The importance of glenoid version in patients with anterior dislocation of the shoulder.

BACKGROUND Although increased retroversion of the glenoid has been shown to be an important factor in posterior instability of the shoulder, there are few studies reporting glenoid bone structure as a risk factor in anterior dislocation of the shoulder. This study aimed to compare glenoid version in patients with anterior dislocation of the shoulder and individuals in a control group with no shoulder problems before undergoing computed tomography and to assess a possible relationship between demographic characteristics and glenoid version angle. METHODS The study group comprised 63 patients (12 women and 51 men; mean age, 35.71 years) with 1 or multiple unilateral anterior dislocations of the shoulder (dislocated group), whereas 63 individuals (11 women and 52 men; mean age, 35.38 years) with no history of shoulder complaints and no signs of instability constituted the control group. The glenoid version angle was measured on an axial cut of the computed tomography scan. RESULTS The glenoid version angles on the dislocated side in the study group were significantly more anteverted than those of the dominant (P < .001) and nondominant (P = .023) shoulders of the control group. The version angles of dislocated shoulders significantly differed from those of nondislocated shoulders of both men (P = .041) and women (P = .049). There was no significant relationship between the glenoid version angle on the dislocated side and dislocation mechanism (P = .883), age group (P = .356), or number of dislocations (P = .971). CONCLUSIONS Glenoid version is an important factor for the development of anterior dislocation of the shoulder.