Deep Surgical Site Infection after Fracture Has a Profound Effect on Functional Outcomes.

Background: Fracture-related infection is one of the most challenging complications in orthopaedic trauma surgery. However, the effect of infection on functional and pain-related outcomes has not been well established. The aims of this study were to evaluate functional recovery for patients with fracture and a deep surgical site infection compared with patients with fracture without infection and to evaluate whether pain severity, social support, and preinjury mental health have a moderating effect on the magnitude and direction of the relationship between deep surgical site infection and functional recovery. Methods: This is a secondary retrospective cohort study using prospectively collected data from the VANCO trial (Local Antibiotic Therapy to Reduce Infection After Operative Treatment of Fractures at High Risk of Infection) and the OXYGEN (Supplemental Perioperative Oxygen to Reduce Surgical Site Infection After High Energy Fracture Surgery) trial. In this study, 2,116 patients with tibial plateau, pilon, or calcaneal fractures at high risk for infection were included. Patients were divided into cohorts of patients who experienced a deep surgical site infection and those who did not. The primary outcome measure was the functional outcome using the Veterans RAND 12-Item Health Survey (VR-12). Results: After controlling for covariates, deep surgical site infection was independently associated with functional outcome, with a 3.3-point reduction in the VR-12 Physical Component Score, and pain severity was independently associated with functional outcome, with a 2.5-point reduction in the VR-12 Physical Component Score. Furthermore, the Brief Pain Inventory pain severity demonstrated an important moderating effect on the relationship between infection and functional outcome. In patients with lower pain scores, infection had a large negative impact on functional outcome, whereas, in patients with higher pain scores, infection had no significant impact on functional outcome. Furthermore, the functional outcome in the entire cohort remains at only 61% of baseline. Conclusions: This study documents the negative impact of postoperative infection on functional recovery after injury, as well as the novel finding of pain severity as an important moderating factor. This study emphasizes not only the importance of developing effective interventions designed to reduce postoperative infection, but also the role that factors that moderate pain severity plays in limiting recovery of physical function. Level of evidence: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Simple design and analysis strategies for solving problems in observational orthopaedic clinical research.

Randomized controlled trials are the gold standard to establishing causal relationships in clinical research. However, these studies are expensive and time consuming to conduct. This article aims to provide orthopaedic surgeons and clinical researchers with methodology to optimize inference and minimize bias in observational studies that are often much more feasible to undertake. To mitigate the risk of bias arising from their nonexperimental design, researchers must first understand the ways in which measured covariates can influence treatment, outcomes, and missingness of follow-up data. With knowledge of these relationships, researchers can then build causal diagrams to best understand how to control sources of bias. Some common techniques for controlling for bias include matching, regression, stratification, and propensity score analysis. Selection bias may result from loss to follow-up and missing data. Strategies such as multiple imputation and time-to-event analysis can be useful for handling missingness. For longitudinal data, repeated measures allow observational studies to best summarize the impact of the intervention over time. Clinical researchers familiar with fundamental concepts of causal inference and techniques reviewed in this article will have the power to improve the quality of inferences made from clinical research in orthopaedic trauma surgery.

Application of Nucleic Acid-Based Strategies to Detect Infectious Pathogens in Orthopaedic Implant-Related Infection.

➤: Implant-associated infection in orthopaedic surgery remains an enormous and largely unsolved clinical problem with a high rate of persistent or recurrent infection. This may be due, at least in part, to the potential for underdiagnosis by traditional microbial culture or the potential for culture to incompletely identify the microbial species present. ➤: Nucleic acid-based diagnostic techniques, focused on using the diagnostic information contained in DNA or RNA to identify microbial species, have been developing rapidly and have garnered escalating interest for both clinical and research applications. ➤: Commonly applied techniques include end-point polymerase chain reaction (PCR), quantitative PCR, Sanger sequencing, and next-generation sequencing. Understanding the specific strengths and weaknesses of each technique is critical to understanding their utility, applying the correct assessment strategy, and critically understanding and interpreting research. ➤: The best practices for interpreting nucleic acid-based diagnostic techniques include considering positive and negative controls, reads per sample, detection thresholds (for differentiating contaminants from positive results), and the primer set or targeted regions.

High-energy open-fracture model with initial experience of fluorescence-guided bone perfusion assessment.

