Summary

All three types of progressive morphologic glenoid bone defects develop in the same manner as they attempt to normalize and form the bone of the glenoid. The new bone formation or normalization of the glenoid led to a lower recurrence rate and an improved rate of return to sport.

Abstract

Background

Nowadays, the morphological development of the glenoid is still a controversial issue in arthroscopic shoulder stabilization, especially when it comes to the progression of the glenoid during each of the following time periods: Moreover, the behavior of the glenoid defect has changed over time, with the morphological structure of the glenoid either undergoing formation, erosion, or normalization. All of these are still being debated.

Purpose

The purpose of this study is to find out how the morphology of the glenoid changes from preoperative to 12 months postoperative in athletes who had arthroscopic shoulder stabilization for three types of Bankart lesions, as well as how this relates to the rate of recurrence of instability and the rate of return to sport in these athletes.

Methods

This study used a retrospective cohort study. Between January 2020 and April 2023, 105 athletes with traumatic anterior shoulder dislocations underwent arthroscopic shoulder stabilization. Group I is the normal type (N = 15), Group II is the erosive type (N = 62), and Group III is the bone fragment type (N = 28) will continuously perform three-dimensional computerized tomography (3D-CT) reconstruction to determine the percentage difference of the bone defect change (∆ % bone defect change) at the unaffected side (reference glenoid size) and the affected side (preoperative) at 1, 6, and 12 months, as well as the rate of recurrence instability and postoperative return to sport.

Results

In terms of the progression of the bone defect change compared with the preoperative glenoid side at 1, 6, and 12 months for groups I, II, and III by using ∆ % bone defect change. At 1 month postoperatively, all groups had significantly different resorptive glenoid (-2.09 ± 0.69; P < 0.01, -1.15 ± 0.37; P < 0.01, and -0.75 ± 1.05; P < 0.05, respectively). At 6 months postoperatively, all three groups had initially normalized and slightly developed bone formation (- 0.91 ±1.07; P< 0.41; 1.51± 0.62; P< 0.02; and 8.77 ±1.34; P< 0.0001, respectively). At 12 months postoperatively, all groups showed significantly increased glenoid bone formation (3.08 ± 1.17; P= 0.02, 5.28 ± 0.69; P< 0.0001, and 13.44± 1.29; P< 0.0001, respectively). In addition, the turn to preoperative morphologic glenoid normalization from 1 month to 12 months compared with unaffected glenoid by using ∆ % bone defect change showed that groups I and III have significantly increased glenoid bone formation (2.68 ± 1.22 and 4.12 ± 1.28, respectively; P< 0.05 for both groups), whereas group II has a bit of an erosive glenoid (-1.95 ± 0.83; P = 0.02). The average recurrence rate is 4.76%, and the rate of return to sport is 91.43%.

Conclusion

All three types of progressive morphologic glenoid bone defects develop in the same manner as they attempt to normalize and form the bone of the glenoid. The new bone formation or normalization of the glenoid led to a lower recurrence rate and an improved rate of return to sport.