Clavicle fracture has the highest incidence among shoulder fractures, accounting for about 2.6%-5.0% of total body fractures. Allman divided clavicle fractures into external 1/3, middle and internal 1/3 fractures according to the clavicle length, and distal fractures account for 21%-28% of all clavicle fractures. Distal clavicle fractures are prone to local instability due to many ligament structures, and there are still many controversies in diagnosis and treatment at present. Although MRI is the most commonly used method to diagnose soft tissue injury, there are still limitations in diagnosing acute fracture. Dual-energy CT (DECT) can reconstruct soft tissue characteristics of joint support structures such as ligaments by using collagen decomposition algorithms of three materials. Currently, tendon and ligament reconstruction in the ankle, wrist, hand, foot, and knee regions has been reported in the literatures. However, DECT has not been reported for ligament reconstruction in distal clavicle fractures.

To explore the value of dual-source CT dual-energy scan in distal clavicle fractures combined with ligament injuries.

From January 2019 to June 2021, 10 patients (6 males and 4 females) with distal clavicle fractures were enrolled in the study, and the ages ranged from 15 to 67 years with an average age of 39.8 years. The DECT imaging technology was used to reconstruct the trapezoidal ligaments and conoid ligaments on the lateral clavicle of both sides. According to the Neer-Craig classification, all patients were type V, and the affected sides were reconstructed by comparing with the healthy sides. A radiologist and an orthopedist independently analyzed all DECT ligament-specific color mapping images. Each reconstructed ligament was divided into proximal, middle, and distal parts and scored respectively using a three-point scale (0 = no "dual-energy staining" , 1 = partial "dual-energy staining" , and 2 = complete "dual-energy staining" ) .

The average total visualization score of the reconstructed ligament was 5 points or more, with a maximum score of 6 points. In the fracture group, the score of trapezoid ligaments was (5.0±0.1) points and the score of the conoid ligaments was (5.2±0.1) points; in the control group, the score of trapezoid ligaments was (5.3±0.2) points, and the score of the conoid ligaments was (5.7±0.2) points. There was a high degree of consistency between the observations of the trapezium ligament and the conical ligament (0.72-0.94) .

DECT imaging technology can be used to qualitatively display the integrity of the trapezoidal ligament and conoid ligament in distal clavicle fractures and provide an essential reference for guiding clinical classification and treatment.