Abstract
BACKGROUND: Loss of shoulder range of motion (ROM) is common after surgical management of anterior shoulder instability; however, it remains unclear to what degree this is related to their injury. AIM: The purpose of this study was to compare passive shoulder ROM in patients with ASI to a normal contralateral shoulder. METHODS: A total of 121 patients undergoing stabilization surgery were prospectively enrolled. Preoperative advanced imaging was used to assess for glenoid bone loss and the presence of off-track Hill-Sachs lesions. Passive ROM was measured in both shoulders while under anaesthesia prior to surgery. RESULTS: In all directions, there was a significant loss of ROM in shoulders with instability. Regression analysis showed that neither a glenoid bone defect nor greater glenoid bone loss were associated with a loss of ROM in any plane. The presence of a Hill-Sachs lesion was significantly associated with a loss of external rotation, while off-track lesions were associated with a loss of ROM in all planes (p < 0.05). CONCLUSION: Patients with anterior shoulder instability lost motion in all directions, with a profound loss of external rotation. The presence of a glenoid bone defect nor greater bone loss did not reliably predict a loss of range of motion. A Hill-Sachs lesion was predictive of a loss of external rotation, while an off-track lesion was predictive of a loss of range in all directions.