Pterion Prep CraniPro VUMC Case Prep
2026-06-27

Case Prep: Lumbar Microdiscectomy

Case / Approach Snapshot

One-Liner

[Age]yo [M/F] with [left/right] [L_-S_] disc herniation causing [L_/S_] radiculopathy presenting with [leg pain/weakness/numbness] [and/or cauda equina syndrome] planned for [left/right] L_-S_ microdiscectomy.

Figures, Imaging & Video

🎥 Operative video — search operative video on YouTube ▸ · The Neurosurgical Atlas ▸

CNS Video Library

🧭 Operative approach: Posterior thoracolumbar approach — detailed corridor setup, step-by-step technique & figures

Neurosurgical Atlas · AO Spine / Surgery Reference · Radiopaedia · PubMed Central — operative figures © linked; see media-sources.md

High-Yield Literature

Curated Image Set

Open-access figures are embedded from PubMed Central articles and kept unique to this guide.

Lumbar Microdiscectomy — Figure 3 Figure 3. Source: Lumbar microdiscectomy and post-operative activity restrictions: a protocol for a single blinded randomised controlled trial — BMC Musculoskelet Disord. 2017 Jul 20;18:312. doi: 10.1186/s12891-017-1681-3; CC BY.

Lumbar Microdiscectomy — Figure 4 Figure 4. Source: Variability in Opioid Prescription Following Primary Single-Level Lumbar Microdiscectomy — Global Spine J. 2020 Aug 28;12(2):263–6. doi: 10.1177/2192568220950678; CC BY-NC-ND.

Lumbar Microdiscectomy — Figure 1 Figure 1. Average billing level and standard deviation for each surgeon for lumbar microdiscectomy from 2018–2019. Source: Differences in evaluation and management coding of outpatient clinic visits for patients undergoing elective spine surgery with use of a standardized template — Journal of Spine Surgery 2023; CC BY-NC-ND.

Lumbar Microdiscectomy — Figure 2 Figure 2. Distribution of billing by each surgeon per level for lumbar microdiscectomy from 2018–2019. Source: Differences in evaluation and management coding of outpatient clinic visits for patients undergoing elective spine surgery with use of a standardized template — Journal of Spine Surgery 2023; CC BY-NC-ND.

Lumbar Microdiscectomy — Fig. 1 Fig. 1. Average operation time stratified by body mass index. Source: Does Obesity Make an Influence on Surgical Outcomes Following Lumbar Microdiscectomy? — Korean Journal of Spine 2014; CC BY-NC.

Lumbar Microdiscectomy — Fig. 2 Fig. 2. Averatge estimated blood loss stratified by body mass index. Source: Does Obesity Make an Influence on Surgical Outcomes Following Lumbar Microdiscectomy? — Korean Journal of Spine 2014; CC BY-NC.

Lumbar Microdiscectomy — Figure 9 Figure 9. Source: Does Obesity Make an Influence on Surgical Outcomes Following Lumbar Microdiscectomy? — Korean J Spine. 2014 Jun 30;11(2):68–73. doi: 10.14245/kjs.2014.11.2.68; CC BY-NC.

Lumbar Microdiscectomy — Figure 10 Figure 10. Source: Does Obesity Make an Influence on Surgical Outcomes Following Lumbar Microdiscectomy? — Korean J Spine. 2014 Jun 30;11(2):68–73. doi: 10.14245/kjs.2014.11.2.68; CC BY-NC.

