[Bone and osteo-articular complications of corticotherapy].
Osteoporosis and epiphyseal aseptic bone necrosis are side-effects of corticosteroid therapy that must be detected and prevented. The incidence of osteoporosis depends on whether radiology or densitometry are used for its evaluation. Bone loss is accounted for by osteoblast depression and decreased intestinal absorption of calcium, responsible for secondary hyperparathyroidism. The clinical progress of steroid-induced osteoporosis is often impressive. Plasma osteocalcin levels are lowered. Nowadays, non-invasive methods of bone mass measurement are indispensable for detection and follow-up. Prevention rests on adjustment of corticosteroid therapy and, above all, on the prescription of calcium and vitamin D; fluoride constitutes the curative treatment. Corticosteroid dosage plays a role in the occurrence of aseptic bone necrosis at an early stage of treatment. The lesions, often multiple and progressive, mostly affect the femur. MRI is the most sensitive examination for early detection. When medical treatment has failed, total hip replacement may be considered.