text: The effect of proximal humeral bone loss on revision reverse total shoulder arthroplasty.
  Revision shoulder arthroplasty can be complicated by osseous and soft tissue deficiencies. Proximal humeral bone loss can result in diminished implant stability and reduced functional outcomes, and some studies have advocated the use of humeral allograft in this setting. This study compares the outcomes of revision reverse total shoulder arthroplasty (RTSA) in patients both with and without proximal humeral bone loss. During a 6-year period, 32 patients were revised to RTSA for failed shoulder hemiarthroplasty. Proximal humeral bone loss was found in 16 patients, with an average loss of 36.3 mm (range, 17.2-66 mm). Patients were followed up an average of 51.2 months with the American Shoulder and Elbow Surgeons score, Simple Shoulder Test score, visual analog scale score for pain, subjective outcome ratings, and radiographs. Significant improvement was found for average American Shoulder and Elbow Surgeons score (30.7 to 66.8), Simple Shoulder Test score (1.6 to 5.3), visual analog scale score (6.0 to 2.6), and forward flexion (51° to 100°) but not for external rotation (15° to 19.1°). No difference was demonstrated for functional or subjective outcomes compared with patients with intact humeral bone, except for active motion. On radiographic examination, 3 patients demonstrated humeral-sided loosening. Five complications were noted in patients with humeral bone loss. Revision RTSA can provide successful outcomes in the presence of proximal humeral bone loss without the use of allograft. Implant stability may be improved by the use of a cemented long-stem monoblock humeral prosthesis in revision settings.