A bone plate assembly including a first plate, a coupler, a second plate, and a guide the first plate defining a window and having a first major surface adapted to conform to a native bone structure. The coupler such as a beveled edge and/or slide mechanism can be formed on a second major surface of the first plate opposite the first major surface. The second plate can be adapted to engage the coupler, to cover the window, and to conform to the native bone structure. The second plate can include through holes adapted to receive bone screws. The guide can be adapted to engage the coupler and to guide at least one of a cutting tool and/or a dilation tool. The native bone structure is distal radius, proximal femur, distal femur, proximal tibia, distal tibia or calcaneus.
