Objective To investigate the effect of glenohumeral bone structure on anterior shoulder instability by three-dimensional CT reconstruction. Methods The clinical data of 48 patients with unilateral anterior shoulder dislocation (instability group) and 46 patients without shoulder joint disease (control group) admitted between February 2012 and January 2024 were retrospectively analyzed. There was no significant difference in gender and side between the two groups (P>0.05). The patients were significantly younger in the instability group than in the control group (P<0.05). The glenoid joint morphological parameters such as glenoid height, glenoid width, ratio of glenoid height to width, glenoid inclination, the humeral containing angle, and glenoid version were measured on three-dimensional CT reconstruction of the glenoid. The differences of the above indexes between the two groups were compared, and the differences of the above indexes between the two groups were compared respectively in the male and the female. Random forest model was used to analyze the influencing factors of anterior shoulder instability. ResultsThe comparison between the two groups and the comparison between the two groups in the male and the female showed that the ratio of of the instability group glenoid height to width was larger than that of the control group, the glenoid width and humeral containing angle were smaller than those of the control group, and the differences were significant (P<0.05); there was no significant difference in glenoid height, glenoid inclination, and glenoid version between the two groups (P>0.05). The accuracy of the random forest model was 0.84. The results showed that the top four influencing factors of anterior shoulder instability were ratio of glenoid height to width, the humeral containing angle, age, and glenoid width. Conclusion Ratio of glenoid height to width and the humeral containing angle are important influencing factors of anterior shoulder instability.
