Early Complications of a Novel Retrograde Intramedullary Femoral Nail in the Treatment of Femur Fractures.

OBJECTIVES: To determine the early implant failure rate of a novel retrograde intramedullary femoral nail. DESIGN: Retrospective cohort study. SETTING: Academic level 1 trauma center. PATIENTS SELECTION CRITERIA: Patients aged 18 years and older with an acute OTA/AO 32-A, 32-B, 32-C, and 33-A fractures or periprosthetic distal femur fracture from April 2018 to April 2022 were included in the study. The 2 interventions compared were the Synthes Expert retrograde/antegrade femoral nail (or control implant) versus the next-generation retrograde femoral nail (RFN)-advanced retrograde femoral nail (RFNA or experimental implant) (Synthes, West Chester, PA). OUTCOME MEASURES AND COMPARISONS: Early implant-related complications between the experimental and control implants were assessed including locking screw back out, screw breakage, intramedullary nail failure, need for secondary surgery, and loss of fracture reduction. RESULTS: Three hundred fourteen patients were identified with a mean age of 31.0 years, and 62.4% of the patients being male. Open fractures occurred in 32.5% of patients with 3.8% of injuries being distal femur periprosthetic fractures. Fifty-six patients were in the experimental group and 258 patients in the control group. Mean follow-up was 46.8 weeks for the control cohort and 21.0 weeks for the experimental cohort. Distal interlocking screw back out occurred in 23.2% (13 of 56) of the experimental group patients and 1.9% (5 of 258) of the control group patients ( P < 0.0001). Initial diagnosis of interlocking screw back out occurred at an average of 3.2 weeks postoperatively (range, 2-12 weeks). Fifty-four percent of patients who sustained screw back out underwent a secondary operation to remove the symptomatic screws (12.5% of all patients treated with the experimental implant required an unplanned secondary operation due to screw back out). A logistic regression model was used to predict screw back out and found the experimental implant group was 4.3 times as likely to experience distal locking screw back out compared with the control group ( P = 0.01). CONCLUSIONS: The retrograde femoral nail-advanced implant was associated with a significantly higher rate of screw back out with a substantial number of unplanned secondary surgeries compared with the previous generation of this implant. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

No Difference in Short-Term Complications following Treatment of Closed Tibial Shaft Fractures with Intramedullary Nailing versus Plate Fixation.

Objectives: Tibial shaft fractures are treated with both intramedullary nailing (IMN) and plate fixation (ORIF). Using a large national database, we aimed to explore the differences in thirty-day complication rates between IMN and ORIF. Methods: Patients in the American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) database who had undergone either tibial IMN or ORIF for closed fractures from 2010 to 2018 were identified using current procedural terminology (CPT) codes. After excluding all patients with open fractures, the propensity score was matching. Univariate and multivariate logistic regressions were used to identify risk factors associated with the thirty-day incidence of complications in the two cohorts. Results: A total of 5,400 patients were identified with 3,902 (72.3%) undergoing IMN and 1,498 (27.7%) ORIF. After excluding any ICD-10 diagnosis codes not pertaining to closed, traumatic tibial shaft fractures, 2,136 IMN and 621 ORIF cases remained. After matching, the baseline demographics were not significantly different between the cohorts. Following matching, the rate of any adverse event (aae) did not differ significantly between the IMN (7.08% (n = 44)) and ORIF (8.86% (n = 55)) cohorts (p=0.13). There was also no significant difference in operative time (IMN = 98.5 min, ORIF = 100 min; p=0.3) or length of stay (IMN = 3.7 days, ORIF = 3.3 days; p=0.08) between the cohorts. Conclusion: There were no significant differences in short-term complications between cohorts. These are important data for the surgeon when considering surgical management of closed tibial shaft fractures.

Prophylactic Common Peroneal Nerve Release for Total Arthroplasty of the Valgus Knee: Surgical Technique and Early Outcomes.

