Glenohumeral bone lesions occurring during the first episode of shoulder dislocation do not influence function at an average of 2 years.

Background: After a first shoulder dislocation, the rate of recurrence varies according to age and type of activity. The rule of bony lesions is logical but not demonstrated. We conducted a study to analyze bony lesions observed after a first episode of anterior shoulder dislocation in patients younger than 50 years of age. We assessed the functional outcomes and rate of recurrence among dislocations depending on bony lesions.

Methods: We conducted a prospective, multicenter study for an average of 2 years that included patients aged 18-50 years who had experienced a first episode of anterior shoulder dislocation and who agreed to undergo computed tomography imaging within 3 weeks of trauma. A minimum follow-up duration of 1 year was required for clinical analysis.

Results: Ninety-two patients, with a mean follow-up duration of 2 years, participated in the study. Ultimately, 13 patients were excluded: 2 were lost to follow-up, 6 underwent stabilization surgery, and 5 had a follow-up duration of less than 1 year. The mean age at inclusion was 27 years and 94% were men. Glenoid lesions were observed in 39% of patients; humeral lesions were present in 95%. Recurrence occurred in 24% of cases. There was no significant difference in functional scores between patients with and without bony lesion. There was a lower rate of residual apprehension in non-recurrent patients compared with those who had experienced recurrence (p = 0.02) and a greater return to sport in the "no recurrence" subgroup (p = 0.02). The risk of recurrence was equivalent, regardless of the status of glenoid, humerus, or bipolar lesions. The sole predictor of recurrence after a first episode of dislocation was age younger than 20 years (p = 0.002).

Conclusion: Our study results provide insight into the functional outcomes and likelihood of dislocation recurrence with bony lesions after initial glenohumeral dislocation. If the first episode occurred before the age of 50 years, bony lesions were common. The overall recurrence rate was 24% with an average time of recurrence of 16 months (1-24). In our study, the presence of glenoid and/or humeral bony lesions doesn't seem to be a risk factor for luxation recurrence.