Incidence of 30-day readmission after total knee arthroplasty and its associated factors in Hong Kong.

Introduction: Total knee arthroplasty (TKA) is one of the most commonly performed orthopaedic procedures worldwide, due to the increased prevalence of osteoarthritis associated with an ageing global population. Although many studies have focused on the causes of readmission among TKA patients within 30 days post-surgery, none have been conducted in Hong Kong. This study investigated the 30-day readmission rate, causes, and risk factors among TKA patients in Hong Kong.

Methods: This retrospective review included patients who underwent TKA at a local university-affiliated hospital between 2001 and 2020. Eligible patients were identified using the Clinical Data Analysis and Reporting System and electronic patient records. Their data were analysed to determine the 30-day readmission rate, risk factors, and underlying causes.

Results: Among the 3827 TKA patients included, the male-to-female ratio was 1:2.78 (1012:2815) and the mean age (±standard deviation) was 71.11±8.82 years. Of these patients, 3.4% underwent unplanned readmission to hospitals through the Accident and Emergency Department within 30 days of TKA. The most common causes of readmission were knee pain (33.1%), knee swelling (26.2%), and gastrointestinal-related conditions (8.5%). Age ≥80 years (odds ratio [OR]=1.63; P=0.01) and hypertension (OR=2.08; P<0.001) were risk factors for readmission. Bilateral simultaneous TKA (OR=0.42; P=0.005) was associated with lower risk of readmission.

Conclusion: The readmission rate in this study was 3.4%, comparable to rates in previous reports. Enhanced patient education and optimised perioperative pain management are needed to minimise hospital readmissions. Fall prevention, cautious painkiller prescribing, and improved nursing care are recommended to prevent readmission.