Influence of Age on Outcome Following Rib Fractures - A Case-Control Analysis.

Background: Thoracic injuries are a very common entity throughout all age groups. With rising numbers of geriatric patients, characteristics of this patient group need to be better defined. The aim of this study was to investigate the impact of age on the outcome of thoracic trauma. In this project we provide a stratification of differentiated age groups regarding outcome parameter on rib fractures. Methods: The study employed a retrospective design using data from patients who sustained thoracic trauma and received treatment at a level I trauma center over a 5-year period. Patients with the same pattern of injury and gender but different age (above and below 70 years) were matched. Results: The mean age of the study population was 57 ± 19 years, 69% were male, 54% of patients had preexisting comorbidities. Hemothorax was present in 109 (16%), pneumothorax in 204 (31%) and lung contusions in 136 patients (21%). The overall complication rate was 36%, with a mortality rate of 10%. The matched pair analysis of 70 pairs revealed a higher prevalence of comorbidities in the older age group. They had significantly fewer pulmonary contusions and pneumothoraces than the younger patients and a shorter length of stay. However, the older age group had a significantly higher mortality rate. Conclusions: Geriatric patients with rib fractures exhibit different patterns of intrathoracic injuries compared to their younger counterparts. Although numeric age may not be the most accurate predictor of adverse outcome, we found that higher age was associated with a clear trend towards an increased mortality rate. Our findings build a basis for further research to evaluate the outcome of age for instance with the tool of a rib fracture scoring system within stratified age groups in order to identify patients at major risk.

Fixation of rib fractures is beneficial for patients with chronic obstructive pulmonary disease, a trauma quality improvement program study.

BACKGROUND: Internal fixation for multiple rib fractures is well established. Patients with underlying chronic obstructive pulmonary disease (COPD) have a higher rate of perioperative complications. It is unclear if these patients are suitable candidates for internal fixation and if surgical interventions are harmful to these patients. STUDY DESIGN AND METHODS: Adult patients with ≥ 3 rib fractures and underlying COPD from the Trauma Quality Improvement Program between 2017 and 2019 were eligible for inclusion. The patients were divided into two treatment groups: operative and non-operative. Furthermore, inverse probability treatment weighting was applied to analyze mortality and adverse hospital events. RESULTS: Patients with COPD in the operative group had higher ventilator use (odds ratio [OR], 3.211; 95% confidence interval [CI], 1.993-5.175; p < 0.001). Additionally, they had a longer length of stay (coefficient ß, 4.139; standard error, 0.829; p < 0.001) and longer ventilator days (coefficient ß, 1.937; standard error, 0.655; p = 0.003) than in the non-operative group. Furthermore, the mortality rate was lower in the operative group than in the non-operative group (OR, 0.426; 95% CI, 0.228-0.798; p = 0.008). CONCLUSION: Internal fixation of rib fractures plays a crucial role in patients with underlying COPD disease. They presented a better mortality rate without an increased perioperative complication rate.

Unexpected Foreign Body-Induced Small Bowel adenocarcinoma: A Case Report.

Background: Foreign body-induced cancer is a traditional way of understanding cancer development. The induction of cancers by exogenous foreign bodies has been identified in many organs. However, small bowel adenocarcinoma induced by foreign bodies has not been reported in the literature, although the incidence of small bowel adenocarcinoma is increasing globally. Case Presentation: A 70-year-old man was hospitalized for persistent right-sided abdominal pain for 3 months. Abdominal computed tomography revealed localized thickening and clustering of the small bowel wall in the right abdominal cavity. A comminuted fracture of the right 11th rib protruding into the abdominal cavity was observed, with a bone fragment located within the intestinal mass. Exploratory laparotomy was performed, and extensive adhesions were noted among the greater omentum, small bowel, mesentery, and right abdominal wall. Radical resection and lymph node dissection of the affected small bowel and appendix were performed. We also excised the rib end and repaired the abdominal wall to prevent further irritation. The patient was discharged 12 days post-surgery and follow-up assessments revealed no reported discomfort. Conclusion: We first report a case of small bowel adenocarcinoma induced by self-bone tissue, along with successful radical tumor excision and thorough foreign body removal. This case highlights the significant role of chronic inflammation in carcinogenesis.

Excision of Giant Chronic Expanding Hematoma of the Thorax Caused by Rib Fractures after Proton Radiotherapy for Lung Cancer.

