Pinnacle polyethylene liner dissociation: a report of 3 cases.

We describe 3 cases of DePuy Pinnacle polyethylene dissociations, their presentations, and treatment. A 34-year-old female with arthritis secondary to dysplasia, a 51-year-old male with avascular necrosis of the femoral head, and a 57-year-old female with osteoarthritis were treated with total hip arthroplasty. Acute nontraumatic polyethylene liner dissociations occurred at 31, 42, and 2 months postoperatively. They were treated with component retention and modular femoral head and liner revision. The 51-year-old male subsequently developed a prosthetic joint infection requiring explant of his components. Although dissociation of polyethylene liners from the DePuy Pinnacle acetabular components is an uncommon complication, this problem may increase in prevalence with longer term follow-up, and vigilance is recommended.