A 92-year-old woman sustained an injury to her left lower extremity after falling from a standing position. Her surgical history is significant for a left hybrid total hip arthroplasty with a cemented femoral stem that was performed 15 years earlier.
Physical examination revealed shortening and deformity of the affected extremity with no neurovascular deficits. Injury radiographs were obtained ( Figs. 71.1 and 71.2 ). The injury pattern was consistent with a Vancouver B2 periprosthetic femoral fracture. The patient underwent surgery for removal of the cement and femoral component, which was revised to a tapered, fluted, modular titanium stem and cerclage cabling ( Figs. 71.3 to 71.5 ; see Fig. 71.2 ).
Algorithms
Chapter Preview
Chapter Synopsis
The indications, surgical technique, complications, and outcomes are described for treatment of periprosthetic fractures of the femur in cases of total hip arthroplasty (THA).
Important Points
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Proper interpretation of preoperative radiographs and classification of the periprosthetic fracture can guide the surgeon in choosing the most appropriate reconstruction.
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Surgical exposure and radiographs are used to fully assess the periprosthetic fracture.
Clinical/Surgical Pearls
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We prefer a posterior approach to the hip for revision THA.
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The distal femur can be accessed through a posterolateral approach.
Clinical/Surgical Pitfalls
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Misinterpretation and treatment of a Vancouver B2 fracture as a B1 can lead to failure if treated with open reduction and internal fixation.
Introduction
Periprosthetic fracture is a known complication of total hip arthroplasty (THA). Periprosthetic fractures can occur intraoperatively and postoperatively. The reported incidence of intraoperative periprosthetic fractures of the femur in primary THA ranges from 0.3% to 1.0% with the use of cemented femoral components and 3% to 20% with the use of cementless femoral components. Revision THA carries a greater risk of intraoperative periprosthetic fracture, with an incidence of 3.6% to 6.3% with the use of cemented femoral components and 17.6% to 20.9% with the use of cementless femoral components. Revision of the femoral component with impaction allografting carries a potential risk of periprosthetic fracture ranging from 4% to 32%. Postoperatively, the risk of periprosthetic fracture for primary and revision THAs is 1% and 4%, respectively.
Local and systemic risk factors predispose patients to periprosthetic fractures. Local risk factors include the use of press-fit femoral components, minimally invasive surgical techniques, complex deformities, osteolysis, cortical stress risers, loose femoral components, and revision surgery. Systemic risk factors include osteopenia, osteoporosis, rheumatoid arthritis, osteomalacia, Paget disease, osteopetrosis, osteogenesis imperfecta, thalassemia, and neuromuscular disorders such as parkinsonism, poliomyelitis, neuropathic arthropathy, cerebral palsy, myasthenia gravis, seizure disorder, and ataxia. Patients awaiting revision THA are often less active or mobile, predisposing them to disuse osteopenia, which can increase their risk of periprosthetic fracture.
The patient’s sex, age at the time of surgery, and length of time since the index surgery have been identified as risk factors predisposing to periprosthetic femoral fracture. A review of 6458 patients who underwent primary THA with cemented femoral components demonstrated an incidence of periprosthetic fracture of 0.8% at 5 years and 3.5% at 10 years. Patients older than 70 years at the time of surgery had a 2.9 times greater risk of sustaining a periprosthetic fracture compared with younger patients. This risk increased to 4.4 times that of younger patients when patients were older than 80 years at the time of primary THA. A separate study evaluated the cumulative incidence of periprosthetic femoral fracture in a consecutive series of 326 patients (354 hips) with an uncemented femoral prosthesis using long-term survivorship analysis. The study authors found a cumulative incidence of periprosthetic femoral fracture of 1.6% at 10 years and 4.5% at 17 years after primary THA.
Indications and Contraindications
Suspicion of intraoperative periprosthetic femoral fracture warrants further inspection by surgical exposure and radiographic examination. Postoperative periprosthetic femoral fracture, whether in the acute or late setting, can be diagnosed by radiographic examination. Radiographs should be taken of the whole femur in two planes. The acetabulum should be imaged to assess for acetabular osteolysis, polyethylene wear, component position, and evidence of component loosening. The images should be compared with previous radiographs to evaluate femoral and acetabular component positions and alignment. Classification of a periprosthetic femoral fracture can help to guide treatment (see Vancouver Classification algorithm).
Nonoperative management may be considered for patients with unacceptable risks of anesthesia or for nondisplaced fractures. Complications related to recumbency, including pneumonia, venous thromboembolic disease, and decubitus ulcers, should be monitored. Vancouver type A G (greater trochanter) fractures ( Fig. 71.6 ) that are minimally displaced or nondisplaced are considered stable because of the gluteus medius and vastus lateralis musculature. Weight bearing is permitted, but active abduction should be avoided for 6 weeks. Vancouver type A L (lesser trochanter) fractures (see Fig. 71.6 ) can be ignored, with no functional or weight-bearing restrictions unless the fracture extends into the medial cortex and destabilizes the stem. Nondisplaced Vancouver type B fractures that do not compromise the stability of the femoral component can be treated with close observation, weight-bearing restrictions, and functional bracing. Routine surveillance requires serial radiographs until fracture union has been achieved.
Equipment
Treatment of periprosthetic femoral fractures associated with THA requires the following equipment:
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Cerclage cables (monofilament or multifilament)
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Plates and screws
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Femoral component extraction tools
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Oscillating saw
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High-speed drill and burs
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C-arm fluoroscopy or portable radiograph machine
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Radiolucent operating table
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Fracture reduction instruments
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Femoral or tibial strut allografts
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Revision femoral components (e.g., cylindrical, tapered, fluted, modular components; proximal femoral replacement) and proximal femoral allograft
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Tools for cement extraction (e.g., hooks, drills, taps, ultrasound cement removal device, light source)
Surgical Technique
Preoperative Considerations
Before surgery, complete radiographs of the pelvis, hip, and femur should be obtained. The surgeon uses the radiographs for preoperative templating and to assess the fracture pattern and location, femoral deformities and remodeling, integrity of the remaining host bone, and length of the remaining isthmus.
Exposure
For revision THA, we prefer a posterior approach to the hip. The surgical incision should be sufficient to allow adequate exposure. For access to the distal aspect of the proximal metaphysis and diaphysis, the gluteus maximus tendon should be identified, tagged, and released. The vastus lateralis and intermedius can be elevated anteriorly off the linea aspera with a Bennett, cobra, or Hohmann retractor. Excessive soft tissue stripping should be avoided, especially around the fracture to prevent devascularization, which can lead to nonunion of the fracture.
An extended trochanteric osteotomy (ETO) may be performed to improve exposure and to facilitate component removal and insertion ( Fig. 71.7 ). After a posterior exposure, the vastus lateralis muscle is elevated to define the extent of the fracture ( Fig. 71.8 ). A Hohmann retractor can be placed to retract the musculature anteriorly ( Fig. 71.9 ). The ETO should be created from the greater trochanter down to the level of the fracture with the use of an oscillating saw and osteotomes ( Figs. 71.10 to 71.12 ). Care should be taken to respect the soft tissue attachments to the osteotomized fragment, which is retracted anteriorly. After femoral reconstruction, the medial and lateral fragments can be draped around the prosthesis and secured with cerclage cables or wires ( Fig. 71.13 ).
