Fibrous dysplasia (FD) is a common benign skeletal disease. In this report, we retrospectively analyzed two cases of monostotic FD with extensive lesions involving the middle and proximal humerus with fractures, where a thorough curettage and autograft followed by interfixation were performed. However, one patient was cured successfully, and the other one had repeated recurrences and pathological fractures. Finally, with the help of computer-aided design and three-dimensional printing technology, the other one patient was cured by unconstrained reverse shoulder arthroplasty combined with allograft-prosthetic composite technology.