The effect of coracoid process transfer on the surgical procedures of shoulder instability

Background: Bone loss of the anteroinferior rim of the glenoid is observed in shoulders with recurrent anterior dislocation. In such shoulders, the size of the defect affects the degree of shoulder instability. Thus, before coracoid process transfer procedures are attempted, the need for bone grafting is a major clinical concern and depends at least partly on the size of the glenoid defect. After the coracoid process transfer is performed, the effect of this procedure on surface area of the glenoid cavity is need to be quantified. The purpose of this study, therefore, was to determine the effect of coracoid process transfer on surface area of the glenoid cavity of cadaveric shoulders in the surgical procedures of shoulder instability.Study Design: A cadaveric laboratory study.Methods: After the shoulder dissection, osseous defects of 21% and 34% of anteroinferior part of the glenoid surface area were created stepwise in 30 cadaveric scapulae, and Latarjet procedure was performed, respectively. Intact and postoperative surface area of the glenoid cavities were photographed, with Canon 400B (55 mm objective) and with a scale placed next to each specimen to indicate its relative size on the photographs. The images were loaded on a computer. The surface area of the photoghraphed glenoid cavities were calculated with use of UTHSCSA Image Tool 3.0 software.Results: The mean surface area of intact glenoid cavity was 969,98 + 129,95 mm2. The postoperative mean surface area of 21% and %34 defective glenoid cavity were 1133,80 + 119,65 mm2 and 1006,50 + 110,69 mm2, respectively. There was a statistically significant difference between the means of surface area of intact glenoid cavity and postoperative surface area of 21% and %34 defective glenoid cavity, (p=0.000, p=0.025; respectively).Conclusion: Coracoid process transfer (Latarjet procedure) significantly increases surface area of glenoid cavity.Key words: Glenoid cavity, shoulder instability, Latarjet procedure.