[Articular complications in sickle cell-thalassemia after childhood. Diagnostic problems].

The osteoarticular complications of drepanocytosis-thalassemia (DT) include: 1) bone infarction, or avascular necrosis (AVN), common at all ages; 2) acute septic arthritis and hematogenous osteomyelitis, that usually affect infants and children. Early diagnosis and treatment of the osteoarticular infectious complications is imperative, to maximize the chances of a favorable outcome, and to prevent the sequelae, ie pathological fractures, chronic osteomyelitis. Early roentgenographic features of involved areas are similar in acute osteomyelitis and in AVN--both of which cause painful bone crises, so as to make osteomyelitis (OM) a diagnostic challenge. Four cases of DT are reported. The patients, 17 to 37 years old, presented with bone infarcts. One of them (the youngest) had also multiple osteomyelitis of long bones. The 99m-Tc-MDP bone scans, performed only on the youngest patient, affected by OM, revealed increased uptake in both AVN and in OM locations, without differential diagnostic features. After a review of the literature, a diagnostic protocol is suggested, based on 99m-Tc colloid marrow scintigraphy for the early differential diagnosis between acute OM (normal or slightly-increased uptake), chronic OM (markedly increased uptake), and AVN (decreased uptake). Furthermore, MR imaging is stressed as the most promising tool, in the next future, for this kind of differential diagnosis.