Symptomatic failure of snap-on bipolar radial head prosthesis

Abstract

As the design of prosthetic radial head components improves, and the understanding of the necessity for early restoration of elbow and forearm stability in complex elbow trauma increases, prosthetic radial head replacement is becoming more common. In fact, open reduction and internal fixation of complex radial head fractures has been shown to have relatively poor results and is susceptible to early failure, nonunion, and poor forearm rotation. Few long-term results of radial head replacements have been published, and the current reports are in small series with a low level of evidence. Some of the largest series are with the Judet bipolar radial head prosthesis (Tornier SAS, Saint-Ismier, France), which uses a bipolar metal/polyethylene component that articulates with a monoblock metal head and stem. The Judet prosthesis has a snap-on mechanism to prevent disengagement. As with polyethylene bipolar inserts in hip replacement surgery, concerns exist with respect to polyethylene wear, especially in younger patients. We have used the Judet bipolar radial head prosthesis for revision radial head replacement surgery because it has the benefit of a longer radial stem. However, of the 14 inserted by the senior author in the last 6 years (between February 2001 and February 2007), we have noted 2 cases of failure of the snap-on mechanism, permitting axial slippage of the bipolar component off and on the head/stem. Both patients presented to us with a new lateral elbow pain that was constant and aching in nature and different from any pain they had had before. We believe the pain was caused by polyethylene wear particles. This condition has not been reported in the literature