YouTube as a digital health platform: A cross-sectional thematic and sentiment analysis of the 100 most-viewed knee osteoarthritis videos.

Knee osteoarthritis (OA) is a prevalent source of pain and disability. As YouTube becomes increasingly used for health information, the nature and impact of OA-related content warrant systematic evaluation. Using the YouTube Data Application Programming Interface, 327 videos were initially retrieved with the terms "knee osteoarthritis," "gonarthrosis," and "degenerative joint disease." After applying exclusion criteria, the 100 most-viewed English-language videos were selected. Metadata and 60,888 user comments were extracted. Videos were thematically categorized into 6 domains: treatment, disease education, symptoms, diagnosis, patient experience, and uncategorized. Sentiment analysis was performed using the TextBlob library, and statistical trends were assessed via Statistical Package for the Social Sciences (SPSS) 29.0. Treatment was the dominant theme (38%), with nonsurgical options like exercise and rehabilitation comprising over half of these videos (55.3%). Educational (24%) and symptom-related content (12%) were also frequent. Viewer engagement peaked in 2022, with the highest number of views and comments. Over time, video uploads and comment activity increased, best modeled by quadratic trends. Seasonal variation in engagement was not significant. Commonly used words included "exercise," "knee," "thank," and "pain." Sentiment analysis revealed a decline in positive comments and a rise in neutral sentiment, while negative sentiment remained stable. YouTube serves as a growing platform for knee OA information, emphasizing conservative treatments. Although engagement and content volume have increased, sentiment has shifted toward neutrality. Given the variability in content quality, healthcare providers should guide patients toward credible, evidence-based resources to optimize digital health literacy.