Abstract
OBJECTIVE: To investigate the impact and diagnostic value of novel indicators based on 3D modeling and fitted sphere analysis for Subacromial Impingement Syndrome (SIS). METHODS: CT data from patients with Subacromial Impingement Syndrome and healthy individuals were imported into a software system to reconstruct a 3D model of the index shoulder. The following parameters were measured: humeral head-pseudo-moving domain volume index, pseudo-moving domain anteversion angle, pseudo-moving domain abduction angle, Critical Shoulder Angle (CSA), Acromion Index (AI), Acromio-humeral Interval (AHI), Lateral Acromial Angle (LAA), Acromion-Greater Tuberosity Impingement Index (ATI), glenoid inclination angle, and glenoid ante/retroversion angle. Influencing factor analysis, Receiver Operating Characteristic curve analysis, and correlation analysis were then performed. RESULTS: The humeral head-pseudo-moving domain volume index, pseudo-moving domain anteversion angle, and pseudo-moving domain abduction angle were all indicators for SIS (P < 0.05). The humeral head-pseudo-moving domain volume index had high accuracy in predicting SIS (AUC = 0.778, P < 0.001), with an optimal threshold of 0.690, at which sensitivity and specificity were 67.0% and 77.0%, respectively. The pseudo-moving domain anteversion angle had no diagnostic value. The pseudo-moving domain abduction angle had high accuracy in predicting SIS (AUC = 0.728, P < 0.001), with an optimal threshold of 75.012, at which sensitivity and specificity were 62.2% and 72.8%, respectively. When the new indicators were used in combination, the accuracy was higher (AUC = 0.859, P < 0.001), with optimal thresholds of 0.528 or 0.542. The humeral head-pseudo-moving domain volume index had correlation with AI, AHI, LAA, and ATI. The pseudo-moving domain anteversion angle showed no correlation with glenoid anteversion/retroversion. The pseudo-moving domain abduction angle had correlation with critical shoulder angle and glenoid superior inclination. CONCLUSION: The new indicators based on 3D modeling and fitted sphere analysis are indicators for SIS. The humeral head-pseudo-moving domain volume index and pseudo-moving domain abduction angle have prognostic value for SIS.