Disassembly of Components of a Monoblock Bipolar Hip Prosthesis Following Dislocation: A Case Report and Review on “Bottle Opener Effect”

Abstract

Disassembly of hip prosthesis is rare but challenging clinical scenario which should be managed by being very watchful and gentle while attempting closed reduction of dislocated hip prosthesis and should have high index of suspicion for possible disassembly of prosthesis via "Bottleopener effect".

Be aware of the “O” sign in the bipolar cup dissociation during closed reduction of bipolar dislocation: A case report

“…Referred to as the "bottle-opener effect," and this dissociation is caused by the bipolar cup being encroached the posterior acetabular rim during the closed reduction. [10] In the current case, a total of 3 dislocations occurred, and the radiographic difference was found in the closed reduction maneuver in which dissociation occurred (Fig. 6).…”

“…Referred to as the “bottle-opener effect,” and this dissociation is caused by the bipolar cup being encroached the posterior acetabular rim during the closed reduction. [ 10 ]…”

Dissociation of Bipolar Hemiarthroplasty of the Hip

“…It occurs during reduction maneuvers of the bipolar prosthesis's locked outer head behind the acetabulum. The capturing ring of the polyethylene cup appears to absorb the twisting force during reduction, according to the findings [ 11 ]. This is thought to be the most common cause of dissociation following bipolar hemiarthroplasty [ 12 ].…”