Perioperative Considerations When Treating Isolated Periprosthetic Distal Femur Fractures

Abstract

Background

Periprosthetic distal femur (PPDF) fractures occur most frequently via low energy mechanisms in elderly patients. This population is often frail and ill-suited to the physiologic burden of trauma and surgery. Here, we describe the perioperative and early hospital course for patients with PPDF fractures, and identify risk factors for poor outcomes.

Methods

Consecutive patients with isolated PPDF fractures from 2005 – 2015 were treated operatively at a Level I trauma center. Perioperative records were reviewed. Complications included wound complications, cardiac complications, pneumonia, thromboembolic events, urinary tract infections (UTIs), sepsis, multiple organ failure, death, and 90-day readmissions.

Results

Thirty-nine patients were treated operatively for isolated PPDF fractures. Mean age was 75.1 years old, 87.2% were women, and 92.3% occurred after falls from standing. Average American Society of Anesthesiologists score was 3.0. Thirty-six patients underwent open reduction and internal fixation with a mean operative time of 108 minutes. Excluding outliers, mean LOS was 4.6 days. Patients admitted to the ICU had longer LOS (p=0.03). Complications occurred in 17.9% of patients, including cardiac events (12.8%) and (5.1%) deaths.

Conclusions

Patients with PPDF fractures frequently have underlying medical comorbidities. A complicated and/or protracted hospital course is not uncommon. Further study to optimize treatment appears warranted.

Level of evidence: Prognostic, level 4.

Introduction

Periprosthetic distal femur (PPDF) fractures represent a devastating fracture pattern. With the frequency of total knee arthroplasty (TKAs) increasing,¹ so too will the incidence of PPDF fractures. When occurring in elderly patients, they can be considered a fragility fracture, and this patient population also has high rates of medical comorbidities. Treatment of these fractures is associated with extensive morbidity, mortality, and costs. As they become more common, it is imperative that the treating physicians understand how to optimize care.

Although perioperative morbidity and mortality for PPDF fractures may be extrapolated from similar fragility fractures such as non-periprosthetic distal femur fractures and hip fractures, there is a paucity of data focusing primarily on patients with PPDF fractures. In their cohort of distal femur fractures, Streubel et al. demonstrated a 23% one-year mortality for non-periprosthetic DF fractures and a 27% one-year mortality rate for PPDF fractures.² When compared to elderly patients undergoing open reduction internal fixation (ORIF) for femoral neck fractures, elderly patients undergoing ORIF for DF fractures were found to have similar rates of any adverse events, serious adverse events, infectious complications, hospital length of stay (LOS), and mortality rates.³

Similar to treating elderly patients with hip fractures, optimizing perioperative medical management and facilitating care to get these patients to the operating room expediently is of utmost importance. Perioperative pathways and multi-disciplinary management has been shown to decrease morbidity in hip fracture patients,^4-5 and it follows that this would affect patients with PPDF fractures, as well. Here we present over ten years of our experience in treating patients with PPDF fractures seeking to better characterize the perioperative course for patients with PPDF fractures and to define variables associated with poorer outcomes. In turn, this may lead to the future development of algorithms to optimize care.

Methods

The protocol for this study was approved by the Institutional Review Board, and all patients or guardians provided consent for participation. We retrospectively reviewed consecutive patients who were treated for isolated PPDF fractures at a Level I trauma center from 2005 – 2015. Fifty-six patients suffered 60 PPDF fractures. Patients were excluded for either nonoperative treatment (N=8 patients, including one patient with bilateral PPDF fractures) or concurrent pathology that could reasonably affect the perioperative course (N=9 patients) including: seven patients with multiple lower extremity fractures including two with bilateral PPDF fractures; one patient with a recurrent, ipsilateral PPDF fracture; one patient with diffuse bodily burns; and one patient with a prior history of extensive knee surgery including extensor mechanism reconstruction. Thirtynine patients had isolated PPDFs treated operatively and these patients are considered in the final data analysis.

Medical charts, including operative notes, preoperative radiographs, and anesthesia records, were reviewed. Demographic data, comorbidities, and MOI were noted. Total LOS and intensive care unit (ICU) stays were recorded. Perioperative data included estimated blood loss (EBL), surgery duration, surgical procedure, and total time of anesthesia care. Preoperative imaging was assessed using the Lewis and Rorabeck classification⁶. Complications were screened for 90-days after initial presentation and included wound complications, cardiac complications, pneumonia, deep vein thrombosis (DVT), pulmonary embolism (PE), sepsis, urinary tract infections (UTIs), multiple organ failure, death, and 90-day readmissions. Final dispositions were recorded, and if a patient was readmitted within 90-days, the level of care required at final discharge was used in analysis.

