Impact of Smoking Status on Early Outcomes and Healthcare Utilization Following Primary Total Knee Arthroplasty: A Retrospective Cohort Study

Background Smoking is a modifiable risk factor associated with adverse surgical outcomes. However, its effects on recovery and healthcare utilization after total knee arthroplasty (TKA) remain unclear. This study evaluated the impact of smoking status on early postoperative pain, complications, and healthcare resource utilization. Methods We retrospectively reviewed 1,124 patients who underwent primary TKA by a single surgeon between 2019 and 2023, stratified as current (n = 87), former (n = 320), or never-smokers (n = 717). Outcomes included visual analog scale (VAS) pain scores, achievement of patient acceptable symptom state (PASS, VAS ≤ 3), readmissions, follow-up calls within six months, length of hospital stay, emergency department visits, opioid refills, and complications. Multivariable analyses were adjusted for age, sex, race, body mass index, coronal deformity, surgical technique, and insurance. Results Across all time points, current smokers reported higher mean VAS scores than never-smokers (mean difference (MD) 0.83, P < 0.0001) and former smokers (MD: 0.63, P = 0.006). The PASS achievement was significantly lower among current smokers, with former (odds ratio (OR) 1.62, P = 0.031) and never-smokers (OR: 1.78, P = 0.006) more likely to achieve PASS. Former smokers initiated more follow-up calls than never-smokers ( P = 0.0006), whereas current smokers demonstrated a similar nonsignificant trend. Readmissions, lengths of stay, emergency department visits, opioid refills, and complication rates were comparable across groups (all P > 0.05). Conclusions Smoking within 30 days of TKA was associated with greater postoperative pain and lower odds of achieving an acceptable pain state compared to former and never-smokers. Differences in follow-up communication suggest that smoking may primarily affect the early recovery trajectory rather than pain-related outcomes alone. Incorporating smoking cessation into preoperative optimization pathways may improve early recovery and reduce resource demand after TKA. Level of Evidence III, retrospective cohort.