Histologic analysis of bony Bankart lesions in recurrent anterior instability of the shoulder

The histologic examination of bony Bankart lesions was performed with hemotoxylin-eosin staining of specimens obtained intraoperatively from 27 patients. We assessed the incidence and extent of degeneration in the bony fragment and the surrounding ligament and the relationship of such pathologic changes to several clinical and radiologic factors. Loss of osteocytes in the bony fragment was defined as osteonecrosis, and loss of fibroblasts in the surrounding ligament was defined as ligament degeneration. Although extensive ligament degeneration was noted in 8 patients (29.6%) (degeneration group), no bony fragment with extensive osteonecrosis was found. The degeneration group showed a statistically higher frequency of dislocation than the other group (P =.045). All bony fragments in the bony Bankart lesion seemed to be viable and could be used to treat the fractured glenoid defect. The surrounding ligaments in cases with a higher frequency of dislocation were often degenerative and might not be good for repair.