1 research outputs found
The Critical Shoulder Angle Can be Accurately and Reliably Determined from ThreeâDimensional Computed Tomography Images
Objective Anteroposterior (AP) radiographs do not necessarily offer the optimal approach to measuring the critical shoulder angle (CSA) due to the malposition of the scapula. Threeâdimensional computed tomography (3DâCT) may offer some advantages, including the ability to rotate the scapula for position alignment and preâoperative planning for reducing CSA. This study aimed to investigate the accuracy and reliability of CSA measurement in 3DâCT and to determine whether there is an association between CSA and rotator cuff tears (RCTs). Methods In this retrospective study we identified 200 patients who received shoulder arthroscopy from 2019 to 2021, including 142 patients (81 females, 61 males) with RCTs and 58 patients (14 females, 44 males) with nonâRCTs. For each participant, CSA was measured from standard shoulder AP radiographs and anterior views of 3DâCT of the scapula by two independent assessors. Interâ and intraâobserver agreements were assessed by the intraclass correlation coefficient (ICC). The relationship between the two measurement methodologies was determined by Spearman's correlation coefficient and BlandâAltman plots. Discriminative capacity was calculated by using receiver operating curve (ROC) analyses in the whole cohort and age subâgroups above and below 45âyears. Results We found perfect interâobserver (ICC >0.96) and intraâobserver (ICC >0.97) reliabilities for CSA measurements obtained from the standard AP radiographs and the 3DâCT. There was a strong correlation between the two methods (r = 0.960, Pâ<â0.001). The mean CSA was 31.7°â±â4.2° in the standard AP radiographs and 31.8°â±â4.4° in the 3DâCT (mean difference 0.02°, P = 0.940; bias 0.02°, limits of agreement â2.29° to +2.33°). ROC analysis of the whole cohort showed that the CSA measured in the standard AP radiographs (area under the ROC curve [AUC] = 0.812, Pâ<â0.001) and the 3DâCT (AUC = 0.815, Pâ<â0.001) predicted RCT with high confidence. ROC analysis of patients aged â„45âyears showed that the CSA measured from the standard AP radiographs (AUC = 0.869, Pâ<â0.001) and the 3DâCT (AUC = 0.870, Pâ<â0.001) were very good at predicting RCTs. Conclusion CSA measured from standard AP radiographs and 3DâCT showed high consistency, and the CSA could be accurately and reliably measured using 3DâCT. CSAs measured from standard AP radiographs and 3DâCT could predict RCTs, especially in patients aged â„45âyears