Timing of Flap Coverage With Respect to Definitive Fixation in Open Tibia Fractures.

OBJECTIVES: We conducted a large, U.S wide, observational study of type III tibial fractures, with the hypothesis that delays between definitive fixation and flap coverage might be a substantial modifiable risk factor associated with nosocomial wound infection. DESIGN: A retrospective analysis of a multicenter database of open tibial fractures requiring flap coverage. SETTING: Fourteen level-1 trauma centers across the United States. PATIENTS: Two hundred ninety-six (n = 296) consecutive patients with Gustilo III open tibial fractures requiring flap coverage at 14 trauma centers were retrospectively analyzed from a large orthopaedic trauma registry. We collected demographics and the details of surgical care. We investigated the patient, and treatment factors leading to infection, including the time from various points in care to the time of soft-tissue coverage. INTERVENTION: Delay definitive fixation and flap coverage in tibial type III fractures. MAIN OUTCOME MEASUREMENTS: (1) Results of multivariate regression with time from injury to coverage, debridement to coverage, and definitive fixation to coverage in the model, to determine which delay measurement was most associated with infection. (2) A second multivariate model, including other factors in addition to measures of flap delay, to provide the estimate between delay and infection after adjustment for confounding. RESULTS: Of 296 adults (227 M: 69 F) with open Gustilo type III tibial fractures requiring flap coverage, 96 (32.4%) became infected. In the multivariate regression, the time from definitive fixation to flap coverage was most predictive of subsequent wound infection (odds ratio 1.04, 95% confidence interval 1.01 to 1.08, n = 260, P = 0.02) among the time measurements. Temporary internal fixation was not associated with an increased risk of infection in both univariate (P = 0.59) or multivariate analyses (P = 0.60). Flap failure was associated with the highest odds of infection (odds ratio 6.83, 95% confidence interval 3.26 to 14.27, P < 0.001). CONCLUSION: Orthoplastic teams that are dedicated to severe musculoskeletal trauma, that facilitate coordination of definitive fixation and flap coverage, will reduce the infection rates in Gustilo type III tibial fractures. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Factors influencing management of bilateral femur fractures: A multicenter retrospective cohort of early versus delayed definitive Fixation.

INTRODUCTION: The purpose of our study was to evaluate the factors that influence the timing of definitive fixation in the management of bilateral femoral shaft fractures and the outcomes for patients with these injuries. METHODS: Patients with bilateral femur fractures treated between 1998 to 2019 at ten level-1 trauma centers were retrospectively reviewed. Patients were grouped into early or delayed fixation, which was defined as definitive fixation of both femurs within or greater than 24 hours from injury, respectively. Statistical analysis included reversed logistic odds regression to predict which variable(s) was most likely to determine timing to definitive fixation. The outcomes included age, sex, high-volume institution, ISS, GCS, admission lactate, and admission base deficit. RESULTS: Three hundred twenty-eight patients were included; 164 patients were included in the early fixation group and 164 patients in the delayed fixation group. Patients managed with delayed fixation had a higher Injury Severity Score (26.8 vs 22.4; p<0.01), higher admission lactate (4.4 and 3.0; p<0.01), and a lower Glasgow Coma Scale (10.7 vs 13; p<0.01). High-volume institution was the most reliable influencer for time to definitive fixation, successfully determining 78.6% of patients, followed by admission lactate, 64.4%. When all variables were evaluated in conjunction, high-volume institution remained the strongest contributor (X2 statistic: institution: 45.6, ISS: 8.83, lactate: 6.77, GCS: 0.94). CONCLUSION: In this study, high-volume institution was the strongest predictor of timing to definitive fixation in patients with bilateral femur fractures. This study demonstrates an opportunity to create a standardized care pathway for patients with these injuries. LEVEL OF EVIDENCE: Level III.

Effect of Intrawound Vancomycin Powder in Operatively Treated High-risk Tibia Fractures: A Randomized Clinical Trial.

