Forrester, Joseph D.

Background Costosternal cartilages and the costal margin, collectively termed costal cartilage, are hyaline cartilage connecting ribs to the sternum and to adjacent ribs, respectively. Presence of intact costal cartilage is essential for elasticity of the chest wall. Anecdotally, costal cartilage injuries are underdiagnosed on trauma CT scan in patients with rib fractures. Our aim was to determine a baseline frequency of acute costal cartilage injury among patients presenting with rib fractures. Methods We performed a retrospective cohort study of injured adult patients admitted to Level I/II trauma centers with rib fractures from January 2020 to July 2024. CT images obtained at admission were manually reviewed by chest wall surgeons for presence of costal cartilage injury. Concordance with the original radiology report was obtained. Multivariable regression was used to analyze factors associated with costal cartilage injury and missed cartilage fractures. Results 1441 patients were identified; 197 (14%) had a costal cartilage fracture. A plurality of injuries included falls (n=667, 46%). Median ISS (Injury Severity Score) was 13 (IQR: 9 to 21), median Abbreviated Injury Scale thorax score was 3 (IQR: 3 to 3), and median number of fractured ribs was 3 (IQR: 3 to 7). 294 (21%) patients had radiographic flail segments, and 136 (9%) had sternal fractures. 172 (87%) patients had a costal cartilage fracture missed on initial trauma chest CT. On multivariable analysis, ISS (adjusted OR (aOR) 1.02 (95% CI 1.01 to 1.04), radiographic flail segment (aOR 1.6 (95% CI 1.10 to 2.31)) and presence of sternal fracture (aOR 1.85 (95% CI 1.19 to 2.89)) were associated with costal cartilage fractures. Only the total number of rib fractures was associated with a missed costal cartilage fracture on univariate analysis (OR 1.17 (95% CI 1.01 to 1.36)). Conclusions Costal cartilage injuries are common and frequently are not identified during interpretation of the initial trauma CT. A higher index of suspicion is warranted for costal cartilage fractures among patients with greater injury burden, radiographic flail segment, and sternal fractures. Level of evidence Level III.

The Wilderness Medical Society convened an expert panel to develop evidence-based guidelines for the prevention and management of tick-borne illness (TBI). Recommendations are graded based on quality of supporting evidence according to criteria put forth by the American College of Chest Physicians. The guidelines include a brief review of the clinical presentation, epidemiology, prevention, and management of TBI in the United States, with a primary focus on interventions that are appropriate for resource-limited settings. Strong recommendations are provided for the use of DEET, picaridin, and permethrin; tick checks; washing and drying clothing at high temperatures; mechanical tick removal within 36 h of attachment; single-dose doxycycline for high-risk Lyme disease exposures versus “watchful waiting;” evacuation from backcountry settings for symptomatic tick exposures; and TBI education programs. Weak recommendations are provided for the use of light-colored clothing; insect repellents other than DEET, picaridin, and permethrin; and showering after exposure to tick habitat. Weak recommendations are also provided against passive methods of tick removal, including the use of systemic and local treatments. There was insufficient evidence to support the use of long-sleeved clothing and the avoidance of tick habitat such as long grasses and leaf litter. Although there was sound evidence supporting Lyme disease vaccination, a grade was not offered as the vaccine is not currently available for use in the United States.