Chronic expanding hematoma (CEH) is defined as a hematoma that gradually expands over months to years. An 82-year-old female underwent proton radiotherapy for left upper lobe lung cancer 10 years previously. Two years after the therapy, a hematoma developed from the left 3rd to 5th dorsal rib fractures and gradually expanded, causing contraction of the left shoulder. Transcatheter arterial embolization was performed; however, the hematoma continued to expand with thrombocytopenia, and the platelet was decreased to 4.2 × 104/µL. Computed tomography showed a 17.2 × 14.0 × 10.0 cm mass between the left scapula and left dorsal ribs. The CEH of the thorax was completely excised with combined resection of the 3rd to 5th ribs, while the brachial plexus was preserved. Postoperatively, the platelet completely recovered and she could raise her left arm. A complete excision with surrounding organs preserved is the strategy used in the treatment of CEH of the thorax.

Does PIC score pick correctly? Evaluation of a modified-PIC based admission a single institution retrospective cohort study.

INTRODUCTION: The Pain, Inspiratory effort, Cough score (PIC) has been developed and widely adopted to guide clinical prognostication for patients with chest wall injury. To date, the efficacy, accuracy, and safety of a PIC based triage system has not been validated. Therefore, this study sought to evaluate the use of a modified-PIC score to triage and down-grade trauma patients with chest wall injury at a single institution. METHODS: A retrospective study was conducted at a large, Level I Trauma Center on patients with chest wall injuries admitted between 1/1/2018-10/31/20,222. On 12/1/2020, our institution implemented a modified-PIC triage tool including the PIC score, age, and severity of chest wall injury. The Pre-PIC (1/1/2018-11/20/2020) and Post-PIC (1/1/2021-10/31/2022) groups were composed based on admission date and outcomes between the two were compared. RESULTS: 2,627 patients comprised the Pre-PIC group and 2,212 patients comprised Post-PIC. The groups didn't differ significantly in demographics or mechanisms of injury except for COVID status. Post-intervention, a greater proportion of patients were triaged to the intermediate care unit instead of the ICU or floor. There were no significant differences in hospital length of stay (LOS), ventilator days, unplanned ICU admission, or mortality in Pre-PIC vs Post-PIC. ICU LOS, rates of ARDS, and cardiac arrest with return of spontaneous circulation (ROSC) were significantly lower in Post-PIC. Multivariable models demonstrated significantly lower ARDS rates and ICU free days. ICU LOS trended towards significance as well. CONCLUSIONS: This is the largest study, to date, evaluating the impact of a modified-PIC triage system on clinical outcomes. The results suggest a modified-PIC triage system may lead to decreased ICU days, ARDS rates, and rates of cardiac arrest w/ ROSC, potentially improving hospital resource allocation. Further prospective and multi-center studies are needed to validate our understanding on the impact of a chest wall scoring system on triage and outcomes.

Retrospective cohort study of video-assisted thoracoscopic precise positioning reduction and internal fixation and thoracotomy reduction and internal fixation in treating multiple rib fractures.

Objective: This study aimed to assess the clinical effect of video-assisted thoracoscopic precise positioning reduction and internal fixation and thoracotomy reduction and internal fixation in the therapy of multiple rib fractures. Methods: A total of 80 patients with multiple rib fractures in First People's Hospital of Jingzhou from January 2021 to December 2022 were separated into control group (CG, 40 cases) and research group (RG, 40 cases) by random number table method. Patients in the CG received thoracotomy reduction and internal fixation. Patients in the RG received video-assisted thoracoscopic precise positioning reduction and internal fixation. Surgery-related indexes, serum interleukin, visual analogue scale (VAS) was used to evaluate postoperative pain, arterial oxygen saturation (SaO2) and oxygenation index (PaO2/FiO2), and pulmonary function indexes were measured in the two groups. Results: After surgery, Visual analog scale (VAS) scores at 24 hour after surgery were reduced compared to six hour and 12 hour after surgery (P<0.05). VAS score at 12 hour after surgery was increased relative to 6 h after surgery (P<0.05), and VAS score at six hour, 12 hour as well as 24 hour after surgery in the RG was lessened in comparison with the CG (P<0.05). One day after surgery, SaO2 and PaO2/FiO2 in two groups were elevated compared to before surgery, and those in RG was increased in contrast to the CG (P<0.05). forced expiratory volume (FEV1), forced vital capacity (FVC), peak expiratory flow velocity (PEF) along with FEV1/FVC levels in two groups were increased (P<0.05). Conclusion: Compared with thoracotomy reduction and internal fixation, video-assisted thoracoscopic accurate positioning and internal fixation in treating patients with multiple rib fractures had a short treatment time, obvious advantages, and strong feasibility.

