Methods This will be a 2-armed double-blind randomised trial of a) zoledronic acid 5mg annually for 3 doses b) placebo drug infusions. Participants will be recruited primarily from rheumatologists and orthopaedic surgeons from multiple centres in Australia. We plan to include 4 major centres in capital cities in Australia and each centre would recruit approximately 30 participants. Potential participants who meet the eligibility criteria will be identified by their treating Rheumatologists or Orthopaedic surgeons, followed by a screening assessment conducted by the study research staff. Eligible participants will be randomised prior to the start of treatment. Prior to treatment, the study research staff will perform a baseline assessment over the phone, including demographic details, age, sex, duration of symptoms, medical history including prior surgery, trauma and medication use and known risk factors for ON. Furthermore at baseline, the Rheumatologists or Orthopaedic surgeon will perform a clinical evaluation using a slightly modified Harris Hip Score (HHS). The study research staff will contact the participants every 6 months to monitor the participant's condition and evaluate pain and disability. Additionally the participants will have a clinical evaluation and MRI scan at 12 months.