Background: Common peroneal nerve (CPN) palsy after primary total knee arthroplasty represents a relatively rare but serious complication. Recently, there has been a growing interest in prophylactic CPN decompression in high-risk patients with significant combined valgus and flexion deformity. This study aimed to examine outcomes at our institution in those undergoing prophylactic CPN decompression at the time of total knee arthroplasty. Methods: A retrospective evaluation of a single-institution experience with selected patients at high risk for CPN palsy who underwent prophylactic nerve decompression through a separate incision at the time total knee arthroplasty was performed between July 1, 2018 and December 31, 2022. Patient demographics as well as perioperative and intraoperative clinical and radiographic measurements were collected and analyzed. Results: A total of 14 patients (15 knees) met our inclusion criteria. The mean preoperative femorotibial angle was 18.6° of valgus (range 13°-22°). The mean preoperative flexion contracture was 4.3° (range 0°-25°). The patients with flexion contractures preoperatively had a mean combined valgus/flexion contracture deformity of 28.8° (range 23°-38°) . There was preservation of nerve function in all knees. No knees required subsequent operative intervention within 90 days of surgery. Conclusions: Early experience with prophylactic CPN release in our high-risk population demonstrates preservation of nerve function in all patients and is reasonable to consider in patients with a large preoperative combined valgus/flexion deformity. Further studies with larger sample sizes would be beneficial in verification of the results with this technique, as well as determining an angular deformity threshold for which CPN release should be considered.

Prediction of Non-Home Discharge Following Total Hip Arthroplasty in Geriatric Patients.

Introduction: The majority of total hip arthroplasty (THA) patients are discharged home postoperatively, however, many still require continued medical care. We aimed to identify important characteristics that predict nonhome discharge in geriatric patients undergoing THA using machine learning. We hypothesize that our analyses will identify variables associated with decreased functional status and overall health to be predictive of non-home discharge. Materials and Methods: Elective, unilateral, THA patients above 65 years of age were isolated in the NSQIP database from 2018-2020. Demographic, pre-operative, and intraoperative variables were analyzed. After splitting the data into training (75%) and validation (25%) data sets, various machine learning models were used to predict non-home discharge. The model with the best area under the curve (AUC) was further assessed to identify the most important variables. Results: In total, 19,840 geriatric patients undergoing THA were included in the final analyses, of which 5194 (26.2%) were discharged to a non-home setting. The RF model performed the best and identified age above 78 years (OR: 1.08 [1.07, 1.09], P < .0001), as the most important variable when predicting non-home discharge in geriatric patients with THA, followed by severe American Society of Anesthesiologists grade (OR: 1.94 [1.80, 2.10], P < .0001), operation time (OR: 1.01 [1.00, 1.02], P < .0001), anemia (OR: 2.20 [1.87, 2.58], P < .0001), and general anesthesia (OR: 1.64 [1.52, 1.79], P < .0001). Each of these variables was also significant in MLR analysis. The RF model displayed good discrimination with AUC = .831. Discussion: The RF model revealed clinically important variables for assessing discharge disposition in geriatric patients undergoing THA, with the five most important factors being older age, severe ASA grade, longer operation time, anemia, and general anesthesia. Conclusions: With the rising emphasis on patient-centered care, incorporating models such as these may allow for preoperative risk factor mitigation and reductions in healthcare expenditure.

Prediction of suitable outpatient candidates following revision total knee arthroplasty using machine learning.

Aims: To identify variables independently associated with same-day discharge (SDD) of patients following revision total knee arthroplasty (rTKA) and to develop machine learning algorithms to predict suitable candidates for outpatient rTKA. Methods: Data were obtained from the American College of Surgeons National Quality Improvement Programme (ACS-NSQIP) database from the years 2018 to 2020. Patients with elective, unilateral rTKA procedures and a total hospital length of stay between zero and four days were included. Demographic, preoperative, and intraoperative variables were analyzed. A multivariable logistic regression (MLR) model and various machine learning techniques were compared using area under the curve (AUC), calibration, and decision curve analysis. Important and significant variables were identified from the models. Results: Of the 5,600 patients included in this study, 342 (6.1%) underwent SDD. The random forest (RF) model performed the best overall, with an internally validated AUC of 0.810. The ten crucial factors favoring SDD in the RF model include operating time, anaesthesia type, age, BMI, American Society of Anesthesiologists grade, race, history of diabetes, rTKA type, sex, and smoking status. Eight of these variables were also found to be significant in the MLR model. Conclusion: The RF model displayed excellent accuracy and identified clinically important variables for determining candidates for SDD following rTKA. Machine learning techniques such as RF will allow clinicians to accurately risk-stratify their patients preoperatively, in order to optimize resources and improve patient outcomes.

