Multiple rib fractures: does flail chest matter?

BACKGROUND: Recent studies have reported significant morbidity and mortality in patients with multiple rib fractures, even without flail chest. The aim of this study was to compare the clinical outcome and incidence of associated chest injuries between patients with and without flail chest, with three or more rib fractures. METHODS: This study included patients with blunt trauma with at least three rib fractures, hospitalised during 2010-2019 in the Hillel Yaffe Medical Center in central Israel (level II trauma centre). Patients with and without radiologically defined flail chest were compared with regard to demographics, Injury Severity Score (ISS), GCS, systolic blood pressure (SBP) on admission, radiological evidence of flail chest, associated chest injuries, length of stay in intensive care unit, length of hospitalisation and mortality. RESULTS: The study included 407 patients, of which 79 (19.4%) had flail chest. Overall, pneumothorax and haemothorax were more common among patients with flail chest (p<0.05). When comparing patients with three to five rib fractures, there was no difference in length of intensive care and length of hospitalisation or mortality; however, there was a higher incidence of pneumothorax (24.6% vs 50.0%, p<0.05). When comparing patients with six or more rib fractures, no difference was found between patients with and without flail chest. CONCLUSION: In patients with three to five rib fractures, pneumothorax is more common among patients with flail chest. Clinical significance of flail chest in patients with more than six rib fractures is questionable and flail chest may not be a reliable marker for severity of chest injury in patients with more than six fractures.

Automatic Detection and Classification of Rib Fractures on Thoracic CT Using Convolutional Neural Network: Accuracy and Feasibility.

OBJECTIVE: To evaluate the performance of a convolutional neural network (CNN) model that can automatically detect and classify rib fractures, and output structured reports from computed tomography (CT) images. MATERIALS AND METHODS: This study included 1079 patients (median age, 55 years; men, 718) from three hospitals, between January 2011 and January 2019, who were divided into a monocentric training set (n = 876; median age, 55 years; men, 582), five multicenter/multiparameter validation sets (n = 173; median age, 59 years; men, 118) with different slice thicknesses and image pixels, and a normal control set (n = 30; median age, 53 years; men, 18). Three classifications (fresh, healing, and old fracture) combined with fracture location (corresponding CT layers) were detected automatically and delivered in a structured report. Precision, recall, and F1-score were selected as metrics to measure the optimum CNN model. Detection/diagnosis time, precision, and sensitivity were employed to compare the diagnostic efficiency of the structured report and that of experienced radiologists. RESULTS: A total of 25054 annotations (fresh fracture, 10089; healing fracture, 10922; old fracture, 4043) were labelled for training (18584) and validation (6470). The detection efficiency was higher for fresh fractures and healing fractures than for old fractures (F1-scores, 0.849, 0.856, 0.770, respectively, p = 0.023 for each), and the robustness of the model was good in the five multicenter/multiparameter validation sets (all mean F1-scores > 0.8 except validation set 5 [512 × 512 pixels; F1-score = 0.757]). The precision of the five radiologists improved from 80.3% to 91.1%, and the sensitivity increased from 62.4% to 86.3% with artificial intelligence-assisted diagnosis. On average, the diagnosis time of the radiologists was reduced by 73.9 seconds. CONCLUSION: Our CNN model for automatic rib fracture detection could assist radiologists in improving diagnostic efficiency, reducing diagnosis time and radiologists' workload.

Determining the clinical significance of the Chest Wall Injury Society taxonomy for multiple rib fractures.

