import { OnePagerSummary, ExamWarning, InfoCardGrid, InfoCard, MnemonicCard, EvidenceCard, VivaScenarioSection, VivaScenario, ExamCheatSheet, ContentSection, ExamPearl, SafetyAlert, NumberHighlightRow, NumberHighlight, Tabs, Tab, ComparisonTable } from '@/components/mdx' RT alone for MSCC" ]} /> ### Metastatic Spinal Cord Compression (MSCC) - Neurological deficit (motor/sensory/sphincter) with imaging-confirmed cord compression - Progressive neurological deterioration despite radiotherapy - Mechanical instability (SINS ≥7) - Radioresistant tumour (renal, melanoma, sarcoma) requiring separation surgery + SBRT - Unknown primary requiring tissue diagnosis ### Primary Spine Tumours - En bloc resection for isolated primary tumour with curative intent (Tokuhashi 12-15) - Decompression and stabilization for locally aggressive benign tumours ### Mechanical Instability - SINS score 7-12: Potentially unstable - consider stabilization - SINS score 13-18: Unstable - requires stabilization ### Absolute Contraindications - Life expectancy <3 months (Tokuhashi 0-5) - consider palliative RT only - Disseminated disease with no surgical benefit expected - Medically unfit for major surgery (ASA 4-5) - Patient/family decline surgery ### Relative Contraindications - Complete paraplegia >48 hours (poor recovery potential) - Radiosensitive tumour (myeloma, lymphoma) - RT may be first-line - Extensive epidural disease at multiple levels - Active systemic infection - Coagulopathy (correct before surgery) ### Essential Imaging - **MRI whole spine**: Skip metastases in 10-30%; cord compression assessment - **CT spine**: Bony anatomy, pedicle screw planning, vertebral body destruction - **CT chest/abdomen/pelvis**: Staging, identify visceral metastases - **PET-CT**: If unknown primary or to assess disease burden ### Prognostic Scoring **SINS Score (Spinal Instability Neoplastic Score)** | Component | Score Range | |-----------|-------------| | Location | 0-3 | | Pain | 0-3 | | Bone lesion | 0-2 | | Alignment | 0-4 | | VB collapse | 0-3 | | Posterolateral involvement | 0-3 | | **Total** | **0-18** | - 0-6: Stable - 7-12: Potentially unstable (consider surgery) - 13-18: Unstable (surgery indicated) **Tokuhashi Score** - 0-8: Conservative/palliative (expected survival <6 months) - 9-11: Palliative surgery (expected survival 6-12 months) - 12-15: Excisional surgery (expected survival >12 months) ### MDT Discussion - Oncology, radiation oncology, spine surgery, palliative care - Establish primary tumour type and prognosis - Plan adjuvant radiotherapy timing ### Implants - Polyaxial pedicle screws (various diameters 5.5-7.5mm) - Titanium or cobalt-chrome rods (5.5mm or 6.0mm) - Cross-links for rotational stability - Cement (PMMA) for screw augmentation and vertebroplasty - Expandable cages for anterior column reconstruction ### Instruments - High-speed burr for laminectomy - Kerrison rongeurs (various sizes) - Penfield dissectors - Nerve hooks and retractors - Bone curettes (various angles) - Bipolar electrocautery ### Monitoring - Intraoperative neuromonitoring (MEPs, SSEPs) - Cell saver - Fluoroscopy or navigation ### Other - Jackson frame or Wilson frame - Radiolucent table - Tumour staging biopsies if needed **Location**: Within spinal canal, often compressed by tumour. **Protection**: Careful tumour debulking, avoid cord retraction, neuromonitoring (MEPs/SSEPs) essential. **Location**: Exit through neural foramina. **Protection**: Identify before decompression, protect during laminectomy, trace if involved in tumour. **Location**: Along vertebral body at each level. **At risk**: Lateral decompression, corpectomy. May require ligation for exposure. **Location**: Left side at thoracolumbar junction. **At risk**: Left-sided thoracolumbar approaches. Injury causes chylothorax. **Location**: Anterior to vertebral bodies. **At risk**: Anterior approaches, screw malposition. Catastrophic if injured. **Location**: Surrounds cord and nerve roots. **At risk**: Tumour invasion through dura, aggressive decompression. Repair if breached. ### Tumour Location Patterns Most metastatic spine tumours follow a predictable pattern: - **Vertebral body**: 70-80% (hematogenous spread via Batson's plexus) - **Posterior elements**: 20-30% (often extends from body) - **Epidural space**: Compression from vertebral body extension or soft tissue mass ### Batson's Venous Plexus Valveless venous network connecting pelvic and thoracic veins to vertebral venous plexus: - Explains predilection for spine metastases - Breast, prostate, lung, kidney, thyroid most common primaries ("BLT with a Kosher Pickle") ### Surgical Corridors **Posterior approach** provides: - Access to posterior elements and epidural