Antipsychotic Use Is Associated With Longer In-hospital Lengths of Stay and Higher Rates of Venous Thromboembolism and Costs of Care After Primary Total Knee Arthroplasty.

Introduction: Studies have shown that antipsychotic medication use may lead to venous thromboembolisms (VTEs); however, this association has not been demonstrated in patients undergoing primary total knee arthroplasty (TKA). Therefore, the purpose of this study was to investigate whether patients taking antipsychotic medications at the time of their primary TKA have higher rates of in-hospital lengths of stay (LOS), VTEs, and costs of care.

Methods: Patients taking antipsychotic medications were identified and matched to a cohort in a 1:5 ratio by age, sex, and medical comorbidities. Patients who had a history of VTEs or hypercoagulable states before their TKA were excluded. The query resulted in 439,579 patients within the study (n = 73,285) and matching cohorts (n = 366,294). Outcomes analyzed included rates of in-hospital LOS, VTEs, and costs of care. A P value less than 0.01 was considered statistically significant.

Results: We found statistically significant longer in-hospital LOS for patients taking antipsychotic medications (3.27 versus 3.02 days, P < 0.0001). Study patients were also found to have a higher incidence and odds ratio of VTEs (2.37 versus 1.04%; odds ratio: 1.86, 95% confidence interval: 1.75-1.97, P < 0.0001). Ninety-day costs of care were also significantly higher in the study cohort ($17,332.70 versus $15,975.00, P < 0.0001).

Conclusion: After adjusting for confounders, patients taking antipsychotic medication were found to have higher rates of in-hospital LOS, VTEs, and costs of care. The study can be used by orthopaedic surgeons to counsel patients taking these medications concerning the potential complications after their procedure.