BACKGROUND: The Chest Wall Injury Society (CWIS) proposals for standardized nomenclature for multiple rib fracture (MRF) classifications were derived by international expert Delphi consensus. This study aimed to validate the CWIS taxonomy using a single-instituion clinical database. METHODS: Computed tomography (CT) scans, of 539 consecutive patients with MRFs admitted to a regional major trauma center over a 33-month period, were reviewed (blinded for clinical outcomes). Every rib fracture in every patient was assessed according to each of the CWIS criteria (the degree of displacement, characterization of the fracture line, location of each fracture, and the relationship to neighboring fractures). The clinical significance of the proposed CWIS definitions were determined from independently coded, routinely collected Hospital Episodes Statistics data. RESULTS: The radiologic aspects of 3,944 individual rib fractures were assessed. Indicators of injury severity (severe displacement greater series length, and flail segment) were positively associated with other fractures (p < 0.001), hemopneumothorax (p < 0.001), pulmonary complications (p = 0.002), adverse outcomes (p = 0.006), mechanical ventilation (p < 0.001) and prolonged hospital and intensive therapy unit length of stay (p = 0.006, p = 0.007 respectively). Four of the CWIS-proposed definitions were correlated with pulmonary complications and adverse outcomes: the categories of displacement, the definition of individual fracture characterization, the presence of a flail segment. Two definitions for which there was CWIS consensus were not correlated with clinical outcomes: the definition of a series to describe associated fractures on neighboring ribs, the inclusion of a paravertebral sector for fracture localization. CONCLUSION: The CWIS rib fracture taxonomy demonstrates clinical relevance. There were associations between the severity of category groups within three of the proposed definitions, based on the clinical outcomes observed. Clinical outcome assessment proved inconclusive for four agreed definitions. Comprehensive, multiinstitutional data collection would be required to provide validation for all the CWIS-proposed definitions. LEVELS OF EVIDENCE: Level IV.

An Interobserver Agreement Study with a New Classification for Rib Fractures.

Background: No consensus exists about the indication for surgical rib fixation in patients with rib fractures. Comparison between studies is difficult since a classification system is lacking for rib fractures. We introduced the first classification system for rib fractures, analogue to the Muller AO classification system and tested the classification with an interobserver agreement study. Methods: The classification is build up by four characters: the first one describes the rib number, the second character describes the location of the fracture in cranial-caudal fashion, the third character describes the fracture type and the fourth character described the subtype of the fracture. An interobserver agreement study was performed with the new classification. Results: Twenty CT scans of patients with rib fractures were analyzed. A total of 197 unilateral and bilateral rib fractures were scored by four reviewers. The interobserver agreement was substantial [Fleiss of 0.62 (95% CI 0.59 0.65)]. Conclusion: This is the first classification for rib fractures worldwide. The interobserver agreement of the classification was substantial. This classification is the first step in identifying patients who would benefit from surgical rib fixation.

A proposed scheme for classifying pediatric rib head fractures using case examples.

Pediatric rib head fractures are typically described as "posterior" or "costovertebral," terms lacking specificity. To resolve this issue, a scheme was developed to describe the location of rib head fractures observed in a pediatric forensic population. The scheme uses three anatomical landmarks, terminus (tip), tubercle, and costovertebral articular surface to divide the rib head into two subregions, costovertebral and costotransverse. Examples of five cases of infants with rib head fractures are presented using this scheme. Forty-eight rib head fractures were observed in these infants with the following frequencies: 56% (three infants) at the terminus; 21% (three infants) in the costovertebral subregion; 21% (one infant) at the costovertebral articular facet; and 2% (one infant) in the costotransverse subregion. Due to the small number of cases assessed, statistical analyses could not be performed; however, the data demonstrate the variation in distribution of pediatric rib head fractures.

Stress fractures of the ribs and upper extremities: causation, evaluation, and management.

Stress fractures are common troublesome injuries in athletes and non-athletes. Historically, stress fractures have been thought to predominate in the lower extremities secondary to the repetitive stresses of impact loading. Stress injuries of the ribs and upper extremities are much less common and often unrecognized. Consequently, these injuries are often omitted from the differential diagnosis of rib or upper extremity pain. Given the infrequency of this diagnosis, few case reports or case series have reported on their precipitating activities and common locations. Appropriate evaluation for these injuries requires a thorough history and physical examination. Radiographs may be negative early, requiring bone scintigraphy or MRI to confirm the diagnosis. Nonoperative and operative treatment recommendations are made based on location, injury classification, and causative activity. An understanding of the most common locations of upper extremity stress fractures and their associated causative activities is essential for prompt diagnosis and optimal treatment.