History of Present Illness

Past Medical History

Imaging Review

MRI Lumbar Spine

CT Lumbar Spine (if MRI contraindicated)

X-rays Lumbar Spine (AP, Lateral, Flexion/Extension)

Labs

Neurological Examination

Motor (Myotomal)

Sensory (Dermatomal)

Reflexes

Provocative Tests

CES Screening

Surgical Planning

Case Logistics, OR Needs & Orders

Diagnosis & Indication

Position

Incision

Approach: Posterior Midline Microsurgical

Key Surgical Steps

  1. Fluoroscopic level confirmation — CRITICAL; wrong-level surgery is a never event
    • Place needle on spinous process, obtain AP fluoroscopy
    • Count from sacrum (most reliable landmark)
    • For L5-S1: palpate sacral promontory/lumbosacral junction
  2. Midline incision — 2-3 cm centered over interlaminar window
  3. Subperiosteal dissection — detach paraspinal muscles from spinous process and lamina on the AFFECTED SIDE ONLY
  4. Self-retaining retractor (McCulloch, tubular retractor for MIS)
  5. Identify interlaminar window:
    • Superior lamina (partial inferior edge)
    • Inferior lamina (partial superior edge)
    • Ligamentum flavum between
  6. Laminotomy: Remove inferior edge of superior lamina with Kerrison rongeur or drill to expose the ligamentum flavum adequately
    • Preserve as much facet joint as possible (> 50% lateral facet must remain to prevent instability)
  7. Ligamentum flavum removal: Detach from deep surface of superior lamina, elevate, and excise with Kerrison rongeur, exposing the epidural space
  8. Identify the traversing nerve root — should be visible crossing the disc space
  9. Retract nerve root medially (gently, with nerve root retractor)
  10. Identify disc herniation:
    • Epidural: Fragment may be visible under the root
    • Subligamentous: Open the posterior longitudinal ligament over the bulge
    • Sequestered: Fragment may have migrated superiorly or inferiorly
  11. Remove disc fragment:
    • Incise annulus (if subligamentous)
    • Remove herniated fragment with pituitary rongeur
    • Enter the disc space and remove loose fragments
    • Explore for free fragments — check cephalad and caudad to the nerve root, and laterally in the axilla of the root
    • Do NOT aggressively curette the disc space (not a fusion — preserve disc height)
  12. Confirm root decompression:
    • Nerve root should be freely mobile
    • Pass nerve hook around the root (360-degree check)
    • Root should be pulsatile (thecal sac pulsation transmitted)
  13. Hemostasis: Bipolar, Gelfoam, thrombin-soaked Gelfoam for epidural bleeding
  14. Closure:
    • Irrigate
    • Fascia: 0 or 2-0 Vicryl
    • Subcutaneous: 3-0 Vicryl
    • Skin: 4-0 Monocryl subcuticular + Dermabond OR staples

Critical Anatomy & Structures at Risk

  1. Traversing nerve root — the root being decompressed; retract gently (medially)
  2. Exiting nerve root — exits under the pedicle ABOVE (e.g., L4 root exits at L4-5 above the disc); at risk if dissection is too lateral/cephalad
  3. Thecal sac / cauda equina — medial to the working corridor
  4. Epidural veins — can cause significant bleeding; bipolar, Gelfoam
  5. Facet joint — preserve > 50% to prevent iatrogenic instability
  6. Great vessels (aorta/IVC/iliac) — anterior to disc space; rare but CATASTROPHIC vascular injury if pituitary rongeur passes through anterior annulus. Do NOT plunge instruments anteriorly

Equipment

Monitoring

Anesthesia Considerations

Potential Complications & Contingencies

  1. Dural tear / CSF leak — primary repair if possible (5-0 or 6-0 Prolene); if not, Duragen + fibrin glue + muscle patch. Flat bed rest x 48-72h post-op
  2. Nerve root injury — gentle retraction only; if motor worse post-op, MRI to rule out hematoma
  3. Wrong-level surgery — prevent with meticulous fluoroscopic confirmation; count from sacrum
  4. Recurrent herniation — 5-15% risk; counsel pre-op. If recurrent: repeat discectomy or consider fusion
  5. Epidural hematoma — meticulous hemostasis; if new deficit post-op → emergent MRI → return to OR
  6. Vascular injury (anterior disc penetration) — EXTREMELY rare but fatal; if sudden hypotension after disc space entry → emergent vascular surgery consultation, laparotomy
  7. Discitis/infection — fever, worsening back pain at 2-4 weeks; MRI with gadolinium, ESR/CRP

