Bony deficiency of the anteroinferior glenoid can contribute to recurrent glenohumeral instability. Glenoid bone loss occurs during acute shoulder dislocation or because of erosion and attrition in more chronic cases of anterior instability. The incidence of bony Bankart lesions after shoulder dislocations ranges from 4% to 70% in the literature, with a higher prevalence in men. These injuries have been previously classified by Bigliani into 3 types, with type I representing an avulsion fracture with attached capsule, type II a medially displaced fragment malunited to the glenoid rim, and type III an erosion of the glenoid diameter with less (IIIA) or more (IIIB) than 25% deficiency. Burkhart and De Beer also demonstrated that glenoid bone loss is associated with a higher risk of surgical failure after arthroscopic soft tissue repair. A number of biomechanical studies have been performed to determine the critical amount of bone loss that results in recurrent instability.
Cadaveric studies have helped us understand the consequences of glenoid bone loss. Itoi reported that anosseous defect of at least 21% of the glenoid length will significantly decrease stability. Similarly, Yamamoto created a model with an osseous defect at 3-o’clock (right shoulder) and concluded that when the defect was equal to or greater than 20% of the glenoid length, there was significantly decreased anterior stability. According to Gerber and Nyffeler, when the length of the glenoid defect was greater than the glenoid radius, resistance to dislocation was reduced by 30%. Furthermore, glenoid bone loss of 20% of the diameter doubles the mean contact pressure in the anteroinferior quadrant and increases peak pressures from 50% to 100%. Therefore, based on the current data, a bony reconstruction procedure is recommended in patients with glenoid bone loss of greater than 20% to 25% to restore the surface area and to avoid high failure rates.
Bony procedures have historically been performed open. However, recent advances in arthroscopic technique have allowed for the reconstruction of glenoid bone defects to restore stability.9,16,18,20 In 2009, the senior author (P.J.M.) described an all-arthroscopic technique developed for this specific condition named the ‘‘bony Bankart bridge’’ (BBB). The purpose of this study was to investigate the clinical outcomes and complications after arthroscopic fixation of anterior glenoid rim fractures using this technique. We hypothesized that the BBB technique would provide good restoration of stability with a high patient satisfaction and a low complication rate.
Full Article: The ‘‘Bony Bankart Bridge’’ Technique for Restoration of Anterior Shoulder Stability