Five cases of early dissociation between the bipolar hip endoprosthesis cup components; either spontaneously or during reduction maneuvers

Bipolar hemiarthroplasty is frequently used in the treatment of intracapsular hip fractures. Although the dissociation between the bipolar components is a very rare complication, it has very serious results and almost always leads to reoperation with revision of the prosthesis. In this regard, there are very few cases reported in the literature. Dissociation can happen during the hip dislocation, the reduction maneuvers, or spontaneously without any dislocation. Here we report early dissociation between bipolar components in two cases during the attempt of closed reduction maneuvers and three cases with spontaneous dissociation without any trauma. To prevent or minimize this complication; the reduction of dislocated hips must be achieved very carefully under general anesthesia with fluoroscopic control. During the initial operation the surgeons must be sure that the bipolar components are locked to each other and after final reduction, especially in osteoarthritic acetabulums, that the cup position is not in varus position. Self-centering (eccentric) cups have reduced the dissociation rate, but could not completely finish it. Therefore further studies are needed for the development of advanced implant designs. DOI: 10.3944/AOTT.2015.14.0364This abstract belongs to the un-edited version of the article and is only for informative purposes. Published version may differ from the current version.