Summary

Lumbar Disc Herniation (LDH) is the displacement of nucleus pulposus material beyond the intervertebral disc space, causing mechanical compression and chemical irritation of the adjacent nerve root (Radiculopathy). The most common levels are L4/L5 (compressing L5 root) and L5/S1 (compressing S1 root). The classic presentation is Sciatica—sharp, shooting pain radiating below the knee. The natural history is favourable: 90% of patients improve within 6-12 weeks without surgery, as the herniated fragment resorbs. Surgery (Microdiscectomy) provides faster pain relief but similar 2-year outcomes to conservative care. [1,2]

Key Facts

• Most Common Levels: L4/L5 and L5/S1 account for 90% of herniations.
• Chemical Radiculitis: It's not just pressure. The nucleus pulposus is an immunologically privileged site. When it leaks, it triggers a massive inflammatory response (TNF-alpha) that sensitizes the nerve. This is why small discs can hurt immensely.
• L5 vs S1:
  • L5 Root: Weak Big Toe Extension (EHL). Numbness Top of Foot.
  • S1 Root: Weak Calf (Plantarflexion). Absent Ankle Jerk. Numbness Lateral Foot.

Clinical Pearls

"The Wait for Resorption": Explain to patients: "Your body views the disc fragment as foreign material and eats it away using enzymes." This validates their pain while explaining why waiting works.

"Crossing Over": A Positive Crossed Straight Leg Raise (Lifting the good leg causes pain in the bad leg) is highly specific (90%) for a herniated disc.

"Foot Drop Check": Ask every sciatica patient to walk on their heels. If they can't, they have an L5 motor deficit. This changes the urgency.

1. Gait

• Heel walking (L5 check).
• Toe walking (S1 check).

2. Tension Signs

• Straight Leg Raise (SLR): Lasegue's Test.
  • Pain radiating below the knee between 30-70 degrees = Positive.
  • Stretches L5/S1 roots.
• Femoral Stretch Test:
  • Patient prone, knee flexed and hip extended.
  • Pain in anterior thigh = Positive.
  • Stretches L2/L3/L4 roots.

3. Neurological Exam

• Power, Tone, Reflexes, Sensation.

                 SCIATICA (RADICULOPATHY)
                        ↓
            ANY RED FLAGS (Cauda Equina)?
            ┌───────────┴───────────┐
           YES                     NO
            ↓                       ↓
      EMERGENCY MRI           CONSERVATIVE CARE
                             (Analgesia + Physio)
                                    ↓
                           IMPROVING AT 6 WEEKS?
                           ┌────────┴────────┐
                          YES                NO
                           ↓                 ↓
                       CONTINUE             MRI
                                             ↓
                                    PERSISTENT PAIN?
                                    ┌────────┴────────┐
                                INJECTION          SURGERY
                             (Transforaminal)    (Microdiscectomy)

Principles

• Time: Most hernias shrink (resorb) over 3-6 months.
• Activity: Stay active. Bed rest is harmful (deconditioning).
• Analgesia:
  • Neuropathic agents: Amitriptyline / Gabapentin (takes weeks to work).
  • NSAIDs: Reduce inflammation.
  • Opioids: Avoid if possible (chronic pain risk).

Transforaminal Epidural Steroid Injection (TFESI)

• Target: The "Safe Triangle" where the nerve root exits.
• Goal: Wash out inflammatory mediators (TNF-alpha) and reduce edema.
• Outcome: 50-60% obtain significant relief. Can buy time for resorption.
• Limit: Max 3-4 per year.

Microdiscectomy

• Indications:
  1. Cauda Equina Syndrome (Emergency).
  2. Progressive Motor Deficit (e.g., worsening foot drop).
  3. Intractable Pain failing 6 weeks of non-op care.
• Technique: Small incision, microscope magnification. Remove only the loose fragment. Leave the rest of the disc.
• Success: 85-90% good/excellent for Leg Pain. Posterior Back Pain may persist.

Natural History

• 90% spontaneous recovery.
• Massive herniations actually resorbed faster than small bulges (due to exposure to vascular epidural space).

Surgery vs Conservative (SPORT Trial)

• Surgery provides faster relief.
• At 2 years, outcomes are similar between surgery and conservative care.
• Surgery is for patients who "Can't wait".

Recurrence

• 5-10% Re-herniation rate after surgery (at the same level).

SPORT Trial (Weinstein et al, 2006)

• Spine Patient Outcomes Research Trial.
• Largest RCT comparing surgery vs non-op.
• Key Finding: Surgery group had better pain/function scores at 3 months and 1 year. The "As Treated" analysis showed significant benefit for surgery in confirmed radiculopathy.

Peul et al (2007) - NEJM

• RCT: Early surgery vs Conservative.
• Result: Early surgery gave faster relief, but no difference at 1 year.
• Conclusion: Timing of surgery is a patient choice based on pain tolerance.

What has happened?

The disc is like a jam doughnut. The outer dough has torn, and the jam has squirted out. This jam is pressing on the nerve that runs down your leg.

Will I need an operation?

Probably not. In 9 out of 10 people, the body cleans up the "jam" (dissolves it) naturally. It takes about 6-12 weeks.

Can I do damage by moving?

No. Hurt does not equal harm. Unless you have significant weakness or bladder issues, keeping moving is the best thing for your spine.

Why not just operate now?

Surgery has risks (infection, nerve damage, fluid leak). Since most people get better naturally, we save surgery for those who truly don't improve.

Q1: Differentiate an L5 from an S1 radiculopathy. A: L5: Weakness of Big Toe Extension (EHL), Numbness on Dorsum of foot. S1: Weakness of Plantarflexion (Calf), Numbness on Lateral border of foot, Loss of Ankle Jerk.

Q2: What is the significance of a "Crossed SLR"? A: High specificity (>90%) for disc herniation. It implies a large central/paracentral herniation that is pulled when the contralateral roots move.

Q3: Describe the chemical basis of radicular pain. A: It is not solely mechanical compression. The nucleus pulposus induces an autoimmune inflammatory response involving Phospholipase A2, COX-2, and TNF-alpha, which sensitizes the dorsal root ganglion.

Q4: Compare the long-term outcomes of Microdiscectomy vs Conservative Care. A: At 1-2 years, there is no significant difference in pain or disability scores. Surgery offers faster resolution of symptoms (Speed, not Destination).

(End of Topic)