Less than 10% of periprosthetic fractures occur following high-energy trauma, and the vast majority occurs after a ground-level mechanical fall. A detailed history of the patient’s preinjury level of function as well as any symptoms related to their joint replacement is essential to determine whether the prosthesis was loose or infected prior to their fracture. Knowledge of the patient’s preinjury ambulatory status and the use of walking aids are helpful. The patient should be questioned about preinjury discomfort or pain with activities of daily living as it may indicate a loose prosthesis. Time, course, and progression of the pain are also helpful clues. Some patients may report progressive instability that suggests implant loosening or bearing surface wear. Whenever possible, prefracture radiographs should be reviewed to detect any changes in component position and axial alignment.

Past medical history, a thorough review of systems, and an accurate inventory of the patient’s current medications are important, because many will require internal medicine consultation preoperatively. Antiplatelet medication, vitamin K antagonists, and immunosuppressive agents are common in this patient population and may impact or delay the surgery. On physical examination, the leg is swollen, tender to palpation, and range of motion is decreased or impossible to evaluate secondary to pain. The skin should be inspected for ulcers, abrasions, lacerations, and ecchymosis particularly around the knee where soft tissues can be problematic. The neurological and vascular status of the limb must be thoroughly evaluated and documented.

Full-length AP and lateral radiographs of the femur should be obtained as well as an AP pelvis. Radiographs of the contralateral femur or knee can be useful when the fracture is comminuted making restoration of leg length or alignment difficult. If the fracture involves the acetabulum, Judet views (obturator and iliac oblique views) are required. A CT scan or even a CT-scan angiogram may be needed for some patients with protusio acetabuli to minimize the risk of intraoperative injury to iliac or femoral vessels or to the ureter. A CT scan of the distal femur may be helpful when there is a comminuted, osteoporotic fracture around the knee, because a hinged knee or distal femoral replacement may be necessary. MRI, ultrasound, and nuclear scans are rarely needed in evaluating periprosthetic fractures.

A history of slow wound healing or drainage at the time of the original joint arthroplasty always raises the possibility of a low-grade infection even years later. Biological markers such as ESR (erythrocyte sedimentation rate) and CRP (C-reactive protein) are less reliable in the context of an acute fracture. A recent study of 204 periprosthetic fractures reported a false positive rate for infection of 43% based on the CRP levels and 31% for the ESR (5). If an occult infection is suspected, an image-guided aspiration is recommended to obtain fluid for a gram stain and cultures. Surgery should be delayed if possible until the cultures results are available. A positive culture drastically changes the surgical treatment and the overall prognosis.

Most periprosthetic fractures are caused by low-energy trauma and are rarely open or complicated by neurovascular injury or a dislocation. The preoperative evaluation can be time consuming because of the need to identify the prosthesis, obtain preinjury radiographs, or rule out an infection. The logistics of obtaining the appropriate implants to cover all possibilities may also take time. Few surgeons are equally skilled at repairing difficult fractures and performing complex prosthetic revisions. Collaboration with skilled arthroplasty colleagues may be wise. It may be in the patient’s best interest to postpone surgery until the preoperative evaluation is complete, all necessary equipment is available, skilled operating personnel are on duty and experienced colleagues ready to help.

Successful surgery requires a medically optimized patient, a knowledgeable and experienced surgical team, and appropriate equipment and implants. Preoperative planning is crucial, and radiographs should be analyzed with particular attention focused on the fracture location, implant stability, and bone quality. Periprosthetic proximal femur fractures are traditionally classified according to the Vancouver classification since this has been shown to correlate with treatment and outcomes. A simple treatment algorithm for these complex fractures is seen in Figure 45.3.

Although a type B1 fracture (stable stem) is the most common fracture pattern, it is not always easy to distinguish it from a type B2 fracture (loose femoral component). Using the patient’s history, prefracture radiographs of the limb and current x-rays, the stability of the implant is estimated. For Vancouver type C fractures treated with plate osteosynthesis, the plate must extend proximal to the tip of the prosthesis to avoid leaving an area of unprotected bone between the proximal end the plate and the tip of the prosthesis. Failure to “overlap” the plate and the femoral stem leaves an area of high stress concentration between the plate/bone distally and stem/bone proximally. A fracture through such area can occur and is exceedingly difficult to treat. Table 45.1 lists 11 important considerations to address in the course of evaluating and treating these complex fractures. Addressing each of the 11 considerations will improve the chance for a successful outcome. Table 45.2 lists the implants that should be immediately available by likelihood of need for each type of fractures.

Implant stability is the major determining factor in deciding patient position. Fracture fixation alone in the presence of a loose implant invariably leads to a poor outcome. Fluoroscopic examination under anesthesia with the patient supine on a radiolucent table may confirm the presence of a loose implant. If all clinical and radiographic testing point toward a well-fixed implant without infection, the patient should be positioned supine on a flat-top radiolucent table. The supine position facilitates fracture reduction as well as assessment of leg length and alignment. Radiolucent sterile triangles are also useful to maintain reduction and alignment.

A fracture table is rarely needed; a femoral distractor or an external fixator can be helpful if there is substantial shortening of the fracture, or skilled assistance unavailable. If there is any doubt about the stability of a hip implant, the patient should be positioned in the lateral decubitus position. This allows femoral fracture fixation, as well as assessment of the femoral or acetabular component stability, and facilitates revision at the same time if necessary. We routinely use a patient positioning device (peg board) to ensure a stable patient position
throughout the procedure. Furthermore, the table should rotate (backward or forward) in order to obtain a true AP radiograph of the pelvis and obturator/iliac oblique views if needed.