Zhang X, Cai G, Jones G, et al. - Zoledronic acid (ZA), when given to treat symptomatic knee osteoarthritis (OA) and bone marrow lesions (BMLs), exerted no impact on knee pain, probably a short-term impact on BML size and led to higher rates of adverse events. Short-term improvement in pain may be achieved with neridronate, but this is based on a single trial.

• This is a meta-analysis of 4 randomized controlled trials of 2–24 months duration including 428 patients (most (84%) took ZA), to determine intravenous bisphosphonates (IVBP) impacts in patients with symptomatic knee OA and BMLs.

• Large effect sizes of IVBP on pain within 3 months [standardized mean differences (SMD)= -2.33] were evident, primarily driven by neridronate (resulting in substantial heterogeneity) with no effect for ZA alone.

• At 3 months, statistically significant differences in knee function were observed (SMD=-0.22).

• Within 6 months, but not at 12 months or two years, improvement in a semi-quantitative measure of BML size was achieved with IVBPs (SMD= -0.52).

• IVBP use was associated with more frequent occurrence of adverse events (risk ratios = 1.19).