Novel classification system of rib fractures observed in infants.

Rib fractures are considered highly suspicious for nonaccidental injury in the pediatric clinical literature; however, a rib fracture classification system has not been developed. As an aid and impetus for rib fracture research, we developed a concise schema for classifying rib fracture types and fracture location that is applicable to infants. The system defined four fracture types (sternal end, buckle, transverse, and oblique) and four regions of the rib (posterior, posterolateral, anterolateral, and anterior). It was applied to all rib fractures observed during 85 consecutive infant autopsies. Rib fractures were found in 24 (28%) of the cases. A total of 158 rib fractures were identified. The proposed schema was adequate to classify 153 (97%) of the observed fractures. The results indicate that the classification system is sufficiently robust to classify rib fractures typically observed in infants and should be used by researchers investigating infant rib fractures.

"Buckle" rib fracture: an artifact following cardio-pulmonary resuscitation detected on postmortem CT.

Buckle rib fractures are incomplete fractures involving the inner cortex alone, and are rarely detected on routine chest X-ray or at autopsy. The characteristics of these fractures have not been well evaluated in situ although they are commonly observed on postmortem CT images especially following CPR. The postmortem CT findings in 42 cases showing buckle rib fractures caused by CPR were reviewed. The cause of death in all cases was non-traumatic. The shape, number, location, and distribution of these buckle rib fractures and their relationship to other types of rib fractures were evaluated using a novel oblique axial multiplanar reconstruction technique. Almost all incomplete rib fractures associated with CPR are buckle rib fractures (90.5%). All rib fractures were distributed from the second to ninth ribs with over 95% being within the second to seventh ribs. Buckle rib fractures are dominant in the seventh to ninth ribs and the proportion of buckle rib fractures located in the vicinity of the costochondral junctions increases with the lower ribs. Over 97% of all CPR associated rib fractures are located in the anterior one third of the ribs based on a new measurement method utilizing oblique axial multiplanar reconstruction of the CT data. When recognition of incomplete or buckle rib fractures on postmortem CT is taken into account, detection of symmetry and continuity of rib fractures typically associated with CPR is improved compared with the detection of complete fractures alone. Recognition of buckle rib fractures and their characteristics on postmortem CT is of benefit to the forensic pathologist in evaluating the possibility of CPR and the differentiation of resuscitative artifact from forensically significant visceral injury observed at autopsy.

Rib fracture repair: indications, technical issues, and future directions.

Rib fracture repair has been performed at selected centers around the world for more than 50 years; however, the operative indications have not been established and are considered controversial. The outcome of a strictly nonoperative approach may not be optimal. Potential indications for rib fracture repair include flail chest, painful, movable rib fractures refractory to conventional pain management, chest wall deformity/defect, rib fracture nonunion, and during thoracotomy for other traumatic indication. Rib fracture repair is technically challenging secondary to the human rib's relatively thin cortex and its tendency to fracture obliquely. Nonetheless, several effective repair systems have been developed. Future directions for progress on this important surgical problem include the development of minimally invasive techniques and the conduct of multicenter, randomized trials.

Structural analysis of human rib fracture and implications for forensic interpretation.

Patterns of rib fractures are of significant clinical and forensic interest. Linking patterns of rib fracture with specific physical events provides a foundation for understanding the nature of traumatic events that are associated with rib fracture in forensic contexts. In this study, isolated human ribs (n = 8) were end-loaded to failure to investigate: (i) local deformations (bone strain) prior to and during structural failure, (ii) location of ultimate failure, and (iii) fracture mode. Structural properties of ribs were used to calculate theoretical stresses to determine whether such calculations could be used to predict site of fracture. Ribs fractured on the sternal side of midshaft in all experiments, but mode of failure varied with transverse, buckle, spiral, and "butterfly" fractures observed. Comparison of calculated stress with observed strain values suggest that experimental, rather than theoretical, approaches will be most productive in furthering understanding rib fracture in forensic contexts.

