Retrospective Evaluation of the Impact of Knee Osteoarthritis Severity on Treatment Outcomes: A Longitudinal Study

Background: Knee osteoarthritis (OA) affects approximately 528 million people worldwide, representing a significant healthcare burden with variable treatment outcomes based on disease severity. Understanding the relationship between severity grading and treatment effectiveness is crucial for optimizing patient management strategies. Objective: To evaluate the impact of knee osteoarthritis severity, assessed using the Kellgren-Lawrence (KL) grading system, on treatment outcomes over a 24-month longitudinal period. Methods: This retrospective longitudinal study analyzed 1,247 patients with knee OA treated between January 2020 and December 2023. Patients were stratified by KL grades (0-4) and treatment modalities (conservative vs. surgical). Primary outcomes included pain scores using Visual Analog Scale (VAS), functional outcomes using Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and Knee injury and Osteoarthritis Outcome Score (KOOS), and quality of life measures at baseline, 6, 12, and 24 months. Results: Patients with KL grades 0-2 showed significantly better responses to conservative treatments, with mean VAS scores improving from 6.2±1.8 to 2.4±1.2 (p<0.001). Advanced OA (KL grades 3-4) demonstrated superior outcomes with surgical interventions, achieving 78% functional improvement compared to 34% with conservative management. Treatment failure rates increased with severity grade, ranging from 12% in KL grade 1 to 67% in KL grade 4 for conservative treatments. Conclusion: Knee osteoarthritis severity significantly influences treatment outcomes, with early-stage disease responding favorably to conservative management while advanced stages require surgical intervention for optimal results. These findings support severity-based treatment algorithms for improved patient outcomes.