Primary cementless acetabular components in hips with severe developmental dysplasia or total dislocation. A concise follow-up, at an average of sixteen years, of a previous report.

UNLABELLED: We previously reported the seven-year results of the use of a hemispherical, porous-coated acetabular component in twenty consecutive primary total hip arthroplasties in a highly selected group, namely, patients with severe developmental dysplasia or total dislocation of the hip. The present report describes the outcomes of those hips nine years later, at an average follow-up of sixteen years (range, 11.5 to nineteen years). Since the time of our prior report, two shells were revised; one revision was done because of aseptic loosening and the other, because of polyethylene liner dissociation without tine fracture. The remaining shells were well fixed. No pelvic osteolysis was evident on plain radiographs. The average polyethylene liner wear rate was 0.09 mm/yr. With failure defined as aseptic loosening of the shell, the average sixteen-year survival for the shell was 92%. We believe that this cup had excellent fixation at a long duration of follow-up of sixteen years in this highly selected set of patients with difficult hip problems. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions to Authors for a complete description of levels of evidence.