High-energy orthopedic injuries cause severe damage to soft tissues and are prone to infection and healing complications, making them a challenge to manage. Further research is facilitated by a clinically relevant animal model with commensurate fracture severity and soft-tissue damage, allowing evaluation of novel treatment options and techniques. Here we report a reproducible, robust, and clinically relevant animal model of high-energy trauma with extensive soft-tissue damage, based on compressed air-driven membrane rupture as the blast wave source. As proof-of-principle showing the reproducibility of the injury, we evaluate changes in tissue and bone perfusion for a range of different tibia fracture severities, using dynamic contrast-enhanced fluorescence imaging and microcomputed tomography. We demonstrate that fluorescence tracer temporal profiles for skin, femoral vein, fractured bone, and paw reflect the increasing impact of more powerful blasts causing a range of Gustilo grade I-III injuries. The maximum fluorescence intensity of distal tibial bone following 0.1 mg/kg intravenous indocyanine green injection decreased by 35% (p < 0.01), 75% (p < 0.001), and 87% (p < 0.001), following grade I, II, and III injuries, respectively, compared to uninjured bone. Other kinetic parameters of bone and soft tissue perfusion extracted from series of fluorescence images for each animal also showed an association with severity of trauma. In addition, the time-intensity profile of fluorescence showed marked differences in wash-in and wash-out patterns for different injury severities and anatomical locations. This reliable and realistic high-energy trauma model opens new research avenues to better understand infection and treatment strategies. Level of evidence: Level III; Case-control.

Masquelet Technique for the Tibia: A Systematic Review and Meta-Analysis of Contemporary Outcomes.

OBJECTIVE: To systematically review outcomes of the Masquelet "induced membrane" technique (MT) in treatment of tibial segmental bone loss and to assess the impact of defect size on union rate when using this procedure. DATA SOURCES: PubMed, EBSCO, Cochrane, and SCOPUS were searched for English language studies from January 1, 2010, through December 31, 2019. STUDY SELECTION: Studies describing the MT procedure performed in tibiae of 5 or more adult patients were included. Pseudo-arthrosis, nonhuman, pediatric, technique, nontibial bone defect, and non-English studies were excluded, along with studies with less than 5 patients. Selection adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses criteria. DATA EXTRACTION: A total of 30 studies with 643 tibiae were included in this meta-analysis. Two reviewers systematically screened titles or abstracts, followed by full texts, to ensure quality, accuracy, and consensus among authors for inclusion or exclusion criteria of the studies. In case of disagreement, articles were read in full to assess their eligibility by the senior author. Study quality was assessed using previously reported criteria. DATA SYNTHESIS: Meta-analysis was performed with random-effects models and meta-regression. A meta-analytic estimate of union rate independent of defect size when using the MT in the tibia was 84% (95% CI, 79%-88%). There was no statistically significant association between defect size and union rate ( P = 0.11). CONCLUSIONS: The MT is an effective method for the treatment of segmental bone loss in the tibia and can be successful even for large defects. Future work is needed to better understand the patient-specific factors most strongly associated with MT success and complications. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Intraoperative assessment of bone viability through improved analysis and visualization of dynamic contrast-enhanced fluorescence imaging: technique report.

Bone devitalization is believed to be a critical determinant of complications such as infection or nonunion. However, intraoperative assessment of bone devitalization, particularly in open fractures and infections, remains highly subjective resulting in variation in treatment. Optical imaging tools, particularly dynamic contrast-enhanced fluorescence imaging, can provide real-time, intraoperative assessment of bone and soft tissue perfusion, which informs the tissues' ability to heal and fight infection. We describe a novel technique to apply indocyanine green-based fluorescence imaging, using a device that is frequently used in the operating room to assess skin or flap perfusion in plastic surgery, to assess bone and deep tissue perfusion in three pertinent cases: (1) a chronic infection/nonunion after a Gustilo type 3A tibia fracture (patient 1), (2) an acute Gustilo type 3C tibia open fracture with extensive degloving/soft tissue stripping (patient 2), and (3) an atrophic nonunion of the humerus (patient 3). In all three cases, fluorescence imaging (both time-specific fluorescence and maximum fluorescence) and derived kinetic maps of time-to-peak, ingress slope, and egress slope demonstrated clear spatial variation in perfusion that corresponded to the patient pathogenesis. The impact of this information on patient outcome will need to be evaluated in future clinical trials; however, these cases demonstrate in principle that optical imaging information has the potential to inform surgical practice, reduce the variation in treatment, and improve outcomes observed in these challenging patients.