Safety of Prepping the External Fixator In Situ During Staged Internal Fixation of Pilon Fractures: A Retrospective Comparative Cohort Study.

OBJECTIVE: (1) To assess the rate of fracture-related infection (FRI) and unplanned reoperation of disinfecting and prepping in the external fixator (Ex-Fix) instrument during definitive open reduction and internal fixation (ORIF) of pilon fractures treated by a staged protocol and (2) to determine whether the amount of time from external fixation to ORIF influences the risk of FRI. DESIGN: Retrospective cohort study. SETTING: Level 1 academic trauma center. PATIENTS: One hundred thirty-three patients who underwent operative treatment for pilon fracture between 2010 and 2020. INTERVENTION: External fixation and ORIF with or without the Ex-Fix prepped in situ during definitive fixation. MAIN OUTCOME MEASUREMENTS: FRI and unplanned reoperation rates. RESULTS: 133 patients were enrolled, of which 47 (35.3%) had Ex-Fix elements prepped in situ. There was an overall infection rate of 23.3% and unplanned reoperation rate of 11.3%, and there was no significant difference in rates between the 2 cohorts. Patients with Ex-Fix elements prepped in situ who developed an FRI had a higher rate of MRSA and MSSA . Diabetes ( P = 0.0019), open fracture ( P = 0.0014), and longer (≥30 days) interval to ORIF ( P = 0.0001) were associated with postoperative FRI. CONCLUSIONS: Prepping elements of the Ex-Fix in situ did not lead to an increase in rates of FRI or unplanned reoperation. Although diabetes and open fracture were associated with FRI risk, a stronger association was a longer interval of Ex-Fix utilization before definitive internal fixation, specifically 30 days or greater. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Novel classification system for periprosthetic distal femoral fractures: a consideration for comminution.

PURPOSE: Comminution is an aspect of periprosthetic distal femoral fractures (PDFFs) that can influence postoperative outcomes and treatment selection, but is not included in current classification systems. We propose a new classification system for PDFFs based on comminution and cortical reads. This study aims to prove its reliability and efficacy to predict fracture severity and guide treatment. METHODS: A retrospective chart review of patients treated with single or dual locking plates for PDFFs was performed. Two fellowship-trained orthopedic joint reconstruction specialists used available imaging to classify each PDFF as either type 1 (minimal or no comminution allowing for reconstruction of medial and lateral cortices), type 2 (comminution reasonably allowing for reconstruction of either medial or lateral cortex), and type 3 (extensive comminution not allowing reasonable reconstruction of medial or lateral cortex). Each PDFF was then analyzed for radiographic outcomes including lateral distal femoral angle (LDFA) and the posterior distal femoral angle (PDFA). RESULTS: Interobserver reliability assessed by Cohen's Kappa statistic was 0.707, and average intraobserver reliability was 0.843, showing substantial reliability. Type 3 PDFFs had greater varus deformity than type 1 (p = 0.0457) or 2 (0.0198). CONCLUSION: The proposed classification system accounts for comminution, demonstrates strong interobserver and intraobserver reliability, and can be used to guide treatment in regard to single versus dual plating. LEVEL OF EVIDENCE: Retrospective comparative study, Level IV.

Cannabis Use Among Lower-Extremity Arthroplasty Patients Does Not Lead to Worse Postoperative Outcomes.

