Clinical characteristics and outcomes of proximal clavicle fractures: A retrospective cohort study from a single Japanese institution.

Background: Clavicle fractures are common injuries, with proximal clavicle fractures being relatively rare. Previous studies have suggested that proximal clavicle fractures are often associated with high-energy trauma and carry a high risk of complications. However, no studies have comprehensively described their clinical characteristics and severity in Japan. This study aimed to evaluate the clinical characteristics of proximal clavicle fractures and their association with injury severity compared to non-proximal clavicle fractures in Japan.

Methods: This retrospective cohort study was conducted at a single community hospital. Patients diagnosed with acute clavicle fractures between April 2013 and March 2023 were included, excluding those presenting with cardiac arrest on arrival or more than 7 days post-injury. Patients were categorized into the proximal group (Robinson classification type 1) and the control group (other types). Data on age, sex, injury mechanism, fracture type, and concomitant injuries were analyzed. The association between fracture type and severity, defined as AIS ≥3 or ISS ≥16, was assessed using multivariate logistic regression.

Results: A total of 361 patients (proximal group 30 vs. control group 331) were included. Patients in the proximal group were significantly older and had a higher proportion of injuries resulting from falls from standing height compared to the control group. There were no significant differences between the groups in the prevalence of severe concomitant injuries (AIS ≥3; 30 % vs. 19 %), major trauma (ISS ≥16; 10 % vs. 11.8 %), or in-hospital mortality. Logistic regression analysis revealed no significant association between proximal clavicle fractures and severe outcomes.

Conclusions: This study focused on acute clavicle fractures tipically encountered in routine orthopediac practice in Japan. Proximal clavicle fractures were more common in older adults and were frequently caused by low-energy falls. Proximal clavicle fractures were not significantly associated with severe concomitant injuries or trauma.