Biomolecular condensates of Chlorocatechol 1,2-Dioxygenase as prototypes of enzymatic microreactors for the degradation of polycyclic aromatic hydrocarbons.

Polycyclic aromatic hydrocarbons (PAHs) are molecules with two or more fused aromatic rings that occur naturally in the environment due to incomplete combustion of organic substances. However, the increased demand for fossil fuels in recent years has increased anthropogenic activity, contributing to the environmental concentration of PAHs. The enzyme chlorocatechol 1,2-dioxygenase from Pseudomonas putida (Pp 1,2-CCD) is responsible for the breakdown of the aromatic ring of catechol, making it a potential player in bioremediation strategies. Pp 1,2-CCD can tolerate a broader range of substrates, including halogenated compounds, than other dioxygenases. Here, we report the construction of a chimera protein able to form biomolecular condensates with potential application in bioremediation. The chimera protein was built by conjugating Pp 1,2-CCD to low complex domains (LCDs) derived from the DEAD-box protein Dhh1. We showed that the chimera could undergo liquid-liquid phase separation (LLPS), forming a protein-rich liquid droplet under different conditions (variable protein and PEG8000 concentrations and pH values), in which the protein maintained its structure and main biophysical properties. The condensates were active against 4-chlorocatechol, showing that the chimera droplets preserved the enzymatic activity of the native protein. Therefore, it constitutes a prototype of a microreactor with potential use in bioremediation.

Venous thromboembolism testing practices after orthopaedic trauma: prophylaxis regimen does not influence testing patterns.

Objectives: To determine venous thromboembolism (VTE) testing patterns in an orthopaedic trauma population and to evaluate for differences in VTE surveillance by prophylaxis regimen through a secondary analysis of the ADAPT trial. Design: Prospective randomized trial. Setting: Level I trauma center. Patients: Three hundred twenty-nine adult (18 years and older) trauma patients presenting with an operative extremity fracture proximal to the metatarsals/carpals or any pelvic or acetabular fracture requiring VTE prophylaxis. Intervention: VTE imaging studies recorded within 90 days post injury. Main Outcome Measurements: Percentage of patients tested for VTE were compared between treatment groups using Fisher's exact test. Subsequently, multivariable regression was used to determine patient factors significantly associated with risk of receiving a VTE imaging study. Results: Sixty-seven patients (20.4%) had VTE tests ordered during the study period. Twenty (29.9%) of these 67 patients with ordered VTE imaging tests had a positive finding. No difference in proportion of patients tested for VTE by prophylaxis regimen (18.8% on aspirin vs. 22.0% on LMWH, P = 0.50) was observed. Factors associated with increased likelihood of VTE testing included White race (adjusted odds ratio [aOR]: 2.61, 95% CI: 1.26-5.42), increased Injury Severity Score (aOR for every 1-point increase: 1.10, 95% CI: 1.05-1.15), and lower socioeconomic status based on the Area Deprivation Index (aOR for every 10-point increase: 1.14, 95% CI: 1.00-1.30). Conclusions: VTE surveillance did not significantly differ by prophylaxis regimen. Patient demographic factors including race, injury severity, and socioeconomic status were associated with differences in VTE surveillance. Level of Evidence: Level I, Therapeutic.

Healthcare personnel opinions regarding the feasibility of a risk-tailored approach to contact precautions for methicillin-resistant Staphylococcus aureus in the acute care setting.

"All or none" approaches to the use of contact precautions for methicillin-resistant Staphylococcus aureus (MRSA) both fail to recognize that transmission risk varies. This qualitative study assessed healthcare personnel perspectives regarding the feasibility of a risk-tailored approach to use contact precautions for MRSA more strategically in the acute care setting.

The reported impact of non-communicable disease investment cases in 13 countries.

