Reply to Letter to the Editor: Bony Increased-offset Reversed Shoulder Arthroplasty: Minimizing Scapular Impingement While Maximizing Glenoid Fixation

Excerpt

We thank Drs. Van Tongel and De Wilde for their interest in and comments regarding our article [1]. In the Methods section, they questioned the following statements: “it is unclear what they mean when they say it is already more lateralized. If they mean the center of rotation, then this is not correct. The center of rotation does not change by enlarging the diameter of the glenosphere.” We wrote: “The disc of cancellous bone graft thickness was adjusted according to the size of the sphere. A 10-mm graft was used for a 36-mm sphere and a 7-mm graft for a 42-mm sphere since it is already more lateralized than the 36 mm.” We refer to the humerus and not the center of rotation. As mentioned by Drs. Van Tongel and De Wilde, using a 10-mm autograft and a 36-mm glenosphere [10 + 18 = 28 mm] or a 7-mm autograft and a 42-mm glenosphere [7 + 21 = 28 mm] leads to the same humeral lateralization. This choice in the surgical technique is based on our experience: using a 42-mm glenosphere and a too-thick autograft (10 or 12 mm, for instance), in a patient without glenoid bone loss might cause difficulty at the time of reducing the humerus, which is dislocated posteriorly for glenoid exposure. Our goal with the BIO-RSA technique is to obtain the same humeral lateralization (28 mm), regardless of the size of the sphere. …