Do we have to redefine type B-fractures of the rib cartilage?

OBJECTIVES: Aim of this work was the evaluation and validation of the AO/OTA classification of the anterior chest wall, here especially for the rib cartilage. METHODS: Study design was a retrospective analysis of patients who were hospitalized with fractures of the thoracic wall in the years 2010-2016. This resulted in a collective of n = 124 patients. All fractures of the anterior chest wall were classified according to their location, dislocation and fracture type according to the AO classification. An analysis of possible subtypes was carried out. RESULTS: 29.0% (36) of the patients had fractures of the rib cartilage. 23 of the 36 (64%) patients had multiple fractures, the total number of single fractures amounted to 94. 53.2% (50) of these fractures were in the right hemithorax, 46.8% (44) in the left hemithorax. 95.7% (90) of the fractures were A-fractures, 4.3% (4) were C-fractures. There were no B fractures. The C fractures also consisted exclusively of A fractures (AA fractures). 59.6% (56) of the fractures showed a dislocation. 30.9% (29) were avulsion fractures of either the osteochondral (22.3% (21)) or the sternocostal junction (8.5% (8)). DISCUSSION AND CONCLUSION: The costal cartilage obviously does not show typical B fractures as we know them from shaft fractures of long bones. We have compiled a structured analysis in the attached manuscript and validated the classification proposal. In conclusion, we propose an adaptation of the classification proposal based on our data with redefining type B fractures as fractures of the osteochondral joints.

Age-Neutral Surgical Stabilization of Rib Fractures: Breaking the Ageism Barrier.

INTRODUCTION: Surgical stabilization of rib fractures (SSRF) is associated with lower rates of mortality and fewer complications. This study evaluates whether the decision to undergo SSRF is associated with age, race, ethnicity, and insurance status and assesses associated clinical outcomes. METHODS: This retrospective analysis included patients ≥45 y old with rib fractures who underwent SSRF in the Trauma Quality Improvement Program from 2016 to 2020. Race, ethnicity, and insurance statuses were collected. Age in years was dichotomized into two groups: 45-64 and 65+. Outcomes included ventilator-associated pneumonia, unplanned endotracheal intubation, acute respiratory distress syndrome, in-hospital mortality, failure to rescue (FTR) after major complications, and FTR after respiratory complications. Logistic regression models were fit to evaluate outcomes, controlling for gender, body mass index, Injury Severity Score, flail chest, chronic obstructive pulmonary disease, congestive heart failure, and smoking. RESULTS: Two thousand eight hundred thirty-nine patients aged 45-64 and 1828 patients aged 65+ underwent SSRF. No significant difference in clinical outcomes was noted between these groups. Analysis showed that the association of SSRF with ventilator-associated pneumonia, unplanned intubation, acute respiratory distress syndrome, in-hospital mortality, FTR after a major complication, or FTR after a respiratory complication did not vary by age (P > 0.05). Black (odds ratio [OR] 0.67; 95% confidence interval [CI]: 0.59-0.77; P < 0.001), Hispanic (OR 0.80; 95% CI: 0.71-0.91; P < 0.001), and Medicaid (OR = 0.85; 95% CI = 0.76-0.95; P = 0.005) patients were less likely to receive SSRF. CONCLUSIONS: No differences in clinical outcomes were measured between adults aged 45-64 and ≥65 who underwent SSRF. Older age should not preclude patients from receiving SSRF. Further work is needed to improve underutilization in Black, Hispanic and Medicaid patients.

A biomechanical study of a polymer material bundled rib fracture fixator.

