Periprosthetic Femoral Fracture Post THR
CIM Case: Periprosthetic Femoral Fracture Post THR
Clinical Scenario
Patient: 78-year-old woman Presentation: Fall at home 2 hours ago, unable to weight-bear, severe right thigh pain Relevant history: Cemented THR 8 years ago for primary osteoarthritis, known osteoporosis on treatment, no pre-injury hip symptoms, lives alone, uses walking stick Examination findings:
- Right leg shortened and externally rotated
- Marked tenderness over mid-thigh
- Unable to straight leg raise
- Swelling and bruising developing over lateral thigh
- Knee examination limited by pain
- Neurovascularly intact distally (palpable pulses, normal sensation, able to move toes)
Investigations Provided
Laboratory Results
| Test | Result | Normal Range | Interpretation |
|---|---|---|---|
| Hb | 98 g/L | 120-150 g/L | ↓ Anaemia (blood loss) |
| WCC | 11.2 ×10⁹/L | 4-11 ×10⁹/L | ↑ Mildly elevated (stress response) |
| Platelets | 245 ×10⁹/L | 150-400 ×10⁹/L | Normal |
| Creatinine | 95 μmol/L | 45-90 μmol/L | ↑ Mildly elevated |
| INR | 1.0 | 0.9-1.1 | Normal |
| Group & Hold | Completed | - | Ready for theatre |
| CRP | 15 mg/L | <5 mg/L | ↑ Mild elevation (acute injury) |
Imaging
Image 1: AP and Lateral Radiographs of Right Hip and Femur
Radiological features:
- Cemented total hip replacement in situ
- Spiral oblique fracture extending from just below lesser trochanter to mid-shaft
- Fracture involves stem tip level
- Cement mantle appears intact
- No obvious radiolucent lines around proximal stem
- Varus angulation at fracture site
- Generalised osteopaenia
Image 2: AP Pelvis for Comparison
Findings:
- Previous X-rays available from 2 years ago
- No significant interval change in stem position
- No previous progressive radiolucent lines
- Comparison confirms no pre-existing loosening
Questions & Model Answers
What classification system do you use for periprosthetic femoral fractures around a hip replacement?
How do you assess stem stability?
This X-ray shows a Vancouver B1 fracture. Describe your operative management.
What if the stem was loose (Vancouver B2)?
What are the outcomes and complications of periprosthetic fracture treatment?
How would you optimise this elderly patient perioperatively?
Key Teaching Points
Pattern Recognition
This pattern suggests Periprosthetic Femoral Fracture:
- Elderly patient with THR and low-energy fall
- Unable to weight-bear with thigh pain (not hip pain)
- Shortened, externally rotated leg
- Fracture around or below prosthetic stem
Vancouver Classification Summary:
| Type | Location | Stem Status | Treatment |
|---|---|---|---|
| A (AG/AL) | Trochanteric | N/A | Usually non-operative |
| B1 | At/below stem | Well-fixed | ORIF with cables + plate |
| B2 | At/below stem | Loose, good bone | Revision long stem ± ORIF |
| B3 | At/below stem | Loose, poor bone | Revision + augmentation/graft |
| C | Well below stem | N/A | Standard fracture fixation |
Critical Decision Point: Is the stem LOOSE?
- Get previous X-rays for comparison
- Look for radiolucent lines, subsidence, cement fractures
- Final assessment is INTRAOPERATIVE
Critical Management Points
- Treat as fragility fracture - orthogeriatric pathway, optimise medically
- Blood loss can be significant - check Hb, resuscitate
- Previous X-rays essential - assess for pre-existing loosening
- B1 = fix fracture only - cables proximally, locking plate distally
- B2/B3 = revise stem - long distally-engaging modular stem
- Early mobilisation - reduces mortality in elderly
Common Examiner Follow-ups
Q: "What is the mortality rate for periprosthetic fractures?"
1-year mortality is 10-20%, similar to hip fracture mortality. These are fragility fractures in elderly patients and should be managed with the same urgency and optimisation as native hip fractures.
Q: "How do you differentiate B1 from B2 radiographically?"
| Feature | B1 (Well-fixed) | B2 (Loose) |
|---|---|---|
| Radiolucent lines | None or stable | Progressive, >2mm, circumferential |
| Stem position | No change | Subsidence or migration |
| Cement mantle | Intact | Fractured or separated |
| Comparison films | Unchanged | Progressive changes |
| Pre-injury symptoms | None | Start-up pain, activity pain |
Key point: If there is ANY doubt about stability, intraoperative assessment is definitive.
Q: "What are your options for a B3 fracture with severe bone loss?"
- Long uncemented modular stem bypassing fracture
- Strut allografts (cortical strut onlay) for structural support
- Impaction bone grafting for contained defects
- Proximal femoral replacement for severe proximal bone loss (tumour prosthesis)
- Careful surgical technique - avoid further bone loss during cement removal
Q: "Can you operate on anticoagulation?"
This is a surgical emergency requiring prompt treatment. Options:
- Warfarin: Reverse with vitamin K ± prothrombin complex concentrate
- DOACs: Consider reversal agents (idarucizumab for dabigatran, andexanet alfa for Xa inhibitors) or wait 24-48h if possible
- Aspirin: Can usually proceed with appropriate haemostasis
- Balance: Weigh thrombotic risk against bleeding risk with haematology input
Related Topics
- Vancouver Classification
- Revision Hip Arthroplasty
- Osteoporosis in Orthopaedic Surgery
- Geriatric Hip Fractures
- Cemented vs Uncemented Stems