[Bone involvement in primary oxalosis. Study of 20 cases]

The authors report 20 cases of primary oxalosis with bone involvement, late revealed in adults in 19 cases. They have studied the clinical, radiological and histological manifestations of this bone oxalosis. 19 cases had an end stage chronic renal failure, either treated by maintenance hemodialysis, or by renal (or liver-renal) graft. 17 patients complained of bone pain after starting hemodialysis; 3 had vertebral crush fractures, and 1 multiple spontaneous fractures. Diffuse bone sclerosis (with a homogeneous pattern on axial skeleton and a patchy appearance on the peripherical skeleton), bone translucency, subperiosteal phalangeal resorption were the main radiological symptoms. Oxalate crystals surrounded by a giant cells granuloma were always observed on bone biopsy (16 cases). Bone resorption was observed in 9 cases, hyperparathyroidism in 14 cases and osteomalacia in 7 cases. Hyperparathyroidism does'nt explain all the clinical and radiological manifestations (especially bone resorption). Bone resorption as other radiological and clinical manifestations can be found without hyperparathyroidism and can increase despite parathyroidectomy; so, bone resorption seems to be partly due to the granulomatous reaction around oxalate crystals rather than hyperparathyroidism.