Data was analyzed using GraphPad (GraphPad Software, Inc., La Jolla, CA) and Microsoft Excel (Microsoft Corp., Redmond, WA). Chi-square tests, t-tests, Fisher exact tests, and Mann Whitney U tests were performed when appropriate. Statistical significance was set to p<0.05.

Results

Demographics

Thirty-nine patients were treated operatively for isolated PPDF fractures. They were mostly female (87.2%) with an average age of 75.1±11.8 y/o (range: 46 – 92 y/o) who suffered falls from standing (92.3%). Mean body mass index was 30.1±8.8. Mean ASA score was 3.0±0.6; 46.2% had a cardiac comorbidities, 25.6% were diabetics, and 20.5% had chronic obstructive pulmonary disease (COPD). There were two patients (5.1%) each with chronic kidney disease (CKD) and moderatelysevere aortic stenosis (AS). Substance use included: 18.2% (6/33) current smokers, 25.0% (7/28) consuming alcohol, and 4.3% (1/23) using illicit substances.

Fracture characteristics and operative treatment

Thirty-eight (97.4%) patients had closed fractures. Preoperative radiographs were available for 37 patients, and 35 (94.6%) had Rorabeck type II fractures; there was one type I and one type III fracture. Patients with stable prostheses (N=36) were treated with a locking condylar plate (N=21, 58.3%), angled blade plate (N=11, 30.6%), locking large fragment plate (N=1, 2.8%), or retrograde intramedullary nail (N=1, 2.8%). There were two patients who underwent primary trans-femoral amputations: one patient was septic with chronic peripheral vascular disease and cellulitis of the fractured extremity, and the amputation was performed in a life-saving effort; the other patient was on hospice care with an open PPDF fracture, and amputation was elected. The type III fracture was treated with a revision TKA. Overall, most patients (N=31, 79.5%) underwent surgical intervention within one day of presentation; most surgical delays were related to preoperative medical optimization. All patients who were delayed three or more days after presentation (hospital day four or five) had cardiac comorbidities (p=0.01). For patients who underwent ORIF, mean anesthesia time was 172±38 minutes and 94.4% had a general endotracheal intubation; operative time was 108±25 minutes with median estimated blood loss (EBL) of 200 mLs (interquartile range (IQR): 137.5 – 250 mLs, range 10 – 1000 mLs).

Perioperative hospitalization course and complications

Excluding one outlier patients who was admitted for 25 days, average initial LOS was 4.6±1.2 days. Five patients required ICU admissions, and ICU admission was associated with longer total hospitalization (p=0.03). Both patients with moderately-severe AS required ICU admission (p=0.01).

Seven (17.9%) patients had at least one perioperative acute medical complication (Table 1). The most common complications were cardiac events (N=5, 12.8%), including three patients with acute myocardial infarction (AMI), one with new onset of supraventricular tachycardia, and one with intraoperative cardiac arrest leading to anoxic brain injury. Patients with cardiac comorbidities (p<0.001) and moderately-severe AS (p=0.01) were more likely to have cardiac complications. No patients developed thromboembolic events or wound complications. Excluding one acute postoperative death and four patients with inadequate follow-up, four (11.8%) patients returned to the hospital within 90 days of their initial presentation. Reasons for readmission included: AMI, sequelae of anoxic brain injury, pain, pneumonia and septic shock; three patients required full admissions. In total, there were two (5.1%) deaths (one during the a patient’s initial hospitalization and one after readmission) and one discharge to a long-term acute care facility.

Table I.

Complications

	N (%)
Anoxic brain injury	1 (2.6%)
Cardiac	5 (12.8%)
Clostridium difficile infection	2 (5.1%)
Death	2 (5.1%)
Deep vein thrombosis	0 (0.0%)
Gastro-intestinal	1 (2.6%)
Pneumonia	1 (2.6%)
Pulmonary	3 (7.7%)
Pulmonary embolism	0 (0.0%)
Renal	1 (2.6%)
Sepsis	2 (5.1%)
Urinary tract infection	3 (7.7%)
Wound infections	0 (0.0%)

Discussion

Treatment of PPDF fractures is difficult, as complex fracture patterns are common and patients are medically complicated. Perioperative courses are challenging, and complications occur often. In order to provide our patients with the best care possible, multi-specialty collaborations are necessary, but care must be provided promptly.