space - Pedicle screw fixation points - Transpedicular access to vertebral body **Separation surgery corridor**: - Create 2-3mm gap between tumour and thecal sac - Allows high-dose SBRT without cord myelopathy - Essential for radioresistant tumours (renal, melanoma) ### Spinal Cord Blood Supply - **Anterior spinal artery**: Supplies anterior 2/3 of cord - **Artery of Adamkiewicz**: Major radicular artery, typically T9-L2 LEFT - Preserve during thoracolumbar tumour surgery **Patient Position**: Prone on Jackson frame or Wilson frame. Arms at sides or 90° abduction. Head in neutral, eyes protected. **Neuromonitoring**: Establish baseline MEPs and SSEPs before positioning. Alert threshold: >50% amplitude loss or 10% latency increase. **Cell Saver**: Set up - metastatic tumour surgery can be bloody. Relative contraindication with haematological malignancies. **Fluoroscopy/Navigation**: Confirm levels. Navigation useful for pathological bone, distorted anatomy. **Preoperative Planning Verification**: - Confirm correct levels on preoperative imaging - Review SINS and Tokuhashi scores - Confirm MDT discussion and adjuvant RT plan - Check bloods: Hb, coagulation, group and save ### Step 1: Positioning and Level Verification - Prone on Jackson frame, arms tucked or abducted - Lateral fluoroscopy to confirm levels - COUNT FROM SACRUM - Mark incision (midline, 2-3 levels above and below tumour) - Establish neuromonitoring baseline **EXAM KEY**: Level counting errors are a "never event." Count from sacrum superiorly, and verify with lateral fluoro before incision. Mark levels with spinal needle if uncertain. ### Step 2: Exposure and Pedicle Screw Placement **Exposure**: - Midline incision over spinous processes - Subperiosteal dissection to transverse processes - Expose 2-3 levels above and below planned decompression **Pedicle Screw Placement**: - Place screws BEFORE decompression (bone landmarks preserved) - Freehand technique or navigation-guided - Entry point: junction of transverse process and lateral border of superior articular facet - In osteopenic bone: consider fenestrated screws with cement augmentation **EXAM KEY**: Place screws BEFORE laminectomy - bone landmarks are easier to identify, and screws provide immediate stability if neurological deterioration during decompression. For osteopenic bone: Use fenestrated screws and inject PMMA under fluoroscopy. Avoid cement extravasation into canal or vessels. Allow polymerization before rod insertion. ### Step 3: Laminectomy Over Compressed Segment - High-speed burr to thin lamina bilaterally - Complete laminectomy with Kerrison rongeurs - Preserve facet joints where possible (unless tumour-involved) - Identify and protect dura throughout **EXAM KEY**: Thin the lamina to "eggshell" thickness with burr before completing with Kerrison - safer for compromised dura and allows tactile feedback before dural contact. ### Step 4: Epidural Tumour Debulking **Posterior Element Tumour**: - Excise tumour-involved lamina en bloc if possible - Extend laterally into pedicle if involved **Epidural Compression** (separation surgery): - Identify plane between tumour and dura - Debulk tumour circumferentially - Goal: create 2-3mm gap from thecal sac for SBRT - Do NOT attempt complete tumour resection (palliative surgery) Goal is to create space for radiotherapy, NOT curative resection. Attempting complete resection increases morbidity without survival benefit in metastatic disease. Leave residual tumour for SBRT. ### Step 5: Transpedicular Vertebral Body Debulking If anterior column involvement: - Curette through pedicle (transpedicular approach) - Remove tumour from vertebral body cavity - Preserve anterior and lateral cortical shell if intact **EXAM KEY**: Transpedicular debulking from posterior approach avoids morbidity of separate anterior approach. Useful for contained vertebral body lesions. ### Step 6: Cement Augmentation of Vertebral Body - If vertebral body debulked or at risk of collapse - Inject PMMA under fluoroscopy through transpedicular cannula - Fill cavity with cement to restore mechanical strength - Watch for extravasation (epidural, foraminal, venous) ### Step 7: Anterior Column Reconstruction (if needed) For significant vertebral body destruction or corpectomy: - Expandable cage through posterolateral approach - OR anterior approach with strut graft/cage (separate procedure) - Provides load-sharing to protect posterior instrumentation ### Step 8: Rod Placement and Final Construct - Pre-contour rods to match sagittal alignment - Insert rods and secure with set screws - Apply compression/distraction as needed - Add cross-links for rotational stability (especially 3+ level constructs) **EXAM KEY**: