What is the step-by-step procedure for managing prolapsed intervertebral disc (PIVD) at L4-L5 using discectomy?

Step-by-Step Procedure for PIVD L4-L5 Managed by Discectomy

Discectomy without fusion is the recommended surgical approach for managing prolapsed intervertebral disc (PIVD) at L4-L5 level when conservative management fails, as fusion is not routinely indicated for primary disc herniation cases. 1

Preoperative Assessment and Planning

1. Patient Selection

   • Confirm radicular symptoms correlating with L4-L5 disc herniation
   • Verify failed conservative management (typically 6-8 weeks)
   • Review MRI showing disc herniation at L4-L5 level
   • Assess for any instability that might require fusion (rare in primary disc herniation)

2. Surgical Planning

   • Choose appropriate approach:
     • Standard open discectomy
     • Microdiscectomy (most common)
     • Minimally invasive options (endoscopic approaches)

Surgical Procedure

1. Anesthesia and Positioning

• General anesthesia (most common) or local anesthesia with sedation
• Position patient prone on Wilson or Jackson frame with abdomen free
• Flex hips and knees to open interlaminar space
• Confirm level with intraoperative fluoroscopy

2. Approach and Exposure

• Make a 2-3 cm midline incision centered over L4-L5 level
• Dissect paraspinal muscles subperiosteally from spinous processes and laminae
• Place self-retaining retractor to maintain exposure
• Identify L4-L5 interlaminar space

3. Decompression

• Perform partial laminotomy/laminectomy of inferior aspect of L4 and superior aspect of L5
• Identify and protect ligamentum flavum
• Carefully incise and remove ligamentum flavum to expose dural sac and nerve root
• Identify the traversing L5 nerve root and retract medially

4. Discectomy

• Identify the herniated disc material
• Protect the nerve root with a root retractor
• Remove herniated disc fragment with pituitary rongeurs and curettes
• Explore disc space to remove any additional loose fragments
• Avoid aggressive disc space curettage to prevent collapse and instability
• Ensure adequate decompression of nerve root

5. Hemostasis and Closure

• Achieve meticulous hemostasis
• Irrigate wound thoroughly
• No drain is typically needed
• Close fascia and subcutaneous tissues with absorbable sutures
• Close skin with sutures or staples

Postoperative Management

1. Immediate Care

   • Mobilize patient within 24 hours
   • Provide appropriate pain management
   • Monitor for neurological deficits or complications

2. Discharge Planning

   • Typically discharge within 24-48 hours
   • Provide wound care instructions
   • Prescribe appropriate pain medications

3. Follow-up Care

   • First follow-up at 2 weeks for wound check
   • Progressive activity as tolerated
   • Avoid heavy lifting, bending, or twisting for 4-6 weeks
   • Initiate physical therapy after 4-6 weeks

Outcomes and Complications

1. Expected Outcomes

   • Success rates of approximately 90-95% for properly selected patients 2
   • Immediate relief of radicular pain in most cases

2. Potential Complications

   • Dural tear (1-5%)
   • Infection (1-2%)
   • Nerve root injury (rare)
   • Recurrent disc herniation (5-10%)
   • Epidural hematoma (rare)
   • Post-laminectomy instability (rare in primary discectomy)

Important Considerations

1. Fusion is Not Routinely Indicated

   • Evidence shows that adding fusion to discectomy for primary disc herniation does not improve outcomes 1
   • Fusion should be reserved for cases with significant instability or chronic axial back pain with severe degenerative changes

2. Minimally Invasive Options

   • Endoscopic discectomy shows comparable outcomes to open techniques with potentially faster recovery 2, 3
   • Transforaminal percutaneous endoscopic lumbar discectomy has shown positive outcomes in approximately 93% of cases 2

3. Recurrence Management

   • Recurrent disc herniation may warrant consideration of fusion, especially if associated with instability or chronic axial pain 1

By following this systematic approach to discectomy for L4-L5 PIVD, surgeons can achieve optimal outcomes while minimizing complications and avoiding unnecessary procedures such as fusion in primary disc herniation cases.