# 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 **Vancouver Classification:** **Description:** Most widely used classification for periprosthetic femoral fractures after THR **Types:** **Type:** Type A **Location:** Trochanteric region **Subtypes:** - AG: Greater trochanter - AL: Lesser trochanter **Treatment:** Usually non-operative unless significantly displaced **Type:** Type B **Location:** Around or just below stem **Subtypes:** **Subtype:** B1 **Stem Status:** Well-fixed stem **Bone Quality:** Good bone stock **Treatment:** ORIF with plate (cerclage + locking plate) **Subtype:** B2 **Stem Status:** Loose stem **Bone Quality:** Good bone stock **Treatment:** Revision to longer stem ± ORIF **Subtype:** B3 **Stem Status:** Loose stem **Bone Quality:** Poor bone stock **Treatment:** Revision to longer stem + bone graft/augmentation **Type:** Type C **Location:** Well below stem **Treatment:** Standard fracture fixation (as for native femur) **Key Decision:** Is the stem LOOSE? This determines B1 vs B2/B3 and dictates treatment > **Consultant Tip:** The key question is stem stability. B1 = fix fracture only. B2/B3 = revise stem. **Radiographic Signs:** **Loosening Features:** - Progressive radiolucent lines around stem (>2mm, circumferential) - Stem subsidence (compare with old films) - Cement fracture or mantle fracture - Change in stem position - Pedestal formation below stem tip - Endosteal scalloping **Well Fixed Features:** - No progressive radiolucent lines - Spot welds in uncemented stems - No subsidence on serial films **Intraoperative Assessment:** **Importance:** Definitive assessment of stability is INTRAOPERATIVE **Method:** - Direct visualization and manipulation of stem - Attempt to move stem with fracture exposed - If any doubt, revise the stem **Preoperative Clues:** - Pre-injury symptoms: pain on stairs, start-up pain suggests loosening - Previous X-rays for comparison essential > **Consultant Tip:** Get previous X-rays. If ANY doubt about stability intraoperatively, revise the stem. **Principles:** - Stem is well-fixed - do NOT revise - Achieve fracture reduction and fixation - Protect the cement mantle and stem **Technique:** **Approach:** Lateral approach to femur, extensile as needed **Exposure:** - Identify fracture pattern - Minimize periosteal stripping - Protect proximal fragment vascularity **Reduction:** - Indirect reduction techniques - Cerclage wires to reduce spiral/oblique components - Restore length, rotation, alignment **Fixation:** - Cerclage cables/wires proximally (around stem) - Locking plate distally (bridging mode) - Cable-plate systems (eg. Dall-Miles, Ogden plate) - Consider double plating for short distal segment **Specific Considerations:** - Cannot put screws through cemented stem portion - Use unicortical screws or cables at stem level - Long plate spanning well beyond fracture - Avoid stress risers at plate ends **Postoperative:** - Protected weight-bearing 6-12 weeks - DVT prophylaxis - Serial X-rays to assess healing > **Consultant Tip:** Cable-plate construct is standard for B1. Cables proximally where you can't use bicortical screws. **Principles:** - Must revise to a longer stem that bypasses fracture - Achieve stability in healthy bone beyond fracture **Stem Options:** **Cemented Long Stem:** **Indication:** Elderly, low demand, good bone quality distally **Technique:** Cement-in-cement or extended removal **Advantages:** Immediate stability, allows early mobilisation **Uncemented Distallyfixing Modular Stem:** **Indication:** Most common choice **Examples:** Revision modular tapered stems (eg. S-ROM, ZMR, MP) **Technique:** - Remove old stem and cement - Reduce fracture - Insert long uncemented stem engaging diaphysis distal to fracture - Fixation relies on distal fit and fill **Advantages:** Biologic fixation, versatility **Additional Fixation:** - Cerclage cables to stabilise fracture around new stem - Plate if fracture pattern requires - Strut allograft for bone