Management of Pathologic Proximal Femur Fractures: Challenges and Considerations

Osteoporotic fractures of the femoral neck and intertrochanteric/subtrochanteric region are commonly encountered by orthopaedic surgeons taking call; pathologic fractures from oncologic processes are less common. Patients’ presentation may resemble a more routine hip fracture, but there are substantial differences in the management of pathologic proximal femur fractures compared with their non-oncologic counterparts. These differences make the management of pathologic proximal femur fractures more challenging. Issues that must be considered include whether the lesion is a primary tumor or metastatic, the location of the fracture, the ability to achieve a stable construct to allow for pain relief and weight bearing, and the expected lifespan of the patient.

Intramedullary nailing of a pathologic intertrochanteric hip fracture assumed to be caused by a metastatic lesion can be catastrophic for primary bone tumors. The entire femoral canal, including the nail entry site and interlocking bolts, would be seeded by the tumor. Subsequently, the patient may require a hip disarticulation for control of tumor spread. Therefore, for the general orthopaedic surgeon, it is essential to ensure that the pathologic fracture is the result of a metastatic tumor or multiple myeloma and not a primary sarcoma.

The primary metastatic tumor causing the fracture can be identified by patient history, physical examination, laboratory tests, advanced imaging, and biopsy. History and physical examination can help determine the primary tumor site in more than 25 percent of patients with bone metastases. Primary tumor sites that commonly metastasize to bone include breast, kidney, lung, prostate, and thyroid. Standard laboratory tests include complete blood count, electrolyte panel, liver function test, thyroid function test, prostate-specific antigen for males, urine analysis, and serum/urine protein electrophoresis. Imaging studies should include radiographs of the hip, femur, and pelvis; whole-body bone scan; and CT scans of the femur, chest, abdomen, and pelvis. A study by Katagiri et al demonstrated that this strategy identified the primary site in 85 percent of patients. MRI of the femur should be performed if there is suspicion that the lesion may be a primary sarcoma. If the pathologic fracture is suspected to be caused by a primary lesion, a biopsy should be performed or directed by an orthopaedic oncologist before any operative intervention. The biopsy should be in line with the planned incision to avoid any unnecessary biopsy tracts, which may contaminate the extremity and compromise limb salvage. Based on the biopsy results, appropriate treatment can then proceed. Primary lesions may require wide resection and reconstruction of the proximal femur. Metastatic lesions are treated with the primary goal of pain relief and durable surgical reconstruction but not cure. An exception to this is a solitary metastatic lesion where curative procedures may improve lifespan, especially with renal metastasis.

Once it has been determined that the pathologic fracture was caused by a metastatic lesion that is not an osteosarcoma, surgical reconstruction can proceed. The goals of surgery are pain relief, restoration of function, early weight bearing, and avoidance of complications associated with prolonged recumbency, including thromboembolic complications, pneumonia, decubitus ulcers, and metastatic hypercalcemia. Preoperative embolization can decrease intraoperative blood loss for highly vascular tumors associated with renal cell and thyroid carcinomas.

Pathologic femoral neck fractures due to metastatic lesions are usually treated with a cemented hemiarthroplasty. Hemiarthroplasty provides a durable reconstruction with good pain relief for patients with limited lifespans. A long-stem hemiarthroplasty can be performed if there are lesions distally in the shaft. A major concern with using a long cemented stem in an unfractured canal is the risk of intraoperative cardiac arrest.

Pathologic fractures involving the intertrochanteric or subtrochanteric region may be treated with a long cephalomedullary nail if there is adequate bone stock in the femoral head and neck to support the implant. Cephalomedullary nailing has been shown to have satisfactory results with a low incidence of revision surgery in patients with moderate-sized proximal femoral metastasis that has not affected the femoral head or neck. For most patients meeting these criteria, the nail construct provides adequate stability for the remainder of the patient’s life. For larger intertrochanteric and subtrochanteric lesions with substantial bone loss, a proximal femoral replacement can provide more durable reconstruction with a lower risk of failure due to tumor progression. However, it is a more extensive reconstruction with greater potential for life-threatening anemia as well as implant-related complications, including dislocation and periprosthetic infection.

Members of the Musculoskeletal Tumor Society were surveyed to determine their preferences for treatment of pathologic intertrochanteric and subtrochanteric femoral fractures. Intramedullary nail fixation was preferred by 45 percent of surgeons, and proximal femoral resection with reconstruction was chosen by 34 percent. These options were followed by hemiarthroplasty with a cemented long-stem prosthesis (15 percent) and open reduction and internal fixation with plates and screws (7 percent). Surgeons preferred intramedullary nailing and proximal femoral replacement in equal numbers if patients had an expected lifespan of more than 6 months.

In summary, orthopaedic surgeons taking call must have a high degree of suspicion that a proximal femur fracture could be pathologic. Factors such as a low-energy mechanism and a history of cancer should immediately alert the surgeon that a fracture may be pathologic. This is especially important in young patients with a femoral neck fracture, who are usually taken to the OR urgently for internal fixation. If a primary tumor is missed and internal fixation is performed, this could prove deadly for the patient. Surgery should not be performed unless a primary tumor or solitary metastasis is ruled out. The treatment for metastatic femoral neck fractures is arthroplasty, as internal fixation has poor outcomes. Pathologic intertrochanteric or subtrochanteric fractures caused by metastatic lesions can be treated with long cephalomedullary nailing if there is good proximal femoral bone stock, including the head and neck region. If proximal bone stock is poor or if there is concern about substantial tumor progression, proximal femoral replacement is a more durable reconstruction. The latter may best be performed by an orthopaedic oncologist or arthroplasty surgeon with experience in complex revision surgery, as the risks of blood loss, infection, and dislocation are significant.

Michael DeRogatis, MD, MS, is an orthopaedic surgery resident at St. Luke’s University Health Network in Bethlehem, Pennsylvania, and serves as a resident member of the AAOS Now Editorial Board.

Paul S. Issack, MD, PhD, FAAOS, FACS, is a clinical associate professor in the Department of Orthopaedic Surgery, Weill Cornell Medical College, and a trauma and adult reconstruction orthopaedic surgeon at New York–Presbyterian Lower Manhattan Hospital. He is also a member of the AAOS Now Editorial Board.

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