Makindo Medical Notes

Related Subjects: |Fractured Neck of Femur |Fractured Shaft Femur |Supracondylar Femur Fractures |Femoral fractures |Fractured Tibia and Fibula

Supracondylar Femur Fractures 🦴 occur just above the knee joint. They are uncommon but serious, often from high-energy trauma (RTAs, falls) or low-energy in elderly/osteoporotic bone. These fractures may involve the articular surface and carry a risk of knee stiffness, malunion, and post-traumatic arthritis.

📖 About

• Unusual fracture located in the distal femur, just proximal to the condyles.
• Seen in young adults after high-energy trauma and in elderly patients with osteoporosis after low-energy falls.
• May occur above a total knee replacement (periprosthetic fracture).

⚙️ Aetiology

• High-force injuries: RTAs, falls from height, sports accidents.
• Low-force in osteoporotic or pathological bone.
• Fracture line may extend into knee articular cartilage → ↑ risk of arthritis.

🩺 Clinical Features

• Severe localised pain, swelling, deformity of distal thigh/knee.
• Unable to bear weight 🚶❌.
• Check for neurovascular compromise:
  • Femoral/popliteal artery injury → absent pulses.
  • Peroneal/tibial nerve injury → motor/sensory deficit.
• Look for compartment syndrome signs 🚨.

🧪 Investigations

• X-rays: AP & lateral of femur, including hip and knee.
• CT: for intra-articular extension or surgical planning.
• Bloods: trauma panel (FBC, U&E, coagulation, group & save).

⚠️ Complications

• Malunion / nonunion.
• Vascular injury: femoral or popliteal artery damage → limb-threatening.
• Compartment syndrome of the thigh/leg.
• Fat embolism (esp. young adults with long bone fractures).
• Venous thromboembolism (DVT/PE).
• Osteomyelitis (esp. open fractures).
• Post-traumatic knee arthritis (if articular involvement).

💊 Management

• Initial (ATLS): ABCDE, IV access, fluids, analgesia. Check distal pulses + neurology. Splint limb, apply sterile dressings to wounds.
• Open fractures 🚨: IV antibiotics (e.g., co-amoxiclav or clindamycin), tetanus prophylaxis, urgent ortho referral for debridement + fixation.
• Definitive management:
  • Usually operative:
    • Intramedullary nail (retrograde via knee or antegrade via hip).
    • Locking plate fixation for comminuted/osteoporotic bone.
    • External fixation as temporary measure in polytrauma or open fractures.
  • Above a total knee replacement:
    • If prosthesis stable → fixation around it.
    • If loose → revision arthroplasty may be required.
• Rehabilitation: early physiotherapy, progressive weight-bearing depending on fixation stability.
• VTE prophylaxis: LMWH unless contraindicated.

📌 OSCE / Exam Pearls

• Always assess neurovascular status in distal femur fractures (femoral/popliteal artery at risk).
• Periprosthetic supracondylar fracture is a classic viva question → may require revision TKR if implant loose.
• Think “high force in young, low force in elderly.”
• CT often needed to define intra-articular extension.

📚 References

• ATLS®: Advanced Trauma Life Support, 10th edition.
• Rockwood & Green’s Fractures in Adults, 9th edition.
• BOAST Guidelines: Distal Femur Fractures.