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

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

Discectomy without fusion is the recommended surgical approach for managing prolapsed intervertebral disc (PIVD) at L4-L5 level, as fusion is unnecessary for primary disc herniation cases and may increase complications without improving outcomes. 1

Preoperative Considerations

• Confirm failure of conservative management before proceeding with surgery
• Verify disc herniation location and characteristics through MRI imaging
• Ensure proper patient selection: those with radicular symptoms rather than just axial back pain

Surgical Procedure Steps

1. Patient Positioning and Preparation

• Position patient prone on a radiolucent operating table with abdomen free
• Apply appropriate padding at pressure points
• Prep and drape the lumbar region using sterile technique
• Confirm level with fluoroscopy

2. Incision and Approach

• Make a midline or paramedian incision (approximately 2-3 cm) centered over the L4-L5 interspace
• Dissect subcutaneous tissue and fascia
• Perform subperiosteal dissection of paraspinal muscles from spinous processes and laminae

3. Exposure

• Place self-retaining retractors to maintain exposure
• Identify the L4-L5 interlaminar space
• Remove ligamentum flavum to expose the dural sac and nerve root

4. Discectomy Procedure

• Gently retract the dural sac and nerve root medially
• Identify the disc herniation
• Perform annulotomy (incision of the annulus fibrosus)
• Remove herniated disc material using pituitary rongeurs and curettes
• Ensure complete decompression of the nerve root
• Explore the disc space to remove any loose fragments

5. Hemostasis and Closure

• Achieve meticulous hemostasis
• Irrigate the surgical field
• Close in layers: fascia, subcutaneous tissue, and skin
• Apply sterile dressing

Postoperative Management

• Early mobilization (typically within 24 hours)
• Pain management with appropriate analgesics
• Gradual return to activities
• Physical therapy for core strengthening

Alternative Approaches

For selected cases, minimally invasive options may be considered:

• Full-endoscopic discectomy via interlaminar approach 2
• Transforaminal percutaneous endoscopic lumbar discectomy 3

Important Considerations

Evidence Against Routine Fusion

• Studies demonstrate that adding fusion to discectomy for primary disc herniation does not improve outcomes 1
• A retrospective review of 3956 cases showed that 70% of patients with discectomy alone returned to work versus only 45% in the fusion group 1
• Fusion increases surgical complexity, prolongs operative time, and potentially increases complication rates without proven medical necessity 1

Potential Complications

• Dural tear/CSF leak
• Nerve root injury
• Infection
• Recurrent disc herniation (approximately 4-5%) 3
• Postoperative discal pseudocyst (rare complication) 4

Keys to Success

• Proper patient selection
• Adequate decompression of neural elements
• Complete removal of herniated disc material
• Preservation of facet joints to maintain stability
• Meticulous hemostasis

The evidence clearly supports discectomy alone as the appropriate surgical intervention for PIVD at L4-L5, with fusion being unnecessary and potentially detrimental in most primary disc herniation cases.