Altered spatial learning, cortical plasticity and hippocampal anatomy in a neurodevelopmental model of schizophrenia-related endophenotypes.

Adult rats exposed to the DNA-methylating agent methylazoxymethanol on embryonic day 17 show a pattern of neurobiological deficits that model some of the neuropathological and behavioral changes observed in schizophrenia. Although it is generally assumed that these changes reflect targeted disruption of embryonic neurogenesis, it is unknown whether these effects generalise to other antimitotic agents administered at different stages of development. In the present study, neurochemical, behavioral and electrophysiological techniques were used to determine whether exposure to the antimitotic agent Ara-C later in development recapitulates some of the changes observed in methylazoxymethanol (MAM)-treated animals and in patients with schizophrenia. Male rats exposed to Ara-C (30 mg/kg/day) at embryonic days 19.5 and 20.5 show reduced cell numbers and heterotopias in hippocampal CA1 and CA2/3 regions, respectively, as well as cell loss in the superficial layers of the pre- and infralimbic cortex. Birth date labeling with bromodeoxyuridine reveals that the cytoarchitectural changes in CA2/3 are a consequence rather that a direct result of disrupted cortical neurogenesis. Ara-C-treated rats possess elevated levels of cortical dopamine and DOPAC (3,4-didyhydroxypheylacetic acid) but no change in norepinephrine or serotonin. Ara-C-treated rats are impaired in their ability to learn the Morris water maze task and showed diminished synaptic plasticity in the hippocampocortical pathway. These data indicate that disruption of neurogenesis at embryonic days 19.5 and 20.5 constitutes a useful model for the comparative study of deficits observed in other gestational models and their relationship to cognitive changes observed in schizophrenia.

Are Geriatric Patients Who Sustain High-Energy Traumatic Injury Likely to Return to Functional Independence?

OBJECTIVES: To evaluate physical function and return to independence of geriatric trauma patients, to compare physical function outcomes of geriatric patients who sustained high-energy trauma with that of those who sustained low-energy trauma, and to identify predictors of physical function outcomes. DESIGN: Retrospective. SETTING: Urban Level I trauma center. PATIENTS: Study group of 216 patients with high-energy trauma and comparison group of 117 patients with low-energy trauma. INTERVENTION: Injury mechanism (high- vs. low-energy mechanism). MAIN OUTCOME MEASUREMENT: Patient-Reported Outcomes Measurement Information System Physical Function (PROMIS PF) patient-reported outcome measure, and change in living situation and mobility. RESULTS: Physical function outcomes and return to independence differed between patients with high-energy and low-energy injuries. High-energy geriatric trauma patients had significantly higher PROMIS PF scores compared with low-energy geriatric trauma patients (PROMIS PF score 42.2 ± 10.4 vs. 24.6 ± 10.4, P < 0.001). High-energy geriatric trauma patients were able to ambulate outdoors without an assistive device in 67% of cases and were living independently 74% of the time in comparison with 28% and 45% of low-energy geriatric trauma patients, respectively (P < 0.001, P < 0.001). Multivariate linear regression analysis demonstrated that low-energy mechanism injury was independently associated with a 13.2 point reduction in PROMIS PF score (P < 0.001). CONCLUSIONS: Geriatric patients greater than 1 year out from sustaining a high-energy traumatic injury seem to be functioning within the expected range for their age, whereas low-energy trauma patients seem to be functioning substantially worse than both age-adjusted norms and their high-energy cohorts. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Do Orthopaedic Resident and Fellow Case Logs Accurately Reflect Surgical Case Volume?

OBJECTIVE: The purpose of this study is to determine whether orthopedic resident and fellow case logs accurately reflect trainee case volume. DESIGN: For each orthopedic case performed at our institution between 7/1/14 and 10/31/14, the names of trainees who participated were obtained from the chart. The trainee Accreditation Council for Graduate Medical Education case logs were queried to determine if the procedure in question was logged and, if so, which current procedural terminology (CPT) codes were reported. The CPT codes reported by the trainees were compared to those reported by the attendings in the billing database. To ascertain the opinions of trainees regarding coding, a survey was conducted. SETTING: University of Maryland Medical Center (Baltimore, MD), a tertiary and quaternary care center which features a state-wide trauma referral center as well as orthopedic residency and fellowship training programs. PARTICIPANTS: All orthopedic surgery residents and fellows present at the institution during the study period. RESULTS: Trainees failed to log their cases 24% of the time (465/1925), including 25% (283/1117) for residents and 23% (182/808) for fellows (p = 0.16). Among cases that were logged, CPT codes were missed 46% of the time (673/1460) and extra codes were added 28% of the time (412/1460) compared to the attendings. In the survey, most trainees stated that it was "extremely" or "very" important for them to be able to code correctly (83%; 29/35). CONCLUSIONS: In this study of orthopedic trainee case logging practices, cases were not logged 24% of the time. Caution should be taken with activities which rely on trainee case logs given the potential for inaccuracy.

Predictors of Unplanned Reoperation After Operative Treatment of Pelvic Ring Injuries.

