A device is used to treat periprosthetic fractures, such as a fracture below the stem of a total hip replacement (THR). The device includes a clamp that is fixed to the exposed stem of the THR and a coupling, such as a morse taper, extending distally away from the stem. A post is inserted into the canal of the distal femur below the fracture. The post has a coupling extending proximally away from the distal femur. The couplings on the clamp and post are joined to create a stable connection between the patient's hip and distal femur. Instead of connecting the clamp with the post directly, one or more adapters may be provided to adjust the length and angulation of the treated limb. The device may also connect a THR stem with a Total Knee Arthroplasty (TKA) that includes a stem.