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Information

 Bone and Soft-Tissue Disorders

= LOOSER LINES = LOOSER ZONES = OSTEOID SEAMS = MILKMAN SYNDROME

= insufficiency stress fractures + nonunion (incomplete healing ← mineral deficiency)

Path: area of unmineralized woven bone occurring at sites of mechanical stress / nutrient vessel entry

Associated with:

  1. Osteomalacia / rickets
  2. Paget disease (“banana fracture”)
  3. Osteogenesis imperfecta tarda
  4. Fibrous dysplasia
  5. Organic renal disease in 1%
  6. Renal tubular dysfunction
  7. Congenital hypophosphatasia
  8. Congenital hyperphosphatasia (“juvenile Paget disease”)
  9. Vitamin D malabsorption / deficiency
  10. Neurofibromatosis

mnemonic: “POOF”

  • Paget disease
  • Osteomalacia
  • Osteogenesis imperfecta
  • Fibrous dysplasia

Common locations:

scapulae (axillary margin, lateral + superior margin), medial femoral neck + shaft, pubic + ischial rami, ribs, lesser trochanter, ischial tuberosity, proximal ⅓ of ulna, distal ⅓ of radius, phalanges, metatarsals, metacarpals, clavicle

  • typically bilateral + symmetric at right angles to bone margin
  • paralleled by marginal sclerosis in later stages
  • healing fracture with little / no callus response
  • 2–3-mm stripe of lucency at right angle to cortex (= osteoid seam formed within stress-induced infractions (PATHOGNOMONIC) + nonunion (= incomplete healing due to mineral deficiency)