Non-communicable diseases (NCDs) are a leading health and development challenge worldwide. Since 2015, WHO and the United Nations Development Programme have provided support to governments to develop national NCD investment cases to describe the socioeconomic dimensions of NCDs. To assess the impact of the investment cases, semistructured interviews and a structured process for gathering written feedback were conducted between July and October 2022 with key informants in 13 countries who had developed a national NCD investment case between 2015 and 2020. Investment cases describe: (1) the social and economic costs of NCDs, including their distribution and projections over time; (2) priority areas for scaled up action; (3) the cost and returns from investing in WHO-recommended measures to prevent and manage NCDs; and (4) the political dimensions of NCD responses. While no country had implemented all the recommendations set out in their investment case reports, actions and policy changes attributable to the investment cases were identified, across (1) governance; (2) financing; and (3) health service access and delivery. The pathways of these changes included: (1) stronger collaboration across government ministries and partners; (2) advocacy for NCD prevention and control; (3) grounding efforts in nationally owned data and evidence; (4) developing mutually embraced 'language' across health and finance; and (5) elevating the priority accorded to NCDs, by framing action as an investment rather than a cost. The assessment also identified barriers to progress on the investment case implementation, including the influence of some private sector entities on sectors other than health, the impact of the COVID-19 pandemic, and changes in senior political and technical government officials. The results suggest that national NCD investment cases can significantly contribute to catalysing the prevention and control of NCDs through strengthening governance, financing, and health service access and delivery.

Factors that Promote and Protect Against Financial Toxicity after Orthopaedic Trauma: A Qualitative Study.

INTRODUCTION: Financial toxicity is highly prevalent in patients after an orthopaedic injury. However, little is known regarding the conditions that promote and protect against this financial distress. Our objective was to understand the factors that cause and protect against financial toxicity after a lower extremity fracture. METHODS: A qualitative study was conducted using semi-structured interviews with 20 patients 3 months after surgical treatment of a lower extremity fracture. The interviews were audio-recorded, transcribed verbatim, and analyzed using thematic analysis to identify themes and subthemes. Data saturation occurred after 15 interviews. The percentage of patients who described the identified themes are reported. RESULTS: A total of 20 patients (median age, 44 years [IQR, 38 to 58]; 60% male) participated in the study. The most common injury was a distal tibia fracture (n = 8; 40%). Eleven themes that promoted financial distress were identified, the most common being work effects (n = 14; 70%) and emotional health (n = 12; 60%). Over half (n = 11; 55%) of participants described financial toxicity arising from an inability to access social welfare programs. Seven themes that protected against financial distress were also identified, including insurance (n = 17; 85%) and support from friends and family (n = 17; 85%). Over half (n = 13; 65%) of the participants discussed the support they received from their healthcare team, which encompassed expectation setting and connections to financial aid and other services. Employment protection and workplace flexibility were additional protective themes. CONCLUSION: This qualitative study of orthopaedic trauma patients found work and emotional health-related factors to be primary drivers of financial toxicity after injury. Insurance and support from friends and family were the most frequently reported protective factors. Many participants described the pivotal role of the healthcare team in establishing recovery expectations and facilitating access to social welfare programs.

Fix or Replace? Patient Preferences for the Treatment of Geriatric Lower Extremity Fractures: A Discrete Choice Experiment.

Introduction: When considering treatment options for geriatric patients with lower extremity fractures, little is known about which outcomes are prioritized by patients. This study aimed to determine the patient preferences for outcomes after a geriatric lower extremity fracture. Materials and Methods: We administered a discrete choice experiment survey to 150 patients who were at least 60 years of age and treated for a lower extremity fracture at a Level I trauma center. The discrete choice experiment presented study participants with 8 sets of hypothetical outcome comparisons, including joint preservation (yes or no), risk of reoperation at 6 months and 24 months, postoperative weightbearing status, disposition, and function as measured by return to baseline walking distance. We estimated the relative importance of these potential outcomes using multinomial logit modeling. Results: The strongest patient preference was for maintained function after treatment (59%, P < .001), followed by reoperation within 6 months (12%, P < .001). Although patients generally favored joint preservation, patients were willing to change their preference in favor of joint replacement if it increased function (walking distance) by 13% (SE, 66%). Reducing the short-term reoperation risk (12%, P < .001) was more important to patients than reducing long-term reoperation risk (4%, P = .33). Disposition and weightbearing status were lesser priorities to patients (9%, P < .001 and 7%, P < .001, respectively). Discussion: After a lower extremity fracture, geriatric patients prioritized maintained walking function. Avoiding short-term reoperation was more important than avoiding long-term reoperation. Joint preservation through fracture fixation was the preferred treatment of geriatric patients unless arthroplasty or arthrodesis provides a meaningful functional benefit. Hospital disposition and postoperative weightbearing status were less important to patients than the other included outcomes. Conclusions: Geriatric patients strongly prioritize function over other outcomes after a lower extremity fracture.

