Periprosthetic Fractures Around Total Hip Arthroplasty
Post-Arthroplasty Femoral Fracture | Vancouver Classification | Revision Arthroplasty
Vancouver Classification
Critical Must-Knows
- Stem stability assessment is THE critical decision driver
- B1 = Stable Stem → ORIF (Preserve stem)
- B2/B3 = Loose Stem → Revision Arthroplasty
- Obtain full-length femur radiographs (MANDATORY)
- Always screen for infection (ESR/CRP) preoperatively
Clinical Pearls
- "Most common error: Attempting ORIF on a loose stem (guaranteed failure)
- "Intraoperative fracture: STOP, assess, and stabilize immediately
- "Risk factors: Elderly female, osteoporosis, uncemented stems
- "Don't forget the acetabulum (associated loosening or fractures)
Clinical Imaging
Imaging Gallery
Critical Exam Points
Stem Stability
The Single Most Important Assessment. Differentiating B1 (stable) from B2 (loose) dictates treatment. Getting this wrong is an automatic fail.
Infection Screen
Mandatory Pre-op Check. Always rule out septic loosening presenting as fracture. Missed infection leads to catastrophic failure of fixation.
Imaging Protocol
Full-Length Femur Views. Essential to see distal extent of fracture and plan bypass fixation length (2 cortical diameters).
Risk Factors
Prevention is Key. Recognize high-risk patients (osteoporotic females, revision cases) and use prophylactic cables or gentle technique.
Quick Decision Guide
| Scenario | Classification | Stem Status | Treatment |
|---|---|---|---|
| Trochanteric fracture, stable hip | Vancouver A | Stable | Conservative (unless displaced/unstable) |
| Fracture around stem, stem WELL FIXED | Vancouver B1 | Stable | ORIF (Plate + Cables) |
| Fracture around stem, stem LOOSE, good bone | Vancouver B2 | Loose | Revision THA (Long Uncemented Stem) |
| Fracture around stem, stem LOOSE, POOR bone | Vancouver B3 | Loose | Revision (Impaction Graft or Megaprosthesis) |
| Fracture well below stem tip | Vancouver C | Stable | ORIF (Distal Femur Plate) |
IMPLANTAssessing Stem Stability (B1 vs B2/B3)
| I | Interface Lucent lines greater than 2mm suggest loosening |
| M | Movement Pain with weight bearing suggests loosening |
| P | Position Subsidence or migration on serial films |
| L | Lysis Periprosthetic osteolysis around stem |
| A | Alignment Change in stem version or varus/valgus tilt |
| N | New bone Pedestal formation at stem tip (sign of loosening) |
| T | Testing Intraoperative direct assessment if uncertain |
| I | Interface Lucent lines greater than 2mm suggest loosening | L | Lysis Periprosthetic osteolysis around stem | T | Testing Intraoperative direct assessment if uncertain |
| M | Movement Pain with weight bearing suggests loosening | A | Alignment Change in stem version or varus/valgus tilt | ||
| P | Position Subsidence or migration on serial films | N | New bone Pedestal formation at stem tip (sign of loosening) |
Hook:Check the IMPLANT before you plan your fixation strategy.
Overview and Epidemiology
Rising Burden
Periprosthetic femoral fracture is now among the top 3-4 reasons for THA revision across major joint registries (NJR, AJRR, AOANJRR, Swedish/Nordic). Incidence is rising globally with ageing populations, the dominance of uncemented stems, and the growing cumulative pool of primary THAs.
Intraoperative Risk Factors
Technical Factors:
- Revision surgery (4-7% risk)
- Uncemented stem insertion (press-fit)
- Undersized canal preparation
- Excessive impaction force
Patient Factors:
- Rheumatoid arthritis
- Severe osteoporosis
- Anterior femoral cortical defects
Postoperative Risk Factors
Implant-Related:
- Aseptic loosening with osteolysis
- Stress shielding (cortical thinning)
- Retained cement mantle
Patient-Related:
- Age over 70 years
- Female sex (2.5x higher risk)
- Frequent falls
Epidemiology of Periprosthetic Fracture (Primary THA)
- Intraoperative fracture in 1.7% overall; 14x more common with uncemented stems (3.0% vs 0.23% cemented)
- 20-year cumulative postoperative fracture probability 3.5% (7.7% uncemented vs 2.1% cemented)
- Within 30 days, postop fracture risk after an uncemented stem was 10x higher than cemented
- Intraoperative fractures most common in women and patients over 65, usually at the calcar during stem placement (60%)
- Vancouver AG was the most common postoperative type (32%); 67% followed a fall
Anatomy and Biomechanics
Stress Shielding
Pathophysiology: Rigid metallic stems transfer load distally, bypassing the proximal femur. This leads to adaptive bone resorption (Wolff's Law), causing cortical thinning and osteopenia in the proximal femur, significantly increasing fracture risk from minor trauma.
Bone Quality
- Osteolysis: Wear debris induces cytokine-mediated bone loss
- Cortical Thinning: less than 4mm cortex increases fracture risk exponentially
- Bone Density: Osteopenia common in THA population
Danger Zones
- Anterior Cortex: At femoral bow apex (common perforation site)
- Proximal Lateral Cortex: Aggressive broaching risk
- Calcar: Varus stem malposition
Classification Systems
Vancouver Classification
Duncan & Masri (1995) - The universal Gold Standard based on: Location, Stability, and Bone Stock.
| Type | Location | Stem Status | Bone Stock | Management |
|---|---|---|---|---|
| AG | Greater Trochanter | Stable | Variable | Conservative vs ORIF |
| AL | Lesser Trochanter | Stable | Variable | Conservative |
| B1 | Around Stem | **STABLE** | Good | **ORIF** (preserve stem) |
| B2 | Around Stem | **LOOSE** | Good | **Revision** (Long Stem) |
| B3 | Around Stem | **LOOSE** | Poor | **Revision** (Impaction/Megaprosthesis) |
| C | Below Stem | Stable | Variable | **ORIF** (Plate/Nail) |
Vancouver Classification Reliability
- Interobserver agreement substantial: kappa 0.69 (consultants), 0.61 (trainees)
- Intraobserver kappa 0.74-0.90 (substantial to almost perfect)
- Validity in 37 type B cases: 81% agreement on B1/B2/B3 subgroup, kappa 0.68
- Authors emphasise intraoperative assessment of implant stability when radiographs are equivocal
Clinical Assessment
NO PASSRed Flags (NO PASS)
| N | Neurovascular Sciatic nerve palsy? |
| O | Open fracture Rare but critical |
| P | Pain Out of proportion (Compartment Syndrome) |
| A | Acetabulum Don't miss pelvic discontinuity |
| S | Sepsis Infected arthroplasty? |
| S | Skin Compromised soft tissue envelope |
| N | Neurovascular Sciatic nerve palsy? | P | Pain Out of proportion (Compartment Syndrome) | S | Sepsis Infected arthroplasty? |
| O | Open fracture Rare but critical | A | Acetabulum Don't miss pelvic discontinuity | S | Skin Compromised soft tissue envelope |
Hook:If you see these, do NO PASS go - call senior immediately.
History
- Mechanism: Low energy fall vs trauma
- Pain: Prodromal thigh/groin pain (suggests loosening)
- Pre-injury Function: Independent vs bedbound
- Comorbidities: Osteoporosis, RA, steroids
Examination
- Inspection: Shortening, rotation, swelling
- Palpation: Tenderness, crepitus
- Neurovascular: Sciatic/Femoral nerve check MANDATORY
- Systemic: Signs of infection/sepsis
Red Flags
Immediate Orthopaedic Review Required:
- Open Fracture: Rare but critical
- Neurovascular Compromise: Sciatic nerve palsy
- Compartment Syndrome: High index of suspicion
- Septic Loosening: Red, hot, swollen joint with fracture
Investigations
Imaging Protocol
Full-Length Femur (AP/Lat): Mandatory to plan fixation length. AP Pelvis: Assess cup and contralateral side. Hip Views: Detailed fracture pattern.
Indicated for B3 fractures (bone stock), acetabular involvement, or uncertain comminution. Use Metal Artifact Reduction Sequence.
ESR & CRP: Mandatory in ALL cases to rule out septic loosening. Aspiration if elevated.
Clinical Warning
Management Algorithm
Non-Operative Management
Indications: Undisplaced Type A, stable Type C in non-ambulatory patients, medically unfit for surgery. Protocol: Protected weight bearing 6-12 weeks, serial x-rays. Failure: Progressive displacement greater than 5mm or intractable pain requires surgery.
Surgical Technique
Vancouver B1: Fixation (Stem Preserving)
Prerequisite: You MUST be certain the stem is STABLE. If in doubt, treat as loose (revision).
Steps
Incision centered on trochanter, split fascia lata. Elevate vastus lateralis anteriorly. Preserve perforators.
Gentle traction and bone clamps. Verify stem alignment fluoroscopically.
Proximal: Cables/screws around stem (unicortical or cable-plate). Distal: Bicortical locking screws (min 4-6). Bypass: Plate must extend 2 cortical diameters (10-15cm) distal to fracture.
Consider concomitant strut allografts for medial comminution or osteopenia.
FIXATIONB1 Fixation Principles
| F | Fracture reduction Anatomic alignment |
| I | Implant preservation Keep stable stem |
| X | eXtended fixation Bypass by 2 diameters |
| A | Augmentation Strut grafts if needed |
| T | Tension band Lateral plate positioning |
| I | Immediate stability Rigid construct |
| O | Osteogenic Preserve soft tissue |
| N | No weight bearing Protected rehab |
| F | Fracture reduction Anatomic alignment | A | Augmentation Strut grafts if needed | O | Osteogenic Preserve soft tissue |
| I | Implant preservation Keep stable stem | T | Tension band Lateral plate positioning | N | No weight bearing Protected rehab |
| X | eXtended fixation Bypass by 2 diameters | I | Immediate stability Rigid construct |
Hook:Good FIXATION saves the stem.
Complications
Early
- Infection: 3-8% (higher than primary)
- Dislocation: 20-40% in revisions (use dual mobility/constrained liners)
- DVT/PE: 1-2% symptomatic VTE
- Nerve Injury: Sciatic (cable passage)
Late
- Nonunion: 5-20% (poor biology/stability)
- Loosening: Subsequent aseptic loosening
- Refracture: At plate tip (stress riser)
- Hardware Failure: Plate breakage
Outcomes & the 'Loose Stem' Signal (National Registry)
- A loose stem was present at the time of fracture in 66% (after primary THA) and 51% (after revision)
- 88% of fractures were Vancouver type B, but radiographic preoperative subgrouping was difficult
- High failure rate: 66-month survival (reoperation as endpoint) only 74.8% (plus or minus 5.0%)
- Implant design was associated with fracture risk
Postoperative Care
Rehabilitation Protocol
Toe-touch or restricted (20kg) weight bearing. Hip precautions (prevent dislocation). DVT prophylaxis (35 days).
Progress weight bearing as callus appears. Abductor strengthening. Transition to cane.
Full weight bearing once united. Return to baseline function. Osteoporosis management (Bisphosphonates).
Bone Health
Fragility-fracture bone-health workup (consistent across international osteoporosis guidance):
- Correct vitamin D deficiency (target greater than 50 nmol/L)
- Ensure adequate calcium intake (diet plus supplement to ~1000 mg/day)
- Start anti-resorptive therapy (bisphosphonate or denosumab) once fracture healing is established, with DXA and falls-risk assessment.
Outcomes and Prognosis
| Type | Union Rate | Revision Rate (5y) | Functional Return |
|---|---|---|---|
| B1 (ORIF) | 90-95% | 5-10% | 60-70% baseline |
| B2 (Revision) | 85-90% | 15-25% | 40-60% baseline |
| B3 (Salvage) | N/A | 20-30% | 30-50% baseline |
| C (ORIF) | greater than 90% | 5% | 70-80% baseline |
Important
Evidence Base
Demographics & Implant Factors (Swedish Register)
- 1049 fractures (1979-2000); a majority of late fractures occurred around a loose stem
- Implant-related factors were significantly associated with fracture occurrence
- Treatment results were poor with low long-term survivorship and high complication rates
- Established the periprosthetic fracture burden as a rising, costly complication
Epidemiology in Revision THA
- Intraoperative fracture incidence 12% in revision THA (3x higher than primary)
- Intraoperative fractures 3x more common with uncemented stems (19% vs 6% cemented)
- 20-year probability of postoperative fracture 11%; risk similar for cemented and uncemented
- Most common postoperative type was Vancouver B1 (31%)
Mortality After Periprosthetic Femoral Fracture
- Postoperative fracture after primary THA: modestly increased death risk (HR 1.19), confined to patients with comorbid orthopaedic conditions
- Intraoperative fracture in primary THA: no excess mortality (HR 1.03)
- In revision THA, neither intra- nor post-operative fracture carried excess mortality
- 1112 intraoperative and 704 postoperative fractures analysed across 30,782 THAs
Patient-Specific Risk Calculator
- 16,696 primary THAs; 5-year patient-specific risk ranged 0.5-25% by comorbid profile
- Non-modifiable: female (HR 1.6), older age, osteoporosis (HR 1.7), non-OA indication (fracture HR 2.2)
- Modifiable: uncemented fixation (HR 2.5), collarless stem (HR 1.3), non-anterior approach (lateral HR 2.9)
- Demonstrates surgeon decisions (fixation, implant, approach) materially shift risk
Exam Viva Scenarios
Use these scenarios to practise clinical reasoning and management decisions
Scenario 1: B1 vs B2 Assessment
"78F falls at home. Primary THA 8 years ago. X-ray shows fracture around stem."
Scenario 2: Surgical Technique B1
"You decide a patient has a B1 fracture (stable stem). Describe your fixation."
Scenario 3: B3 Salvage Decision
"82F with B3 fracture (loose stem, severe bone loss). Medically frail."
MCQ Practice Points
B1 vs B2
Q: What is the most significant predictor of failure after ORIF of periprosthetic fractures? A: Loose stem (Misdiagnosis of B2 as B1). Fixation of a loose stem leads to cantilever failure of the plate or nonunion.
Fixation Length
Q: What is the minimum recommended distal fixation length beyond the fracture? A: 2 cortical diameters (typically 10-15cm). Short plates create stress risers and lead to refracture.
Mortality
Q: What is the approximate 1-year mortality after periprosthetic hip fracture? A: 10-15%. This reflects the frailty and comorbidities of the population, similar to native hip fractures.
Cable vs Screw
Q: When do you use cables versus screws in periprosthetic fracture fixation? A: Cables proximally (where the stem occupies the canal), screws distally (where biocortical purchase is possible). This "cable-plate" construct provides optimal fixation.
Strut Graft
Q: What is the indication for cortical strut grafts? A: Significant bone loss or cortical defects (B2/B3). Strut grafts provide biological healing scaffold and mechanical support. Can be allograft or autograft.
Differential Diagnosis
The painful THA with a possible fracture must be distinguished from other causes of acute or progressive hip/thigh pain. The two errors that fail candidates are missing infection (septic loosening masquerading as fracture) and missing occult loosening in an apparently intact femur.
Differentiating the Painful Periprosthetic Hip
| Diagnosis | Key Features | Discriminator | Action |
|---|---|---|---|
| Periprosthetic fracture | Trauma/fall, deformity, inability to weight-bear | Visible fracture line on full-length femur films | Classify (Vancouver) + assess stem stability |
| Aseptic loosening (no fracture) | Prodromal start-up thigh pain, gradual onset | Radiolucent lines, subsidence, pedestal; no cortical break | Workup for revision; exclude infection |
| Periprosthetic joint infection | Rest pain, warmth, effusion, raised CRP/ESR | Aspiration (cell count, culture, alpha-defensin) | Treat as infected loosening; never ORIF over sepsis |
| Acetabular fracture / pelvic discontinuity | Groin pain, cup migration | AP pelvis: cup migration, broken Kohler's line | CT pelvis; cup-cage / triflange planning |
| Stress / insufficiency fracture (no implant break) | Activity-related groin/thigh pain, osteoporosis/bisphosphonate | Subtle cortical reaction; MRI/bone scan if films normal | Protect, treat bone health, monitor |
| Trochanteric bursitis / abductor pathology | Lateral tenderness, pain on resisted abduction | Localised soft-tissue signs, normal bone | Conservative; injection / abductor imaging |
Controversies & Areas of Uncertainty
Vancouver B2: fix or revise?
