Which oblique view is helpful in diagnosing spondylolysis in athletes?

• A. AP pelvis view
• B. Oblique lumbar spine view
• C. Lateral knee view
• D. AP thoracic spine

Answer: (B)

The key idea is that spondylolysis is a stress fracture of the pars interarticularis, and this region is best seen on an oblique projection that opens up the pars. An oblique view of the lumbar spine shows the pars interarticularis in profile, so a fracture line there appears more clearly as a defect or a “collar” on the Scotty Dog sign. This makes the oblique lumbar spine radiograph the most sensitive plain-film test for detecting spondylolysis, especially in athletes with back pain. Other views—like AP pelvis, lateral knee, or AP thoracic spine—do not visualize the pars interarticularis as well and often miss the lesion. If suspicion remains after radiographs, MRI or CT can confirm an early fracture.