ACUTE BONE PAIN FOLLOWING RENAL-TRANSPLANTATION - DIFFERENTIATION BETWEEN BENIGN BONE EDEMA AND AVASCULAR NECROSIS

Two patients are reported who presented within the first 3 months post transplantation with acute bone pain where serial magnetic resonance i maging (MRI) allowed differentiation between bone edema, which resolve d spontaneously, and avascular necrosis (AVN) requiring core decompres sion. Case 1 had ill-defined images consistent with bone edema that re solved, whereas case 2 developed well-demarcated lesions in the femora l condyles and tibial epiphyses which were confirmed as AVN at surgery . Alternative explanations for bone edema were not evident. We would s uggest that in any transplant recipient who develops acute bone pain, MRI is the initial diagnostic modality of choice. Evidence of developm ent of well-demarcated lesions on serial MR scans indicate early AVN. However, on current evidence it is difficult to predict which lesions will progress and until greater experience becomes available, we would recommend intraosseous plethysmography and venography so that incipie nt or early AVN can be treated by core decompression of the affected b one.