Effect of Aspirin Versus Low-Molecular-Weight Heparin Thromboprophylaxis on Medication Satisfaction and Out-of-Pocket Costs: A Secondary Analysis of a Randomized Clinical Trial.

BACKGROUND: Current guidelines recommend low-molecular-weight heparin for thromboprophylaxis after orthopaedic trauma. However, recent evidence suggests that aspirin is similar in efficacy and safety. To understand patients' experiences with these medications, we compared patients' satisfaction and out-of-pocket costs after thromboprophylaxis with aspirin versus low-molecular-weight heparin. METHODS: This study was a secondary analysis of the PREVENTion of CLots in Orthopaedic Trauma (PREVENT CLOT) trial, conducted at 21 trauma centers in the U.S. and Canada. We included adult patients with an operatively treated extremity fracture or a pelvic or acetabular fracture. Patients were randomly assigned to receive 30 mg of low-molecular-weight heparin (enoxaparin) twice daily or 81 mg of aspirin twice daily for thromboprophylaxis. The duration of the thromboprophylaxis, including post-discharge prescription, was based on hospital protocols. The study outcomes included patient satisfaction with and out-of-pocket costs for their thromboprophylactic medication measured on ordinal scales. RESULTS: The trial enrolled 12,211 patients (mean age and standard deviation [SD], 45 ± 18 years; 62% male), 9725 of whom completed the question regarding their satisfaction with the medication and 6723 of whom reported their out-of-pocket costs. The odds of greater satisfaction were 2.6 times higher for patients assigned to aspirin than those assigned to low-molecular-weight heparin (odds ratio [OR]: 2.59; 95% confidence interval [CI]: 2.39 to 2.80; p < 0.001). Overall, the odds of incurring any out-of-pocket costs for thromboprophylaxis medication were 51% higher for patients assigned to aspirin compared with low-molecular-weight heparin (OR: 1.51; 95% CI: 1.37 to 1.66; p < 0.001). However, patients assigned to aspirin had substantially lower odds of out-of-pocket costs of at least $25 (OR: 0.15; 95% CI: 0.12 to 0.18; p < 0.001). CONCLUSIONS: Use of aspirin substantially improved patients' satisfaction with their medication after orthopaedic trauma. While aspirin use increased the odds of incurring any out-of-pocket costs, it protected against costs of ≥$25, potentially improving health equity for thromboprophylaxis. LEVEL OF EVIDENCE: Therapeutic Level II . See Instructions for Authors for a complete description of levels of evidence.

Skin Antisepsis before Surgical Fixation of Extremity Fractures.

BACKGROUND: Studies evaluating surgical-site infection have had conflicting results with respect to the use of alcohol solutions containing iodine povacrylex or chlorhexidine gluconate as skin antisepsis before surgery to repair a fractured limb (i.e., an extremity fracture). METHODS: In a cluster-randomized, crossover trial at 25 hospitals in the United States and Canada, we randomly assigned hospitals to use a solution of 0.7% iodine povacrylex in 74% isopropyl alcohol (iodine group) or 2% chlorhexidine gluconate in 70% isopropyl alcohol (chlorhexidine group) as preoperative antisepsis for surgical procedures to repair extremity fractures. Every 2 months, the hospitals alternated interventions. Separate populations of patients with either open or closed fractures were enrolled and included in the analysis. The primary outcome was surgical-site infection, which included superficial incisional infection within 30 days or deep incisional or organ-space infection within 90 days. The secondary outcome was unplanned reoperation for fracture-healing complications. RESULTS: A total of 6785 patients with a closed fracture and 1700 patients with an open fracture were included in the trial. In the closed-fracture population, surgical-site infection occurred in 77 patients (2.4%) in the iodine group and in 108 patients (3.3%) in the chlorhexidine group (odds ratio, 0.74; 95% confidence interval [CI], 0.55 to 1.00; P = 0.049). In the open-fracture population, surgical-site infection occurred in 54 patients (6.5%) in the iodine group and in 60 patients (7.3%) in the chlorhexidine group (odd ratio, 0.86; 95% CI, 0.58 to 1.27; P = 0.45). The frequencies of unplanned reoperation, 1-year outcomes, and serious adverse events were similar in the two groups. CONCLUSIONS: Among patients with closed extremity fractures, skin antisepsis with iodine povacrylex in alcohol resulted in fewer surgical-site infections than antisepsis with chlorhexidine gluconate in alcohol. In patients with open fractures, the results were similar in the two groups. (Funded by the Patient-Centered Outcomes Research Institute and the Canadian Institutes of Health Research; PREPARE ClinicalTrials.gov number, NCT03523962.).