INTRODUCTION: Smoking and general categorizations of substance use are linked with increased postoperative complications following total knee arthroplasty (TKA) and total hip arthroplasty (THA). There is a lack of similar evidence on how cannabis use may affect outcomes after arthroplasty. The present study aims to compare postoperative outcomes in cannabis users versus non-cannabis users who underwent THA/TKA. We hypothesize that cannabis users will have no difference in primarily the complication rate, revision rate, and secondarily post-operative Patient-Reported Outcomes Information System (PROMIS) scores, hospital stay, or pain compared to matched controls. METHODS: Billing codes were used to generate lists of hip/knee arthroplasty patients from 2013 to 2019 at our institution. In the case group, cannabis use was confirmed via chart review. Cannabis-using patients were matched appropriately with non-users by (1) the same arthroplasty procedure; (2) BMI ± 3.5; (3) age ± 3 years; (4) sex. Data on postoperative outcomes were collected from charts and compared between groups using either a Chi-square test for qualitative variables or a paired t-test for quantitative variables. RESULTS: A total of 24 patients with an average age of 57.1 and a BMI of 30.6 were confirmed to have isolated cannabis use. They were matched to 24 patients with an average age of 57.6 and a BMI of 31.4. There were no significant differences in the complication rate (4.2% vs 4.2%, p=1.00), the revision rate (0% vs 4.2%, p=0.31), days of hospital stay (2.7 vs 3.3, p=0.22), or postoperative pain (4.7 vs 4.9, p=0.86). Similarly, there were no significant differences in all PROMIS score measures. DISCUSSION/CONCLUSIONS: Current research shows that cannabis use may lead to increased revision arthroplasty and decreased mortality, with mixed findings regarding post-surgical complications. The present study suggests that cannabis-using patients have no difference in postoperative complication rate, revision rate, PROMIS scores, hospital stay, or pain compared to matched controls.

Fatigue Failure of Semiconstrained Total Knee Replacement: Magnetic Resonance Imaging Diagnosis With Tips and Tricks for Extraction and Reconstruction.

Modular components allow for the precise adjustment of sizing and balancing in knee replacement and are widely used in revision total knee arthroplasty. While they have a significant advantage over monoblock implants, these components may be associated with fretting and corrosion at modular junctions. We report the case of a fracture of a morse taper adapter bolt in a 65-year-old female with a history of multiple revision knee arthroplasties. Only a few cases of fracture of the taper adapter bolt have been previously reported. We reinforce 2 learning points in this report: the utility of magnetic resonance imaging as an aid in diagnosing total knee failure when initial radiographs are unremarkable and the use of techniques such as anterior quadrangular femoral osteotomy when an implant is unable to be removed via conventional techniques.

Optimizing Total Joint Arthroplasty for Patients Living With Human Immunodeficiency Virus.

Introduction Significant advancements in human immunodeficiency virus (HIV) treatment have led to an increasing life expectancy among patients living with HIV (PLWH). Given this rise in life expectancy, as well as the ability to lead a more active lifestyle, the rate of total joint arthroplasty (TJA) in this population is increasing. Unfortunately, the current medical literature surrounding the safety and efficacy of TJA in this patient population is indeterminant. Therefore, the purpose of this study was to determine if optimization of PLWH prior to TJA would result in any changes in the incidence of postoperative complications and hospital length of stay (LOS) when compared to historically reported data.  Materials and methods A retrospective study was performed of all PLWH 18 years and older who underwent either a primary total knee arthroplasty (TKA) or total hip arthroplasty (THA) between 2009 and 2019 at our academic institution. Medical records were reviewed for each patient to assess demographics, comorbidities, preoperative laboratory studies, operative details, length of hospital stay, complications, and follow-up time. Patients were optimized using our institution's current optimization guidelines: body mass index (BMI) less than 40 kg/m2, hemoglobin >12 g/dL, no tobacco use within 30 days of surgery, albumin >3.5 g/dL. Independent-sample t-tests and Pearson's chi-square tests were used to evaluate the continuous and categorical variables, respectively. Results This study included 47 TJA in PLWH, including 14 TKA and 33 THA. Out of the 47 patients, 13 (27.7%) were fully optimized for all four variables: BMI, hemoglobin, non-smoking status, and albumin. There was no significant difference between the group of PLWH that was completely optimized and the group that was not in any patient characteristics, preoperative labs, intraoperative variables, or postoperative variables, including length of hospital stay and complications. A larger proportion of patients not completely optimized was found to be active smokers (p=0.0003). All complications occurred in cases in which the patients were not fully optimized. Subgroup analysis of PLWH, who were completely optimized, showed an average LOS of 4.3+/-1.5 days following TKA and 2.9+/-1.1 days following THA. Subgroup analysis of PLWH not completely optimized showed that each case was optimized for at least one variable and that those optimized for albumin had the largest (12.2%) number of complications. Conclusion PLWH can achieve a low rate of complications and LOS similar to that of the general population if medically and nutritionally optimized. Additional research is necessary to reveal well-defined parameters for achieving a higher rate of optimization prior to surgery in this important patient population.