Cross-links are mandatory for rotational stability in tumour surgery where bone quality is compromised. Place at least one cross-link per construct. ### Step 9: Final Inspection and Haemostasis - Inspect decompression site for residual compression - Check neuromonitoring - MEPs/SSEPs stable or improved - Meticulous haemostasis - tumour bed bleeds significantly - Consider topical hemostatic agents (Floseal, Surgicel) - Irrigate copiously ### Step 10: Closure - Place subfascial drains (Jackson-Pratt) to prevent haematoma - Close deep fascia with heavy absorbable suture (0-Vicryl) - Subcutaneous and skin closure - Dry dressing ### Step 11: Postoperative Care **Immediate**: - ICU or HDU observation overnight - Neuro checks every 1-2 hours - DVT prophylaxis (LMWH when haemostasis secure) - Mobilize when medically stable **Adjuvant Therapy**: - Radiotherapy planning within 2-4 weeks - SBRT for separation surgery cases - Oncology follow-up for systemic therapy ### Step 12: Follow-up and Surveillance - Clinical review 2 weeks, 6 weeks, 3 months - MRI at 3 months to assess tumour response - Ongoing oncology/palliative care coordination - Repeat imaging if new symptoms RT alone for ambulatory MSCC patients", "Surgery ideally within 24-48hr while ambulatory function remains", "SINS score ≥7 indicates potential instability requiring stabilization", "Tokuhashi guides surgical extent - breast cancer = 9-11 range" ]} traps={[ "Delaying surgery for oncology review - time-critical decision", "Forgetting whole spine MRI (10-30% have skip metastases)", "Over-aggressive surgery for palliative situation", "Not checking calcium (hypercalcemia common in malignancy)" ]} followUp={["Her SINS score is 12. What does this mean and how does it affect your surgical plan?"]} /> RT alone for MSCC", "Must have reasonable prognosis and single level of compression", "Surgery within 48hr preserves ambulatory function", "Separation surgery + SBRT for radioresistant tumours" ] }, { heading: "Surgical Principles", points: [ "Place pedicle screws BEFORE laminectomy (landmarks preserved)", "2-3 levels above and below tumour for fixation", "Cement augmentation for osteopenic bone", "Cross-links for rotational stability", "Separation surgery: 2-3mm gap for SBRT, NOT complete resection" ] }, { heading: "Exam Tips", points: [ "Know SINS score components and thresholds", "Cite Patchell trial for MSCC management", "Radioresistant tumours: renal, melanoma, sarcoma (separation surgery)", "Radiosensitive tumours: myeloma, lymphoma (RT first-line)", "Common primaries: Breast, Lung, Thyroid, Kidney, Prostate (BLT with Kosher Pickle)" ] } ]} /> 1. Patchell RA, Tibbs PA, Regine WF, et al. Direct decompressive surgical resection in the treatment of spinal cord compression caused by metastatic cancer: a randomised trial. Lancet. 2005;366(9486):643-648. 2. Fisher CG, DiPaola CP, Ryken TC, et al. A novel classification system for spinal instability in neoplastic disease: an evidence-based approach and expert consensus from the Spine Oncology Study Group. Spine. 2010;35(22):E1221-E1229. 3. Tokuhashi Y, Matsuzaki H, Oda H, et al. A revised scoring system for preoperative evaluation of metastatic spine tumor prognosis. Spine. 2005;30(19):2186-2191. 4. Laufer I, Iorgulescu JB, Chapman T, et al. Local disease control for spinal metastases following "separation surgery" and adjuvant hypofractionated or high-dose single-fraction stereotactic radiosurgery: outcome analysis in 186 patients. J Neurosurg Spine. 2013;18(3):207-214. 5. Bilsky MH, Laufer I, Fourney DR, et al. Reliability analysis of the epidural spinal cord compression scale. J Neurosurg Spine. 2010;13(3):324-328. 6. National Institute for Health and Care Excellence (NICE). Metastatic spinal cord compression in adults: risk assessment, diagnosis and management. CG75. 2008 (updated 2014). 7. Rades D, Fehlauer F, Schulte R, et al. Prognostic factors for local control and survival after radiotherapy of metastatic spinal cord compression. J Clin Oncol. 2006;24(21):3388-3393. 8. Yamada Y, Bilsky MH, Lovelock DM, et al. High-dose, single-fraction image-guided intensity-modulated radiotherapy for metastatic spinal lesions. Int J Radiat Oncol Biol Phys. 2008;71(2):484-490. 9. Klimo P Jr, Thompson CJ, Kestle JR, Schmidt MH. A meta-analysis of surgery versus conventional radiotherapy for the treatment of metastatic spinal epidural disease. Neuro Oncol. 2005;7(1):64-76. 10. Fourney DR, Frangou EM, Ryken TC, et al. Spinal instability neoplastic score: an analysis of reliability and validity from the spine oncology study group. J Clin Oncol. 2011;29(22):3072-3077.

Spine Tumour Decompression and Stabilization

Spine Tumour Decompression and Stabilization