Total elbow replacements consist of humeral and ulnar components usually made of metal. Various metals including stainless steel, tantalum, titanium, vanadium, cobalt, chromium, tungsten, nickel, and molybdenum have all been tested and now are used mainly as alloys developed to resist corrosion and fatigue. All metals and alloys appear the same on radiographs.
Various total elbow arthroplasy models:
- Ultrahigh molecular weight polyethylene ulnar components have been used in older prosthesis models. Currently, polyethylene liners, or bushings are used at the articular surfaces. Polyethylene is the same material used for ski bottoms, runners on snow mobiles, and cutting boards.
- Polymethylmethacrylate cement is used for fixation.
|Souter-Strathclyde Implant using a metal humeral component and polyethylene ulnar component|
|Polyethylene liner (bushing) between metal humeral and ulnar components.|
Radial head implants are constructed from either silicone elastomer (Silastic) or metals. Silastic prostheses were popular in the past; however, they have since fallen out of favor due to multiple complications including fragmentation and particulate induced synovitis [4,5]
|Silicone implant synovitis. Baseline radiograph with radial head silastic implant. Follow-up study demonstrates fragmentation and destruction of prosthesis.|
|Sagittal T2 and Axial STIR sequences of elbow demonstrate fragmentation of the Silastic implant (blue arrows) and marked synovial proliferation (red arrows). Skin marker (green arrow) was placed by the patient who complained of a mass. Silicone stem (S) in radius.|