The study of screw placement parameters for Ogawa type I acromial fractures by 3D simulation

Abstract

Background Acromial fractures are rare and there is no consensus on fixation, but an increasing number of studies have reported using two screws to fix Ogawa type I acromial fractures. The objective of this study was to obtain the ideal length, diameter, insertion point, and angle of the screw using a novel 3D simulation. Methods The scapular CT data of 100 individuals were obtained to reconstruct 3D models. The transparency of the 3D model was then downgraded along the axial perspective (the view perpendicular to the cross section of the acromion axis) to find the maximum translucent area. Two virtual screws were placed at the anterior edge of the acromion until they penetrated the posterior cortical bon. The largest diameters and lengths of the screw were measured, and the direction and insertion point of the screw were observed. Results The mean maximum lengths of the medial and lateral screws were 43.33 ± 6.17 mm and 39.23 ± 6.01 mm, respectively. The mean maximum diameters of the medial and lateral screws were 4.71 ± 1.23 mm and 4.97 ± 1.07 mm, respectively. Differences in screw length, diameter, and insertion point between males and females were found. The differences in screw angle between sexes were not statistically significant. Conclusions Based on a 3D model test, we recommend the size, entry points, and angles of screws for Ogawa type I acromial fractures, providing valuable guidance for clinical work. More accurate screw parameters can be obtained preoperatively by establishing an individualized 3D model.

Ipsilateral fractures of the acromion and coracoid processes of the scapula

“… 1 , 4 However, using 2 cannulated screws was sufficient and gave a reliable fixation method instead of Kirschner wire or tension band fixation without postoperative complications, and some authors reported a 94% healing rate. 8 Coracoid fractures frequently occur in conjunction with other scapula or shoulder girdle injuries. 1 , 9 The surgical indications for acromial fractures are determined by angular abnormality and displacement.…”