Cluster hole versus solid cup in total hip arthroplasty: a randomized control trial.

Acetabular osteolysis has been linked to polyethylene debris that is generated in the hip migrating through screw holes in the acetabular component. Solid-backed acetabular components were designed to decrease this osteolysis. This prospective trial randomized 100 patients undergoing total hip arthroplasty to either a solid-backed or a cluster-hole acetabular component-all without screws. At 5years post-surgery, 34.4% of all patients had osteolytic lesions that were visible on CT. There was no significant difference in either presence or volume of the osteolytic lesions, cup migration or functional outcomes (OHS) between the groups. There may no longer be a detriment to using cluster-hole cups instead of solid cups in all hips. This would then give the surgeon the option to use screws for stability as required.