Osteomalacia, illustration. Osteomalacia is a pathological condition of adult bone where newly formed bone matrix is inadequately mineralised. This disease may be caused by phosphate deficiency, abnormal metabolism of vitamin D or failures in the mineralisation process. The weakened bone density/strength results in abnormal macroscopic and microscopic morphology of bone, with abnormally thick osteoid seams that are slow to mineralise. Being weight-bearing, the pelvis shows hypercurvature of the ischium, lateral lengthening of iliac bones, diminished transverse pelvic inlet and anterior protrusion of the pubic symphysis. In chronic cases, fractures of the pelvis, ribs, femoral neck, or spine are common. From Bollinger, O. 1901 Atlas und Gundriss der Pathologischen Anatomie, vol 2. Lehmann, Munich.