Step deformity

  • Step deformity is a skeletal deformity in which 2 adjacent bones which should be aligned with each other are displaced and are at different levels – resembling a step of a staircase
  • Examples:
    • Step deformity of spine
      • two adjacent vertebra are at different levels
      • can be identified by palpating the spinous process
      • spinous process appears prominent due to anterior/posterior displacement of adjacent vertebra (spondylolisthesis)
    • Step defromity of infraorbital ridge
      • seen in zygomatic bone (tripod fracture)
    • Step deformity of knee
      • seen in rupture of cruciate ligaments
      • results in displacement of tibia and fibula relative to femur
    • Step deformity below acromion
      • seen  in separation of acromioclavicular joint