Factors related to large bone defects of bipolar lesions and a high number of instability episodes with anterior glenohumeral instability

Abstract

Background Significant bone defects are associated with poor clinical results after surgical stabilization in cases of glenohumeral instability. Although multiple factors are thought to adversely affect enlargement of bipolar bone loss and increased shoulder instability, these factors have not been sufficiently evaluated. The purpose of this study was to identify the factors related to greater bone defects and a higher number of instability episodes in patients with glenohumeral instability. Methods A total of 120 consecutive patients with symptomatic unilateral instability of the glenohumeral joint were retrospectively reviewed. Three-dimensional surface-rendered/registered models of bilateral glenoids and proximal humeri from computed tomography data were matched by software, and the volumes of bone defects identified in the glenoid and humeral head were assessed. After relationships between objective variables and explanatory variables were evaluated using bivariate analyses, factors related to large bone defects in the glenoid and humeral head and a high number of total instability episodes and self-irreducible dislocations greater than the respective 75th percentiles were evaluated using logistic regression analyses with significant variables on bivariate analyses. Results Larger humeral head defects (P < .001) and a higher number of total instability episodes (P = .032) were found to be factors related to large glenoid defects. On the other hand, male sex (P = .014), larger glenoid defects (P = .015), and larger number of self-irreducible dislocations (P = .027) were related to large humeral head bone defects. An increased number of total instability episodes was related to longer symptom duration (P = .001) and larger glenoid defects (P = .002), and an increased number of self-irreducible dislocations was related to larger humeral head defects (P = .007). Conclusions Whereas this study showed that bipolar lesions affect the amount of bone defects reciprocally, factors related to greater bone defects differed between the glenoid and the humeral head. Glenoid defects were related to the number of total instability episodes, whereas humeral head defects were related to the number of self-irreducible dislocations.

Native Glenoid Depth and Hill-Sachs Lesion Morphology in Traumatic Anterior Shoulder Instability

“…27,35,39 Despite having a lower regression coefficient than the native glenoid depth, the glenoid depth of the affected shoulder was also shown to be an independent indicator of HSL depth, suggesting that the postinjury condition of the glenoid concavity may have some bearing on HSL depth. Moreover, when the previously disregarded feature, native glenoid depth, was included in the regression model, the glenoid bone loss, which has been shown to greatly influence the HSL size in previous research, 27,28,36,40 did not exhibit any significant correlations with HSL depth, width, or volume. This showed that the morphological association between bipolar bone loss might be misestimated when considering only 2D glenoid characteristics without the concavity depth.…”

“…HSL morphology significantly affects the clinical manifestations, treatment strategies, and prognosis for patients with anterior shoulder instability. 8,16,27 In terms of the HSL size, a deep and wide HSL commonly leads to frequent frank dislocations that necessitate manual reduction, 27,56 and the preferred surgical approach for these cases might switch from the routinely used remplissage procedure to osteochondral allograft transplant due to the increased need for biomechanical stability. 15,46,58 In terms of the HSL location, a more medial HSL indicates a larger Hill-Sachs interval according to the glenoid track concept, 2,9 which would increase risk of engagement and recurrent instability after isolated Bankart repair.…”

“…Age, sex, dominant side, symptom duration, total number of instability episodes, number of dislocations, type of sports, type and traumatic cause of primary instability, Beighton score, glenoid bone loss, glenoid depth, and version of bilateral shoulders were included in the regression model. 23,27,31,36,37,39,43 The intraclass correlation coefficient was used to assess the intra- and interobserver reliabilities and was classified as good (>0.75), fair (0.5-0.75), and poor (<0.5). 1 All data were analyzed with SPSS software (Version 25.0; IBM).…”

“…5,8,9,25,38,55 As a result, it is critical to understand the factors that affect HSL morphology in order to optimize early-stage risk evaluation and surgical decision making. 27,35,39 Glenoid characteristics have been regarded as the key factors affecting HSL morphology because the impaction of the humeral head into the anterior glenoid rim causes HSL during an instability event. 5,12,41 Previous studies concentrated on 2-dimensional (2D) measurements of glenoid characteristics in the en face view; in the case of bipolar bone loss, the size and location of the HSL were influenced by the severity of glenoid defects.…”

A Case Series of Whether Arthroscopic Bankart Repair Following Primary Traumatic Anterior Shoulder Dislocation Versus Recurrent Dislocation in Soldiers Has Any Effect on the Postoperative Recurrence Rate

“…It is well known that bone loss in the glenoid and humeral head greatly influences shoulder instability [ 25 - 29 ]. In our study, based on radiographs, we did not observe any significant differences between first-time and recurrent group patients with regard to bone loss.…”