Association of Patient-Level and Hospital-Level Factors With Timely Fracture Care by Race.

Importance: Racial disparities in treatment benchmarks have been documented among older patients with hip fractures. However, these studies were limited to patient-level evaluations. Objective: To assess whether disparities in meeting fracture care time-to-surgery benchmarks exist at the patient level or at the hospital or institutional level using high-quality multicenter prospectively collected data; the study hypothesis was that disparities at the hospital-level reflecting structural health systems issues would be detected. Design, Setting, and Participants: This cohort study was a secondary analysis of prospectively collected data in the PREP-IT (Program of Randomized trials to Evaluate Preoperative antiseptic skin solutions in orthopaedic Trauma) program from 23 sites throughout North America. The PREP-IT trials enrolled patients from 2018 to 2021, and patients were followed for 1-year. All patients with hip and femur fractures enrolled in the PREP-IT program were included in analysis. Data were analyzed April to September 2022. Exposures: Patient-level and hospital-level race, ethnicity, and insurance status. Main Outcomes and Measures: Primary outcome measure was time to surgery based on 24-hour time-to-surgery benchmarks. Multilevel multivariate regression models were used to evaluate the association of race, ethnicity, and insurance status with time to surgery. The reported odds ratios (ORs) were per 10% change in insurance coverage or racial composition at the hospital level. Results: A total of 2565 patients with a mean (SD) age of 64.5 (20.4) years (1129 [44.0%] men; mean [SD] body mass index, 27.3 [14.9]; 83 [3.2%] Asian, 343 [13.4%] Black, 2112 [82.3%] White, 28 [1.1%] other) were included in analysis. Of these patients, 834 (32.5%) were employed and 2367 (92.2%) had insurance; 1015 (39.6%) had sustained a femur fracture, with a mean (SD) injury severity score of 10.4 (5.8). Five hundred ninety-six patients (23.2%) did not meet the 24-hour time-to-operating-room benchmark. After controlling for patient-level characteristics, there was an independent association between missing the 24-hour benchmark and hospital population insurance coverage (OR, 0.94; 95% CI, 0.89-0.98; P = .005) and the interaction term between hospital population insurance coverage and racial composition (OR, 1.03; 95% CI, 1.01-1.05; P = .03). There was no association between patient race and delay beyond 24-hour benchmarks (OR, 0.96; 95% CI, 0.72-1.29; P = .79). Conclusions and Relevance: In this cohort study, patients who sought care from an institution with a greater proportion of patients with racial or ethnic minority status or who were uninsured were more likely to experience delays greater than the 24-hour benchmarks regardless of the individual patient race; institutions that treat a less diverse patient population appeared to be more resilient to the mix of insurance status in their patient population and were more likely to meet time-to-surgery benchmarks, regardless of patient insurance status or population-based insurance mix. While it is unsurprising that increased delays were associated with underfunded institutions, the association between institutional-level racial disparity and surgical delays implies structural health systems bias.

Spatial and temporal patterns in dynamic-contrast enhanced intraoperative fluorescence imaging enable classification of bone perfusion in patients undergoing leg amputation.

Dynamic contrast-enhanced fluorescence imaging (DCE-FI) classification of tissue viability in twelve adult patients undergoing below knee leg amputation is presented. During amputation and with the distal bone exposed, indocyanine green contrast-enhanced images were acquired sequentially during baseline, following transverse osteotomy and following periosteal stripping, offering a uniquely well-controlled fluorescence dataset. An unsupervised classification machine leveraging 21 different spatiotemporal features was trained and evaluated by cross-validation in 3.5 million regions-of-interest obtained from 9 patients, demonstrating accurate stratification into normal, suspicious, and compromised regions. The machine learning (ML) approach also outperformed the standard method of using fluorescence intensity only to evaluate tissue perfusion by a two-fold increase in accuracy. The generalizability of the machine was evaluated in image series acquired in an additional three patients, confirming the stability of the model and ability to sort future patient image-sets into viability categories.

Osteoporosis Diagnosis, Management, and Referral Practice After Fragility Fractures.

