Background: Metal prostheses are useful for restoring elbow and
forearm stability when the radial head cannot be fixed after a fracture.
Because the anatomy of the radial head is difficult to reproduce with a
prosthesis, two different options have been proposed: a bipolar prosthesis
with a fixed stem and a mobile head, and a monoblock prosthesis with a smooth
stem that is intentionally fixed loosely in the neck of the radius. One
concern with a fixed-stem implant with a mobile head has been the risk of
osteolysis. The purpose of this study was to evaluate radiographic changes
reflecting or suggesting progressive osteolysis in patients with a bipolar
radial head prosthesis.
Methods: The functional and radiographic outcomes following
treatment of fifty-one comminuted fractures of the radial head with a bipolar
radial head prosthesis in fifty-one consecutive patients were evaluated at a
mean of 8.4 years postoperatively. There were eleven isolated comminuted
fractures involving the entire radial head. Thirty-four fractures were
associated with a posterior elbow dislocation, and six patients had a
posterior Monteggia lesion.
Results: According to the Mayo Elbow Performance Index, fourteen
elbows were graded as excellent; twenty-five, as good; nine, as fair; and
three, as poor. Radiographic changes reflecting or suggesting progressive
osteolysis were present in thirty-seven patients. Complications occurred in
ten patients, but only one underwent surgical treatment, for an ulnar
Conclusions: Although satisfactory midterm functional results were
achieved in thirty-nine of the fifty-one patients, the high prevalence of
adverse radiographic changes suggesting periprosthetic osteolysis should alert
clinicians to this possible drawback of the use of bipolar radial head
prostheses, especially in young and/or active patients.
Level of Evidence: Therapeutic Level IV. See Instructions
to Authors for a complete description of levels of evidence.