BMI Does Not Affect Intra-articular Injection Outcomes in Knee Osteoarthritis: A Pooled Analysis of Two Randomized Trials

Background Knee osteoarthritis (OA) is a leading cause of disability, yet the role of BMI in intra-articular injection efficacy remains unclear. This study evaluates whether BMI influences short-term outcomes of intra-articular injections for knee OA. Methods A pooled analysis of two trials including 55 patients with grade 2–3 knee OA (Kellgren-Lawrence) received injections of ketorolac, triamcinolone, or hypertonic dextrose. Outcomes (VAS, WOMAC, Lequesne Index) were assessed at baseline, 1 month, and 3 months. BMI categories (normal, overweight, obese) were analyzed for correlation with treatment response using Spearman’s rho. Results No significant correlation was found between BMI and injection outcomes across all timepoints (p > 0.05 for all measures). Overweight (58.2%) and obese (34.5%) patients showed similar improvements to normal-weight counterparts. Conclusion BMI did not affect short-term intra-articular injection outcomes, supporting its use across all BMI categories for knee OA symptom relief.