Importance: Despite the widespread use of systemic antibiotics to prevent infections in surgically treated patients with fracture, high rates of surgical site infection persist. Objective: To examine the effect of intrawound vancomycin powder in reducing deep surgical site infections. Design, Setting, and Participants: This open-label randomized clinical trial enrolled adult patients with an operatively treated tibial plateau or pilon fracture who met the criteria for a high risk of infection from January 1, 2015, through June 30, 2017, with 12 months of follow-up (final follow-up assessments completed in April 2018) at 36 US trauma centers. Interventions: A standard infection prevention protocol with (n = 481) or without (n = 499) 1000 mg of intrawound vancomycin powder. Main Outcomes and Measures: The primary outcome was a deep surgical site infection within 182 days of definitive fracture fixation. A post hoc comparison assessed the treatment effect on gram-positive and gram-negative-only infections. Other secondary outcomes included superficial surgical site infection, nonunion, and wound dehiscence. Results: The analysis included 980 patients (mean [SD] age, 45.7 [13.7] years; 617 [63.0%] male) with 91% of the expected person-time of follow-up for the primary outcome. Within 182 days, deep surgical site infection was observed in 29 of 481 patients in the treatment group and 46 of 499 patients in the control group. The time-to-event estimated probability of deep infection by 182 days was 6.4% in the treatment group and 9.8% in the control group (risk difference, -3.4%; 95% CI, -6.9% to 0.1%; P = .06). A post hoc analysis of the effect of treatment on gram-positive (risk difference, -3.7%; 95% CI, -6.7% to -0.8%; P = .02) and gram-negative-only (risk difference, 0.3%; 95% CI, -1.6% to 2.1%; P = .78) infections found that the effect of vancomycin powder was a result of its reduction in gram-positive infections. Conclusions and Relevance: Among patients with operatively treated tibial articular fractures at a high risk of infection, intrawound vancomycin powder at the time of definitive fracture fixation reduced the risk of a gram-positive deep surgical site infection, consistent with the activity of vancomycin. Trial Registration: ClinicalTrials.gov Identifier: NCT02227446.

Single-Stage Versus 2-Stage Bilateral Intramedullary Nail Fixation in Patients With Bilateral Femur Fractures: A Multicenter Retrospective Review.

OBJECTIVE: To evaluate rates of complications in patients with bilateral femur fractures treated with intramedullary nailing (IMN) during either 1 single procedure or 2 separate procedures. DESIGN: A multicenter retrospective review of patients sustaining bilateral femur fractures, treated with IMN in single or 2-stage procedure, from 1998 to 2018 was performed at 10 Level-1 trauma centers. SETTING: Ten Level-1 trauma centers. PATIENTS/PARTICIPANTS: Two hundred forty-six patients with bilateral femur fractures. INTERVENTIONS: Intramedullary nailing. MAIN OUTCOME MEASURES: Incidence of complications. RESULTS: A total of 246 patients were included, with 188 single-stage and 58 two-stage patients. Gender, age, injury severity score, abbreviated injury score, secondary injuries, Glasgow coma scale, and proportion of open fractures were similar between both groups. Acute respiratory distress syndrome (ARDS) occurred at higher rates in the 2-stage group (13.8% vs. 5.9%; P value = 0.05). When further adjusted for age, gender, injury severity score, abbreviated injury score, Glasgow coma scale, and admission lactate, the single-stage group had a 78% reduced risk for ARDS. In-hospital mortality was higher in the single-stage cohort (2.7% compared with 0%), although this did not meet statistical significance (P = 0.22). CONCLUSIONS: This is the largest multicenter study to date evaluating the outcomes between single- and 2-stage IMN fixation for bilateral femoral shaft fractures. Single-stage bilateral femur IMN may decrease rates of ARDS in polytrauma patients who are able to undergo simultaneous definitive fixation. However, a future prospective study with standardized protocols in place will be required to discern whether single- versus 2-stage fixation has an effect on mortality and to identify those individuals at risk. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Compartment Syndrome: Evaluation of Skeletal Muscle Ischemia and Physiologic Biomarkers in Controlled Conditions Within Ex Vivo Isolated Muscle Bundles.