Prosthetic Joint Infection due to Histoplasma capsulatum in a Patient from Trinidad: Workup, Pathology, and Treatment.

Histoplasma capsulatum is a rarely reported cause of prosthetic joint infections. This current case report is of a patient from Trinidad, with a history of a right total knee replacement (TKR), who underwent a successful two-stage revision due to a Histoplasmosis capsulatum periprosthetic joint infection (PJI). This case report offers a unique treatment plan to successfully treat Histoplasmosis capsulatum periprosthetic joint infections and emphasizes the importance of obtaining an accurate travel history.

Comminuted periprosthetic distal femoral fractures have greater postoperative extension malalignment.

INTRODUCTION: Comminution is a significant aspect of periprosthetic distal femoral fracture characterization and may influence post-surgical outcomes. Existing classification systems that guide treatment decisions do not take into account comminution and current literature is unclear on which surgical approach is optimal. We hypothesize that fractures with comminution will have poorer quality post-reduction alignment, especially with a lateral approach. MATERIALS AND METHODS: 37 study patients were identified with billing codes designating a distal femoral periprosthetic fracture. A retrospective chart review was performed to categorize fractures by absence or presence of comminution and medial parapatellar versus lateral surgical approach. These patients underwent an imaging evaluation for the primary outcome of reduction quality including the anatomic lateral distal femoral angle (LDFA) and the posterior distal femoral angle (PDFA). Differences in radiographic outcomes were analyzed with Wilcoxon/Kruskal-Wallis tests, and analysis by approach was through Fisher's exact test. RESULTS: Patients with comminuted fractures had significantly greater extension of the fragment (PDFA = 95.4° vs 90.0°, p = 0.018) and similar coronal alignment (LDFA = 85.3° vs 86.3°, p = 0.83) of the knee compared to non-comminuted fractures after surgical reduction. This difference was more prominent amongst those treated with a lateral approach (PDFA = 96.1° vs 89.4°, p = 0.032) than with a medial approach (PDFA = 93.7° vs 91.5°, p = 0.41) (Table 1). DISCUSSION: Current classification systems and treatment guidelines for periprosthetic distal femoral fractures do not adequately address several issues that may influence treatment outcomes, especially comminution. Comminuted fractures had greater post-reduction extension malalignment, falling outside the recommended PDFA range of 87-90°, especially with a lateral approach. Consideration should be given to surgical approach and techniques to reduce excessive extension when treating comminuted periprosthetic distal femoral fractures.

Comparing Revision Total Knee Arthroplasty Stems at a High-Volume Revision Center.