Rib stress fractures.

The ribs are an uncommon site of stress fracture. Typical locations are the first rib anterolaterally, the fourth through ninth ribs laterally and posterolaterally, and the posteromedial upper ribs. Muscular forces are predominantly responsible for these fractures. This article reviews the mechanisms of injury in various activities and illustrates the scintigraphic appearance of rib stress fractures.

Absorbable plates for rib fracture repair: preliminary experience.

BACKGROUND: Absorbable prostheses are currently used in a variety of bone reconstructions and fixations. METHODS: This is a case series of rib fracture fixation using absorbable plates and screws consisting of 70:30 poly(L-lactide-co-D,L-lactide) from April 2001 through November 2002. RESULTS: Ten patients underwent rib fracture fixation with absorbable plates and screws. Indications included flail chest with failure to wean (five patients), acute pain with instability (four patients), and chest wall defect (one patient). All patients with flail chest weaned from mechanical ventilation successfully. All patients with pain and instability reported rapid subjective improvement or resolution. The patient with a chest wall defect repair returned to full athletic activity without limitations at 6 months. Thoracoscopic assistance was used in three cases and muscle-sparing incisions were used in eight cases. Two patients with screw fixation only developed loss of rib fracture reduction. One patient developed a wound infection requiring drainage. The period of follow-up ranged from 3 to 18 months. CONCLUSION: Absorbable plates produce good clinical results and are an option for rib fracture repair. Two-point fixation (screw fixation plus suture cerclage) is required. Further refinements in technique should focus on minimally invasive methods.

Assessing the true risk of abdominal solid organ injury in hospitalized rib fracture patients.

BACKGROUND: Despite the lack of evidence, traditional trauma teaching has suggested that low rib fractures increase the risk of abdominal solid organ injury (ASOI). This study was designed to assess if in fact this is true, and to try and define other factors that increased the risk of ASOI in rib fracture patients. METHODS: The charts of 476 hospitalized rib fracture trauma patients were reviewed. Data were collected for age; sex; Injury Severity Score (ISS); rib fracture location; and the presence or absence of injuries to the abdominal organs, head, neck, face, thorax, great vessel, heart, thoracolumbar spine, pelvis, and extremities. RESULTS: The probability of liver injury increased with the presence of any right-sided rib fracture, any low rib fracture, female gender, young age, and an elevated ISS. The probability of splenic injury increased with the presence of left-sided rib fractures only, any low rib fracture, young age, and an elevated ISS. CONCLUSION: In hospitalized trauma patients, low rib fractures, right-sided rib fractures, female gender, young age, and an elevated ISS increased the probability of liver injury; and low rib fractures, left-sided only rib fractures, young age, and an elevated ISS increased the probability of splenic injury. Associated pelvic fractures and long bone fractures did not increase the likelihood of ASOI in this cohort.

Rib fractures in the elderly.