3D Hydrogel Encapsulation Regulates Nephrogenesis in Kidney Organoids.

Stem cell-derived kidney organoids contain nephron segments that recapitulate morphological and functional aspects of the human kidney. However, directed differentiation protocols for kidney organoids are largely conducted using biochemical signals to control differentiation. Here, the hypothesis that mechanical signals regulate nephrogenesis is investigated in 3D culture by encapsulating kidney organoids within viscoelastic alginate hydrogels with varying rates of stress relaxation. Tubular nephron segments are significantly more convoluted in kidney organoids differentiated in encapsulating hydrogels when compared with those in suspension culture. Hydrogel viscoelasticity regulates the spatial distribution of nephron segments within the differentiating kidney organoids. Consistent with these observations, a particle-based computational model predicts that the extent of deformation of the hydrogel-organoid interface regulates the morphology of nephron segments. Elevated extracellular calcium levels in the culture medium, which can be impacted by the hydrogels, decrease the glomerulus-to-tubule ratio of nephron segments. These findings reveal that hydrogel encapsulation regulates nephron patterning and morphology and suggest that the mechanical microenvironment is an important design variable for kidney regenerative medicine.

Pain/Stress, Mitochondrial Dysfunction and Neurodevelopment in Preterm Infants.

Introduction Preterm infants experience tremendous early life pain/stress during their neonatal intensive care unit (NICU) hospitalization, which impacts their neurodevelopmental outcomes. Mitochondrial function/dysfunction may interface between perinatal stress events and neurodevelopment. Nevertheless, the specific proteins or pathways linking mitochondrial functions to pain-induced neurodevelopmental outcomes in infants are remain unidentified. Our study aims to investigate the associations among pain/stress, proteins associated with mitochondrial function/dysfunction, and neurobehavioral responses in preterm infants. Methods We conducted a prospective cohort study, enrolling 33 preterm infants between September 2017 and July 2022 at two affiliated NICUs located in Hartford and Farmington, CT. NICU Network Neurobehavioral Scale (NNNS) datasets were evaluated to explore potential association with neurobehavioral outcomes. The daily pain/stress experienced by infant's during their NICU stay was documented. At 36-38 weeks post-menstrual age (PMA), neurobehavioral outcomes were evaluated using the NNNS and buccal swabs were collected for further analysis. Mass spectrometry-based proteomics was conducted on epithelial cells obtained from buccal swabs to evaluate protein expression level. Lasso statistical methods were conducted to study the association between protein abundance and infants' NNNS summary scores. Multiple linear regression and Gene Ontology (GO) enrichment analyses were performed to examine how clinical characteristics and neurodevelopmental outcomes may be associated with protein levels and underlying molecular pathways. Results During NICU hospitalization, preterm premature rupture of membrane (PPROM) were negatively associated with neurobehavioral outcomes. The protein functions including leptin receptor binding activity, glutathione disulfide oxidoreductase activity and response to oxidative stress, lipid metabolism, phosphate and proton transmembrane transporter activity were negatively associated with neurobehavioral outcomes, in the contrast, cytoskeletal regulation, epithelial barrier and protection function were found to be associated with the optimal neurodevelopmental outcomes. In addition, mitochondrial function associated proteins including SPRR2A, PAIP1, S100A3, MT-CO2, PiC, GLRX, PHB2, and BNIPL-2 demonstrated positive association with favorable neurodevelopmental outcomes, while proteins of ABLIM1, UNC45A, Keratins, MUC1, and CYB5B showed positive association with adverse neurodevelopmental outcomes. Conclusion Mitochondrial function-related proteins were observed to be associated with early life pain/stress and neurodevelopmental outcomes in infants. Large-scale studies with longitudinal datasets are warranted. Buccal proteins could be used to predict potential neurobehavioral outcomes.

