Post-transplant distal-limb bone-marrow oedema: MR imaging and therapeutic considerations

Abstract

Background. In recent years a previously unrecognized pain syndrome of the distal lower limbs after organ transplantation has been noted. A relationship to cyclosporin A was suspected, but no clear aetiology and pathogenesis have been established. Methods. During the last 30 months we diagnosed the pain syndrome in 10 patients after renal transplantation. We prospectively followed and evaluated the patients during their clinical courses and through pathological laboratory findings and magnetic resonance imaging (MRI). Results. In all patients symptoms developed within 6 months of transplantation after otherwise uncomplicated clinical courses without graft rejection episodes. Impressive bone-marrow oedema on MRI as well as elevated serum alkaline phosphatase was seen in all patients, and often exceeded the duration of clinical symptoms. All patients were instructed to avoid stress to the extremities through immobility, and steroid doses were tapered down. Within 14 weeks, eight patients were free of symptoms. Two patients have not experienced remission after 3 and 4 months respectively. None of the patients developed signs of osteonecrosis. Conclusion. Post-transplant distal limb bone-marrow oedema presents with distinct clinical findings and signs of bone-marrow oedema on MRI. Proven standard treatment does not exist. In our experience the elevation of the extremities, the strict avoidance of physical strain, and a stepwise withdrawal of steroids facilitates progressive disappearance of symptoms. Long-term damage to the affected osteal structures has not been seen, in contrast to avascular femoral-head necrosis.