Periprosthetic Femoral Fracture — Vancouver Classification & Management

The Vancouver Classification

The Vancouver classification (Duncan and Masri) is the universally adopted framework for periprosthetic femoral fractures around a hip stem. Its strength is that it is comprehensive yet treatment-directing: it combines three factors - the site of the fracture, the stability of the stem, and the quality of the bone stock - and each combination maps to a defined surgical strategy. It has good inter- and intra-observer reliability and validity for guiding management.

The Three Types

Type A — Trochanteric

• AG = greater trochanter; AL = lesser trochanter
• Usually low-energy, frequently associated with osteolysis from polyethylene wear particles - the lysis weakens the bone
• Most are stable and managed non-operatively with protected weight-bearing
• Fix a displaced AG fragment that destabilises the abductor mechanism (tension-band wiring, claw/hook plate, cables)
• A significant AL avulsion may be a marker of underlying osteolysis and impending stem compromise - investigate the stem

Type B — The Decisive Zone (around or just distal to the stem tip)

This is where the examination is won or lost. Once a fracture is localised to the stem-tip region, the only question that matters is: is the stem still well-fixed?

• B1 - well-fixed: the implant is sound; this is a fracture problem, so fix the fracture and leave the stem
• B2 - loose, good bone: the implant has failed; plating it ignores the cause - revise the stem
• B3 - loose, poor bone: as B2 but the bone cannot support a standard revision - reconstruction or replacement

Type C — Well Distal to the Stem Tip

Treated as an ordinary distal/diaphyseal femoral fracture. The stem's fixation status is irrelevant to the fracture itself, BUT the construct must respect the in-situ implant: overlap the plate proximally with the stem to avoid an unsupported inter-implant segment.

Assessing Stem Stability — The Crux

History

• Pre-injury thigh pain or start-up pain is the classic clue to a pre-existing loose stem - it can reclassify an apparent B1 to a B2

Radiographs

• Full-length femur films (AP and lateral) including the joint above (hip) and below (knee)
• Signs of loosening: subsidence/migration, complete radiolucent lines at the bone-cement or bone-implant interface, cement-mantle fracture, debonding, pedestal formation, varus tilt
• Compare with the immediate post-operative film for migration

Intra-operative Test

• When stability is uncertain after history and imaging, expose and test the stem directly. If it is loose, convert to a revision (B2/B3). Plating a stem that is in fact loose is the principal avoidable error.

From Vancouver Type to Operation

Why B1 vs B2 Changes Everything

A B1 fracture is fundamentally a fracture around a sound implant - the biomechanical problem is the broken bone, so ORIF restores it. A B2 fracture is an implant that has failed - the loosening pre-dated or accompanied the fracture, so simply plating the bone leaves the loose stem in place to drive ongoing failure. The revision stem itself acts as an internal splint that bypasses and stabilises the fracture while solving the loosening. This is why misclassification is so costly: the two operations are entirely different.

Bone Stock — Separating B2 from B3

• B2: enough proximal bone to support a revision stem that gains fixation in the diaphysis - the workhorse is the uncemented modular/monoblock tapered fluted stem, which obtains rotational and axial stability in the diaphysis distal to the fracture
• B3: proximal bone is inadequate (severe lysis, comminution, multiple previous revisions, poor quality). Options:
  • Long revision stem with bone graft / impaction grafting / allograft-prosthetic composite - restores stock; favoured in younger, higher-demand patients
  • Proximal femoral replacement (megaprosthesis) - sacrifices stock but allows immediate weight-bearing; favoured in the frail elderly where rapid mobilisation outweighs bone preservation

Fixation Principles (when you are fixing, not revising)

• Span the whole femur - a long plate from the trochanteric region to the distal metaphysis avoids creating a new stress riser at a plate end
• Combination fixation around the stem - cables/cerclage and unicortical locking screws proximally (where the stem occupies the canal) with bicortical screws distally
• Cortical strut allograft - can augment a plate (especially in poor bone or to add a second plane of fixation), acting as a biological onlay that incorporates over time
• Avoid inter-implant stress risers - if a knee implant or a second plate is present, overlap constructs; never leave a short unsupported bone segment between two stiff implants

The Frailty Lens

Because mortality approaches that of a native hip fracture, the construct should ideally permit early weight-bearing. A megaprosthesis or a stable long-stem revision allows this; a tenuous plate fixation in poor bone that demands prolonged restricted weight-bearing is often the wrong answer in a frail patient even when "anatomically" possible.

Pre-operative Preparation (all types)

Work-up: Full-length femur radiographs (hip and knee included); CT if intra-articular extension, bone loss assessment or stem-tip detail is needed. Identify the implant (stem make/taper, cemented vs uncemented, head size) and have the previous operation note if revision is possible. Confirm the diagnosis is not infection (CRP/ESR, aspiration if indicated) - a periprosthetic fracture can be the presentation of an infected loose stem.

Medical optimisation: Orthogeriatric review, anticoagulation management, group-and-save/crossmatch (revision can be high-blood-loss), anaesthetic assessment. Aim for early surgery on a planned list with the right implants and revision trays available.

Vancouver B1 — ORIF (well-fixed stem)

Step 1: Approach and exposure

Lateral or direct lateral approach to the femur over the fracture. Preserve the soft-tissue envelope and blood supply - use indirect/biological reduction; avoid stripping the fracture fragments.

