Guest Editorial: An Appeal for Evidenced-based Care and Adoption of Best Practices in the Management of Displaced Femoral Neck Fractures

From the Editor-in-Chief, In this month’s Guest Editorial, Clinical Orthopaedics and Related Research® Deputy Editor Charles N. Cornell MD identifies several ways orthopaedic surgeons can improve upon the care of older patients with displaced femoral neck fractures. I share his concern that more-than-ample research supports the use of cemented stems, THA for selected patients, and a comprehensive-care approach for these vulnerable patients, and yet these approaches are not normative in many parts of the world, including the United States. I believe his recommendations represent a thoughtful synthesis of the best-available evidence on the topic.

As an attending orthopaedic surgeon at the Hospital for Special Surgery and a Professor of Clinical Orthopedic Surgery at Weill Cornell Medical College, Dr. Cornell has extensive knowledge of adult reconstructive surgery, hip fracture care, and lower-extremity arthroplasty; he has written extensively on all these topics.

— Seth S. Leopold MD

Hip fractures in older patients might be the most-common serious diagnosis that orthopaedic surgeons treat; in fact, taking “serious” to mean “potentially life-ending”, it may be the only serious diagnosis that many orthopaedic surgeons will treat after graduating from residency. The risk of death after this injury is not hypothetical: About one patient in five with a hip fracture will not survive a year after the injury [5]. According to the National Osteoporosis Foundation, a woman’s risk of experiencing a hip fracture is equal to her combined risk of developing breast, uterine, and ovarian cancer [18]. Stated another way, the likelihood that a 50-year-old white woman will die from a hip fracture is 2.8%, which is about the same as her risk of death from breast cancer and four times greater than the likelihood she will die from endometrial cancer [3]. Most of those who survive will not walk as well as they did prior to the injury, and some will not walk at all; many will have chronic pain [6]. For these reasons, it seems important that for this diagnosis—maybe more than any other that we commonly treat—we get it right.

Unfortunately, the evidence suggests that as a specialty, we don’t. An important research effort has developed some well-supported guidelines to guide the care of older patients with femoral neck fractures [15]. Despite those evidence-based recommendations and others [21] little has changed in the operative treatment of displaced femoral neck fractures in the Medicare population in the past 20 years [17]. Based on what we now know, there are three areas in which we need to improve: Using cement when performing hemiarthroplasty, deciding between hemiarthroplasty and THA, and following available protocol-driven hospital-based approaches for the care of these patients.

Cemented stems are associated with a reduced risk of thigh pain, revision, and acute and long-term periprosthetic fracture compared to uncemented stems [7-9, 11-13, 24, 25]. Despite this strong evidence, my personal experience—derived from attendance at local fracture rounds and morbidity conferences, national meetings addressing the topic of hip fracture care, and acting as a reviewer on this topic for a number of orthopaedic journals and the Deputy Editor for trauma at Clinical Orthopaedics and Related Research®—suggests use of uncemented devices for this indication remain dismayingly common in the United States and elsewhere. Considering what seems like an obvious advantage to using cement for this indication, why isn’t it the norm?

I speculate that there are three main reasons: Surgeon convenience, transfer bias, and concern about bone cement implantation syndrome (BCIS) in older, more-vulnerable patients. The convenience factor, given what we know about the procedures, is troublesome. Surgeons must balance a few extra moments of surgical time against the risk of substantial harms that may come to patients who receive cementless hemiarthroplasty stems; this seems like an easy choice to make. In terms of transfer bias, I suspect that many hip fracture patients do not consistently followup with their original surgeons, but instead undergo revision elsewhere, leading to the impression in the mind of the original surgeon that the choice of a cementless stem was justified. Additionally, the risk of periprosthetic fracture after uncemented hemiarthroplasty seems to be in the range of 1.7% to 4% [14, 20]; this number is a small enough number that it can be difficult to detect as a problem in the context of a single surgeon’s experience. Large studies consistently affirm that this risk is much greater than the risk of fracture among patients who received cemented stems [7-9 11-13, 24, 25], and because of that, these studies identify a genuine burden on the entire healthcare system.

