Failure of a Non-Porous-Coated Acetabular Component Inserted without Cement in Primary Total Hip Arthroplasty* **

Abstract

ABSTRACT

Thirty-four patients (thirty-eight hips) had a primary total hip arthroplasty with insertion of a non-porous-coated titanium-alloy acetabular component without cement. This component is initially stabilized with use of a central acetabular polyethylene peg, which is inserted into the pelvis, as well as supplementary cortical-bone screws inserted into the ilium. The original diagnosis was degenerative joint disease in thirty-four hips and avascular necrosis in four hips. Twenty-five femoral components were inserted with cement, and thirteen non-porous-coated femoral implants were inserted without cement. The acetabulum was prepared with so-called line-to-line reaming.

Thirty-five hips in thirty-one patients were available for clinical and radiographic follow-up at a mean of 4.5 years (range, two to seven years). Serial measurements of the position of the acetabular component revealed that eighteen cups (51%) had migrated. Of these, eleven had been revised. Radiolucent lines of at least one millimeter in thickness at the bone-prosthesis interface were noted adjacent to all but six of the acetabular components.

Although this series was small, it demonstrates an unacceptably high rate of failure of non-porous-coated acetabular components after a relatively short duration. We question the efficacy of this acetabular component, inserted without cement, as part of a primary total hip arthroplasty.