MODEL RELEASED. Elbow replacement surgery. Image 6 of 11. Plug (transparent) and part of a prosthetic elbow (centre right) during elbow replacement surgery. The plug will be inserted into a hole drilled into the humerus (upper arm bone) to prevent the cement used to fix the shaft of the implant from spreading too far into the bone. Another implant will be fitted to the radius (lower arm bone) to create a hinge joint that articulates in exactly the same way as a normal elbow joint. Joints may need to be replaced due to injury or disease, such as arthritis as in this case. For a sequence showing the operation see M551/407-M551/417.