To the Editor

I congratulate Smith et al. for their excellent work on pelvic osteolysis [2]. They have developed a simple, reliable, and inexpensive tool to quantify osteolytic changes detected on plain radiographs. More precisely, they have developed an elegant means of measuring the area of osteolysis on plain radiographs.

The main purpose of evaluating retroacetabular osteolysis is to determine when to perform a simple polyethylene liner exchange. Ideally, this should be performed before the osteolysis has led to aseptic loosening of the cementless acetabular prosthesis. In a previous study, I and my coauthors tried to correlate osteolysis with acetabular stability and we found that it was not the area of osteolysis that was predictive of acetabular loosening [1]. Instead, it was the percentage of the acetabular component associated with osteolysis that predicted acetabular stability [1].

It would be great if the tool developed by Smith et al. could be used to quantify the percentage of the acetabular prosthesis that was associated with osteolysis.