Inferior medial abutment. The inferior aspect of the articulation is carefully checked for unwanted contact between the medial aspect of the humerus and the glenoid. (Reproduced, with modification, from: Clinton J, Warme WJ, Lynch JR, Lippitt SB, Matsen FA. Shoulder hemiarthroplasty with nonprosthetic glenoid arthroplasty: the ream and run. Tech Shoulder & Elbow Surg. 2009 Mar;10[1]:43-52. Reproduced with permission of Wolters Kluwer Health.)