BACKGROUND: Rib fractures are one of the most common blunt injuries, accounting for approximately 10% of all trauma patients and 60% of thoracic injuries. Multiple rib fractures, especially flail chest, can cause local chest wall softening due to the loss of rib support, leading to paradoxical breathing, severe pain, and a high likelihood of accompanying lung contusions. OBJECTIVE: This study investigates the mechanical properties of a new polymer material rib internal fixator to provide theoretical data for its clinical use. METHODS: We conducted in vitro mechanical tests on 20 fresh caudal fin sheep ribs, using different fracture models across four randomly assigned groups (five ribs per group). The fixators were assessed using non-destructive three-point bending, torsion, and unilateral compression tests, with results averaged. Additionally, finite element analysis compared stress and strain in the polymer fixators and titanium alloy rib plates during bending and torsion tests. RESULTS: In vitro tests showed that the polymer fixators handled loads effectively up to a maximum without increase beyond a certain displacement. Bending and torsion tests via finite element analysis showed the polymer material sustained lower maximum equivalent stresses (84.455 MPa and 14.426 MPa) compared to titanium alloy plates (219.88 MPa and 46.47 MPa). CONCLUSION: The polymer rib fixator demonstrated sufficient strength for rib fracture fixation and was superior in stress management compared to titanium alloy plates in both bending and torsion tests, supporting its potential clinical application.

Traumatic Pulmonary Embolism.

Pulmonary embolism (PE) is a life-threatening illness caused by a blood clot obstructing a pulmonary artery, resulting in decreased blood supply to the lungs. PE is a high-stakes diagnosis with considerable morbidity and death if left untreated. This case emphasizes the increased risk of PE associated with trauma and stresses the importance of this differential diagnosis in patients who report dyspnea following physical trauma. Understanding the risk factors and processes that contribute to PE in trauma patients is critical for accurate diagnosis and treatment.

Cumulative rib fracture risk after stereotactic body radiotherapy in patients with localized non-small cell lung cancer.

INTRODUCTION: Rib fracture is a known complication after stereotactic body radiotherapy (SBRT). Patient-related parameters are essential to provide patient-tailored risk estimation, however, their impact on rib fracture is less documented compared to dosimetric parameters. This study aimed to predict the risk of rib fractures in patients with localized non-small cell lung cancer (NSCLC) post-SBRT based on both patient-related and dosimetric parameters with death as a competing risk. MATERIALS AND METHODS: In total, 602 patients with localized NSCLC treated with SBRT between 2010-2020 at Odense University Hospital, Denmark were included. All patients received SBRT with 45-66 Gray (Gy)/3 fractions. Rib fractures were identified in CT-scans using a word embedding model. The cumulative incidence function was based on cause-specific Cox hazard models with variable selection based on cross-validation model likelihood performed using 50 bootstraps. RESULTS: In total, 19 % of patients experienced a rib fracture. The cumulative risk of rib fracture increased rapidly from 6-54 months post-SBRT. Female gender, bone density, near max dose to the rib, V30 and V40 to the rib, gross tumor volume, and mean lung dose were significantly associated with rib fracture risk in univariable analysis. The final multi-variable model consisted of V20 and V30 to the rib and mean lung dose. CONCLUSION: Female gender and low bone density in male patients are significant predictors of rib fracture risk. The final model predicting cumulative rib fracture risk of 19 % in patients with localized NSCLC treated with SBRT contained no patient-related parameters, suggesting that dosimetric parameters are the primary drivers.

A bone tumor-like chest wall mass lesion with pathological rib fractures observed 13 years after lung stereotactic body radiotherapy: A case report.

Although stereotactic body radiotherapy (SBRT) is a curative treatment option for stage I non-small cell lung cancer (NSCLC), limited data are available regarding chest wall (CW) toxicities during an extended follow-up of over 10 years. We report an unusual case of a bone tumor-like CW mass lesion with pathological rib fractures observed 13 years after SBRT for peripheral lung cancer. Despite the initial suspicion of radiation-induced sarcoma, a subsequent incisional biopsy revealed no evidence of malignancy, and a definitive diagnosis of osteonecrosis was made. Thus, long-term observation of over 10 years is required to identify late chronic complications following SBRT.

Incidence and impact of involuntary rib fracture after intercostal spreading for thoracotomy.