The most-substantive concern raised about use of bone cement in this context is BCIS, a rare condition that occurs in 0.2 to 4.3% of patients, with the highest risk observed among patients receiving long-stem prostheses for pathologic fractures [4, 19]. And while we have seen diminished incidences reported during the past decade [4, 19], surgeons have legitimate reason to fear BCIS, since it can cause refractory hypotension, hypoxia, cardiovascular collapse, and death.

The etiology of the syndrome is not fully understood, but it clearly relates to the volume of material embolized to the pulmonary circulation, as well as reaction to the chemical composition of the cement. Although mild forms that have no effect on outcome can occur in up to 30% of patients [4, 19], it is important to identify high-risk patients, such as those being treated with long-stem prostheses for metastatic disease and patients with evidence of COPD, pulmonary hypertension, and right heart failure. All patients receiving bone cement in this context should receive aggressive monitoring during these procedures [8, 11], and perhaps patients with advanced COPD and right heart failure should receive cementless fixation instead. But for those patients who are not at high risk for BCIS, a few simple interventions [4, 19] can reduce the risk of serious harm arising from the use of bone cement in this setting [16]. And because of this, BCIS should not be the argument for performing cementless hemiarthroplasty, given the 17-fold increase in the hazard ratios for subsequent reoperation [8, 9] when uncemented fixation is used for femoral neck fracture.

I grant that choosing between hemiarthroplasty and THA for a patient with a femoral neck fracture is slightly more complicated. That said, robust evidence suggests that THA is less painful, offers better mobility and function, and reduces the need for revision surgery in patients who were reasonably independent and functional prior to the injury compared to hemiarthroplasty [1, 2, 23, 26]. This does not, of course, apply to patients with dementia or those who did not walk well prior to the injury. Those patients generally were not included in the randomized trials on this topic [1, 2, 23, 26] and so are best treated with hemiarthroplasty, which is a faster and less-expensive operation to perform compared to THA.

Considering the evidence supporting THA for many patients with femoral neck fractures, why do so few receive this operation [10]? In fairness, there are some good reasons: THA adds technical complexity, longer surgeries with perhaps greater blood loss, and an increased risk of dislocation. Dislocation is three times higher (9%) compared to hemiarthroplasty (3%) when surgeons use conventional total hip replacement components [2, 22]. Senile dementia is a risk for dislocation following arthroplasty for femoral neck fracture. However, dual-mobility cups can mitigate these problems in many patients with femoral neck fractures [1, 23]. The advantages provided by the dual-mobility cup (particularly its low risk of dislocation and reoperation) suggest that surgeons should perform THA for displaced femoral neck fracture except, perhaps, in patients who are medically unfit for the larger surgery and for those who do not walk in the community.

I suspect that part of this failure to incorporate best practices across the United States based on strong evidence comes down to who is doing the surgery. Hip fractures are exceedingly common, arrive at all hours, and involve a high-risk population that benefits from urgent surgical care. Hip fracture care has not been regionalized [17] in the United States, and as such, so much of care of hip fracture patients is provided by general orthopaedic surgeons. Perhaps because of this, simplicity of approach, efficiency, and convenience may govern most care decisions under these circumstances. Medical centers that create specialized services and clinical pathways designed for elderly patients with fragility fractures are already showing improved survival and functional recovery [15]. Plans to add hip fractures to bundled payment programs may provide the needed impetus to change practice incorporating these evidenced-based principles.

Until then, I believe that individual surgeons can make a dramatic difference in the care of patients with femoral neck fractures. All surgeons who perform hemiarthroplasty are capable of performing cemented hemiarthroplasty, and they should do so. While not all will feel comfortable performing THA, those who can, should (that is, in patients with few comorbidities and good pre-fracture walking ability), and when they do so, they should consider using a dual-mobility cup. Finally, surgeons should partner with their hospitals and healthcare systems to develop protocol-driven in-hospital approaches to care based on published examples that are thoughtful, well described, and easily accessible to those who wish to adopt them [15, 21].