Differences in readmission rates for two total knee arthroplasty prostheses

The readmission rates of cruciate-retaining (CR) and a posterior-stabilizing (PS) total knee arthroplasty (TKA) have not been extensively evaluated. We aimed to determine the following: (1) What are the readmission rates of TKA performed with the use of CR and PS prostheses at 30, 60, and 90 days following discharge? (2) Were the causes of the unplanned readmission surgically or medically related? (3) What were the medical comorbidities associated with readmission? A prospectively collected database of 845 TKAs (441 CR and 404 PS TKAs) at 22 institutions (24 surgeons) was reviewed. Outcomes evaluated included the incidence of readmission at 30, 60, and 90 days after discharge, medical/surgical cause, and medical comorbidities. There were no significant differences in readmission rates between the two cohorts at the different time points. There was a readmission rate of 2% at 30 days and 3.2% at 60 days for the CR group, and 2.2% at 30 days and 4.0% at 60 days for the PS group after discharge. Medical causes accounted for a majority of the readmissions in both the CR and PS cohort. Readmitted patients had a higher incidence of increased body mass index, cardiovascular disorders, diabetes, and musculoskeletal disorders. The readmission rates for both prostheses in the setting of primary TKA are encouraging because these rates are lower than previously reported outcomes. The authors believe that the positive midterm clinical performance of the prostheses used in this study may have contributed to the lower readmission rates.