Abstract
Objectives:
Bone remodeling is quite common phenomenon after glenoid reconstruction and excessive bone resorption may weaken joint stability. The purpose of the computed tomography (CT)-based research was to quantitatively evaluate the effect of the medial-lateral position of the iliac crest bone block on the graft remodeling after the Lilian’s way (a modified Eden-Hybinette procedure).
Methods:
A total of 62 patients who underwent the Lilian’s way for the treatment of anterior shoulder instability with sutures-button system between May 2017 and July 2022 were included. Patients without CT scans of preoperative, immediately postoperative or a minimum of 12 months after surgery were excluded. The medial-lateral as well as the superior-inferior position of the bone block after surgery, and the diameter, depth, version, surface area of the glenoid at different time points were measured. Statistical analyses and multivariate logistic regression analyses were used to determine variables on excessive bone resorption. The cutoff value was analyzed using a receiver operating characteristic curve.
Results:
Complete graft resorption was observed in only 1 case and excessive bone resorption was detected in 17.7% (11/62) patients. The medial-lateral position of the bone block, glenoid depth as well as its increment immediate after surgery differed significantly between patients with and without excessive bone resorption. Multivariate logistic regression analysis revealed excessive bone resorption to be only correlated with the medial-lateral position of the graft (Odd ratio, 0.191; P=0.002). The cutoff value was -0.5 mm (area under the curve, 0.934; 95% CI, 0.870-0.998; P＜0.001; sensitivity, 84%; specificity, 100%). Most of cases (81.8%, 9/11) with excessive bone resorption was observed when the entire surface of graft was distant from the extrapolated glenoid curvature.
Conclusions:
The medial-lateral positioning of the bone block is a critical determinant in the remodeling process and excessive bone resorption would occur if the grafts were placed too medially. To achieve a deeper glenoid concavity and more stable glenohumeral joint with physiological pear-shaped glenoid surface, 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.