Revision strategy for posterior extrusion of the CHARITE polyethylene core

Abstract

STUDY DESIGN: This is a case report of a posterior extrusion of the polyethylene core from a CHARITE arthroplasty. This is the first reported case of posterior dislocation of the polyethylene and the revision strategies used to correct this problem. OBJECTIVE: To report a novel failure mechanism and revision strategy for CHARITE total disc arthroplasty (TDA). SUMMARY OF BACKGROUND DATA: Case report at a Level 1 tertiary care referral center in the northeastern United States. METHODS: This is a case report and review of the literature of a patient who sustained posterior dislocation of the polyethylene core from a CHARITE TDA several months after the index procedure. RESULTS: Core dislocation is a known complication of TDA. However, of the known reported dislocations all have been anterior. This case describes the first known occurrence of posterior core dislocation and the revision strategy for this problem. CONCLUSION: This case report highlights the first known case of a posterior dislocation of a CHARITE core. It is likely that altered biomechanical forces generated over time attributed to device failure. An instrumented posterior fusion with removal of the core is what ultimately led to a stable revision construct.