Bony Bankart lesions are commonly associated with anterior or anterior-inferior glenohumeral dislocations, often caused by a traumatic event. The prevalence of osseous Bankart lesions reportedly ranges from 7.9% to 50.0% in shoulders that exhibit traumatic glenohumeral instability. Acute osseous Bankart lesions must be differentiated from chronic cases and are defined by acute glenohumeral dislocations with a glenoid rim fracture within 3 to 6 months of the initial injury. In contrast, chronic lesions, particularly in cases of recurrent anterior instability, often present as bony erosion of the anterior glenoid rim caused by osseous lysis.
Although it has been shown that acute Bankart lesions can be successfully treated nonoperatively if the fracture is concentrically reduced, Nakagawa reported a high percentage of fragment absorption within 1 year after an acute injury. Recent advancements in arthroscopic technologies have made arthroscopic bony reconstruction possible. Additionally, recent case series have shown favorable outcomes after arthroscopic bony repair with suture anchors for patients with bone defects ranging in size from 11.4% to 49.0% of the inferior glenoid width.
Two techniques for arthroscopic bony repair of acute bony Bankart lesions have been described in the literature. The method described by Porcellini involved implementation of 1 anchor in the fracture, corresponding to a single-row repair. In contrast, the ‘‘bony Bankart bridge’’ technique described by Millett and Braun used a double-row technique that deployed anchors at the medial and lateral borders of the fracture site. Favorable clinical outcomes have been reported for both techniques.
Giles compared both of the described fixation techniques in a cadaveric biomechanical model with a simulated osseous defect size of 15% without creating a labral avulsion. The authors reported significant differences in fragment displacement at various loading conditions; however, they reported that these small, but statistically significant, differences were likely clinically insignificant. In conjunction with the reported nonsignificant differences in failure strength and load transfer between the 2 techniques, the authors concluded that the 2 techniques were biomechanically equivalent. However, several studies have shown that significantly increased anterior glenohumeral instability associated with glenoid rim lesions only occurs for defects exceeding 20% of the glenoid surface area. Thus, controversy exists regarding the need for surgical repair in glenoid rim defects of less than 20%. There exists no biomechanical data to date comparing arthroscopic bony repair techniques for osseous Bankart lesions with defect sizes exceeding 20% of the glenoid surface area.
Therefore, the purpose of this study was to compare the time zero reduction of distance across the fracture and bio- mechanical stability associated with the single-row technique described by Porcellini and the double-row technique described by Millett and Braun of bony Bankart lesions with a 25% defect. The double-row technique was hypothesized to provide improved fracture reduction and superior stability compared with the single-row technique.