deficiency (B3) **Postoperative:** Depends on construct - often touch weight-bearing 6 weeks > **Consultant Tip:** For B2, you need to revise AND fix. Long distally-engaging stem bypasses the fracture. **Outcomes:** **Union Rates:** - B1 with adequate fixation: >90% union - B2/B3 with revision: 85-95% union - Nonunion rates higher in elderly, poor bone **Mortality:** - 1-year mortality ~10-20% in elderly - Similar to hip fracture mortality **Complications:** **Intraoperative:** - Fracture propagation - Cement extravasation - Neurovascular injury **Early Postoperative:** - Dislocation (especially B2/B3 revisions) - Infection - DVT/PE - Medical complications **Late:** - Nonunion (5-15%) - Malunion - Stem loosening - Refracture - Implant failure **Risk Factors:** - Rheumatoid arthritis - Osteoporosis - Long-term steroid use - Female sex - Revision arthroplasty > **Consultant Tip:** Mortality is significant - these are fragility fractures in elderly. Optimise medically and mobilise early. **Perioperative Optimisation:** **Preoperative Assessment:** | System | Assessment | Intervention | |--------|------------|--------------| | **Cardiovascular** | ECG, troponin if indicated | Cardiology review if ischaemic changes | | **Respiratory** | Chest X-ray, oxygen saturation | Chest physio, nebulisers if needed | | **Renal** | Creatinine, eGFR | IV fluids, hold nephrotoxics | | **Haematological** | FBC, group & hold, coagulation | Transfuse if Hb <70-80 g/L | | **Metabolic** | Electrolytes, glucose | Correct abnormalities | | **Nutritional** | Albumin | Nutritional supplementation | **Orthogeriatric Pathway:** | Component | Detail | |-----------|--------| | **Early surgery** | Within 36 hours if medically fit | | **Geriatrician co-management** | Daily review, medical optimisation | | **Delirium prevention** | Orientation, sleep hygiene, minimise opioids | | **DVT prophylaxis** | LMWH + mechanical compression | | **Anaesthetic review** | Spinal vs general, risk stratification | **Osteoporosis Management:** | Intervention | Timing | |--------------|--------| | **Vitamin D and calcium** | Postoperatively | | **Bone density assessment** | Once recovered | | **Bisphosphonate/denosumab** | After fracture healing (6-8 weeks) | | **Falls assessment** | Prior to discharge | | **Home modifications** | OT assessment | **This Patient's Specific Issues:** | Issue | Management | |-------|------------| | Anaemia (Hb 98) | May need transfusion perioperatively | | Mild renal impairment | Careful fluid balance, avoid NSAIDs | | Known osteoporosis | Continue treatment, falls prevention | | Lives alone | Consider rehabilitation placement | | Uses walking stick | May need upgrade to frame postoperatively | **Postoperative Care:** | Day | Focus | |-----|-------| | **Day 0-1** | Pain control, mobilise with physio, DVT prophylaxis | | **Day 1-3** | Progress weight-bearing as allowed, delirium prevention | | **Day 3-7** | Rehabilitation goals, discharge planning | | **Discharge** | Falls prevention, osteoporosis plan, follow-up arranged | **Discharge Planning:** | Consideration | Assessment | |---------------|------------| | **Mobility** | Safe ambulation with appropriate aids | | **Social support** | Lives alone - may need package of care | | **Cognition** | Delirium resolved, safe for discharge | | **Follow-up** | Orthopaedic clinic, osteoporosis review | > **Consultant Tip:** Treat like a hip fracture - orthogeriatric pathway, early surgery, early mobilisation. Optimise osteoporosis to prevent further fractures. --- ## 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 1. **Treat as fragility fracture** - orthogeriatric pathway, optimise medically 2. **Blood loss can be significant** - check Hb, resuscitate 3. **Previous X-rays essential** - assess for pre-existing loosening 4. **B1 = fix fracture only** - cables proximally, locking plate distally 5. **B2/B3 = revise stem** - long distally-engaging modular stem 6. **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