PURPOSE OF REVIEW: The purpose of this manuscript is to review the current diagnosis, management, and referral practices of patients with osteoporosis after a fragility fracture from the orthopedic surgeon's perspective. RECENT FINDINGS: Effective treatments are available for osteoporosis that significantly decrease the risk of additional fractures. Despite recommendations for improved post-fragility fracture osteoporosis management, the rate of diagnosis and treatment is still unacceptably low. Patients sustaining a low-energy fracture should be evaluated for osteoporosis with discussion of beginning pharmacological treatment. Antiresorptive and anabolic agents are available treatment options. Fracture Liaison Services can help to coordinate the care of these patients and improve the rate of diagnosis and initiation of therapy. Dartmouth-Hitchcock is working to improve the bone health for our patients utilizing a multidisciplinary team-based approach. This process is intended to lead to increased recognition of osteoporosis within our institution and close the capture gap between hospital discharge and initiation of osteoporosis pharmacotherapy.

Assessing Soft Tissue Perfusion Using Laser-Assisted Angiography in Tibial Plateau and Pilon Fractures: A Pilot Study.

OBJECTIVES: To determine whether skin perfusion surrounding tibial plateau and pilon fractures is associated with the Tscherne classification for severity of soft tissue injury. The secondary aim was to determine if soft tissue perfusion improves from the time of injury to the time of definitive fracture fixation in fractures treated using a staged protocol. DESIGN: Prospective cohort study. SETTING: Academic trauma center. PATIENTS: Eight pilon fracture patients and 19 tibial plateau fracture patients who underwent open reduction internal fixation. MAIN OUTCOME MEASURES: Skin perfusion (fluorescence units) as measured by LA-ICGA. RESULTS: Six patients were classified as Tscherne grade 0, 9 as grade 1, 10 as grade 2, and 2 as grade 3. Perfusion decreased by 14 fluorescence units (95% confidence interval, -21 to -6; P < 0.01) with each increase in Tscherne grade. Sixteen patients underwent staged fixation with an external fixator (mean time to definitive fixation 14.1 days). The mean perfusion increased significantly at the time of definitive fixation by a mean of 13.9 fluorescence units (95% confidence interval 4.8-22.9; P = 0.01). CONCLUSIONS: LA-ICGA perfusion measures are associated with severity of soft tissue injury surrounding orthopaedic trauma fractures and appear to improve over time when fractures are stabilized in an external fixator. Further research is warranted to investigate whether objective perfusion measures are predictive of postoperative wound healing complications and whether this tool can be used to effectively guide timing of safe surgical fixation. LEVEL OF EVIDENCE: Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence.

Virtual reality-based physical therapy for patients with lower extremity injuries: feasibility and acceptability.

INTRODUCTION: Traditional physical therapy (PT) requires patients to attend weekly in-office supervised physical therapy appointments. However, between 50% and 70% of patients who would benefit do not receive prescribed PT due to barriers to access. Virtual Reality (VR) provides a platform for remote delivery of PT to address these access barriers. METHODS: We developed a VR-PT program consisting of training, games, and a progress dashboard for 3 common lower extremity physical therapy exercises. We enrolled orthopaedic trauma patients with lower extremity injuries. Patients completed a VR-PT session, consisting of training and one of the exercise-based games. Pre- and post-VR-PT questionnaires were completed. RESULTS: We enrolled 15 patients with an average age of 51 years. Fourteen patients said they would enroll in a randomized trial in which they had a 50% chance of receiving VR-PT vs receiving standard of care. When asked to rate their experience using the VR-PT module on a scale from 0-10-with 0 being anchored as "I hated it" and 10 being anchored as "I loved it"-the average rating was 7.5. Patients rated the acceptability of VR-PT as a 3.9 out of 5, the feasibility as a 4.0 out of 5, and the usability as a 67.5 out of 100. CONCLUSION: The response to VR-PT in this pilot study was positive overall. A VR-based PT program may add value for both patients and clinicians in terms of objective data collection (to aid in compliance monitoring, progression toward goals and exercise safety), increased engagement and increased access.

Orthopaedic Surgeon Physiological Indicators of Strain as Measured by a Wearable Fitness Device.

