Three-dimensional Deformities of Non-operative Midshaft Clavicle Fractures: A Surface Matching Analysis

OBJECTIVE:: The purpose of this study was to describe the three-dimensional deformities of midshaft clavicle fractures, which had been treated nonoperatively, using computed tomography (CT) surface matching. METHODS:: Twenty-one patients with unilateral midshaft clavicle fracture, who had been treated nonoperatively, were enrolled and evaluated retrospectively. The three-dimensional deformity of the fractured clavicle was evaluated by CT surface matching. CT scans of 21 age- and sex-matched patients with initial traumatic shoulder dislocation or proximal humeral fracture were enrolled as a control group, and the differences in three-dimensional deformities and lengths of the clavicles between the fracture group and the control group were evaluated. A correlation analysis was also performed between rotational deformities and clavicular length shortening. RESULTS:: The affected clavicle showed 1.3 ± 6.9 degrees of downward angular deformity, 2.1 ± 8.0 degrees of anterior angular deformity, and 5.0 ± 4.9 degrees of anterior rotational deformity. Compared with the control group, the fractured clavicle showed larger anterior rotational deformity (P = 0.021). Shortening of the clavicle demonstrated negative correlation with anterior axial rotation (R = −0.534, P = 0.013), but no correlation was found between clavicular shortening and the other two rotational deformities. CONCLUSION:: In cases of midshaft clavicle fracture, the distal fragment usually rotates anteriorly due to its anatomical relationships. Shortening deformity following clavicle fracture was reported to change shoulder kinematics, and anterior rotational deformity might adversely affect scapular motion.