Spondylolisthesis: Meyerding Grading, Scotty Dog Sign & Rehab MCQs

Spondylolisthesis

Spondylolisthesis is the forward slippage of one vertebra over the one below it. It is a common cause of back pain in adolescents (gymnasts) and the elderly.

1. Classification (Wiltse)

• Type I (Dysplastic): Congenital defect of the sacrum/L5 arch.
• Type II (Isthmic): Defect in the Pars Interarticularis (Spondylolysis). Most common in young athletes. Usually L5-S1.
• Type III (Degenerative): Due to facet joint arthritis. No pars defect. Most common in elderly. Usually L4-L5.

2. Diagnosis

The "Scotty Dog" Sign:
Seen on Oblique X-rays.
- A normal vertebra looks like a dog.
- If the dog has a "collar" on its neck, it is a fracture of the Pars Interarticularis (Spondylolysis).
- If the head is separated from the body (decapitated), it is Spondylolisthesis.

3. Meyerding Grading

Based on the percentage of slip of the upper vertebra on the lower one:

• Grade I: 0-25%
• Grade II: 25-50%
• Grade III: 50-75%
• Grade IV: 75-100%
• Spondyloptosis: >100% (Vertebra falls off completely).

4. Physiotherapy Management

• Flexion Exercises (Williams): To open the intervertebral foramen.
• Core Stability: Transversus abdominis and Multifidus strengthening.
• Hamstring Stretching: Tight hamstrings are a hallmark sign (Phalen-Dickson sign).
• Avoid: Hyperextension exercises.

25 Practice MCQs

Q1. Spondylolisthesis is defined as:

Answer: A). Usually anterior translation.

Q2. Spondylolysis refers specifically to:

Answer: A). Lysis = Break. Listhesis = Slip.

Q3. The "Scotty Dog" sign is best seen on which X-ray view?

Answer: C). Visualizes the pars and facet joints.

Q4. Grade II slip indicates slippage of:

Answer: B). Meyerding classification.

Q5. The collar on the Scotty Dog's neck represents:

Answer: A). A break in the neck of the dog.

Q6. Degenerative Spondylolisthesis (Type III) most commonly affects:

Answer: B). Due to facet orientation and mobility.

Q7. Isthmic Spondylolisthesis (Type II) most commonly affects:

Answer: A). Common in gymnasts/weightlifters.

Q8. Phalen-Dickson sign refers to:

Answer: A). Classic gait disturbance in high-grade slips.

Q9. Which exercise is generally AVOIDED in Spondylolisthesis?

Answer: A). Extension shears the vertebra further forward.

Q10. A "Step Deformity" is palpable when:

Answer: A). Palpable shelf at the level of the slip.

Q11. Spondyloptosis corresponds to:

Answer: A). The vertebra falls completely off the one below.

Q12. Inverted Napoleon Hat sign on AP pelvic X-ray indicates:

Answer: A). L5 body overlaps the sacrum, looking like a hat.

Q13. Surgical fusion is indicated if:

Answer: A). High grades are unstable.

Q14. Degenerative Spondylolisthesis rarely exceeds:

Answer: A). The neural arch is intact, limiting the slip.

Q15. Retrolisthesis is:

Answer: A). Less common than anterolisthesis.

Q16. Which sport has the highest risk of Isthmic Spondylolisthesis?

Answer: A). Repetitive hyperextension causes fatigue fracture of pars.

Q17. Spinal Stenosis is most commonly associated with:

Answer: A). The intact neural arch moves forward, pinching the cord/cauda equina against the disc.

Q18. Reduction of high-grade slips is:

Answer: A). Often fusion in situ is safer.

Q19. The Parsons Interarticularis connects:

Answer: A). The weakest link in the neural arch.

Q20. Conservative management success rate for Grade I is:

Answer: A). Activity modification and core strengthening work well.

Q21. Heart-shaped buttocks are seen in:

Answer: A). Due to vertical sacrum and pelvic tilt.

Q22. Dysplastic Spondylolisthesis is:

Answer: A). High risk of progression.

Q23. Which brace is often used for acute spondylolysis in athletes?

Answer: A). Prevents extension to allow the fracture to heal.

Q24. "Waddling Gait" is associated with:

Answer: A). Due to hamstring tightness and pelvic mechanics.

Q25. SPECT (Bone Scan) is useful for:

Answer: A). Shows "hot spots" of metabolic activity.