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

Bipolar hemiarthroplasty has been reliable and successful treatment for geriatric patients following neck of femur fractures. Dissociation/disassembly of bipolar prosthesis is a rare complication in which separation of outer head from inner head leads to failure of prosthesis and needs revision surgery. The disassembly though commonly seen after years of primary surgery as a result of polyethylene wear leading to fixed varus position of outer head but it can happen in an acute setting anytime in immediate or late post-operative period following posterior dislocation with closed reduction attempt. We describe a rare case of disassembly of monoblock (non-modular) bipolar prosthesis following attempt of closed reduction for posterior dislocation of the prosthesis.