Acronym

LOC - Loss of Cortical Outline

Disruption of the sharp cortical margin of bone, indicating cortical erosion or destruction

Expansion

Loss of Cortical Outline

Purpose

Sign of cortical bone disease (infection, malignancy, inflammatory arthropathy)

Clinical Context

On X-ray, loss of the normally sharp cortical margin indicates pathology. Compare cortical margins across bones and joints; early rheumatoid arthritis shows juxtaarticular LOC.

  • Cortical erosion:
  • Cortical destruction:
  • Bone lysis:

Key Points

  • LOC is a feature of aggressive lesions; see it with infection (osteomyelitis), malignancy, or inflammatory arthropathy (RA)