BACKGROUND: We sought to ascertain the extent to which advanced age influences the morbidity and mortality after rib fractures (fxs), to define the relationship between number of rib fractures and morbidity and mortality, and to evaluate the influence of analgesic technique on outcome. METHODS: A retrospective cohort study involving all 277 patients > or = 65 years old with rib fxs admitted to a Level I trauma center over 10 years was undertaken. The control group consisted of 187 randomly selected patients, 18 to 64 years old, with rib fxs admitted over the same time period. Outcomes included pulmonary complications, number of ventilator days, length of intensive care unit and hospital stay (LOS), disposition, and mortality. The specific analgesic technique used was also examined. RESULTS: The two groups had similar mean number of rib fxs (3.6 elderly vs. 4.0 young), mean chest Abbreviated Injury Scores (3.0 vs. 3.0), and mean Injury Severity Score (20.7 vs. 21.4). However, mean number of ventilator days (4.3 vs. 3.1), intensive care unit days (6.1 vs. 4.0), and LOS (15.4 vs. 10.7 days) were longer for the elderly patients. Pneumonia occurred in 31% of elderly versus 17% of young (p < 0.01) and mortality was 22% for the elderly versus 10% for the young (p < 0.01). Mortality and pneumonia rates increased as the number of rib fxs increased with and odds ratio for death of 1.19 and for pneumonia of 1.16 per each additional rib fracture (p < 0.001). The use of epidural analgesia in the elderly (LOS >2 days) was associated with a 10% mortality versus 16% without the use of an epidural (p = 0.28). In the younger group (LOS >2 days), mortality with and without the use of an epidural was 0% and 5%, respectively. CONCLUSION: Elderly patients who sustain blunt chest trauma with rib fxs have twice the mortality and thoracic morbidity of younger patients with similar injuries. For each additional rib fracture in the elderly, mortality increases by 19% and the risk of pneumonia by 27%. As the number of rib fractures increases, there is a significant increase in morbidity and mortality in both groups, but with different patterns for each group. Further prospective study is needed to determine the utility of epidural analgesia in this population.

Rib stress fractures in elite rowers. A case series and proposed mechanism.

The potential cause of stress fractures of the rib in elite rowers was examined by a retrospective review of 14 fractures in 10 patients. Fractures occurred on the antero- to posterolateral aspects of ribs 5 through 9 and were most often associated with long-distance training and heavy load per stroke. A review of the literature yields striking similarities between these stress fractures and fractures caused by cough. It is suggested that actions of the serratus anterior and external oblique muscles on the rib cause stress fracture because of the repetitive bending forces in both rowing and coughing. A technique involving less use of both muscles through a truncated arm pull-through and a decreased layback position at the end of the stroke, and equipment changes to decrease length of the lever arm, should yield a decreased risk of rib stress fractures in rowing.

Stress fractures of the ribs in golfers.

During a collaborative review at three institutions, we documented 19 cases of stress fractures of the ribs in golfers. There were 13 men and 6 women with an average age of 39 years (range, 29 to 51). The 4th to 6th ribs were the most commonly injured. All fractures occurred along the posterolateral aspect of the ribs, and nine patients had fractures in more than one rib. Sixteen golfers sustained injury on the leading arm side of the trunk. Eighteen golfers were beginners, and the one experienced golfer had dramatically increased his practice time on the driving range before injury. Plain radiographs were usually diagnostic. However, bone scintigraphy was necessary to reach a diagnosis in three cases. A delay in diagnosis of 6 to 8 months occurred in two cases that were originally misdiagnosed as back strains. Stress fractures of the ribs in golfers may be more common than previously realized and may be incorrectly diagnosed as recalcitrant back strains. Based on the findings of other studies, we think fatigue of the serratus anterior is the mechanism of injury. We recommend strengthening the serratus anterior as rehabilitation after this injury and in a general conditioning program for golfers.

[The role of the radiological hemithorax examination in closed trauma of the chest]. / Ruolo dell'esame radiologico dell'emicostato nei traumi chiusi del torace.

January, 1992, to September, 1994, a hundred and seventy-eight blunt chest trauma patients were examined with plain chest films and detailed rib studies. The patients were subdivided into three groups according to: a) the presence/absence of rib fractures correlated with clinical data; b) the depiction of rib fractures and/or thoracic complications; c) treatment customization in the presence/absence of rib fractures. In our series of patients the clinical data and the presence of rib fractures were poorly correlated. The detection rates of minor and major complications were also investigated on plain chest films and detailed rib studies. Plain chest films most frequently depicted the complications requiring conservative or surgical management and gave the indication for further imaging investigations. The detailed rib studies of the involved hemithorax yielded no further information useful to therapy except in few cases: and should therefore be limited to the cases exhibiting complications on chest films, which may benefit from surgical fixation. The accurate study of rib fractures is paramount in the cases where legal action may be undertaken.