Single Dose Therapy of Zoledronic Acid for the Treatment of Transient Osteoporosis of Hip.

OBJECTIVE: To shorten the natural course of transient osteoporosis of hip (TOH), which is a self-limiting idiopathic condition and requires 6-12 months for the resolution of symptoms, various therapies including treatment with bisphosphonates have been attempted. There exist fewer case reports evaluating the effect of bisphosphonates in TOH and most of them lack radiographic evidence of resolution of disease. The present study was carried out with an aim to evaluate the clinical and radiological outcomes of TOH patients subsequent to treatment with a single dose of zoledronic acid.

METHODS: Data of 19 adult male and non-pregnant female patients with TOH treated with zoledronic acid were included in the study. Efficacy was assessed using changes in clinical signs and symptoms, visual analogue scale pain score, and changes in bone marrow edema (BME) in magnetic resonance imaging (MRI).

RESULTS: Mean age of the patients was 42.1 years, 17 being males. The mean time of onset of symptom was 4 weeks. Subsequent to treatment, the patients were pain-free and had no limp within an average of 2.8 weeks (range, 2-5 weeks) and remained asymptomatic at a mean follow-up of 35 months (range, 6-54 months). The post-treatment MRI showed resolution of BME in approximately 84% (16/19) of patients at 3 months. No major adverse events were reported. None of the patients progressed to avascular necrosis at their last follow-up.

CONCLUSION: Intravenous single dose administration of zoledronic acid provides early pain relief and complete reversal of TOH. Consequently, zoledronic acid is proposed as a new paradigm in the management of TOH.