Pamidronate treatment of steroid associated osteonecrosis in young patients treated for acute lymphoblastic leukaemia--two-year outcomes.

AIMS: To assess outcomes of young patients with osteonecrosis (ON) treated with pamidronate in terms of relief of pain, prevention of progress and bony collapse of involved area. PATIENTS AND METHODS: A non-randomised interventional study in six patients with a history of acute lymphoblastic leukaemia (ALL) for which treatment protocols included long-term, high dose use of glucocorticoids. Subsequent development of ON was treated with a bisphosphonate (pamidronate) for 2 years. Mobility and pain control were assessed regularly with MRI and X-ray of affected areas at 0, 12 and 24 months.
RESULTS: Reduction in pain was reported in four of six patients in the first year with increased mobility. Two patients who had radiological evidence of joint destruction prior to treatment and when continued on corticosteroids reported no improvement in pain or mobility. In the second year, patients who started treatment in the first few months after diagnosis were stable while patients who had treatment initiated later deteriorated but had less pain than prior to treatment with pamidronate. MRIs of affected areas were completely unchanged over 2 years. X-rays revealed no new bony collapse in four of six patients after 12 months of treatment. However, three of six patients continued to undergo extensive collapse of femoral heads (one at 12 months, two at 24 months) and all these required urgent hip replacement.
CONCLUSION: Pamidronate treatment has a palliative effect in control of pain and may delay the natural history of bony collapse in the acute phase of ON, especially in early treated patients, but does not prevent late bone collapse and joint destruction in corticosteroid treated patients with ALL. Larger studies are needed to provide evidence as to whether bisphosphonate is indicated for treatment of ON for patients using corticosteroids.