OBJECTIVES: To evaluate the incidence of unplanned reoperations after pelvic ring injuries and to develop a risk prediction model. DESIGN: Retrospective review. SETTING: Level I Trauma Center. PATIENTS: The medical records of 913 patients (644 male and 269 female patients; mean age, 39 years; age range, 16-89 years) with unstable pelvic ring fractures operatively treated at our center from 2003 to 2015 were reviewed. INTERVENTION: Multiple logistic regression analysis was conducted to evaluate the relative contribution of associated clinical parameters to unplanned reoperations. A risk prediction model was developed to assess the effects of multiple covariates. MAIN OUTCOME MEASUREMENTS: Unplanned reoperation for infection, fixation failure, heterotopic ossification, or bleeding complication. RESULTS: Unplanned reoperations totaled 137 fractures, with an overall rate of 15% (8% infection, 6% fixation failure, <1% heterotopic ossification, and <1% bleeding complication). Reoperations for infection and fixation failure typically occurred within the first month after the index procedure. Four independent predictors of reoperation were open fractures, combined pelvic ring and acetabular injuries, abdominal visceral injuries, and increasing pelvic fracture grade. No independent association was shown between reoperation and patient, treatment, or other injury factors. CONCLUSIONS: Unplanned reoperations were relatively common. Infection and fixation failure were the most common indications for unplanned reoperations. Factors associated with reoperation are related to severity of pelvic and abdominal visceral injuries. Our findings suggest that these complications might be inherent and in many cases unavoidable despite appropriate current treatment strategies. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

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.

Construct Validation of a Novel Hip Fracture Fixation Surgical Simulator.

INTRODUCTION: A surgical simulation platform has been developed to simulate fluoroscopically guided surgical procedures by coupling computer modeling with a force-feedback device as a training tool for orthopaedic resident education in an effort to enhance motor skills and potentially minimize radiation exposure. The objective of this study was to determine whether the simulation platform can distinguish between novice and experienced practitioners of percutaneous pinning of hip fractures. METHODS: Medical students, orthopaedic residents, orthopaedic trauma fellows, and attending surgeons completed in situ hip-pinning simulation that recorded performance measures related to surgical accuracy, time, and use of fluoroscopy. Linear regression models were used to compare the association between performance and practitioner experience. RESULTS: Notable associations were shown between performance and practitioner experience in 10 of the 15 overall measures (P < 0.05) and 9 of 11 surgical accuracy parameters (P < 0.05). CONCLUSION: This novel simulation platform can distinguish between novice and experienced practitioners and defines a performance curve for completion of simulated in situ hip pinning. This important first step lays the groundwork for subsequent validation studies, which will seek to demonstrate the efficacy of this simulator in improving clinical performance by trainees completing a sequence of skills-training modules.

Variations in the Organisms Causing Deep Surgical Site Infections in Fracture Patients at a Level I Trauma Center (2006-2015).

OBJECTIVES: To quantify the current bacteriology of deep surgical site infections (SSIs) after fracture surgery at 1 institution and to compare those data with historical controls at the same institution, assessing variations in infecting organisms over the past decade. DESIGN: Retrospective review. SETTING: Level I trauma center. PATIENTS/PARTICIPANTS: Two hundred forty-three patients requiring surgical intervention for deep SSI between January 2011 and December 2015 were compared with 211 patients requiring surgical intervention for deep SSI between December 2006 and December 2010. INTERVENTION: None. MAIN OUTCOME MEASUREMENTS: Bacteria were categorized as Staphylococcus aureus, coagulase-negative staphylococci (CoNS), Streptococcus, Enterococcus, gram-negative rods (GNR), gram-positive rods, anaerobes, or negative cultures. The proportion of each bacterial type was determined and compared with previously published data from the same trauma center (December 2006 to December 2010). RESULTS: Patients most commonly had S. aureus infections (48%), followed by GNR (40%) and CoNS (19%). The proportion of CoNS species (26% vs. 12%, P < 0.01) in infected patients was significantly higher during the current study period compared with historical controls. The proportion of S. aureus species in infected patients was significantly less during the current study period (39% vs. 56%, P < 0.01). The reduction in the proportion of S. aureus species in infected patients was driven by a decrease in the proportion of methicillin-resistant S. aureus (MRSA) in the overall sample. CONCLUSIONS: Bacteriology of deep SSI of fractures has changed substantially over the past decade at our center, specifically the proportions of GNR, CoNS, and MRSA. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Survivorship After High-Energy Geriatric Trauma.

OBJECTIVES: To evaluate in-hospital, 1-year, and 5-year survivorship of geriatric patients after high-energy trauma, to compare survivorship of geriatric patients who sustained high-energy trauma with that of those who sustained low-energy trauma, and to identify predictors for mortality. DESIGN: Retrospective. SETTING: Urban Level I trauma center. PATIENTS: Study group of 1849 patients with high-energy trauma and comparison group of 761 patients with low-energy trauma. INTERVENTION: Each patient was observed from the time of index admission through the end of the study period or until death or readmission. MAIN OUTCOME MEASUREMENT: Long-term survivorship based on the Social Security Death Index. RESULTS: Survivorship between patients with high-energy and low-energy injuries was statistically significant. Among patients who sustained high-energy injuries, in-hospital mortality was 8%, 1-year mortality was 15%, and 5-year mortality was 25%. Among patients who sustained low-energy injuries, in-hospital mortality was 3%, 1-year mortality was 23%, and 5-year mortality was 40%. Low-energy mechanism of injury was an independent predictor for 1-year and 5-year mortality, even when controlling for Charlson Comorbidity Index (CCI), Injury Severity Score (ISS), age, sex, body mass index (BMI), and admission Glasgow Coma Scale (GCS) score. CONCLUSIONS: Geriatric patients with high-energy injuries and those with low-energy injuries seem to represent different patient populations, and low-energy mechanism seems to be a marker for frailty. High-energy mechanism was associated with lower long-term mortality rates, even when controlling for CCI, ISS, age, sex, BMI and admission GCS score. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.