Step 2: Confirm the stem really is well-fixed

Before committing to a plate, satisfy yourself the stem is sound (imaging plus, if any doubt, an intra-operative test). If it proves loose, abandon ORIF and revise (B2 pathway).

Step 3: Reduction

Reduce the fracture using cables/clamps with biological technique. Restore length, alignment and rotation. Bridging fixation is appropriate for comminuted patterns.

Step 4: Plate application — span the femur

Apply a long lateral locking plate extending from the trochanteric region to the distal metaphysis. Use a combination construct: proximally, where the stem fills the canal, use cerclage cables and unicortical locking screws (and screws angled around the stem); distally use bicortical screws. Consider a cortical strut allograft as an anterior onlay to augment fixation in poor bone or to add a second fixation plane.

Vancouver B2 — Revision (loose stem, adequate bone)

Step 1: Extended exposure / approach

Use an approach that allows controlled access to the femoral canal - an extended trochanteric osteotomy (ETO) is often used to remove a well-cemented or distally fixed stem and to access cement, while preserving abductor continuity for repair.

Step 2: Remove the failed stem and cement

Extract the loose stem; remove all cement (and the cement restrictor) if cemented. Debride and prepare the canal.

Step 3: Revision stem bypassing the fracture

Insert a long uncemented tapered fluted (titanium) stem that gains rotational and axial fixation in the diaphysis distal to the fracture, bypassing the fracture by at least about two cortical diameters. Modular designs allow independent setting of length, version and offset.

Step 4: Stabilise the fracture and reattach the trochanter

Reduce the fracture around the stem with cerclage cables; supplement with a plate/strut if the fracture pattern demands it (B2 +/- ORIF). Reattach the ETO/greater trochanter with cables.

Vancouver B3 — Reconstruction or Replacement (loose stem, deficient bone)

• Young / higher-demand, restorable stock: long revision stem with bone graft / impaction grafting / allograft-prosthetic composite to rebuild proximal bone
• Frail elderly: proximal femoral replacement (megaprosthesis) - sacrifices bone stock but allows immediate weight-bearing, prioritising rapid mobilisation and survival over reconstruction
• Address instability risk after major proximal reconstruction (consider dual-mobility or constrained articulation given soft-tissue compromise)

Vancouver C — ORIF as a fracture (overlap the stem)

• Treat as a distal/diaphyseal femoral fracture with a distal femoral locking plate (or a retrograde nail where geometry allows and no knee implant interferes)
• Crucially, overlap the plate with the stem proximally (cables / unicortical or locking screws around the stem) so there is no unsupported segment between the plate and the stem tip - this prevents an inter-implant stress riser and refracture

Periprosthetic Distal Femur (around a TKA) — brief

• Classification: Su (based on level relative to the femoral component) and Lewis-Rorabeck (displacement and component fixation)
• Retrograde intramedullary nail: suitable when the femoral component has an open box that admits the nail and the component is well-fixed; gives load-sharing fixation
• Distal femoral locking plate: versatile, especially for very distal fractures or a closed-box component; biological/bridging application
• Distal femoral replacement: for a loose femoral component, very distal/comminuted unreconstructable fractures, or the frail elderly needing immediate weight-bearing
• Beware the inter-implant zone: if a hip stem is also present (or a long plate is used), avoid leaving an unsupported segment between the two implants

Outcomes

Mortality

• Periprosthetic femoral fracture carries mortality approaching that of a native hip fracture - around 10% at 1 year, and higher in the frail and comorbid. This reframes management toward fragility-fracture principles: orthogeriatric co-care, prompt surgery, and a construct that permits early mobilisation.

Union and fixation

• Well-classified and well-executed B1 ORIF and B2/B3 revisions achieve high union/stability rates; the major determinant of failure is misclassification (plating a loose stem) and inadequate constructs (short plates, inter-implant gaps).
• Cortical strut allografts incorporate over time and can augment fixation in poor bone.

Registry context

• National joint registries (NJR UK, AOANJRR Australia, AJRR US, Swedish/Nordic registries) document a rising absolute number of periprosthetic femoral fractures driven by increasing arthroplasty volume and an ageing population. Periprosthetic fracture is a recognised and growing indication for revision. Registry data also informs implant- and fixation-related fracture risk (for example, some collarless polished tapered cemented stems are associated with a recognised periprosthetic fracture pattern).

Rehabilitation Principles

Goal: early, safe weight-bearing

• The construct should ideally allow early weight-bearing because prolonged non-weight-bearing is poorly tolerated and dangerous in the elderly
• Revision to a stable long stem and proximal/distal femoral replacement generally permit early/immediate weight-bearing
• ORIF weight-bearing depends on fracture pattern, bone quality and construct strength - progress under guidance; a tenuous fixation in poor bone is a reason to reconsider the strategy rather than to impose long restriction

Multidisciplinary pathway

• Orthogeriatric co-management throughout admission
• VTE prophylaxis; delirium prevention; nutrition and bone-health optimisation (treat the underlying osteoporosis)
• Physiotherapy from day 1; occupational therapy and discharge planning early
• Falls assessment and secondary-prevention - many of these patients fall again

Follow-up

• Serial radiographs to confirm union/stability and exclude implant migration or inter-implant refracture
• Monitor for late infection and instability after revision
• Bone-health clinic referral - a periprosthetic fragility fracture is a sentinel event