Unplanned readmissions after primary total knee arthroplasty in Korean patients: Rate, causes, and risk factors.

Background: Unplanned hospital readmissions are indicators of the quality and performance of a health care system, but data on early readmission after primary total knee arthroplasty (TKA) in the Asian population are limited. The purpose of this study was to determine the causes, risk factors, and rate of unplanned readmission after primary TKA at a single institution in Korea.

Methods: We analyzed all primary TKAs from 2004 to 2013 using the data from our institutional electronic database. A total of 4596 TKAs were performed on 3049 patients. All unplanned readmissions within 30 and 90days of discharge were identified, categorized into arthroplasty-related, medical, and other orthopedic causes.

Results: The overall unplanned readmission rate was 1.9% (n=59) within 30days and 3.3% (n=101) within 90days, and both the 30 and 90day readmission rates remained stable over the entire study period. The majority of readmissions involved arthroplasty-related causes; the most common cause being wound problems, accounting for 22% (13/59) within 30days and 24% (24/101) within 90days. Age (P=0.029) and hypertension (P=0.021) were identified as risk factors for unplanned readmissions after TKA.

Conclusions: This study demonstrates that unplanned readmissions after TKA are not infrequent in Korean patients and has identified wound complication as the most frequent cause of unplanned readmissions. Optimized care systems should be established to minimize unplanned readmissions, particularly for patients with high risk factors.