Alumina Heads Minimize Wear and Femoral Osteolysis Progression After Isolated Simple Acetabular Revision

Abstract

Patients with THA requiring cup revision for acetabular osteolysis may have a stable stem component without loosening. However, it is unclear whether isolated cup revision halts femoral osteolysis progression. We asked (1) whether and to what degree osteolysis progresses after isolated acetabular revision with a change of the femoral head and (2) whether an alumina or metal bearing better reduces osteolysis progression and wear with a polyethylene (PE) cup. We retrospectively evaluated 150 patients who underwent 165 acetabular revisions but no treatment for proximal femoral osteolysis in hips with stable femoral components. Mean age at revision was 63 years (range, 48-74 years). All hips received a new PE cup; 83 hips received new alumina heads and 82 new metal heads. Radiographs (mean followup, 15 years; range, 10-25 years) were assessed to measure osteolysis, loosening, and PE wear. Revisions of the femoral stem were recorded. An isolated cup revision with a change of the femoral head halted femoral osteolysis progression for 10 years in 133 hips (81%), with a greater percentage without progression in hips with alumina heads (99% versus 62% with metal head). Alumina heads were better than metal heads at reducing the area of osteolysis progression (47 versus 250 mm(2)) and wear (0.07 versus 0.14 mm/year) and increasing the survival probability before femoral revision (98% versus 85% at 15 years' followup). An isolated cup revision with a new alumina femoral head (in hips that have a stable stem component without loosening) usually halts femoral osteolysis progression (no change or osseous restoration) over 10 years if the osteolysis is less than 1000 mm(2). Level III, therapeutic study. See Instructions for Authors for a complete description of levels of evidence.