The radial head is a commonly fractured bone of the elbow joint. Primary treatment of radial head fractures can be non-operative if there is minimal displacement of the fragments. In more complicated fractures with more displacement and more bone fragments, screws and plates cannot adequately stabilize the elbow, and a replacement of the radial head may be indicated. No matter what treatment is done, the best way to have optimal outcomes is by early range-of-motion exercises and limiting the time of casting.
Radial Head Fracture
Radial head fractures can occur along with other injuries to the soft tissues and bone of the wrist, forearm and elbow. Treatment is dependent on the level of displacement or separation of the bony fragments and the total number of fragments involved.
Indications for Radial Head Replacement
The radial head replacement is utilized to help prevent movement of the radius bone. When the radius bone migrates, it can lead to chronic wrist pain. The radial head prosthesis aims to prevent significant change in the anatomy of the forearm and wrist. Replacement of the radial head is usually reserved for severe fractures that are displaced or cannot be repaired with screws and/or plates. The AAOS Comprehensive Review says that for fractures of the radial head involving three or more fragments, radial head replacement should be considered as the surgical treatment.
When the elbow has been dislocated, a Vitallium prosthesis is indicated. This specific prosthesis is more stable than the silicone prosthesis, but if the implant fit is too tight, there will be loss of extension or the ability to fully straighten the elbow, even after physical therapy.
Allograft of Radial Head Replacement
The use of allograft radial head as a replacement is indicated when the fracture extends into the radial neck. An allograft is using bone from another person as a replacement piece instead of metal or silicone.
A silicone replacement can be used as a temporary spacer to allow for healing of soft tissues. The silicone can break down, leading to a synovitis, or inflammation of the joint. The prosthetic has a higher failure rate when it is made of silicone due to the high stresses on the prosthesis at the radiocapitellar joint, the site where the prosthesis comes into contact with the distal humerus bone. Using the silicone as a spacer allows the radius to heal in proper position prior to its removal.
Early range-of-motion exercises are done after an initial one to two week period of immobilization in a splint and sling. Improvement is progressive with time and physical therapy exercises. In a study of outcomes in the Journal of Bone and Joint Surgery (JBJS) of radial head arthroplasty by Dr. Ruby Grewal of St Joseph's Health Care of Ontario, Canada, it was found that most patients recover in six months with slightly more recovery over the next 18 months. Patients reported high satisfaction at both three months and two years post-operatively after radial head replacement.