Atypical Femoral Fractures: What Do We Know About Them?

Abstract

Background: The use of cementless acetabular components in total hip arthroplasty has gained popularity over the past decade. Most total hip arthroplasties being performed in North America currently use cementless acetabular components. The objective of this systematic review and meta-analysis was to compare the survivorship and revision rate of cemented and cementless acetabular components utilized in total hip arthroplasty. Methods: A primary literature search in PubMed identified 3488 articles, of which 3407 did not meet the inclusion criteria and were excluded. Only English-language articles on either the survivorship or revision rate of primary total hip arthroplasty at a minimum of ten years of follow-up were included. The present study analyzed forty-five articles reporting the long-term outcome of cementless acetabular components, twenty-nine reporting the outcome of cemented acetabular components, and seven comparing cemented and cementless acetabular components. Meta-analysis (with a random-effects model) was performed on the data from the seven comparative studies, and study-level logistic regression analysis (with a quasibinomial model) was performed on the pooled data on the eighty-one included articles to determine a consensus. The studies were weighted according to the number of total hip arthroplasties performed. Results: The meta-analysis did not reveal any effect of the type of acetabular component fixation on either survivorship or revision rate. The regression analysis revealed the estimated odds ratio for survivorship of a cemented acetabular component to be 1.60 (95% confidence interval, 1.32 to 2.40; p = 0.002) when adjustments for factors including age, sex, and mean duration of follow-up were made. Conclusions: The preference for cementless acetabular components on the basis of improved survivorship is not supported by the published evidence. Although concerns regarding aseptic loosening of cemented acetabular components may have led North American surgeons toward the nearly exclusive use of cementless acetabular components, the available literature suggests that the fixation of cemented acetabular components is more reliable than that of cementless components beyond the first postoperative decade.