An apparatus for reinforcing bone and tools for mounting the same are provided. The apparatus (10) comprises an implant, including a barrel (200) and a device (100). The implant can be expanded by a tool, comprising an outer tube (400) and a base (405), a hollow body (500) and a handler (600). The tool can be bound to the implant to place the implant into a bone to be treated and adjust the expansion degree. The tool can be replaced by an injector apparatus (60), which comprises a container (800) for bone cement and an injecting handler (1000). The injector apparatus can inject a mixture for reinforcing bone (e.g., bone cement) into the bone through an exit, the device, the aperture, the barrel and the window of the barrel, and into the to-be treated area.