Community perceptions, acceptability, and the durability of house screening interventions against exposure to malaria vectors in Nyimba district, Zambia.

BACKGROUND: House screening remains conspicuously absent in national malaria programs despite its recognition by the World Health Organization as a supplementary malaria vector-control intervention. This may be attributed, in part, to the knowledge gap in screen durability or longevity in local climatic conditions and community acceptance under specific cultural practices and socio-economic contexts. The objectives of this study were to assess the durability of window and door wire mesh screens a year after full house screening and to assess the acceptability of the house screening intervention to the participants involved. METHODS: This study was conducted in Nyimba district, Zambia and used both quantitative and qualitative methods of data collection and analysis. Both direct observation and questionnaires were employed to assess the durability of the screens and the main reasons for damage. Findings on damage were summarized as percentages. Focus group discussions were used to assess people's knowledge, perceptions, and acceptability of the closing eaves and house screening intervention. Deductive coding and inductive coding were used to analyse the qualitative data. RESULTS: A total of 321 out of 400 (80.3%) household owners of screened houses were interviewed. Many window screens (90.3%) were intact. In sharp contrast, most door screens were torn (n = 150; 46.7%) or entirely removed (n = 55; 17.1%). Most doors (n = 114; 76%) had their wire mesh damaged or removed on the bottom half. Goats (25.4%), rust (17.6%) and children (17.1%) were cited most as the cause of damage to door screens. The focus group discussion elicited positive experiences from the participants following the closing of eaves and screening of their windows and doors, ranging from sleeping peacefully due to reduced mosquito biting and/or nuisance and having fewer insects in the house. Participants linked house screening to reduced malaria in their households and community. CONCLUSION: This study demonstrated that in rural south-east Zambia, closing eaves and screening windows and doors was widely accepted. Participants perceived that house screening reduced human-vector contact, reduced the malaria burden and nuisance biting from other potentially disease carrying insects. However, screened doors are prone to damage, mainly by children, domestic animals, rust, and termites.

Does the OTA Open Fracture Classification Align With the Gustilo-Anderson Classification? A Study of 2215 Open Fractures.

OBJECTIVES: To characterize the Orthopaedic Trauma Association Open Fracture Classification (OTA-OFC) and Gustilo-Anderson classification of open extremity fractures and determine if there is meaningful alignment between these grading systems. DESIGN: Retrospective case series. SETTING: Level I academic trauma center. PATIENT SELECTION CRITERIA: Adult patients with at least 1 operatively treated open extremity fracture and surgeon-assigned OTA-OFC and Gustilo-Anderson classification. OUTCOME MEASURES AND COMPARISONS: Frequency, distribution, and association measures of OTA-OFC category scores and Gustilo-Anderson classification types. RESULTS: Two thousand twenty-seven patients (mean age, 43.1 ± 17.5 years) with 2215 fractures were included. Gustilo-Anderson type I or II fractures (n = 961; 43%) most frequently had the least severe scores for all OTA-OFC categories. Type IIIA fractures (n = 978; 44%) were most often assigned intermediate scores for OTA-OFC Bone Loss (n = 564; 58%). Type IIIB fractures (n = 204, 9%) were most often assigned intermediate OTA-OFC Skin scores (n = 120; 59%). Type IIIC fractures (n = 72; 3%) were most often assigned the most severe OTA-OFC Arterial score (n = 60; 83%). In the multivariable model, OTA-OFC Contamination scores showed little association (ß = 0.05; 95% confidence interval [CI], 0.01-0.09) with Gustilo-Anderson classification severity. Conversely, higher OTA-OFC Arterial (ß = 0.50; 95% CI 0.44-0.56) and Skin (ß = 0.46; 95% CI, 0.40-0.51) scores were strongly associated with more severe Gustilo-Anderson classifications. CONCLUSIONS: OTA-OFC Contamination scores were weakly associated with Gustilo-Anderson classification severity for open fractures. The study findings suggest that the current Gustilo-Anderson classification does not adequately account for injury contamination, a known predictor of infection. LEVEL OF EVIDENCE: Diagnostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Risk-stratified thromboprophylaxis effects of aspirin versus low-molecular-weight heparin in orthopedic trauma patients: A secondary analysis of the PREVENT CLOT trial.

