12/07/2025
This classification is commonly used on MRI to describe the severity of intervertebral disc degeneration, especially in the lumbar spine.
🟢 Grade I – Normal Disc
• Bright white nucleus on MRI (high water content)
• Clear distinction between nucleus & annulus
• Normal disc height
• No disc bulge
🟡 Grade II – Mild Degeneration
• Slightly decreased signal (less bright)
• Still clear distinction between nucleus and annulus
• Normal or slightly reduced disc height
🟠 Grade III – Moderate Degeneration
• Intermediate gray signal (further water loss)
• Blurring between nucleus and annulus
• Mild loss of disc height
• Possible disc bulge
🔴 Grade IV – Severe Degeneration
• Dark disc (low signal, low hydration)
• No clear nucleus/annulus distinction
• Moderate to severe disc height loss
• Often associated with bulge or protrusion
⚫ Grade V – Advanced Degeneration
• Collapsed disc space
• Very dark signal (severely dehydrated)
• Endplate changes (Modic changes may be present)
• Loss of normal disc structure
Clinical Note for Physiotherapists:
• Grades I–II: Preventive rehab, posture correction, ergonomics
• Grades III–IV: Core strengthening, manual therapy, symptom management
• Grade V: Often needs multidisciplinary management; sometimes surgical consult