Introduction: Hybrid fixation and fully cemented fixation are commonly used in revision total knee arthroplasty (rTKA). These two techniques are typically done based on surgeon preference and one has not demonstrated superiority over the other. The purpose of this study was to examine if there was a difference in survivorship between the two different techniques. Methods: A retrospective cohort study of all consecutive patients undergoing rTKA (CPT 27487) from January 1, 2011 to January 1, 2018 at a single academic center was performed. Patients were divided into cemented and hybrid rTKA groups with comparison of patient demographic, clinical and radiological outcomes, reoperation, change in post-operative hemoglobin (HgB), and length of stay (LOS). Results: A total of 133 rTKA for 122 patients were identified: 30.1% in the cemented and 69.9% in the hybrid groups. There was no significant difference in age (p = 0.491), sex (p = 0.250), laterality (p = 0.421), or body mass index (BMI) (p = 0.609) between the two groups. Mean LOS (hybrid 4.13 days, cemented 3.65 days; p = 0.356) and change in Hgb (hybrid 2.95 mg/dL, cemented 2.62mg/dL; p = 0.181) were not statistically different between the groups. Mean follow up for the hybrid (25.4 months, range 2-114 months) and cemented (24.6 months, range 3-75.5 months) rTKA was not statistically significant (p = 0.825). Overall survival rates were 80.9% in the hybrid and 84.6% in the cemented groups (p = 0.642). Conclusions: Hybrid and fully cemented rTKA techniques have similar survival rates at a minimum followup of 2 years. Additionally, in our cohort, age, gender, and BMI were not associated with failure in either group. Furthermore, we did not observe differences in LOS or change in hemoglobin suggesting early postoperative complications may not differ between cemented and hybrid stemmed groups. Continued long-term research is required for defining the best rTKA technique.

Risk Factors for Infection and Subsequent Adverse Clinical Results in the Setting of Operatively Treated Pilon Fractures.

OBJECTIVE: To determine patient-specific and injury-specific factors that may predict infection and other adverse clinical results in the setting of tibial pilon fractures. DESIGN: Retrospective chart review. SETTING: Level 1 academic trauma center. PATIENTS: Two hundred forty-eight patients who underwent operative treatment for tibial pilon fractures between 2010 and 2020. INTERVENTION: External fixation and/or open reduction and internal fixation. MAIN OUTCOME MEASUREMENTS: Fracture-related infection rates and specific bacteriology, risk factors associated with development of a fracture-related infection, and predictors of adverse clinical results. RESULTS: Two hundred forty-eight patients were enrolled. There was an infection rate of 21%. The 3 most common pathogens cultured were methicillin-resistant Staphylococcus aureus (20.3%), Enterobacter cloacae (16.7%), and methicillin-resistant Staphylococcus aureus (15.5%). There was no significant difference in age, sex, race, body mass index, or smoking status between those who developed an infection and those who did not. Patients with diabetes mellitus ( P = 0.0001), open fractures ( P = 0.0043), and comminuted fractures (OTA/AO 43C2 and 43C3) ( P = 0.0065) were more likely to develop a fracture-related infection. The presence of a polymicrobial infection was positively associated with adverse clinical results ( P = 0.006). History of diabetes was also positively associated with adverse results ( P = 0.019). CONCLUSIONS: History of diabetes and severe fractures, such as those that were open or comminuted fractures, were positively associated with developing a fracture-related infection after the operative fixation of tibial pilon fractures. History of diabetes and presence of a polymicrobial infection were independently associated with adverse clinical results. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

High- Versus Low-Energy Acetabular Fracture Outcomes in the Geriatric Population.