INTRODUCTION: Symptoms of stress, depression, and burnout are prevalent in medicine, adversely affecting physician performance. We investigated real-time measurements of physiological strain in orthopaedic resident and faculty surgeon volunteers and identified potential daily stressors. METHODS: We performed a prospective blinded cohort pilot study in our academic orthopaedic department. Physicians used a wearable fitness device for 12 weeks to objectively measure heart rate variability (HRV), a documented parameter of overall well-being. Baseline burnout levels were assessed using the Maslach Burnout Inventory questionnaire. Daily surveys inquiring on work responsibilities (clinic, operating room [OR], or "other") were correlated with physiological parameters of strain. Descriptive statistics and linear mixed effects modeling were used to evaluate bivariate relationships. RESULTS: Of the 21 participating surgeons, 9 faculty and 12 residents, there was a response rate of 95.2% for the initial burnout survey. Daily surveys were completed for 63.8% (54.9 ± 22.3 days) of the total collection window, and surgeons wore the device for 83.2% of the study (71.6 ± 25.0 days). Residents trended toward lower personal accomplishment and greater psychological detachment on the Maslach Burnout Inventory, with 5 surgeons including 1 faculty surgeon (11.1%) and 4 resident surgeons (33.3%) found to have negatively trending HRV throughout the study period demonstrating higher physiological strain. Time in the OR led to increased next-day HRV (y-intercept = 47.39; B = 4.90; 95% confidence interval, 2.14-7.66; P < 0.001), indicative of lower physiological strain. An increase in device-reported sleep from a surgeon's baseline resulted in a significant increase in next-day HRV (y-intercept = 50.46; B = 0.64; 95% confidence interval, 0.11-1.17; P = 0.02). DISCUSSION: Orthopaedic residents, more than faculty, had physiologic findings suggestive of burnout. Time in the OR and increased sleep improved physiological strain parameters. Real-time biometric measurements can identify those at risk of burnout and in need of well-being interventions. LEVEL OF EVIDENCE: Level III.

Effect of Tourniquet Use During Surgical Treatment of Open Fractures.

BACKGROUND: We sought to evaluate whether tourniquet use, with the resultant ischemia and reperfusion, during surgical treatment of an open lower-extremity fracture was associated with an increased risk of complications. METHODS: This is a retrospective cohort study of 1,351 patients who had an open lower-extremity fracture at or distal to the proximal aspect of the tibia and who participated in the FLOW (Fluid Lavage of Open Wounds) trial. The independent variable was intraoperative tourniquet use, and the primary outcome measures were adjudicated unplanned reoperation within 1 year of the injury and adjudicated nonoperative wound complications. RESULTS: Unplanned reoperation and nonoperative wound complications were roughly even between the no-tourniquet (18.7% and 19.1%, respectively) and tourniquet groups (17.8% and 20.8%) (p = 0.78 and p = 0.52). Following matching, as determined by model interactions, tourniquet use was a significant predictor of unplanned reoperation in Gustilo Type-IIIA (odds ratio, 3.60; 95% confidence interval, 1.16 to 11.78) and IIIB fractures (odds ratio, 16.61; 95% confidence interval, 2.15 to 355.40). CONCLUSIONS: The present study showed that tourniquet use did not influence the likelihood of complications following surgical treatment of an open lower-extremity fracture. However, in cases of severe open fractures, tourniquet use was associated with increased odds of unplanned reoperation; surgeons should be cautious with regard to tourniquet use in this setting. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

PREVENTion of CLots in Orthopaedic Trauma (PREVENT CLOT): a randomised pragmatic trial protocol comparing aspirin versus low-molecular-weight heparin for blood clot prevention in orthopaedic trauma patients.

INTRODUCTION: Patients who sustain orthopaedic trauma are at an increased risk of venous thromboembolism (VTE), including fatal pulmonary embolism (PE). Current guidelines recommend low-molecular-weight heparin (LMWH) for VTE prophylaxis in orthopaedic trauma patients. However, emerging literature in total joint arthroplasty patients suggests the potential clinical benefits of VTE prophylaxis with aspirin. The primary aim of this trial is to compare aspirin with LMWH as a thromboprophylaxis in fracture patients. METHODS AND ANALYSIS: PREVENT CLOT is a multicentre, randomised, pragmatic trial that aims to enrol 12 200 adult patients admitted to 1 of 21 participating centres with an operative extremity fracture, or any pelvis or acetabular fracture. The primary outcome is all-cause mortality. We will evaluate non-inferiority by testing whether the intention-to-treat difference in the probability of dying within 90 days of randomisation between aspirin and LMWH is less than our non-inferiority margin of 0.75%. Secondary efficacy outcomes include cause-specific mortality, non-fatal PE and deep vein thrombosis. Safety outcomes include bleeding complications, wound complications and deep surgical site infections. ETHICS AND DISSEMINATION: The PREVENT CLOT trial has been approved by the ethics board at the coordinating centre (Johns Hopkins Bloomberg School of Public Health) and all participating sites. Recruitment began in April 2017 and will continue through 2021. As both study medications are currently in clinical use for VTE prophylaxis for orthopaedic trauma patients, the findings of this trial can be easily adopted into clinical practice. The results of this large, patient-centred pragmatic trial will help guide treatment choices to prevent VTE in fracture patients. TRIAL REGISTRATION NUMBER: NCT02984384.

