Case 12 Recurrent lumbar disc prolapse
Figure 12.1: MRI of the patient sagittal T2.
- Q1: Which root is affected in an L4-5-disc herniation?
- A posterolateral L4-L5 disc herniation affects the L5 nerve root, while a far-lateral herniation affects the L4 nerve root.
- Q2: Why are symptoms and signs more severe in recurrent cases than in de novo ones, even with smaller-sized discs?
- This is because fibrosis and adhesions developed after the first surgery restricts the movement of the nerve root, making it more vulnerable to compression.
- Q3: What is the percentage of failed back syndrome after lumbar operations?
- It’s difficult to calculate percentage accurately but it’s about 30%.
- Q4: What are the Causes of post op failed back syndrome?
It includes:
- Inadequate decompression (mostly residual lateral recess stenosis)
- Aggressive decompression (compromising spinal stability)
- Patient selection (work claimers mostly and psychotic patients)
- Deficient decision (neglected instability)
- Recurrent disc Thecal and roots scarring
- What is pelvic incidence (PI)?
- The angle is measured between two lines: the first from the center of the femoral head to the middle of the upper S1 plate, and the second a perpendicular line to the upper S1 plate. This value is unchangeable and specific to each patient. It helps in the correction of abnormal lumbar lordosis. A PI-LL (pelvic incidence minus lumbar lordosis) greater than 11 degrees indicates mismatching and correlates with the patient’s axial symptoms. It is also the sum of the sacral slope and pelvic tilt. All these measurements are taken in the sagittal plane.
Figure 12.1: sacral slope and pelvic incidence.