summary Osteomalacia is a metabolic bone disease where defective mineralization results in a large amount or unmineralized osteoid. Diagnosis is made based on a thorough evaluation of serum labs, clinical features, and radiographic findings. Treatment involves medical management with Vitamin D supplementation and resolving the underlying etiology. Etiology Mechanism qualitative defect as opposed to a quanitative defect like osteoporosis Epidemiology Incidence rare in the US (approximately 1 in 1000) much less common than osteoporosis because of adequate exposure to sunlight and dairy products fortified with vitamin D Demographics rickets is found in children (open physis) osteomalacia is found in adults (closed physis) Risk factors the following conditions predispose a patient to osteomalacia vitamin-D deficient diets malabsorption e.g. celiac disease renal osteodystrophy hypophosphatemia chronic alcoholism tumors (tumor-induced osteomalacia) drugs drugs associated with vitamin D deficiency phenytoin phenobarbital rifampin cholestyramine cadmium glucocorticoids drugs affecting phosphate homeostasis aluminium-containing phosphate-binding antacid ifosfamide drugs affecting bone mineralization aluminium etidronate fluoride Presentation Symptoms generalized bone and muscle pain fractures of long bones, ribs and vertebrae proximal muscle weakness weakness fatigue Physical exam inspection waddling gait from hip pain and thigh weakness difficulty rising from chair and climbing stairs Imaging Radiographs findings Looser's zones (insufficiency fractures) medial femoral cortex pubic ramus scapula fractures (especially in the proximal femur/femoral neck) biconcave vertebral bodies trefoil pelvis protrusio acetabuli Bone scan findings increased activity Studies Labs Lab values Serum Ca Serum P Alk phos PTH 25-(OH)vit D 1,25-(OH)vit D Urinary Ca Osteomalacia Low Low High High Low Low Low Osteoporosis Normal Normal Variable Normal Normal Normal Normal Tumor induced osteomalacia Low Very low Low Low Low Low Low Osteopetrosis Normal Normal High Normal Normal Normal Normal Histology Characteristic histology includes technique requires transiliac biopsy for definitive diagnosis findings widely separated osteoid seams Treatment Nonoperative large doses of oral vitamin D (1000IU/day), treat underlying cause indications most patients technique specific subgroups of patients on long-term anticonvulsant therapy supplement with 400-800IU/day of vitamin D with hepatobiliary disease supplement with 25(OH)-vit D with renal disease supplement with 1,25(OH)2 vit D
All Videos (0) Podcasts (1) Basic Science⎪Osteomalacia Basic Science - Osteomalacia Listen Now 7:19 min 12/2/2020 278 plays 5.0 (2)