Assessment of coincidence and defect sizes in Bankart and Hill–Sachs lesions after anterior shoulder dislocation: a radiological study

Abstract

Bankart and Hill-Sachs lesions are often associated with anterior shoulder dislocation. The MRI technique is sensitive in diagnosing both injuries. The aim of this study was to investigate Bankart and Hill-Sachs lesions with MRI to determine the correlation in occurrence and defect sizes of these lesions. Between 2006 and 2013, 446 patients were diagnosed with an anterior shoulder dislocation and 105 of these patients were eligible for inclusion in the study. All patients were examined using MRI. Bankart lesions were classified as cartilaginous or bony lesions. Hill-Sachs lesions were graded I-III using a modified Calandra classification. The co-occurrence of injuries was high [odds ratio (OR) = 11.47; 95% confidence interval (CI) = 3.60-36.52; p < 0.001]. Patients older than 29 years more often presented with a bilateral injury (OR = 16.29; 95% CI = 2.71-97.73; p = 0.002). A correlation between a Bankart lesion and the grade of a Hill-Sachs lesion was found (ρ = 0.34; 95% CI = 0.16-0.49; p < 0.001). Bankart lesions co-occurred more often with large Hill-Sachs lesions (O = 1.24; 95% CI = 1.02-1.52; p = 0.033). If either lesion is diagnosed, the patient is 11 times more likely to have suffered the associated injury. The size of a Hill-Sachs lesion determines the co-occurrence of cartilaginous or bony Bankart lesions. Age plays a role in determining the type of Bankart lesion as well as the co-occurrence of Bankart and Hill-Sachs lesions. This study is the first to demonstrate the use of high-quality MRI in a reasonably large sample of patients, a positive correlation of Bankart and Hill-Sachs lesions in anterior shoulder dislocations and an association between the defect sizes.