The treatment of complex proximal humeral fractures remains challenging, especially in patients with osteoporosis. Locking plate fixation has become a standard in stabilizing these fractures; however, complication rates are still high. In particular, loss of reduction with varus misalignment and subsequent cut-out of the proximal screws is frequent. Recently the restoration of medial support has been named as the primary aim of operative treatment. This article describes an alternative technique using intramedullary augmentation on the basis of a case report and explains the concept of medial support in locking plate fixation of proximal humeral fractures. Options, findings and recommendations of different procedures are presented in this respect. The importance of correct reduction of the medial cortices, the use of calcar screws, the double-plate fixation method as well as the presented technique of intramedullary augmentation are discussed.