Anatomic considerations for arthroscopic glenoid reconstruction using iliac crest grafts: a radiologic study.

BACKGROUND: Arthroscopic glenoid reconstruction using autografts is an advanced procedure that requires experience and preparation. Knowledge about anatomic pitfalls is therefore important to establish well-positioned portals and prevent neurovascular damage. METHODS: We included 43 computed tomography scans from 43 patients. The distance between the tip of the coracoid process and a perpendicular line representing the anteroinferior glenoid was measured. From these results an anteroinferior working portal was designed, and the angulation needed for screw insertion to fixate a hypothetical graft was measured. In a second step, 9 patients underwent magnetic resonance imaging scans 34 ± 10 months after glenoid reconstruction, and the distance between the screw approach path and the neurovascular bundle was measured. RESULTS: In the analyzed scans, average defect size was 23%, and the coracoid process to the anteroinferior glenoid distance was 32 ± 7 mm. We thus hypothesized that a corridor 20 to 30 mm inferior to the coracoid process would be the ideal position for a working portal. Through this portal, 85% of screws could be applied with 0° to 30° angulation. When the postoperative scans were analyzed, the distance from the neurovascular bundle showed an average of 26 ± 6 mm for the superior screw and 21 ± 5 mm for the inferior screw. CONCLUSIONS: The ideal distance between the coracoid process and an anteroinferior working portal is 32 mm. Having established the portal, instruments should not be inserted pointing in a medial direction of the coracoid process due to the proximity of the neurovascular bundle.

Mid-term clinical results of an arthroscopic glenoid rim reconstruction technique for recurrent anterior shoulder instability.

INTRODUCTION: Glenoid bone loss in recurrent anterior instability of the shoulder needs to be addressed to restore joint stability. Over the last years, several arthroscopic methods have been described to treat this condition. However, no clinical mid-term results have been presented for arthroscopic iliac crest bone grafting procedures. METHODS: We included 32 patients with significant glenoid bone loss and repetitive dislocations of the shoulder who were treated in our shoulder unit with a previously described all-arthroscopic reconstruction technique. All patients filled out a questionnaire evaluating repetitive dislocations, consumption of pain medicine, Constant Score (CS, adapted to age and gender), activities of daily living (ADL), visual analogue scale for pain (VAS) as well as the Western Ontario Shoulder Instability Index (WOSI). Additionally, all complications were recorded. RESULTS: After a mean follow-up of 42 months, three traumatic dislocations had been observed. With an ADL of 25 points (95% CI 24-27), a WOSI of 71% (95% CI 65-76) and CS of 87 points (95% CI 82-92), our patients showed good functional results. The VAS result for pain was 2.1 (95% CI 1.5-2.6). No patient reported the regular usage of pain medicine related to the shoulder instability at final follow-up. CONCLUSION: The all-arthroscopic glenoid reconstruction using iliac crest grafts shows good functional results with a recurrence rate of 9%. At final follow-up 42 months after surgery, our patients showed low pain levels and acceptable complications.

Bone grafts used for arthroscopic glenoid reconstruction restore the native glenoid anatomy.

PURPOSE: Recurrent anterior instability of the glenohumeral joint is a demanding condition, especially in cases of glenoid bone loss. Various treatment options have been described, such as arthroscopic grafting techniques and the Latarjet procedure. In this study, the degree to which an arthroscopically applied iliac crest graft restores the glenoid anatomy was evalutated. METHODS: Nine patients (three women and six men) with an average age of 31 ± 9 years (21-46 years) who were treated with an arthroscopic iliac crest graft technique were included in this study. After a mean follow up of 34 ± 10 months (19-50 months) after the procedure, MRI scans of both shoulders were performed and the glenoid width, Glenoid Index (GI), Pixel Signal intensity (PSI), thickness of the tissue covering the articular aspect of the graft, inclination, version, concavity and balance stability angle were measured. RESULTS: All scans showed the cultivation of tissue on the graft, which visually resembled the cartilage of the native ipsilateral glenoid. Additionally, reshaping of the graft to repair the glenoid configuration could be observed. Glenoid width (p = 0.022) and GI (p < 0.001) increased significantly through surgery. The tissue examined on the graft showed a significant pixel intensity gap (p = 0.017) but comparable thickness (n.s.) in relation to native cartilage. The remaining parameters did not differ significantly between both shoulders. CONCLUSION: In the cohort presented, iliac crest grafts were able to restore the glenoid configuration, and the glenoid was re-shaped to its native contour. Additionally, cartilage-like scar tissue with similar thickness as healthy cartilage was formed on the articular side of the graft. These results suggest that glenoid reconstruction is not only important for prevention of recurrence, but also for restoration of the native glenoid anatomy. LEVEL OF EVIDENCE: Level III-retrospective cohort study.

Mapping of glenoid bone loss in recurrent anterior shoulder instability: is there a particular deficit pattern?

BACKGROUND: Glenoid bone loss in recurrent anterior shoulder instability is a challenging problem for shoulder surgeons, and knowledge about the anatomy of glenoid deficits is scarce. In this study, we tried to evaluate the pattern of this pathology. METHODS: Our analysis included 44 shoulders from 44 patients with recurrent anterior shoulder instability accompanied by a clinically relevant glenoid bone loss. The defect size, the localization of the inferior defect edge, and the defect angle were measured, and osseous landmarks were identified. An en face view on 2-dimensional computed tomography scans of each patient was fitted onto a template to create a deficit map for small (<23%) and large (>23%) defects. RESULTS: The study cohort consisted of 9 women and 35 men with a mean age of 33 ± 11 years at the date of the scan. The defect size and localization of the inferior defect edge showed significant differences between both groups, indicating a more posterior position of larger defects. The defect angle, however, showed no significant difference between small and large defects. Both groups showed a vertical defect pattern. CONCLUSION: The osseous glenoid deficit in recurrent anterior shoulder instability shows a vertical pattern with no remarkable differences between small and large defects. This finding can influence biomechanical models as well as surgical reconstruction.