What diagnosis is associated with a structural defect causing forward displacement of a vertebra?

• A. Spondylolysis
• B. Spondylolisthesis
• C. Herniated disk
• D. Fractured vertebra

Answer: (A)

The correct diagnosis associated with a structural defect causing forward displacement of a vertebra is spondylolisthesis. This condition occurs when one vertebra slips forward over the one below it, leading to a misalignment of the spine. It often results from defects in the bony encasement of the vertebrae, such as a fracture or a developmental defect known as spondylolysis, which can weaken the area and predispose an individual to slippage.

In contrast, spondylolysis refers specifically to a defect in the bony structure, often at the pars interarticularis, but does not inherently involve the forward slippage of the vertebra. A herniated disk is related to the displacement of intervertebral disk material and does not involve vertebral displacement. A fractured vertebra can occur in isolation due to trauma or trauma-related conditions but doesn’t typically describe a slippage scenario. Thus, spondylolisthesis is the most accurate term for the condition characterized by a vertebra’s forward displacement.