Cementing acetabular liners into secure cementless shells for polyethylene wear provides durable mid-term fixation.

Abstract

In a previous experiment studying cementation of liners into cementless acetabular shells, placing grooves in the liner in a spider-web configuration created the greatest construct strength. Scoring shells without screw holes or other texturing helped prevent failure at the shell-cement interface. However, it was unclear whether these practices caused durable constructs in patients. We therefore determined (1) rerevision rates; (2) functional scores (Harris hip scores, WOMAC, and SF-36); (3) acetabular loosening rates; and (4) acetabular osteolysis rates in patients in whom we cemented nonconstrained liners into well-fixed and well-positioned acetabular shells. We prospectively followed 30 patients with 31 total hip arthroplasties in which a worn acetabular liner was revised by cementing a new liner into the existing shell that was stable and well positioned. Acetabular liners were prepared as determined by our previous study. Twenty-seven of the 30 patients (28 hips) were evaluated clinically. We recorded revisions and determined radiographic loosening and osteolysis. The minimum clinical followup was 2 years (mean, 5.3 years; range, 2-10 years). Twenty-six hips (87%) had minimum 2-year radiographic followup with an average length of 4.8 years. No hip required rerevision during the followup interval. Two hips (6%) dislocated once, both treated nonoperatively. Harris hip scores, WOMAC, and SF-36 scores increased over preoperatively at last followup. All acetabular shells and liners were radiographically stable without evidence of loosening or progressive acetabular osteolysis. Cementation of a liner into a well-fixed cementless shell after scoring in a spider-web configuration provided secure fixation with no failures of the construct at average 5.3 years followup. Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.