The AO 90 degrees humeral blade plate is a relatively new device, whose primary indication and previously described use is for proximal humeral fracture non-union. This study describes the use of the humeral blade plate for extended indications-fixation of segmentally comminuted proximal humeral fractures in two patients and fixation of humeral intercalary allografts after primary humeral neoplasm resection in three patients. A mean follow-up of 20 months revealed union in both fractures and five of the six allograft-host junctions. One patient required subsequent bone grafting for non-union at a proximal allograft-host junction. Functional results were excellent in three patients, good in one, and fair in one. Problems encountered intraoperatively were directly related to the limited array of implants. The long plates which were needed had blades which were too long and required intra-operative trimming in three cases. In four cases, additional plates were used to supplement the blade plate for distal fixation. In conclusion, the humeral blade plate is a useful device for fixation in these extended indications, but longer plates with 30.0 and 40.0-mm blade lengths should be made available.