OBJECTIVES: To identify potential physiologic markers of muscle ischemia to serve as diagnostic indicators of compartment syndrome. We hypothesize that muscle bundles in hypoxic conditions will elicit decreases in potential hydrogen (pH) and increases in lactate and potassium that correlates with decreased muscle twitch forces. METHODS: We performed an ex vivo evaluation of individual skeletal muscle bundles obtained from a swine's diaphragm that were exposed to hypoxic conditions and compared with control groups. Over a 4-hour period, we evaluated the following parameters for each muscle bundle: muscle twitch forces and levels of potassium, lactate, and pH. Comparisons between the hypoxic and control groups were calculated at each time point using the 2-tailed Wilcoxon rank sum test for nonparametric data. Longitudinal associations between biomarkers and muscle twitch forces were tested using repeated measures analyses. RESULTS: The hypoxic group elicited more significant decreases in normalized muscle twitch forces than the control group at all time points (0.15 g vs. 0.55 g at 4 hours, P < 0.001). Repeated measures analyses of the hypoxic group demonstrated a statistically significant association between potassium, lactate, and normalized peak force over the course of time. Potassium demonstrated the strongest association with a 1 mmol/L unit increase in potassium associated with a 2.9 g decrease in normalized peak force (95% confidence interval -3.3 to -2.4, P < 0.001). The pH of all muscle baths increased over the course of time at similar rates between the study groups. CONCLUSIONS: This study used an ex vivo ischemic skeletal muscle model as a representation for pathophysiologic pathways associated with compartment syndrome. In this experimental approach we were unable to evaluate the pH of the muscle bundles due to continuous applied gassing. Our findings support further evaluations of potassium and lactate levels as potential diagnostic markers.

Epidemiology of Glenohumeral Instability Related to Sporting Activities Using the FEDS (Frequency, Etiology, Direction, and Severity) Classification System: A Multicenter Analysis.

BACKGROUND: Glenohumeral instability is common in athletes. There are an estimated 0.12 episodes of instability per 1000 sporting exposures. Instability can lead to time away from sport and an increased risk of shoulder arthritis. PURPOSE: To determine the prevalence, demographic data, anatomic features, and likelihood of surgery for the different types of instability as defined by the FEDS (frequency, etiology, direction, and severity) classification system for different sports. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: Databases at 3 institutions (University of Iowa, Vanderbilt University, and University of Pennsylvania) were searched for International Classification of Diseases--Ninth Revision codes related to shoulder instability in 2010. Demographic data, symptoms, causes, imaging findings, and operative reports were obtained. Data were entered into a custom-designed REDCap online survey. Patients with subjective instability related to sporting activities were included for analysis. RESULTS: A total of 184 athletes had glenohumeral instability; 20.1% were female. The mean age at the time of the first instability episode was 19.0 years for both male and female patients. The most common sports were football (29.3%), basketball (19.0%), and wrestling (9.8%). The most common type of instability based on the FEDS system was occasional, traumatic, anterior dislocation. Surgery was performed on 69.6% of athletes, and 14.1% had a recurrence of instability after surgery overall. Football had the highest rate of recurrence postoperatively at 23.8%. There was no difference in surgery rates between athletes with subluxations versus dislocations (P = .8458). Surgery was significantly more likely in those with frequent dislocations (P < .0001) and posterior instability (P = .027). There was a 10.7% recurrence rate overall with conservative treatment. CONCLUSION: Glenohumeral instability most commonly occurs in contact sports, affects male more than female patients, and is most frequently in the anterior direction. Recurrent instability is most common in football players. Attention should be turned to the specific characteristics of each type of instability to determine the best treatment for each athlete.

Epidemiology of the Frequency, Etiology, Direction, and Severity (FEDS) system for classifying glenohumeral instability.

HYPOTHESIS: The purpose of this multicenter epidemiologic study was to determine the distribution of patients within the Frequency, Etiology, Direction, and Severity (FEDS) classification system to determine which categories are of clinical importance. METHODS: Shoulder instability patients were identified using International Classification of Diseases, Ninth Revision coding data from 3 separate institutions from 2005-2010. Data were collected retrospectively. Details of instability were recorded in accordance with the FEDS classification system. Each patient was assigned a classification within the FEDS system. After all patients were assigned to a group, each group was individually analyzed and compared with the other groups. RESULTS: There are a total of 36 possible combinations within the FEDS system. Only 16 categories were represented by at least 1% of our patient population. Six categories captured at least 5% of all patients with shoulder instability. Only 2 categories represented greater than 10% of the population: solitary, traumatic, anterior dislocation, with 95 patients (24.8%), and occasional, traumatic, anterior dislocation, with 63 patients (16.4%). CONCLUSIONS: There are 16 categories within the FEDS classification that are clinically significant. Solitary, traumatic, anterior dislocation and occasional, traumatic, anterior dislocation were the most frequently observed in our cohort.

Limited Approaches to Calcaneal Fractures.

