Neck of femur fracture

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Quick Overview

Neck of femur (NOF) fractures are common orthopaedic emergencies, predominantly affecting elderly patients with osteoporosis. Time-critical management within 36 hours reduces mortality and complications. NICE CG124 mandates orthogeriatric co-management and structured perioperative care bundles. Classification determines surgical approach: intracapsular fractures risk avascular necrosis (AVN) due to disrupted blood supply; extracapsular fractures preserve blood supply but cause significant blood loss.

Core Facts & Concepts

📊 Classification & Blood Supply

Fracture TypeLocationBlood SupplyAVN RiskSurgical Options
IntracapsularWithin joint capsuleDisrupted (retrograde vessels)High (10-30%)DHS if undisplaced; hemiarthroplasty/THR if displaced
ExtracapsularIntertrochanteric/subtrochantericPreserved (periosteal)LowDHS (intertrochanteric); intramedullary nail (subtrochanteric)

Figure 1: AP pelvis X-ray showing displaced intracapsular neck of femur fracture with disrupted Shenton's line

⏰ Time-Critical Thresholds (NICE CG124)

  • Surgery within 36 hours of admission (or diagnosis if already inpatient)
  • Delays >36h increase 30-day mortality by 30%
  • Pre-op assessment by orthogeriatrician within 72 hours of admission

Garden Classification (Intracapsular)

  • Type I: Incomplete/impacted (undisplaced)
  • Type II: Complete but undisplaced
  • Type III: Complete, partially displaced
  • Type IV: Complete, fully displaced
  • Types III-IV have highest AVN risk (30%)

🚩 Red Flags

  • Age <60 with NOF fracture → investigate pathological cause (metastases, myeloma)
  • Inability to straight leg raise → suggests fracture
  • Shortened, externally rotated leg (classic presentation)

Problem-Solving Approach

1️⃣ Immediate Management (First Hour)

  • Analgesia: Fascia iliaca block (preferred) or femoral nerve block
  • NBM status, IV access, bloods (FBC, U&E, coagulation, G&S)
  • Pressure area care (heel protection)
  • VTE prophylaxis (LMWH unless contraindicated)

Figure 2: Lateral hip X-ray showing basicervical neck of femur fracture

2️⃣ Surgical Decision Algorithm

  • Intracapsular undisplaced (Garden I-II) → Internal fixation (cannulated screws/DHS)
  • Intracapsular displaced (Garden III-IV):
    • Independent walker → Total hip replacement (THR)
    • Limited mobility/comorbidities → Hemiarthroplasty (cemented if age >70)
  • Extracapsular intertrochanteric → Dynamic hip screw (DHS)
  • Extracapsular subtrochanteric → Intramedullary nail (higher biomechanical stress)

3️⃣ Perioperative Care Bundle (NICE CG124)

  • Orthogeriatric review within 72h
  • Bone protection: Calcium/Vitamin D supplementation
  • Falls assessment and prevention plan
  • Mobilise day 1 post-op with physiotherapy
  • FRAX score for future fracture risk

Analysis Framework

Surgical Option Selection by Patient Factors

Patient ProfileFracture TypePreferred SurgeryRationale
Independent, mobile, cognitively intactDisplaced intracapsularTHR (cemented/uncemented)Lower revision rate, better function
Limited mobility, dementia, frailDisplaced intracapsularCemented hemiarthroplastyFaster surgery, adequate for low demand
Any mobility statusUndisplaced intracapsularInternal fixation (screws)Preserve native joint, lower morbidity
Any mobility statusIntertrochantericDHSGold standard, stable fixation
Any mobility statusSubtrochantericIntramedullary nailBiomechanically superior for shaft extension

🚩 Complications by Timeframe

  • Immediate: Fat embolism, blood loss (500-1000ml extracapsular)
  • Early (<6 weeks): DVT/PE, pneumonia, pressure sores, delirium
  • Late (>6 weeks): AVN (intracapsular), non-union, implant failure, leg length discrepancy

Visual Aid

Key Points Summary

36-hour rule: Surgery within 36h of admission/diagnosis mandatory (NICE CG124) - delays increase mortality 30%

Intracapsular fractures: High AVN risk (disrupted blood supply); displaced → arthroplasty; undisplaced → internal fixation

Extracapsular fractures: Preserved blood supply, low AVN risk; DHS for intertrochanteric, IM nail for subtrochanteric

Surgical selection: Independent mobile patients with displaced intracapsular → THR; limited mobility → cemented hemiarthroplasty

Perioperative bundle: Fascia iliaca block, orthogeriatric co-management within 72h, mobilise day 1, bone protection (calcium/vitamin D)

Garden classification: I-II undisplaced (fixation), III-IV displaced (arthroplasty) - higher numbers = higher AVN risk

Red flags: Age <60 (pathological fracture?), inability to straight leg raise, shortened externally rotated leg

⚠️ Warning: Never delay surgery for "medical optimization" beyond 36h unless life-threatening condition - mortality benefit of early surgery outweighs most medical risks

Practice Questions: Neck of femur fracture

Test your understanding with these related questions

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Flashcards: Neck of femur fracture

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What is a late sign in Cauda Equina Syndrome _____

TAP TO REVEAL ANSWER

What is a late sign in Cauda Equina Syndrome _____

Urinary Incontinence

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