Association of COVID-19 With Achieving Time-to-Surgery Benchmarks in Patients With Musculoskeletal Trauma.

Importance: In response to the COVID-19 pandemic, many hospital systems were forced to reduce operating room capacity and reallocate resources. The outcomes of these policies on the care of injured patients and the maintenance of emergency services have not been adequately reported. Objective: To evaluate whether the COVID-19 pandemic was associated with delays in urgent fracture surgery beyond national time-to-surgery benchmarks. Design Setting and Participants: This retrospective cohort study used data collected in the Program of Randomized Trials to Evaluate Preoperative Antiseptic Skin Solutions in Orthopaedic Trauma among at 20 sites throughout the US and Canada and included patients who sustained open fractures or closed femur or hip fractures. Exposure: COVID-19-era operating room restrictions were compared with pre-COVID-19 data. Main Outcomes and Measures: Surgery within 24 hours after injury. Results: A total of 3589 patients (mean [SD] age, 55 [25.4] years; 1913 [53.3%] male) were included in this study, 2175 pre-COVID-19 and 1414 during COVID-19. A total of 54 patients (3.1%) in the open fracture cohort and 407 patients (21.8%) in the closed hip/femur fracture cohort did not meet 24-hour time-to-surgery benchmarks. We were unable to detect any association between time to operating room and COVID-19 era in either open fracture (odds ratio [OR], 1.40; 95% CI, 0.77-2.55; P = .28) or closed femur/hip fracture (OR, 1.01; 95% CI, 0.74-1.37; P = .97) cohorts. In the closed femur/hip fracture cohort, there was no association between time to operating room and regional COVID-19 prevalence (OR, 1.07; 95% CI, 0.70-1.64; P = .76). Conclusions and Relevance: In this cohort study, there was no association between meeting time-to-surgery benchmarks in either open fracture or closed femur/hip fracture during the COVID-19 pandemic compared with before the pandemic. This is counter to concerns that the unprecedented challenges associated with managing the COVID-19 pandemic would be associated with clinically significant delays in acute management of urgent surgical cases and suggests that many hospital systems within the US were able to effectively implement policies consistent with time-to-surgery standards for orthopedic trauma in the context of COVID-19-related resource constraints.

Intraoperative fluorescence perfusion assessment should be corrected by a measured subject-specific arterial input function.

SIGNIFICANCE: The effects of varying the indocyanine green injection dose, injection rate, physiologic dispersion of dye, and intravenous tubing volume propagate into the shape and magnitude of the arterial input function (AIF) during intraoperative fluorescence perfusion assessment, thereby altering the observed kinetics of the fluorescence images in vivo. AIM: Numerical simulations are used to demonstrate the effect of AIF on metrics derived from tissue concentration curves such as peak fluorescence, time-to-peak (TTP), and egress slope. APPROACH: Forward models of tissue concentration were produced by convolving simulated AIFs with the adiabatic approximation to the tissue homogeneity model using input parameters representing six different tissue examples (normal brain, glioma, normal skin, ischemic skin, normal bone, and osteonecrosis). RESULTS: The results show that AIF perturbations result in variations in estimates of total intensity of up to 80% and TTP error of up to 200%, with the errors more dominant in brain, less in skin, and less in bone. Interestingly, error in ingress slope was as high as 60% across all tissue types. These are key observable parameters used in fluorescence imaging either implicitly by viewing the image or explicitly through intensity fitting algorithms. Correcting by deconvolving the image with a measured subject-specific AIF provides an intuitive means of visualizing the data while also removing the source of variance and allowing intra- and intersubject comparisons. CONCLUSIONS: These results suggest that intraoperative fluorescence perfusion assessment should be corrected by patient-specific AIFs measured by pulse dye densitometry.

Quantitative Lesser Trochanter Profile Versus Cortical Step Sign in Assessing Femoral Malrotation After Femoral Nailing.

