L4–L5 Disc Herniation with Minimal L4 Nerve Root Effacement

L4–L5 disc herniation = nucleus pulposus protrusion through annulus fibrosus at L4–L5 level.

Minimal L4 Root Effacement

The herniation slightly narrows the lateral recess/foramen, lightly contacting the exiting L4 nerve root (which exits above the L4 pedicle).

Clinical Correlation

• L4 root → medial leg/foot sensation, quadriceps strength, knee jerk.
• Minimal effacement may be asymptomatic or cause mild radiculopathy (anterior thigh pain, knee weakness).
• L5 root (traversing) more commonly compressed at L4–L5 → lateral leg/dorsum foot symptoms.

Management

• Conservative (6–12 wks): NSAIDs, PT (McKenzie, core), activity modification, epidural steroid injection.
• Surgical (microdiscectomy): Progressive deficit, intractable pain, cauda equina.

Imaging findings must correlate with exam; many asymptomatic herniations exist.