Revision Arthroplasty for Periprosthetic Femoral Fracture

Introduction

Periprosthetic femoral fracture complicating hip arthroplasty is relatively common. The reported incidence is just below 1% after primary reconstruction and up to 4.2% after revision surgery. These cases present a challenge to the orthopedic surgeon because the fracture is often complicated by significant osteopenia, bone loss, and multiple medical comorbidities that make the patient intolerant of a physiologically taxing surgical procedure and prolonged postoperative weight-bearing restrictions.

Optimal treatment remains unclear, although conventional teaching advocates surgical reduction and fixation of fractures with a well-fixed stem and revision arthroplasty bypassing the fracture in cases of total hip implant instability. The Vancouver classification has proved valuable in guiding the surgeon because it has high interobserver and intraobserver reliability. Treatment can be implemented based on this classification, which takes into account the fracture location and stem stability. This premise has been challenged recently, and superior results have been reported with stem revision compared with open reduction and internal fixation, even in cases with well-fixed femoral components.

The decision to use fixation or revision arthroplasty is based on fracture- and patient-related factors. We present a technique for revision arthroplasty that is applicable in all scenarios in which there remains an intact isthmus distal to the fracture.

Surgical Technique

Most periprosthetic femoral fractures are low-energy injuries with only modest displacement that often is partially splinted by the femoral stem. The fractures may be initially managed with adequate analgesics and bed rest while awaiting definitive care. High-energy fractures with significant displacement and ongoing fracture motion are best managed initially with balanced skeletal traction if surgical intervention is delayed.

Examination and Imaging

The preoperative medical evaluation is routine. Although not urgent, the time to definitive surgical care should be minimized to avoid the well-documented increase in morbidity and mortality in the hip fracture population. The previous operative reports and implant record should be obtained if feasible.

Standard radiographic evaluation includes an anteroposterior radiograph of the pelvis, anteroposterior and cross-table lateral radiographs of the affected hip, and full-length views of the femur. Occasionally, computed tomography may help in assessing the fracture morphology, particularly a minimally displaced Vancouver B fracture pattern.

Preoperative Planning

The importance of surgical experience cannot be overstated when revision arthroplasty for periprosthetic fracture is contemplated. This type of revision requires a large exposure and involves considerable blood loss, even when performed with utmost efficiency. To minimize operative time and complications, preoperative planning is essential.

Every effort is made to identify existing implants for ease of removal and to have an appropriate modular liner available for exchange. Surgical exposure is planned based on the fracture pattern. Radiographic templating assists in determining the appropriate length and diameter of femoral stem needed to bypass the fracture. Vertical length from the fracture to the hip center of rotation may be measured, which can be useful for crosschecking intraoperative measurements.

Planning adjunctive fracture fixation techniques preoperatively enables faster operative decision making and ensures the appropriate materials are readily available ( Box 72.1 ). The following technique is described for a modular, tapered, fluted stem and conical proximal body. We have found this construct to be superior based on several factors:

Secure distal fixation (axial and rotational) with even a short length of intact isthmus (1-2 cm)
A modulus of elasticity resembling bone that minimizes thigh pain and allows proximal fracture remodeling
A conical proximal body that allows anatomic fracture fixation with femoral version not limited by proximal femoral geometry
Proximal modularity that allows fine-tuning of the length and offset after implanting the definitive distal segment

Box 72.1

Preoperative Checklist

Acetabular Side

Modular liner for existing cup
Acetabular explant system
Revision acetabular cup
Cemented polyethelene liner (if cementing liner into well-fixed cup is a consideration)

Femoral Side

Revision stem of adequate length
Cerclage cable system
Allograft femoral strut
Trochanteric cable and plate system
Large bone-holding or bone-reduction clamps
Allograft cancellous graft

Procedure

Mechanical and chemical prophylaxis for deep venous thrombosis is initiated on presentation if surgery will be delayed longer than 24 hours, and preoperative antibiotic prophylaxis is routine. Antiseptic preparation and draping are performed to allow exposure of the entire length of the femur. Blood-conservation techniques are used, and allogenic blood should be readily available.

A peg board or equivalent positioning table is used. Although not routine, acetabular revision may be indicated based on intraoperative findings, and appropriate pelvic positioning aids in determining the cup position and functional range of motion after reconstruction.

A lateral approach to the femur allows visualization of the fracture. Great care is taken to ligate perforating vessels. At this point, distal dissection is limited to the fracture site to minimize ongoing blood loss as proximal preparation proceeds.

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