Thoracotomy with rib spreading still remains the preferred approach for complex surgery. Rib fracture is considered a frequent involuntary event during this approach, but its real incidence has not been adequately investigated yet. In this study, we evaluated the incidence of rib fracture after thoracotomy, the possible risk factors and the relationship with post-operative pain and complications. We retrospectively analyzed the medical records of single-institution patients submitted to lateral thoracotomy from January 2016 to June 2023. Exclusion criteria were traumatic etiology and a medical history of osteoporosis. The presence of rib fracture was retrieved by surgical reports or post-operative chest X-ray. Basal and evoked pain after surgery was assessed by Visual Analogue Scale. The considered 30-day post-operative complications were atelectasis, need of endoscopic broncho-aspiration, pneumonia and pleural effusion. A total of 367 consecutive patients underwent thoracotomy in the study period. The median age was 68 (interquartile range 60-75) years. Rib fracture was detected in 179/367 (48.8%) patients. Incidence did not significantly vary throughout years (p = 0.98). The risk of developing post-thoracotomy rib fractures was significantly associated with age greater than the median value (p = 0.003). The presence of rib fracture was related to significantly more elevated evoked pain at 48 h after surgery (p = 0.039) and a higher incidence of complications (32/179 vs 20/188; p = 0.047). Our study demonstrated that rib fracture occurs in almost half of the thoracotomies. Older patients are more likely to develop this event, which significantly correlates to increased evoked post-operative pain and higher rate of post-operative complications.

Long-term trends in incidence and outcomes of rib fractures: A population-based data linkage study from New South Wales, Australia.

OBJECTIVE: Determine long-term trends in population-based incidence and outcomes of rib fracture hospitalisations. METHODS: This was a data linkage study of rib fracture cases identified between 2015 and 2022 in New South Wales, Australia. Routinely collected health data were linked between ED, admitted patient and death registry data collection. The primary outcomes were age-specific incidence of rib fracture hospitalisation cases and risk-adjusted 30 days mortality. Other outcomes of interest were hospital length of stay (LOS), admission rate and ICU admissions. RESULTS: A total of 70 609 cases were analysed. Overall, the number of rib fracture hospitalisations increased by 25% between 2015 and 2022. The highest proportion of cases was in the 45-65 years (28%) and 65-85 years (31%) age groups. On a per population basis, the incidence rate increased by 2% per annum. After adjusting for age, comorbidity and injury severity, there was no significant trend in 30 days mortality observed between 2015 and 2022. The median inpatient LOS was 4 days with 38% of patients staying 1-2 days. Regional and rural areas were associated with more severe chest injuries. CONCLUSION: Rib fracture hospitalisations have increased with older patients driving this trend.

Development and Validation of an Artificial Intelligence Model for Detecting Rib Fractures on Chest Radiographs.

Background: Chest radiography is the standard method for detecting rib fractures. Our study aims to develop an artificial intelligence (AI) model that, with only a relatively small amount of training data, can identify rib fractures on chest radiographs and accurately mark their precise locations, thereby achieving a diagnostic accuracy comparable to that of medical professionals. Methods: For this retrospective study, we developed an AI model using 540 chest radiographs (270 normal and 270 with rib fractures) labeled for use with Detectron2 which incorporates a faster region-based convolutional neural network (R-CNN) enhanced with a feature pyramid network (FPN). The model's ability to classify radiographs and detect rib fractures was assessed. Furthermore, we compared the model's performance to that of 12 physicians, including six board-certified anesthesiologists and six residents, through an observer performance test. Results: Regarding the radiographic classification performance of the AI model, the sensitivity, specificity, and area under the receiver operating characteristic curve (AUROC) were 0.87, 0.83, and 0.89, respectively. In terms of rib fracture detection performance, the sensitivity, false-positive rate, and free-response receiver operating characteristic (JAFROC) figure of merit (FOM) were 0.62, 0.3, and 0.76, respectively. The AI model showed no statistically significant difference in the observer performance test compared to 11 of 12 and 10 of 12 physicians, respectively. Conclusions: We developed an AI model trained on a limited dataset that demonstrated a rib fracture classification and detection performance comparable to that of an experienced physician.

Surgical stabilization of rib fractures in anticoagulated patients: Proceed with caution?