Operative Note Template

Preoperative Diagnosis: [Left/Right] L_-S_ disc herniation with [L_/S_] radiculopathy

Postoperative Diagnosis: Same

Procedure: [Left/Right] L_-S_ microsurgical lumbar discectomy

Surgeon: Assistant: Anesthesia: General endotracheal anesthesia

EBL: Minimal (___ mL) Fluids: Specimens: Disc material (send to pathology if concern for infection/tumor) Drains: None Complications: None Implants: None

Indications: The patient is a [age]yo [M/F] with [left/right] [L_/S_] radiculopathy due to a [left/right] L_-S_ [paracentral/foraminal] disc herniation. The patient failed [duration] of conservative management including [PT, NSAIDs, epidural injections]. [The patient presented with progressive L5 foot drop / cauda equina syndrome requiring urgent surgery.] After discussion of risks, benefits, and alternatives, the patient elected to proceed with microsurgical discectomy.

Description of Procedure: After informed consent was verified and the surgical site was marked, the patient was brought to the operating room. General endotracheal anesthesia was induced. The patient was carefully log-rolled to the prone position on a [Wilson frame / Jackson table]. The abdomen was confirmed to be free and hanging. All pressure points were padded, the eyes were free of pressure, and the endotracheal tube was secured. A time-out was performed.

The lower back was prepped and draped in standard sterile fashion. Cefazolin [2g] was administered. The appropriate surgical level was confirmed with AP fluoroscopy using a spinal needle placed at the [L_-S_] interspinous space [counting from the sacrum].

Incision: A [2.5 cm] midline incision was made centered over the [L_-S_] interspace. Dissection was carried through the thoracolumbar fascia. The paraspinal muscles were elevated subperiosteally from the spinous process and lamina on the [left/right] side. A self-retaining retractor was placed.

Laminotomy and decompression: The interlaminar window at [L_-S_] was identified. Using a [Kerrison rongeur / high-speed drill], the inferior edge of the [L_] lamina was removed to expose the ligamentum flavum. The ligamentum flavum was detached from the undersurface of the lamina and excised, exposing the epidural space. [The facet joint was preserved.]

Discectomy: Under the operating microscope, the traversing [L_/S_] nerve root was identified. The root was gently retracted medially. A [large/moderate] [paracentral/foraminal] disc fragment was identified [compressing the nerve root / extruded into the epidural space / migrated cephalad-caudad]. The fragment was removed with a pituitary rongeur. The posterior longitudinal ligament was incised and the annular defect was explored. Additional loose disc material was removed from the disc space. A nerve hook was passed around the nerve root [superiorly, inferiorly, and laterally], confirming complete decompression. The nerve root was freely mobile and pulsatile.

Hemostasis: Hemostasis was achieved with bipolar cautery and [Gelfoam / thrombin-soaked Gelfoam]. The wound was irrigated with antibiotic-containing saline.

Closure: The thoracolumbar fascia was closed with [0 Vicryl] interrupted sutures. The subcutaneous tissue was closed with [3-0 Vicryl]. The skin was closed with [4-0 Monocryl subcuticular suture and Dermabond / staples]. A sterile dressing was applied.

Postoperative: The patient was carefully log-rolled to the supine position, awakened from anesthesia, extubated, and found to have [improved leg pain / intact motor function / baseline neurological status]. The patient was transferred to the PACU in stable condition.

Postoperative Plan

Chief-Level Case Review

Use these as the senior-level mental model for Lumbar Microdiscectomy:

Common Pimp Questions

Use these to pressure-test preparation for Lumbar Microdiscectomy:

  1. What neurologic level and root are responsible for the presenting deficit?
  2. What is the decompression target and how will you know it is adequately decompressed?
  3. What instability, deformity, bone-quality, or fusion variable changes the construct?
  4. What vascular, visceral, dural, or neural structure is the main structure at risk?
  5. What postop brace, drain, mobilization, MAP, antibiotic, and DVT plan should be ordered?

Attending Preference Variables

Items that commonly vary by surgeon or institution: