High-Yield Summary
- The Vancouver Classification stratifies periprosthetic hip fractures by fracture location, implant stability, and bone stock quality, directly guiding management strategy.
- Type A fractures involve the trochanteric region; Type B fractures occur around or just distal to the stem and are subdivided by implant stability and bone stock; Type C fractures are well distal to the implant.
- Implant stability assessment is critical: stable stems (B1) favor fixation, unstable stems (B2/B3) require revision arthroplasty.
- Bone stock quality differentiates B2 (good bone) from B3 (poor bone), influencing reconstructive complexity and implant choice.
- Accurate classification requires high-quality radiographs and CT imaging when implant stability is uncertain.
Clinical Fundamentals
Relevant Anatomy and Biomechanics
The proximal femur’s structural integrity is paramount for load transfer in total hip arthroplasty (THA). The femoral stem relies on metaphyseal and diaphyseal fixation, with the greater and lesser trochanters serving as critical muscle attachment sites influencing hip biomechanics. Periprosthetic fractures disrupt this balance, compromising implant stability and load distribution.
Epidemiology
Periprosthetic femoral fractures occur in 0.1-18% of primary and revision THAs, with incidence rising due to aging populations and increased implant longevity. Risk factors include osteopenia, female sex, rheumatoid arthritis, and prior revision surgery. Early recognition and classification are essential to prevent morbidity and optimize functional outcomes.
Classification & Diagnosis
| Vancouver Type | Description | Implant Stability | Bone Stock Quality | Clinical Implication |
|---|---|---|---|---|
| A | Trochanteric fractures (AG: Greater, AL: Lesser) | Stable | N/A | Usually managed non-operatively or with fixation |
| B1 | Around or just distal to stem, stem stable | Stable | Good | Open reduction and internal fixation (ORIF) preferred |
| B2 | Around or just distal to stem, stem loose | Unstable | Good | Revision arthroplasty required |
| B3 | Around or just distal to stem, stem loose | Unstable | Poor | Complex revision with bone grafting or megaprosthesis |
| C | Well distal to stem | Stable | N/A | Managed as standard femoral shaft fracture |
Diagnostic Pearls
- Implant stability is best assessed via radiographs showing stem subsidence, radiolucent lines, or migration; CT can clarify ambiguous cases.
- Bone stock evaluation requires assessment of cortical thinning, osteolysis, and cavitary defects.
- Misclassification of B2 as B1 leads to fixation failure; always err on the side of revision if implant stability is uncertain.
Decision-Making Algorithm
Non-Operative vs. Operative Criteria
- Type A fractures with minimal displacement and stable implants may be treated conservatively with protected weight-bearing.
- Type C fractures, distal to the implant, behave like standard femoral shaft fractures and are managed with ORIF.
- Type B fractures require precise implant stability assessment:
- B1 fractures with stable stems and good bone stock undergo ORIF using locking plates or cables.
- B2 fractures necessitate revision arthroplasty with longer stems bypassing the fracture site.
- B3 fractures require complex revision with structural allografts, porous metal augments, or megaprostheses due to compromised bone stock.
Surgical Approach and Implant Choice
- ORIF for B1 fractures uses minimally invasive techniques when possible to preserve soft tissue and blood supply.
- Revision arthroplasty for B2/B3 fractures demands extended exposure, removal of loose components, and reconstruction tailored to bone loss severity.
- Cemented stems may be preferred in poor bone stock; modular, tapered, fluted stems provide diaphyseal fixation in revision cases.
Surgical Mastery & Pearls
Step-by-Step Conceptual Overview
- Preoperative Planning: Obtain high-quality AP and lateral radiographs; consider CT for implant stability and bone stock assessment. Plan implant removal and fixation strategy.
- Exposure: Use extensile approaches (posterolateral or extended trochanteric osteotomy) for revision cases; minimize soft tissue disruption in fixation cases.
- Fracture Reduction: Achieve anatomic alignment; provisional fixation with clamps or cables.
- Implant Management:
- For B1 fractures, preserve the stem and apply locking plates spanning the fracture with supplemental cables.
- For B2/B3 fractures, remove the loose stem carefully to avoid further bone loss.
- Reconstruction:
- Use long revision stems bypassing the fracture by at least two cortical diameters.
- Address bone defects with structural grafts or porous metal augments as needed.
- Fixation: Secure plates with bicortical screws where possible; cables augment fixation around the prosthesis.
- Closure and Postoperative Care: Ensure stable fixation; initiate protected weight-bearing protocols based on fracture type and fixation stability.
Intraoperative Red Flags
- Unexpected stem loosening during fixation attempts mandates conversion to revision arthroplasty.
- Excessive bone loss or comminution may require intraoperative modification to megaprosthesis.
- Poor fracture reduction or unstable fixation predicts nonunion and implant failure.
Evidence-Based Synthesis
Landmark studies validate the Vancouver Classification as the gold standard for guiding treatment, correlating implant stability with outcomes. Recent literature emphasizes the high failure rates of ORIF in misclassified B2 fractures, reinforcing the necessity of accurate preoperative assessment. Advances in modular revision stems and porous metal augments have improved outcomes in B3 fractures, though consensus on optimal reconstruction remains evolving. Comparative trials highlight that early revision arthroplasty in unstable fractures reduces reoperation rates and improves functional recovery compared to fixation attempts. However, heterogeneity in bone quality assessment and implant design complicates standardization, underscoring the need for individualized surgical planning.
Master Class Pro-Tip
When managing Vancouver B2 and B3 fractures, anticipate the need for extended trochanteric osteotomy to facilitate stem removal and optimize exposure. Preserve the abductors by meticulous soft tissue handling and consider prophylactic cerclage wiring proximal to the osteotomy to prevent propagation fractures. Employ modular, tapered fluted stems that achieve diaphyseal fixation beyond compromised metaphyseal bone, ensuring at least 5 cm of stable cortical contact. This approach minimizes stress risers and maximizes implant longevity, distinguishing the master surgeon’s strategy from routine revision techniques.
