Relationship between polyethylene wear, pelvic osteolysis, and clinical symptomatology in patients with cementless acetabular components. A framework for decision making.

The purpose of this study is to assess the relationship between acetabular component polyethylene wear, pelvic osteolysis, and clinical symptoms to determine when operative intervention should occur and to predict the degree of difficulty of the revision. Fifty-four revisions of failed cementless acetabular components were performed in 52 patients. All cases demonstrated polyethylene wear radiographically, and in 43 cases (80%), osteolysis of the pelvis was seen. Symptoms of groin or buttock pain were seen in 45 of 54 cases (83%). Preoperative staging of the disease process included one patient with wear radiographically but neither symptoms nor lysis (stage I), 10 patients with wear and pain (stage IIA), 8 patients with wear and lysis but no pain (stage IIB), and 35 patients with wear, lysis, and pain (stage III). Patients in stages I and IIA could be revised with cementless components without structural allograft. Patients in stages IIB and III required structural allograft in 79% and cemented components in 53%. Cemented components were used when there was less than 50% contact between host-bone and prosthesis. Polyethylene wear alone (stage I) is an indication of impending failure, and when symptoms develop (stage IIA), revision should be undertaken. The development of radiographic lysis is a critical event, and as soon as osteolysis develops (stage IIB or III), revision should be undertaken immediately. From the perspective of the revision surgeon, there is great value in the early intervention for polyethylene wear and pelvic osteolysis.