Twelve-monthly zoledronic acid infusions in patients with symptomatic knee osteoarthritis (OA) and bone marrow lesions did not considerably decrease cartilage volume loss over a period of 2 years, as came forward in the results from a randomized clinical trial published in ‘JAMA’.

Guoqi Cai et al. assessed the effects of zoledronic acid intravenous (IV) on knee cartilage volume loss in symptomatic knee OA patients and with bone marrow lesions.

This was a 24-month, randomized double-blind placebo-controlled trial conducted in multiple centres and comprised of patients aged ≥50 years with symptomatic knee OA. The MRI was used to detect the subchondral bone marrow lesions in patients enrolled from November 2013 to September 2015. Total of 113 patients was given zoledronic acid IV with either 5 mg in a 100-mL saline solution and 110 patients were given a placebo saline solution at baseline and 12 months. 

The primary outcome of the study was the change in tibiofemoral cartilage volume over 24 months. The change in knee pain evaluated via visual analog scale (VAS) and the Western Ontario and McMaster Universities Osteoarthritis Index over 3, 6, 12, 18, and 24 months and variation in bone marrow lesion size over 6 and 24 months, were the three main predefined secondary outcomes.

Out of 223 participants registered (mean age 62.0 years and 52% being female), 190 completed the trial. The change in tibiofemoral cartilage volume did not significantly vary amongst the zoledronic acid group and the placebo over 24 months. There were no significant between-group differences observed for any of the secondary outcomes. Commonly observed side effect with zoledronic acid mostly comprised of acute reactions (described as symptoms within 3 days of administration of infusion) as compared with placebo.