BACKGROUND: Surgical stabilization of rib fractures (SSRF) is increasingly performed, however the outcome of patients undergoing SSRF while on pre-injury antithrombotic therapy remains unknown. We compared surgical variables and outcomes of patients who were and were not on antithrombotic therapy. We hypothesize pre-injury anticoagulation is associated with delay in SSRF and worse outcomes. METHODS: For this retrospective cohort study, we queried the Chest Injury International Database, for patients undergoing SSRF between 08/2018 and 03/2022. Antithrombotic therapy was categorized into antiplatelet and anticoagulant use. Primary outcome was time from admission to SSRF. Secondary outcomes included SSRF duration and complications. Numerical data were presented as median (IQR), categorical data as number (%). Inverse probability weighting was used to control for confounding. RESULTS: Two hundred and eighteen SSRF patients were included, 25 (11 %) were on antithrombotic therapy. These patients were older (72 years, (65-80) versus 57 years, (43-66); p < 0.001) with lower ISS (14, (10-20) versus 21, (14-30); p = 0.002). Time from admission to SSRF was comparable (2 days, (1-4) versus 2 days, (1-4); p = 0.37) as was operative time (154 mins, (120.0-212.0) versus 177 mins, (143.0-210.0); p = 0.34). Patients using antithrombotics had fewer ICU-free days (24 (22-26) versus 28 (23-28); p = 0.003) but more ventilator free days (28, (28-28) versus 27 (27-28); p < 0.008). After adjusting for confounding, pre-injury anticoagulation was not significantly associated with delayed SSRF (Relative Risk, RR=1.37, 95 % CI 0.30-6.24), operative time (RR=1.07, 95 % CI0.88-1.31), IFD <=28 (RR=2.05, 95 %CI:0.33-12.67), VFD<=27 (RR=0.71, 95 %CI:0.15-3.48) or complications (RR=0.55, 95 % CI0.06-5.01). CONCLUSION: Pre-injury antithrombotic drug use neither delayed SSRF nor impacted operative time in patients requiring SSRF and was not associated with increased risk of complications. Our data suggest SSRF can be safely performed without delay in patients who use anticoagulation pre-injury. LEVEL OF EVIDENCE: IV. STUDY TYPE: Therapeutic/care management.

Intercostal nerve electrodiagnostic testing in rib fractures.

INTRODUCTION/AIMS: Intercostal nerve injury can occur after rib fractures, resulting in denervation of the abdominal musculature. Loss of innervation to the rectus abdominis and intercostal muscles can cause pain, atrophy, and eventual eventration, which may be an underrecognized and thus undertreated complication of rib fractures. We investigated the clinical utility of intercostal nerve electrodiagnostic testing following rib fractures to diagnose and localize nerve injury at levels T7 and below. METHODS: Five patients with displaced bicortical rib fractures involving the 7th-11th ribs and clinical eventration of the ipsilateral abdominal wall underwent intercostal nerve conduction studies (NCS) and needle electromyography (EMG) on the affected side. EMG of the rectus abdominis and intercostal muscles was performed with ultrasound guidance, and ultrasound measurements of rectus abdominis thickness were obtained to assess for atrophy. RESULTS: Average patient age was 59.4 years and average body mass index (BMI) was 31.5 kg/m2. Intercostal NCS and EMG were able to reliably diagnose and localize intercostal nerve damage after rib fractures. Ultrasound demonstrated an average rectus abdominis transverse cross-sectional thickness of 0.534 cm on the affected side, compared with 1.024 cm on the non-affected side. DISCUSSION: Intercostal electrodiagnostic studies can diagnose and localize intercostal nerve damage after displaced rib fractures. Musculoskeletal ultrasound can be used to diagnose and quantify rectus abdominis atrophy and to accurately and safely guide needle EMG to the intercostal and rectus abdominis muscles.

Pectoralis Muscle Index as Predictor of Outcomes in Patients With Severe Blunt Chest Wall Injury.

INTRODUCTION: Sarcopenia has been shown to portend worse outcomes in injured patients; however, little is known about the impact of thoracic muscle wasting on outcomes of patients with chest wall injury. We hypothesized that reduced pectoralis muscle mass is associated with poor outcomes in patients with severe blunt chest wall injury. METHODS: All patients admitted to the intensive care unit between 2014 and 2019 with blunt chest wall injury requiring mechanical ventilation were retrospectively identified. Blunt chest wall injury was defined as the presence of one or more rib fractures as a result of blunt injury mechanism. Exclusion criteria included lack of admission computed tomography imaging, penetrating trauma, <18 y of age, and primary neurologic injury. Thoracic musculature was assessed by measuring pectoralis muscle cross-sectional area (cm2) that was obtained at the fourth thoracic vertebral level using Slice-O-Matic software. The area was then divided by the patient height in meters2 to calculate pectoralis muscle index (PMI) (cm2/m2). Patients were divided into two groups, 1) the lowest gender-specific quartile of PMI and 2) second-fourth gender-specific PMI quartiles for comparative analysis. RESULTS: One hundred fifty-three patients met the inclusion criteria with a median (interquartile range) age 48 y (34-60), body mass index of 30.1 kg/m2 (24.9-34.6), and rib score of 3.0 (2.0-4.0). Seventy-five percent of patients (116/153) were male. Fourteen patients (8%) had prior history of chronic lung disease. Median (IQR) intensive care unit length-of-stay and duration of mechanical ventilation (MV) was 18.0 d (13.0-25.0) and 15.0 d (10.0-21.0), respectively. Seventy-three patients (48%) underwent tracheostomy and nine patients (6%) expired during hospitalization. On multivariate linear regression, reduced pectoralis muscle mass was associated with increased MV duration when adjusting for rib score and injury severity score (ß 5.98, 95% confidence interval 1.28-10.68, P = 0.013). CONCLUSIONS: Reduced pectoralis muscle mass is associated with increased duration of MV in patients with severe blunt chest wall injury. Knowledge of this can help guide future research and risk stratification of critically ill chest wall injury patients.