INTRODUCTION: High-energy mechanisms of acetabular fracture in the geriatric population are becoming increasingly common as older adults remain active later in life. This study compared outcomes for high- versus low-energy acetabular fractures in older adults. MATERIALS AND METHODS: We studied outcomes of 22 older adults with acetabular fracture who were treated at a level-I trauma center over a 4-year period. Fourteen patients were categorized as low-energy mechanism of injury, and 8 were identified as a high-energy mechanism. We analyzed patient demographics with univariate logistic regressions performed to assess differences in high- and low-energy group as well as patient characteristics compared with surgical outcomes. RESULTS: Most high-energy mechanisms were caused by motor vehicle collision (n = 4, 50.0%), with most having posterior wall fractures (50.0%). Among patient characteristics, the mechanism of injury, hip dislocation, fracture types, and fracture gap had the largest differences between energy groups effect size (ES: 2.45, 1.43, 1.36, and 0.83, respectively). The high-energy group was more likely to require surgery (odds ratio [OR] = 2.80, 95% CI: 0.26-30.70), develop heterotopic bone (OR = 4.33, 95% CI: 0.33-57.65), develop arthritis (OR = 3.60, 95% CI: 0.45-28.56), and had longer time to surgery (mean = 4.8 days, standard deviation [SD] = 5.8 days) compared to low-energy group (mean = 2.5 days, SD = 2.3 days). DISCUSSION: The results of this case series confirm previous findings that patients with high-energy acetabular fractures are predominantly male, younger, and have fewer comorbidities than those who sustained low-energy fractures. Our results demonstrate that the majority of the high-energy fracture patients also suffered a concurrent hip dislocation with posterior wall fracture and experienced a longer time to surgery than the low-energy group. CONCLUSION: Geriatric patients who sustained high-energy acetabular fractures tend to have higher overall rates of complications, including infection, traumatic arthritis, and heterotopic bone formation when compared with patients with a low-energy fracture mechanism.

The role of preoperative vascular imaging and embolisation for the surgical resection of bilateral hip heterotopic ossification.

The surgical excision of heterotopic ossification can provide improved function for patients; however, complications can include damage to nearby vessels and nerves, blood loss and recurrence. In the preoperative planning for excision, our case report describes the combination of CT angiography, preoperative embolisation of involved vascular structures and the use of intraoperative vascular surgery for dissection around key structures to aid in the reduction of morbidity in these patients.

Cerebral fat embolism syndrome (FES): similar cases with different outcomes.

Fat embolism syndrome (FES) is a rare multisystem, clinical syndrome occurring in 0.9%-2.2% of long-bone fractures. The severity of FES can vary from subclinical with mild respiratory changes and haematological aberrations to a fulminant state characterised by sudden onset of severe respiratory and neurological impairment. Here we present two patients with cerebral FES secondary to femur fracture. Both patients exhibited profound neurological impairment with varied outcomes. Our cases highlight the importance of a high clinical suspicion of FES in patients with long-bone fractures and neurological deterioration. We recommend early plate osteosynthesis to prevent additional emboli in patients with FES and situational placement of intracranial pressure monitoring. Finally, cerebral FES has low mortality even in a patient with tentorial herniation and fixed, dilated pupils.

Biomechanical Evaluation of Osteoporotic Proximal Periprosthetic Femur Fractures With Proximal Bicortical Fixation and Allograft Struts.

OBJECTIVES: To evaluate the strength of proximal bicortical fixation using a novel osteoporotic synthetic bone model of Vancouver B1 periprosthetic proximal periprosthetic femur fractures (PFFs) and to assess the influence of strut allograft augmentation with regard to allowing early assisted weight bearing. The secondary aim was to evaluate whether the strut position, either medial or anterior, influenced the strength of the construct. METHODS: Thirty synthetic osteoporotic femurs were implanted with cemented stems. A segmental defect made distal to the stem simulated a fracture and was repaired with a stainless steel locking compression plate and 2 stainless steel proximal locking attachment plates. Specimens were then divided into 3 groups: no-strut, medial strut, and anterior strut. Cadaveric femoral struts were wired to the specimens. Cyclic axial compression simulated assisted weight bearing and was followed by loading to failure. RESULTS: Medial struts required higher failure load than no-strut (P = 0.008) and more energy to failure than anterior (P = 0.018) or no-strut (P < 0.001). The higher load to failure, however, would not be advantageous in clinical practice because estimates for assisted weight bearing after fractures in average-weight patients are well below these failure loads. Furthermore, all specimens tolerated cyclical loading. All failures occurred distal to the plate originating at the last screw hole. CONCLUSIONS: Failure loads for all groups were above what would be expected for low-demand activities of assisted weight bearing. Therefore, proximal bicortical fixation should allow for early, assisted weight bearing without allograft strut augmentation even with lower density bone.