We describe the novel quantitative lesser trochanter profile (QLTP) technique to determine the magnitude and direction of femoral malrotation and to compare its performance with the cortical step sign technique. For this assessment, 9 orthopaedic surgeons estimated the magnitude and direction of femoral malrotation with each technique in 198 anteroposterior view images of the proximal cadaveric femur and osteotomy sites. Based on the results, the main benefit of the QLTP technique over the cortical step sign technique is the ability to determine the direction of femoral malrotation. The QLTP technique was also more accurate in measuring malrotation and had less error. However, the QLTP technique requires additional imaging, and the mean difference in error between the 2 techniques might not be clinically meaningful.

Effectiveness of local anesthetic injection in geriatric patients following operative management of proximal and diaphyseal femur fracture.

INTRODUCTION: Geriatric fracture patients are at risk for poorly controlled pain and side effects of opioid medications. The arthroplasty literature has demonstrated that infiltration of long-acting local anesthetic or anesthetic cocktails improves pain control and reduces post-operative opioid use resulting in better postoperative mobility without the deleterious effects of narcotics. Despite having a higher risk for adverse events, there is limited data among geriatric trauma patients. The aim this study was to evaluate whether local anesthetic infiltration (LAI) into the soft tissues surrounding the surgical field reduces narcotic use or pain scores in patients undergoing surgical management of proximal and diaphyseal femur fractures. MATERIALS AND METHODS: A retrospective review was performed of patients age >65 undergoing operative intervention for proximal and diaphyseal femur fracture. The electronic record was utilized to determine if local anesthetic was injected into the surgical wound, the amount of narcotics administered over 48 h in four-hour intervals, and to obtain visual analog scale (VAS) pain scores associated with patients post-operative course in four-hour intervals. The amount of narcotics was converted to morphine milligram equivalents (MME). RESULTS: Among 477 patients with femur fracture, 358 did not receive LAI and 119 patients received LAI. Baseline demographics, fracture types, and surgical procedure were equivalent between the groups. In the first 28 h following surgery, compared with those who did not receive LAI, those who did required significantly less opioid (57.8 MME versus 94.3 MME, p = 0.034) and despite decreased narcotics, had equal pain scores (mean difference 0.37, p = 0.22). There was no difference in rates of post-operative complications. CONCLUSION: LAI is associated with a reduction in opioid consumption in geriatric fracture patients with equivalent pain scores. Optimizing pain control is a critical issue in caring for geriatric fracture patients since both under-treated pain and opioid medications are implicated in postoperative delirium, complications, and ability to mobilize early. More research is needed to identify effective ways to optimize pain management in this at-risk patient population.

Is prescribed lower extremity weight-bearing status after geriatric lower extremity trauma associated with increased mortality?

OBJECTIVES: Evaluate whether mortality after discharge is elevated in geriatric fracture patients whose lower extremity weight-bearing is restricted. DESIGN: Retrospective cohort study SETTING: Urban Level 1 trauma center PATIENTS/PARTICIPANTS: 1746 patients >65 years of age INTERVENTION: Post-operative lower extremity weight-bearing status MAIN OUTCOME MEASURE: Mortality, as determined by the Social Security Death Index RESULTS: Univariate analysis demonstrated that patients who were weight-bearing as tolerated on bilateral lower extremities (BLE) had significantly higher 5-year mortality compared to patients with restricted weight-bearing on one lower extremity and restricted weight-bearing on BLE (30%, 21% and 22% respectively, p < 0.001). Cox regression analysis controlling for variables including age, Charlson Comorbidity Index, Injury Severity Scale, combined UE/LE injury, injury mechanism (high vs low), sex, BMI and GCS demonstrated that, in comparison to patients who were weight bearing as tolerated on BLE, restricted weight-bearing on one lower extremity had a hazard ratio (HR) of 0.97 (95% confidence interval 0.78 to 1.20, p = 0.76) and restricted weight-bearing in BLE had a HR of 0.91 (95% confidence interval 0.60 to 1.36, p = 0.73). CONCLUSIONS: In geriatric patients, prescribed weight-bearing status did not have a statistically significant association with mortality after discharge, when controlling for age, sex, body mass index, medical comorbidities, Injury Severity Scale (ISS), mechanism of injury, nonoperative treatment and admission GCS. This remained true in when the analysis was restricted to operative injuries only.