Protocols are in place at our hospital to streamline care of patients who present to the emergency department.^7-8 A multi-disciplinary approach to treating trauma patients is involved, and care is initiated frequently even before the patients arrives (ie: after the trauma system has been activated or after the call from a transferring facility). For the geriatric population, medicine co-management is the norm and has been shown to decrease perioperative morbidity.^4-5 Patients are efficiently optimized for surgery, which is evidenced by the majority of patients having surgery on the day of, or the day after presentation. However, there is a delicate balance between medical optimization and expeditious surgery, as recent literature suggests some aspects of medical work-ups may lead to increased costs, surgical delays, and overall LOS without reducing complications or improving outcomes.^9-10 Surgical delays have been associated with increased mortality in this population,^11-14 emphasizing the need for communication and teamwork between medical and surgical services.

From the surgeon’s perspective, how to treat these patients represents a difficult decision. After conversations among the treating surgeon, patients, and families, nonoperative care was elected in eight patients. Due to a number of factors including ambulatory status, comorbidities, fracture complexity, and quality of life expectations, these decisions were made. Two patients required trans-femoral amputations for life-saving and palliative reasons. Of those who underwent ORIF, the majority were treated with plate and screw constructs. In order to prevent implant failure prior to healing, two to three months of non-weight bearing is frequently necessary. Elderly patients have difficulty complying with restricted weight-bearing, and immobility and non-weight bearing cause further deconditioning.^15-16 In patients with hip fractures, prolonged immobility is associated with worse postoperative function and increased mortality.¹⁷ However, unlike hip fracture patients who have more stable implant-osseous constructs or have prostheses, patients with PPDF fractures have the potential for a more difficult postoperative rehabilitation course.

Our data supports the premise that patients with PPDF fractures are frequently unwell at the time of injury. In elderly patients with fragility fractures, multiple preoperative comorbidities or an ASA class of 3 or 4 yields higher risk for postoperative complications and mortality.^18-19 Not unexpectedly, here we found that a preoperative cardiac comorbidity placed patients at increased risk of developing a cardiac complication. In general, patients with moderately-severe AS are particularly susceptible to perioperative complications. After non-cardiac surgery, AS has been shown to increase the risk of nonfatal AMI and mortality.^20-21 It follows that we found moderately-severe AS to be associated with cardiac complications and ICU admissions.

Substance use in known to affect outcomes in patients undergoing orthopaedic procedures. The effects of tobacco and alcohol use on perioperative complications in orthopaedic patients has been well described. In arthroplasty patients, patients who smoke and consume alcohol are at an increased risk of systemic postoperative complications;^22-24 smoking has been linked to increased ICU requirements.²⁵ Unfortunately, our data is underpowered to draw an association between either smoking or alcohol use and complications.

Available literature focusing directly on the perioperative course of patients with PPDF fractures is limited. To our knowledge, this represents the first dedicated study on this subject. Our data is strengthened in that we have 39 patients with isolated PPDFs, a fracture pattern that is going to become increasingly frequent as TKAs become more ubiquitous. Further, excluding the patient who died during the initial hospitalization, 89.5% of our patients had follow-up data available for review, minimizing bias from a lack of patient continuity. There are limitations to this study as well. We do not evaluate healing, including rates of union, malunion, or nonunion, which clearly have implications for outcomes. Functional scores are also not evaluated, as this is a more intermediate or long-term issue. This is also a retrospective study, which is not controlled for bias, sample heterogeneity, and inconsistencies in data available for abstraction.

Our findings highlight the medical and surgical complexity of treating patients with PPDF fractures and the need for a multi-disciplinary approach. Patients should be advised that there is a notable risk for complications, and prognosis is somewhat guarded. The majority of patients do well after a PPDF fracture; however, there were many who experienced complications and had readmissions. Our goal is to mitigater isk but to realize that despite optimization of patient status, surgical care does entail risk for complications. Continuous reassessment and refinement of treatment practices is essential. Consistent communication with patients and families regarding risks, benefits, and expectations, while weighing treatment options on an individual basis, is crucial.