<prompt> Umbau Zones are seen in all except -AP 90OsteomalaciaRicketsOsteogenesis imperfectaOsteomyelitis  <response>: Looser zones, also known as cortical infractions, Milkmans linesor Looser-Umbauzonen, are wide, transverse lucencies traversing part way through a bone, usually at right angles to the involved cortex and are associated most frequently with osteomalacia and rickets. They are pseudofractures and considered a type of insufficiency fracture. Typically, the fractures have sclerotic irregular margins and are often symmetrical. Aetiology osteomalacia renal osteodystrophy fibrous dysplasia hyperthyroidism Paget disease of bone X-linked hypophosphataemia osteogenesis imperfecta 