Limb Salvage Surgery

LSS Basics - Limb-Saving Logic

Limb Salvage Surgery (LSS) aims to remove a bone tumor while preserving the limb's function and appearance, offering an alternative to amputation.

• Core Goals:
  • Oncological: Complete tumor removal with wide, negative margins.
  • Functional: Preserve/restore maximum limb function.
  • Cosmetic: Achieve an acceptable appearance.
• Key Considerations for Feasibility:
  • Tumor type, grade, and stage (e.g., Enneking staging).
  • Anatomic location and extent of tumor.
  • Involvement of neurovascular structures.
  • Skeletal maturity (potential for growth plate preservation).
  • Patient's overall health, comorbidities, and expectations.
• General Prerequisites:
  • Tumor must be resectable with adequate surgical margins.
  • Sufficient soft tissue available for wound closure and coverage.
  • Feasible reconstructive option for the skeletal defect and soft tissues.

⭐ Successful LSS critically depends on achieving adequate (wide) surgical margins, typically 1-2 cm of healthy tissue circumferentially around the tumor, to minimize local recurrence risk. This is a key factor for oncological outcome.

Pre-LSS Prep - Mapping The Mission

• Confirm Diagnosis: Image-guided core needle biopsy (preferred). Avoid ill-placed incision.
• Local Staging (Tumor Extent):
  • X-ray: Initial view; lesion character, matrix.
  • MRI (Contrast): Crucial. Defines intra/extraosseous extent, neurovascular (NV) bundle, joint, skip lesions.
• Systemic Staging (Metastasis Search):
  • CT Chest (HRCT): Lung mets (sarcoma commonest site).
  • Whole Body Bone Scan: Skeletal mets, skip lesions.
  • PET-CT: Selected cases; metabolic activity, neoadjuvant therapy response.
• Staging System:
  • MSTS (Enneking): Guides surgical margins (Stages IA, IB, IIA, IIB, III).
• MDT Approach: Essential for comprehensive planning. ⭐ > Neoadjuvant chemotherapy response in osteosarcoma & Ewing's sarcoma is a vital prognostic indicator, assessed after induction and before surgery.

LSS In Action - Cut & Construct

• Goal: Complete tumor removal + functional limb reconstruction.
• Resection ("Cut"):
  • Wide Excision: Crucial for ↓ recurrence. Follow Enneking principles for negative margins.
    • Intraop frozen section verifies margins.
  • Neurovascular Preservation: Meticulous dissection; preserves viability/function.
  • Biopsy Tract Excision: Remove with specimen; prevents seeding.
• Reconstruction ("Construct"):
  • Endoprosthetic Replacement: Most common; metallic implants (custom mega-prosthesis).
  • Osteoarticular Allografts: Cadaveric bone-cartilage units.
  • Arthrodesis: Joint fusion for stability; sacrifices motion.
  • Rotationplasty: Ankle acts as knee (e.g., Van Nes); for young patients.
  • Vascularized Grafts: e.g., Fibula; biological reconstruction.
  • Distraction Osteogenesis: Gradual bone lengthening (Ilizarov).

⭐ Distal femur is the most common site for endoprosthetic replacement in LSS, followed by proximal tibia.

Post-Op Path - Challenges & Care

• Key Challenges:
  • Infection: Most feared; meticulous asepsis, antibiotics.
  • Wound Complications: Dehiscence, skin necrosis.
  • Implant Issues: Loosening, fracture, failure.
  • Bone Healing: Non-union, delayed union, especially post-allograft.
  • Tumor Recurrence: Local or systemic; mandates strict follow-up.
  • Functional Limitations: Stiffness, pain, reduced mobility.
• Essential Care:
  • Wound Management: Vigilant monitoring, drain care.
  • Pain Control: Effective analgesia.
  • Rehabilitation: Early, intensive physiotherapy for optimal function.
  • Adjuvant Therapy: Chemo/Radiotherapy as per protocol.
  • Surveillance: Regular imaging (X-ray, MRI) & clinical assessment.

⭐ Deep infection remains the most common reason for failure of limb salvage surgery, often necessitating amputation or revision surgery with significant morbidity.

High‑Yield Points - ⚡ Biggest Takeaways

• Limb Salvage Surgery (LSS) aims for functional limb preservation in malignant bone tumors with oncologic safety.
• Wide local excision achieving negative margins is critical for local control.
• Reconstruction uses endoprostheses, allografts, or autologous grafts.
• Neoadjuvant chemotherapy improves resectability in osteosarcoma and Ewing's sarcoma.
• Key complications: infection, implant failure, local recurrence.
• Oncologic outcome rivals amputation with clear margins; function is often superior.
• Contraindications: Extensive neurovascular involvement, inability to achieve wide margins.