BACKGROUND: The PREVENT CLOT trial concluded that thromboprophylaxis with aspirin was noninferior to low-molecular-weight heparin (LMWH) in preventing death after orthopedic trauma. However, it was unclear if these results applied to patients at highest risk of thrombosis. Therefore, we assessed if the effect of aspirin versus LMWH differed based on patients' baseline risk of venous thromboembolism (VTE). METHODS: The PREVENT CLOT trial enrolled 12,211 adult patients with fractures. This secondary analysis stratified the study population into VTE risk quartiles: low (<1%) to high (>10%) using the Caprini score. We assessed stratum-specific treatment effects using the win ratio method, in which each patient assigned to aspirin was paired with each assigned to LMWH. In each pair, we compared outcomes hierarchically, starting with death, then pulmonary embolism, deep vein thrombosis, and bleeding. The secondary outcome added patients' medication satisfaction as a fifth composite component. RESULTS: In the high-risk quartile (n = 3052), 80% had femur fracture, pelvic, or acetabular fractures. Thoracic (47%) and head (37%) injuries were also common. In the low risk quartile (n = 3053), most patients had a tibia fracture (67%), 5% had a thoracic injury, and less than 1% had head or spinal injuries. Among high risk patients, thromboembolic events did not differ statistically between aspirin and LMWH (win ratio, 0.94; 95% confidence interval [CI], 0.82-1.08, p = 0.42). This result was consistent in the low (win ratio, 1.15; 95% CI, 0.90-1.47, p = 0.27), low-medium (win ratio, 1.05; 95% CI, 0.85-1.29, p = 0.68), and medium-high risk quartiles (win ratio, 0.94; 95% CI, 0.80-1.11, p = 0.48). When medication satisfaction was considered, favorable outcomes were 68% more likely with aspirin (win ratio, 1.68; 95% CI, 1.60-1.77; p < 0.001). CONCLUSION: Thromboembolic outcomes were similar with aspirin or LMWH, even among patients at highest risk of VTE. Aspirin was favored if medication satisfaction was also considered. LEVEL OF EVIDENCE: Therapeutic/Care Management; Level II.

Socioeconomic status is associated with greater hazard of post-discharge mortality than race, gender, and ballistic injury mechanism in a young, healthy, orthopedic trauma population.

OBJECTIVES: To explore the utility of legacy demographic factors and ballistic injury mechanism relative to popular markers of socioeconomic status as prognostic indicators of 10-year mortality following hospital discharge in a young, healthy patient population with isolated orthopedic trauma injuries. METHODS: A retrospective cohort study was performed to evaluate patients treated at an urban Level I trauma center from January 1, 2003, through December 31, 2016. Current Procedure Terminology (CPT) codes were used to identify upper and lower extremity fracture patients undergoing operative fixation. Exclusion criteria were selected to yield a patient population of isolated extremity trauma in young, otherwise healthy individuals between the ages of 18 and 65 years. Variables collected included injury mechanism, age, race, gender, behavior risk factors, Area Deprivation Index (ADI), and insurance status. The primary outcome was post-discharge mortality, occurring at any point during the study period. RESULTS: We identified 2539 patients with operatively treated isolated extremity fractures. The lowest two quartiles of socioeconomic status (SES) were associated with higher hazard of mortality than the highest SES quartile in multivariable analysis (Quartile 3 HR: 2.2, 95% CI: 1.2-4.1, p = 0.01; Quartile 4 HR: 2.2, 95% CI: 1.1-4.3, p = 0.02). Not having private insurance was associated with higher mortality hazard in multivariable analysis (HR 2.0, 95% CI: 1.3-3.2, p = 0.002). The presence of any behavioral risk factor was associated with higher mortality hazard in univariable analysis (HR: 1.8, p < 0.05), but this difference did not reach statistical significance in multivariable analysis (HR: 1.4, 95%: 0.8-2.3, p = 0.20). Injury mechanism (ballistic versus blunt), gender, and race were not associated with increased hazard of mortality (p > 0.20). CONCLUSION: Low SES is associated with a greater hazard of long-term mortality than ballistic injury mechanism, race, gender, and medically diagnosable behavioral risk factors in a young, healthy orthopedic trauma population with isolated extremity injury.

