Summary
Both the medial-lateral position and steepness of the bone block are critical determinants for the improvement of BSSR. To achieve a deeper glenoid concavity and more stable glenohumeral joint, we recommend placing the graft at a distance no more than 0.5mm medial from the bony glenoid surface with a well-matched articular surface to the extrapolated glenoid curvature.
Abstract
Purpose
to quantitatively evaluate the risk factors influencing the BSSR during remodeling process after glenoid reconstruction.
Methods
Between May 2017 and July 2022, 62 patients with CT scans of preoperative, immediately postoperative and a minimum of 12 months after surgery were included. All of them underwent the Lilian’s way for anterior shoulder instability with sutures-button system. The position of the bone block after surgery, and the diameter, depth, version, surface area of the glenoid at different time points were measured. The steepness, BSSR and the resorption rate of bone block area as well as bone block width were calculated. Additionally, the relationship between glenoid morphological parameters and the BSSR was assessed.
Results
Overall, the bone block procedure significantly increased the BSSR immediately after surgery. Although the BSSR decreased subsequently during remodeling process, the mean value concerning the last CT scans is still higher than that of the contralateral side (39.4% vs 36.9%). In addition to the significant correlation with glenoid depth and version after surgery, the increment of BSSR immediate after surgery was closely correlated with the media-lateral position and the steepness of the bone block (both of P<0.001). Among the patients (n=53) with improved glenoid depth immediate after surgery, the reduction of BSSR following the remodeling process showed significant association with the resorption rate of bone block width. In all patients (13%, 8/62) with a final BSSR that was under the critical value of 29.3%, the entire surfaces of grafts were initially placed distant from the extrapolated glenoid curvature.
Conclusion
Both the medial-lateral position and steepness of the bone block are critical determinants for the improvement of BSSR. To achieve a deeper glenoid concavity and more stable glenohumeral joint, we recommend placing the graft at a distance no more than 0.5mm medial from the bony glenoid surface with a well-matched articular surface to the extrapolated glenoid curvature.