PURPOSE OF REVIEW: To review literature published in the last 3 years related to minimally invasive approaches to calcaneal fracture fixation. RECENT FINDINGS: Numerous randomized control trials, cohort studies, and meta-analyses have been done in the last 3 years comparing surgical treatment of calcaneus fractures. These studies indicate minimally invasive procedures decrease wound complication rates and achieve similar radiographic and clinical outcomes to open reduction internal fixation. In comparing different surgical treatment methods to non-operative treatment, operative management has increased complication rates but may lead to better functional outcomes in certain patient populations. Optimal treatment for displaced intra-articular calcaneus fractures continues to be debated. Current literature would suggest that the decision to operate be based on patient and fracture characteristics and surgeon capabilities. Minimally invasive techniques aim to improve patient reported outcomes and quality of life while decreasing complications and offer another option for surgeons in the treatment of displaced intra-articular calcaneal fractures.

Predictors for Surgery in Shoulder Instability: A Retrospective Cohort Study Using the FEDS System.

BACKGROUND: Shoulder instability is a common cause of pain and dysfunction in young, active patients. While studies have analyzed risk factors for recurrent instability and failure after instability surgery, few have examined which variables are associated with initial surgery in this patient population. PURPOSE: To identify variables that may be associated with surgical intervention in patients with shoulder instability in the context of the FEDS (frequency, etiology, direction, severity) classification, a system that may be useful in the surgical treatment of shoulder instability patients. STUDY DESIGN: Cohort study (prognosis); Level of evidence, 2. METHODS: A database of patients treated for shoulder instability from 3 separate institutions from 2005 to 2010 was generated using International Classification of Diseases-9th Revision data. Data were collected via retrospective review. Injury data were categorized according to the FEDS system. Data were analyzed for significance, with the primary outcome of surgical intervention. Summary statistics were used to assess which variables were associated with eventual surgery. To test the unadjusted bivariate associations between shoulder surgery and each data point, Pearson chi-square tests were used for categorical variables and Wilcoxon tests were used for continuous variables. RESULTS: Over the study time period, 377 patients were treated for shoulder instability. Patients who had surgery were more likely younger, had recurrent instability, and had their initial injury while playing a sport. Most patients had anterior instability; however, there was a greater proportion of posterior instability patients in the operative group. Severity of dislocation, measured by whether the patient required help to relocate the shoulder, was not significantly associated with eventual surgery. While imaging was not available for all patients, surgical patients were more likely to have magnetic resonance imaging findings of anterior labral injury and less likely to have a supraspinatus or subscapularis tear. CONCLUSION: Patients who underwent surgery for shoulder instability were younger, more likely to have experienced recurrent instability, and more likely to have sustained their original injury while playing sports. The FEDS classification, particularly the frequency and etiology of the patient's shoulder instability, may be helpful in identifying patients with a higher likelihood of undergoing surgical treatment.

Short-term sensitization of colon mechanoreceptors is associated with long-term hypersensitivity to colon distention in the mouse.

BACKGROUND & AIMS: Using a mouse model that reproduces major features of irritable bowel syndrome (long-lasting colon hypersensitivity without inflammation), we examined the contributions of 2 proteins, transient receptor potential vanilloid 1 (TRPV1) and acid-sensing ion channel 3 (ASIC3), on development of behavioral hypersensitivity and assessed the function of colon mechanoreceptors of hypersensitive mice. METHODS: Visceral nociceptive behavior was measured as the visceromotor response (VMR) to colorectal distention (CRD) before and after intracolonic treatment with zymosan or saline. Colon pathology was assessed in parallel experiments by quantifying myeloperoxidase activity, intralumenal pH, and tissue histology. Electrophysiologic experiments were performed on naïve and zymosan-treated hypersensitive mice using an in vitro colon-pelvic nerve preparation. RESULTS: Zymosan, but not saline, produced significant and persistent increases in the VMRs of control mice; zymosan produced nonsignificant increases in the VMRs in TRPV1 and ASIC3 knockout mice. Colon myeloperoxidase activity and pH were unaffected by either CRD or intracolonic treatments. Pelvic nerve mechanoreceptors recorded from zymosan-treated or naïve mice had similar sensitivity to stretch of the colon. When applied acutely, zymosan sensitized muscular/mucosal mechanoreceptors in both naïve and hypersensitive mice. CONCLUSIONS: Zymosan produced sensitization of colon mechanoreceptors acutely in vitro and chronic (>or=7 weeks) behavioral hypersensitivity in the absence of inflammation. The behavioral hypersensitivity was partially dependent on both TRPV1 and ASIC3 because deletions of either of these genes blunted zymosan's effect, suggesting that these proteins may be important peripheral mediators for development of functional (ie, noninflammatory) visceral hypersensitivity.