Secondary Bony Defects after Soft Tissue Reconstruction in Limb-Threatening Lower Extremity Injuries: Does the Approach to Flap Elevation Matter?

BACKGROUND: Limb-threatening lower extremity injuries often require secondary bone grafting after soft tissue reconstruction. We hypothesized that there would be fewer wound complications when performing secondary bone grafting via a remote surgical approach rather than direct flap elevation. METHODS: A retrospective cohort study was performed at a single Level 1 trauma center comparing complications after secondary bone grafting in patients who had undergone previous soft tissue reconstruction after open tibia fractures between 2006 and 2020. Comparing bone grafting via a remote surgical incision versus direct flap elevation, we evaluated wound dehiscence requiring return to the operating room as the primary outcome. Secondary outcomes were deep infection and delayed amputation. RESULTS: We identified 129 patients (mean age: 40 years, 82% male) with 159 secondary bone grafting procedures. Secondary bone grafting was performed via a remote surgical approach in 54% (n = 86) and direct flap elevation in 46% (n = 73) of cases. Wound dehiscence requiring return to the operating room occurred in one patient in the flap elevation group (1%) and none of the patients in the remote surgical approach. The odds of deep wound infection (OR, 1.77; p = 0.31) or amputation (OR, 1.43; p = 0.73) did not significantly differ between surgical approaches. No significant differences were found in complications between the reconstructive surgeon elevating and re-insetting the flap and the orthopaedic trauma surgeon performing the flap elevation and re-inset. CONCLUSION: Direct flap elevation for secondary bone grafting after soft tissue reconstruction for open tibia fractures did not result in more complications than bone grafting via a remote surgical approach. These findings should reassure surgeons to allow other clinical factors to influence the surgical approach for bone grafting.

Predicting Which Species of Bacteria Will Cause an Infection After Fracture Surgery.

The aim of this study was to develop and validate risk prediction models for deep surgical site infection (SSI) caused by specific bacterial pathogens after fracture fixation. A retrospective case-control study was conducted at a level I trauma center. Fifteen candidate predictors of the bacterial pathogens in deep SSI were evaluated to develop models of bacterial risk. The study included 441 patients with orthopedic trauma with deep SSI after fracture fixation and 576 control patients. The main outcome measurement was deep SSI cultures positive for methicillin-sensitive Staphylococcus aureus (MSSA), methicillin-resistant S aureus (MRSA), gram-negative rods (GNRs), anaerobes, or polymicrobial infection within 1 year of injury. Prognostic models were developed for five bacterial pathogen outcomes. Mean area under the curve ranged from 0.70 (GNRs) to 0.74 (polymicrobial). Strong predictors of MRSA were American Society of Anesthesiologists (ASA) classification of III or greater (odds ratio [OR], 3.4; 95% CI, 1.6-8.0) and time to fixation greater than 7 days (OR, 3.4; 95% CI, 1.9-5.9). Gustilo type III fracture was the strongest predictor of MSSA (OR, 2.5; 95% CI, 1.6-3.9) and GNRs (OR, 3.4; 95% CI, 2.3-5.0). ASA classification of III or greater was the strongest predictor of polymicrobial infection (OR, 5.9; 95% CI, 2.7-15.5) and was associated with increased odds of GNRs (OR, 2.7; 95% CI, 1.5-5.5). Our models predict the risk of MRSA, MSSA, GNR, anaerobe, and polymicrobial infections in patients with fractures. The models might allow for modification of preoperative antibiotic selection based on the particular pathogen posing greatest risk for this patient population. [Orthopedics. 2024;47(1):e19-e25.].

Using Discrete Choice Experiments to Quantify Patient Preferences.

