Periprosthetic Femoral Fractures Around Hip Arthroplasty: Vancouver Classification and Treatment

Overview

Periprosthetic femoral fractures around hip arthroplasty stems are becoming more common as the number of arthroplasties rises; one projection expects their number to increase by about 4.6% per decade over the next 30 years. In a Mayo Clinic series of 32,644 primary THAs, the 20-year probability of postoperative periprosthetic fracture was 3.5% overall, 7.7% after cementless stems and 2.1% after cemented stems. Fracture risk is low in the first decade and rises in the second. Treatment is driven by fracture location, stem stability and bone stock, summarized by the Vancouver classification. (Rockwood)

Vancouver Classification (Rockwood)

• Distinguishing a well-fixed from a loose stem in the presence of a fracture can be difficult. Test stem stability intraoperatively and be prepared to revise a loose stem.

• An intraoperative Vancouver version uses zones A (metaphysis), B (diaphysis around the stem tip) and C (beyond the longest revision stem), with subtypes 1 (cortical perforation), 2 (undisplaced linear crack) and 3 (displaced or unstable). Intraoperative detection generally leads to more surgical intervention than later detection.

Risk Factors and Incidence (Rockwood)

• Intraoperative metaphyseal fractures are technique dependent with metaphyseal fit-and-fill stems; in one lateral-approach series they occurred in 5.6%, all in women. An unrecognized metaphyseal crack may propagate and subside early after surgery.

• Postoperative type A fractures occurred in 2.6% of one cementless design, typically through osteolytic cysts 4 to 11 years after THA.

• Cementless stems carry a higher risk than cemented stems.

Preoperative Evaluation (Rockwood)

• Quality orthogonal radiographs to judge fracture pattern, stem fixation, acetabular component fixation and remaining bone stock. Obtain the original operative note to identify implants so that liners can be ordered if needed.

• Prefracture mechanical thigh or groin pain suggests stem loosening when radiographs are equivocal.

• ESR and CRP are of uncertain value with an acute fracture; aspirate the hip preoperatively if infection is suspected.

Treatment by Type (Rockwood)

Type A

• Most AG fractures are stable, held by the soft-tissue sleeve connecting the abductors and vastus lateralis, and can be treated symptomatically with weight bearing as tolerated. Intraoperatively recognized stable fractures can be managed similarly or fixed.

• Nonoperative treatment is contraindicated when the trochanter is completely detached without a soft-tissue sleeve (risk of migration, nonunion and instability) or when implant stability is compromised.

• Protect with a walker or crutches, avoid active abduction and abductor strengthening, and obtain serial radiographs early to detect displacement.

• Widely displaced or symptomatic AG fractures are treated with a claw (hook) plate: drive the claws through the gluteus medius insertion into the trochanteric tip, choose a plate long enough to place two or three cables about 2 cm apart around the stem below the fracture apex, and add a vertically oriented cable to reinforce proximal fixation. Very short plates are associated with failure. Bone graft osteolytic defects while preserving soft-tissue stabilizers.

• Medial calcar cracks found intraoperatively: image to define their extent (they can spiral toward the stem tip). Treat limited undisplaced cracks with one or two cerclage cables; if propagation exists, bypass the distal extent with a lateral plate. Large lesser trochanter or medial cortical fractures with tapered press-fit stems usually need cables with or without revision to a distally fixed stem.

Type B

• Rarely treated nonoperatively when found intraoperatively. Postoperatively, an incomplete or undisplaced diaphyseal crack with an excellent stem may be observed with protected weight bearing; in one small series with teriparatide, union occurred in 100% of B1 and 75% of B2 fractures. Operate early if stem subsidence or displacement is likely, especially with proximally fitting stems.

• B1: ORIF with plate and screws, cortical onlay allografts or both. Recently some advocate revision to a long modular stem bypassing the fracture regardless of stem stability, allowing earlier weight bearing in patients fit for larger surgery.

• B2 and B3: revise the femoral component, usually to a long stem giving intramedullary stability, adding a lateral plate, allograft struts (most clearly indicated with B3 bone loss) or both. Severe bone loss may need an allograft-prosthesis composite, impaction grafting or proximal femoral replacement. ORIF or nonoperative care is reserved for patients with limited capacity for surgery or limited demands.

