Gender differences in Glenoid and Coracoid Dimensions evaluated through 3D Printed bone models in the context of Anterior Shoulder Instability Surgery – An exploratory study

Abstract

Introduction: Nonrecognition of smaller bone anatomy in the context of the Latarjet procedure may increase the chance of complications and worsen it outcomes, and this should be addressed preoperatively by accurate measuring of bone anatomy. Measurement of bone dimension can be performed through 3d printed bone models nowadays and therefore we aimed to evaluate glenoid and coracoid process dimensions obtained in 3D printed bone models, assess differences between genders, and compare the results with previously published anatomical studies. We hypothesized that the values obtained in the 3D models would be similar to those previously reported in other anatomical studies and gender differences would also be present. Methods: We retrospectively retrieved shoulder computer tomography scans from 39 adult patients with uninjured scapula. Using the DICOM file of the CT, we performed three-dimensional reconstructions of the scapula, including the glenoid and coracoid. The resulting digital model was then printed in an FDM technology 3D printer. With the 3D Printed models, one of the authors measured the models using a digital caliper. The measurements collected on the Glenoid were Glenoid Superior-Inferior length (GlenSI); and Glenoid Antero-Inferior length (GlenAP) .On the coracoid, the measurements collected were the Coracoid Anterior-Posterior length (CoracAP), the Coracoid Medial-Lateral (CoracML) distance and the Coracoid Superior-Inferior (CoracSI) distance. Those measurements were summarized and underwent statistical comparison between genders. The results were compared with other anatomical studies in the same bone anatomy. Results: We recorded a mean glenoid length (GlenAP) of 28.03 mm (SD = 0.45) and mean glenoid height (GlenSI) of 37,18 mm (SD =0,55). The mean glenoid dimensions differ significantly between male and female gender (p=0,002 and p=0,001, respectively).The coracoid mean length was 22,35 mm (SD=0.47), mean coracoid width was 14,97 mm (SD=0,30), mean coracoid height was9,51 mm (SD=0,22), and those measures also differ significantly between genders. The observed mean values were similar to those previously reported in other anatomical studies. Discussion: We observed that coracoid and glenoid dimensions significantly vary between genders for all of the measurements performed. Measurements obtained in this series are comparable with other similar anatomic studies. Although some limitations exists in our study, we consider 3D-printed bone models in the setting of anatomical studies as a relevant option to traditional cadaveric studies. Conclusion: Gender differences in coracoid and glenoid dimensions were observed and must be considered for the Latarjet procedure. Our results suggest that 3d printed bone models may be used for such evaluation with a good degree of reproducibility of the measurements observed in already published anatomic studies.

Keywords

• 3D Printing
• Latarjet
• Glenoid dimensions
• Coracoid process
• Anatomical differences
• Anterior Shoulder Instability