Discrete choice experiments are a robust technique for quantifying preferences. With this method, respondents are presented with a series of hypothetical comparisons described by attributes with varying levels. The aggregated choices from respondents can be used to infer the relative importance of the described attributes and acceptable trade-offs between attributes. The data generated from discrete choice experiments can aid surgeons in aligning patient values with treatment decisions and support the design of research that is responsive to patient preferences. This article summarizes the application of discrete choice experiments to orthopaedics. We share best practices for designing discrete choice experiments and options for reporting study results. Finally, we suggest opportunities for this method within our field.

Frequency and Characteristics of Posterior Labral Injuries in Operative Acetabular Fractures Treated Through a Posterior Approach: A Prospective Observational Study.

OBJECTIVES: The association between labral injuries and acetabular fractures is unknown. This study aimed to identify the frequency and characteristics of labral injuries in operatively treated acetabular fractures that cannot be identified on preoperative imaging. METHODS: . DESIGN: Prospective observational cohort. SETTING: Level I trauma center. PATIENT SELECTION CRITERIA: Adult patients with an acetabular fracture operatively treated through a posterior approach. OUTCOME MEASURES AND COMPARISONS: The frequency and characteristics of labral injuries. RESULTS: Fifty-three of 71 acetabular fractures (75%; 95% confidence interval, 63%-83%) demonstrated a labral injury visible via the posterior approach. Posterior labral injuries occurred in 89% of operative acetabular fracture patterns involving the posterior wall and most commonly represent a detachment of the posteroinferior labrum (n = 39, 75%). Fractures with a labral injury were more likely to have gluteus minimus damage (93% vs. 61%, P = 0.02), femoral head lesions (38% vs. 17%, P = 0.03), joint capsule detachment (60% vs. 33%, P = 0.05), and fracture patterns involving the posterior wall (89% vs. 50%, P = 0.05). CONCLUSIONS: This study describes the high rate (89%) of posterior labral injuries in posterior wall fractures, the most common injury pattern being a detachment of the posteroinferior labrum. Labral injuries in acetabular fractures may have important clinical implications and this study is the first to identify the frequency and characteristics of these injuries. Further studies should assess the relationship between labral injuries, treatment strategies, and the progression to post-traumatic osteoarthritis. LEVEL OF EVIDENCE: Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence.

Technical Factors Contributing to Nonunion in Supracondylar Distal Femur Fractures Treated With Lateral Locked Plating: A Risk-Stratified Analysis.

OBJECTIVE: To identify technical factors associated with nonunion after operative treatment with lateral locked plating. DESIGN: Retrospective cohort study. SETTING: Ten Level I trauma centers. PATIENT SELECTION CRITERIA: Adult patients with supracondylar distal femur fractures (OTA/AO type 33A or C) treated with lateral locked plating from 2010 through 2019. OUTCOME MEASURES AND COMPARISONS: Surgery for nonunion stratified by risk for nonunion. RESULTS: The cohort included 615 patients with supracondylar distal femur fractures. The median patient age was 61 years old (interquartile range: 46 -72years) and 375 (61%) were female. Observed were nonunion rates of 2% in a low risk of nonunion group (n = 129), 4% in a medium-risk group (n = 333), and 14% in a high-risk group (n = 153). Varus malreduction with an anatomic lateral distal femoral angle greater than 84 degrees, was associated with double the odds of nonunion compared to those without such varus [odds ratio, 2.1; 95% confidence interval (CI), 1.1-4.2; P = 0.03]. Malreduction by medial translation of the articular block increased the odds of nonunion, with 30% increased odds per 4 mm of medial translation (95% CI, 1.0-1.6; P = 0.03). Working length increased the odds of nonunion in the medium risk group, with an 18% increase in nonunion per 10-mm increase in working length (95% CI, 1.0-1.4; P = 0.01). Increased proximal screw density was protective against nonunion (odds ratio, 0.71; 95% CI, 0.53-0.92; P = 0.02) but yielded lower mRUST scores with each 0.1 increase in screw density associated with a 0.4-point lower mRUST (95% CI, -0.55 to -0.15; P < 0.001). Lateral plate length and type of plate material were not associated with nonunion. ( P > 0.05). CONCLUSIONS: Malreduction is a surgeon-controlled variable associated with nonunion after lateral locked plating of supracondylar distal femur fractures. Longer working lengths were associated with nonunion, suggesting that bridge plating may be less likely to succeed for longer fractures. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.