Near-pair patch generative adversarial network for data augmentation of focal pathology object detection models.

Purpose: The limited volume of medical training data remains one of the leading challenges for machine learning for diagnostic applications. Object detectors that identify and localize pathologies require training with a large volume of labeled images, which are often expensive and time-consuming to curate. To reduce this challenge, we present a method to support distant supervision of object detectors through generation of synthetic pathology-present labeled images. Approach: Our method employs the previously proposed cyclic generative adversarial network (cycleGAN) with two key innovations: (1) use of "near-pair" pathology-present regions and pathology-absent regions from similar locations in the same subject for training and (2) the addition of a realism metric (Fréchet inception distance) to the generator loss term. We trained and tested this method with 2800 fracture-present and 2800 fracture-absent image patches from 704 unique pediatric chest radiographs. The trained model was then used to generate synthetic pathology-present images with exact knowledge of location (labels) of the pathology. These synthetic images provided an augmented training set for an object detector. Results: In an observer study, four pediatric radiologists used a five-point Likert scale indicating the likelihood of a real fracture (1 = definitely not a fracture and 5 = definitely a fracture) to grade a set of real fracture-absent, real fracture-present, and synthetic fracture-present images. The real fracture-absent images scored 1.7±1.0, real fracture-present images 4.1±1.2, and synthetic fracture-present images 2.5±1.2. An object detector model (YOLOv5) trained on a mix of 500 real and 500 synthetic radiographs performed with a recall of 0.57±0.05 and an F2 score of 0.59±0.05. In comparison, when trained on only 500 real radiographs, the recall and F2 score were 0.49±0.06 and 0.53±0.06, respectively. Conclusions: Our proposed method generates visually realistic pathology and that provided improved object detector performance for the task of rib fracture detection.

Bilateral first rib fractures with multi-organ complications: A case report and literature review.

Background: Bilateral first rib fractures are rare. This article presented the diagnosis and treatment of a case of bilateral first rib fractures with multi-organ complications and discussed the injury mechanism. Case presentation: A 15-year-old girl fell off a motorcycle. She complained of right neck root pain and right upper limb weakness. The myodynamia of the right upper limb was grade 0, and the sensation disappeared below the level of the elbow joint. The computed tomography (CT) showed bilateral first rib fractures and transverse process fracture of the 6th cervical vertebra. Chest CT revealed a massive hemothorax in the right thoracic cavity, and head magnetic resonance imaging showed bilateral cerebellar infarction. Cervical computed tomography angiography (CTA) revealed a lumen occlusion at the origin of the right subclavian artery. The patient underwent an emergency thoracoscopy, and a re-examination of chest CT indicated that no obvious pleural effusion was found after the hemothorax was cleared. The patient underwent right subclavian arteriography and interventional endovascular thrombolysis, and the right subclavicular artery was patency postoperative. Bilateral first rib fractures and cerebellar infarction were treated conservatively. The brachial plexus injury did not show any signs of recovery after conservative treatment, and she was recommended to be transferred to a superior hospital for surgical treatment. Conclusions: The injury mechanism of bilateral first rib fractures with multi-organ complications was closely related to the initial factor of the right neck root colliding with a bulge on the ground. We believe that the fractures occur as a result of a combination including a high energy trauma from direct impact and a low-energy mechanism from violent muscle contraction caused by neck hyperextension. This case report was helpful for clinicians to understand bilateral first rib fractures and their complications.