Plate construct for B1 fractures

• Use a lateral plate contoured proximally to the trochanteric flare, with at least six to eight holes over the intact femur distal to the fracture, or preferably extending to the condylar region (a distal femoral plate design where possible). A precontoured plate with a sagittal bow matches the femur.

• Provisional fracture reduction and fixation with cables makes plate application straightforward, but the plate must be well contoured and principles of relative stability and biologic (indirect) reduction should be respected.

Type C

Treat as a distal femoral fracture with a lateral locking plate that overlaps the stem proximally to avoid a stress riser between implants, extending distally to include the condyles.

Complications (Rockwood)

Nonunion and fixation failure (especially with short plates or unrecognized stem loosening), refracture between implants, stem subsidence, instability and abductor dysfunction after trochanteric fractures, and infection.

Additional Detail from Campbell

Incidence and risk factors (Campbell)

• Mayo Clinic registry: intraoperative femoral fractures in 1.7% of primary and 12% of revision THAs. In the United States, surgically treated lower-extremity periprosthetic fractures had an annual incidence of about 2.47 per 100,000 in 2015. Most postoperative fractures follow low-energy trauma (high energy in under 10%).

• Risk factors: demographic (elderly, female); medical (osteoporosis, osteopetrosis, bisphosphonate use, prior fragility fracture, comorbidities); anatomic (Dorr A or C femur, cortical defects, previous hip surgery); surgical (cementless or noncollared cementless stems, anterior approach, stem malalignment, taper-slip cemented stems).

Avoiding intraoperative fractures (Campbell)

• Release more capsule if dislocation meets resistance, and resect rim osteophytes first. In protrusio where dislocation is impossible, cut the neck and remove the head piecemeal.

• Broaches crush cancellous bone but cannot safely remove diaphyseal cortex; anticipate this from templating and ream with a straight or flexible reamer before broaching.

• If a fracture occurs during cementless stem insertion, expose it to its distal extent with the broach or implant in place (the gap may otherwise close and be underestimated). Place cerclage cables with a trial one size smaller in the canal, plus one cable distal to the fracture, then reinsert the final component. Consider prophylactic cerclage when the cortex is thin or weakened.

Treatment refinements (Campbell)

• B1: fixation must be rigid; cerclage, bands or isolated screws alone have high failure rates. Constructs have evolved to locking plates with proximal unicortical and distal bicortical screws, often placed percutaneously. Proximal screw plus distal screw fixation is biomechanically stronger than proximal cables alone.

• B2: long-stem cementless revision is preferred (proximally porous-coated modular, distally fluted tapered or extensively porous-coated stems), with cerclage or onlay strut allograft for rotational stability and bone grafting. A meta-analysis found at least equivalent results with ORIF for B2 and B3 fractures, with shorter operative time, less blood loss and lower cost; ORIF may suit low-demand elderly patients with high anesthetic risk when bone stock and fracture pattern allow anatomic reconstruction.

• B3: allograft-prosthesis composite, proximal femoral replacement, or increasingly distally fluted tapered stems, which have achieved union, stability and some restoration of proximal bone stock.

• C: internal fixation leaving the stem undisturbed, avoiding stress concentration between implants.

• Type D (interprosthetic, between hip and knee arthroplasties): ORIF with locking and nonlocking plates when both implants are stable and bone is adequate; otherwise revision with modular proximal, distal or total femoral replacement.

Acetabular periprosthetic fractures (Campbell)

Intraoperative acetabular fracture occurred in 0.4% of 7121 primary THAs, all with uncemented components (mostly monoblock elliptical cups); most were stable and healed with the cup retained or converted to a screw-augmented cup. If fracture stability is achieved, an uncemented hemispherical cup with screws suffices; if implant stability remains doubtful, use an antiprotrusio cage or cup-cage construct.

References

1. Ricci WM. Periprosthetic fractures of the lower extremity. In: Tornetta P III, Ricci WM, Ostrum RF, McKee MD, Ollivere BJ, de Ridder VA, eds. Rockwood and Green's Fractures in Adults. 10th ed. Wolters Kluwer; 2024 (Turkish edition: Erişkin Kırıkları). Chapter 59.

2. Arthroplasty of the hip. In: Azar FM, Sawyer JR, Throckmorton TW, eds. Campbell's Operative Orthopaedics. 15th ed. Philadelphia: Elsevier; 2026. Chapter 4, Fractures.