The dogma is revision for any loose stem. Selected series suggest ORIF of a B2 around a well-fixed-design cemented or polished-tapered stem may succeed in low-demand or high-risk patients, but the dominant registry signal (loose stem to high failure) keeps revision as the default. Reserve fixation for the unfit.
Cemented vs uncemented revision
For B2/B3, modular fluted tapered uncemented stems dominate modern practice with reliable distal fixation. Impaction grafting with a cemented stem restores bone stock (younger patients) but demands restricted weight-bearing. No high-level RCT settles the choice.
Plate vs nail vs combined for Vancouver C
Distal locked plating is standard, but plate-tip stress risers cause refracture. Some advocate overlapping the stem ('plate-stem overlap') or nail-plate combinations to avoid an unprotected segment between implants.
Cemented-stem fracture & cement interdigitation
Whether to revise a fractured cemented stem versus fix-around remains debated, as disturbing the cement mantle is destabilising. Most polished-tapered cemented stems that subside within an intact mantle still behave as 'loose' once the bone fractures.
How to handle controversy in the viva
State the default evidence-based answer first (loose stem to revision; bypass by 2 cortical diameters), then acknowledge the nuance (B2 fixation in the unfit; impaction grafting in the young). Examiners reward candidates who know both the rule and its exceptions.
Guidelines, Registries & Global Practice
Global epidemiology. Periprosthetic femoral fracture complicates roughly 1% of primary and up to ~5% of revision THAs over the implant lifetime, and is consistently among the top reasons for revision in every major registry. Risk is concentrated in elderly women, osteoporotic/inflammatory-arthritis bone, and uncemented femoral fixation. As the global volume of primary arthroplasty rises, absolute fracture numbers are increasing worldwide.
Society & Registry Positions (Side-by-Side)
| Source | Region | Emphasis |
|---|---|---|
| AAOS / orthopaedic consensus | US | Stem-stability-driven algorithm; revision for loose stems (B2/B3); ORIF for stable (B1) and Vancouver C |
| BOA / BOAST (Peri-implant & periprosthetic) | UK | Combined ortho-geriatric pathway, early surgery, senior decision-maker, network referral for complex revision |
| AO Foundation principles | Global | Locked plating with bypass of 2 cortical diameters, cable/locking-attachment plates, biological reduction |
| NJR (UK) / AJRR (US) / AOANJRR (Aus) / SHAR (Sweden) | Multi-region | Higher fracture rates with uncemented stems, especially older women; cemented fixation protective in the elderly |
| Osteoporosis/bone-health guidance (e.g. NOGG, national societies) | Global | Fracture-liaison-style assessment; vitamin D, calcium, anti-resorptive once healing established |
Registry Signal
Across NJR, AJRR, AOANJRR and the Nordic registries, uncemented stems in older patients (especially women over 70-75) carry a higher periprosthetic fracture rate than cemented stems. This is the single most reproducible registry message and underpins selective cemented fixation in the frail elderly.
High- vs Limited-Resource Practice
High-resource: modular fluted tapered revision stems, locking-attachment cable plates, CT with metal-artifact reduction, dual-mobility/constrained liners, orthogeriatric co-management. Limited-resource: conventional cerclage plus long-stem or interlocking constructs, allograft struts where banks exist, cemented revision; emphasis on definitive single-stage fixation given limited revision implant availability.
Periprosthetic Fractures Essentials
Clinical summary
Classification (Vancouver)
- •Type A: Trochanteric (Stable)
- •Type B1: Around stem, Stable to ORIF
- •Type B2: Around stem, Loose to Revision (Long Stem)
- •Type B3: Around stem, Loose, Poor bone to Salvage
- •Type C: Below stem to ORIF
Key Assessment
- •Stem Stability is the #1 Factor
- •Full length femur X-ray Mandatory
- •Pre-op Infection Screen Mandatory
- •IMPLANT mnemonic for loosening signs
Surgical Principles
- •Bypass fracture by 2 cortical diameters
- •Cables proximally, Screws distally
- •Strut grafts for poor bone
- •Revision stems must achieve distal fixation
Complications
- •Infection (3-8%)
- •Dislocation (High risk in revisions)
- •Nonunion/Refracture
- •1-year mortality 10-15%