Factors affecting quality of life after total knee arthroplasty: a prospective observational study

Background: Total knee arthroplasty (TKA) is a widely performed procedure for advanced knee osteoarthritis, and contemporary evaluation increasingly emphasizes patient-reported quality of life (QoL) rather than radiographic or implant-survival outcomes alone. This study aimed to assess the clinical, demographic, and psychological factors affecting QoL after TKA. Methods: A prospective observational study was conducted in the Department of Orthopaedics, Adichunchanagiri Institute of Medical Sciences, from August 2024 to February 2026. One hundred and twenty patients aged over 60 years with Kellgren-Lawrence grade III/IV knee osteoarthritis undergoing primary TKA were enrolled by convenience sampling. Patients were evaluated at baseline and at 6 weeks, 3, 6, and 12 months postoperatively using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Knee Society Score (KSS), Visual Analog Scale (VAS) for pain, and the 10-item Center for Epidemiologic Studies Depression Scale (CES-D10). Predictors of 12-month outcomes were identified using multiple linear regression and binary logistic regression; p<0.05 was considered significant. Results: Sixty-five percent of patients were 60–70 years old and 55% were female. Mean total WOMAC score improved from 62.3±14.8 preoperatively to 10.1±3.9 at 12 months, mean KSS improved from 40.9±13.3 to 89.3±8.1, and mean VAS pain score fell from 8.7±0.9 to 1.6±0.6. The proportion of patients with depressive symptoms fell to 7% at 12 months. Baseline WOMAC, VAS, and CES-D10 scores independently predicted 12-month WOMAC score (R² = 0.464, p<0.001); age, female sex, baseline KSS, and baseline WOMAC predicted 12-month KSS (R²=0.375, p<0.001). Diabetes mellitus, baseline WOMAC, VAS, and CES-D10 scores significantly reduced the odds of achieving “good improvement” in QoL (model χ²=48.12, p<0.001). Conclusions: TKA produces substantial and sustained improvement in pain, function, and psychological well-being over 12 months, with most gains occurring within the first 3–6 months. Greater baseline symptom burden and comorbid diabetes mellitus predict poorer QoL gains, supporting comprehensive preoperative assessment and optimization of modifiable risk factors before surgery.