly over time (from 41.3% early in the period to 5.1% by 2020), and by the end of the study, complication and readmission rates were comparable between groups. Patients who have COPD undergoing TKA constitute a higher-risk population with more complex medical histories. Although crude analyses showed higher early complications and readmissions, these differences were not independent of confounders and diminished over time. Contemporary perioperative optimization and standardized care pathways appear to mitigate historical disadvantages for COPD patients undergoing TKA.