[Diabetic osteoarthropathy. Course and differential diagnosis].

Diabetic neuropathy with reduced sensitivity to pain and mechanical overloading of the joints, associated with frequently disturbed circulation in the lower extremities, are the etiopathogenetic factors of diabetic osteoarthropathy (synonyms: neuroarthropathia diabetica, Charcot joint). In the first stage there is osteonecrotic destruction of bone and cartilage. Clinically, an insidious, painless, noninflammatory hydroarthrosis with massive swelling of the soft tissues is typical. Subsequently, in stage II, irregular transformation of the bone due to multiple resorptive processes occurs. In the third stage this transformation process stabilizes and the bone ends become more pointed and more sclerotic (resembling a licked candy stick). For mechanical reasons, the tarsometatarsal and metatarsophalangeal joints and the metatarsals are primarily affected. However, destruction is also seen in Chopart's joint, the talus, the calcaneus, the ankle joint and the distal tibia. With regard to differential diagnosis, similar clinical pictures are seen in many neuropathic bony changes--tabes dorsalis, syringomyelia, myelodysplasias, congenital analgesia, congenital familial acroosteolysis. More difficult to differentiate are osteomyelitic foci, bone tuberculosis, and malignant bone tumors involving bone destruction.