Zoledronic acid is more efficient than ibandronic acid in the treatment of symptomatic bone marrow lesions of the knee

Purpose The purpose of this study was to determine the efficacy and tolerability of different antiresorptive therapeutic regimens for treating symptomatic bone marrow lesions (BML) of the knee. Methods Patient records of 34 patients with radiologically diagnosed, painful BML of the knee treated with either a bisphosphonate (zoledronic, ibandronic, or alendronic acid) or with a human monoclonal antibody (denosumab) were retrospectively evaluated. Response to treatment was assessed, as change in patient‐reported pain, by evaluation of BML expansion on MRI using the Whole‐Organ Magnetic Resonance Imaging Score (WORMS), and by laboratory analysis of bone turnover markers: C‐terminal cross‐linking telopeptide (CTx) and procollagen type 1 amino‐terminal propeptide (P1NP). Tolerability was evaluated by documentation of adverse reactions. Results Zoledronic acid was more or at least equally effective as the other treatment regimens with response to treatment in 11 of 12 patients (92%). The highest rate of adverse events was noted in 4 of 12 patients (33%) treated with zoledronic acid. CTx and WORMS differentiated well between responders and non‐responders, whereas P1NP failed to do so. Changes in pain correlated moderately with change in WORMS ( r  = − 0.32), weakly with change in CTx ( r  = − 0.07), and not at all with change in P1NP. Conclusion Zoledronic acid appeared to be more effective than other antiresorptive medications—at the cost of more frequent adverse events. While radiological and laboratory evaluation methods may allow for objective treatment monitoring, they appear to capture different dimensions than patient‐reported pain. Level of evidence III.