Early Recurrent Dislocation and Dissociation of Bipolar Cup: Two Intricate Cases and Review of Literature.

Abstract

Background: Bipolar hemiarthroplasty (BHA) is one of the best options to treat femoral neck fracture in elderly patients. However, the early dislocation problem also happens in the bipolar cup. Furthermore, BHA has a specific implant-related complication, namely bipolar cup dissociation, in which the femoral head dissociates from the polyethylene (PE) liner. Early dislocation and dissociation are relatively uncommon but devastating complications and almost always lead to reoperation with revision of the prosthesis. Dislocation and dissociation of the bipolar cup can be challenging to manage and easily turn to recurrent episodes in case of improper handling. We hope to find out the best strategy for treatment early recurrent dislocation and dissociation of the bipolar cup.Methods: We retrospectively reviewed 2 patients who had a history of early recurrent posterior dislocations following primary BHA from 2016 to 2019. What’s more, they had early recurrent bipolar cup dissociation during the attempt of closed reduction maneuvers within 3 months of the original surgery.Results: All the patients were treated with open reduction and revision of Bipolar hemiarthroplasty (BHA). One patient has a good outcome, and no recurrence of dislocation was recorded.Conclusion: Recognition of the risk of dislocation and dissociation of bipolar cup is essential to its prevention and treatment. Complete revision of bipolar parts and the femoral head may be the minimum solution necessary to avoid the early recurrence of bipolar cup dissociation. Further investigations are recommended to strengthen these results.

Dislocation After Bipolar Hemiarthroplasty in Elderly Patient: A Case Report

“…Moriarity et al [9] stated that the dislocated hip HA should be managed by open reduction and be converted to cemented THA. This study was supported by Fan et al, who performed revision surgery of BHA to THA with dual mobility cups, which showed an excellent postoperative result [10].…”