Cementless total hip arthroplasty for primary osteoarthritis in patients aged 55 years and older

Abstract

Background: Cemented total hip arthroplasty has been the treatment of choice for elderly patients with osteoarthritis. We analyzed survival rates of the most common cementless designs used in this age group in Finland.

Patients and methods: Inclusion criteria permitted 10,310 replacements (8 designs) performed in patients aged 55 years or older to be selected for evaluation. The risk of revision of each of the 8 implants was compared with that of a group comprising 3 cemented designs as the reference (9,549 replacements). Survival analyses were performed overall and separately for 3 age cohorts: 55-64 years (6,781 replacements), 65-74 years (8,821 replacements), and 75 years or older (4,257 replacements).

Results: In all patients aged 55 years or more, the Bi-Metric stem had a higher survival rate for aseptic loosening at 15 years than the cemented reference group: 96% (95% CI: 94-98) vs. 91% (CI: 90-92). However, the 15-year survival rates of the Bi-Metric/Press-Fit Universal (71% (CI: 67-75)) and the Anatomic Mesh/Harris-Galante II (72% (CI: 67-78)) total hip replacements were lower than that of the reference group (86% (CI: 84-87)). Information was scarce for patients aged 75 years or more.

Interpretation: Cementless proximal porous-coated stems are a good option for elderly patients. Even though biological fixation is a reliable fixation method in THA, polyethylene wear and osteolysis remain a serious problem for cementless cup designs with unplugged screw holes and low-quality liners.

Figure 1.

Cox-adjusted survival curves for 19,859 stems and 19,859 cups in patients aged 55 years or older with stem designs (panel A) or cup designs (panel B) as the strata factors. The endpoint was defined as stem (A) or cup (B) revision due to aseptic loosening. Adjustment was made for age and sex. For an explanation of abbreviations, see Table 4.

Figure 2.

Cox-adjusted survival curves for 19,859 total hip replacements in patients aged 55 years or older with total hip replacement design as the strata factor. The endpoint was defined as revision of the stem and/or the cup due to aseptic loosening (panel A) or as revision for any reason (B). Adjustment was made for age and sex. For an explanation of abbreviations, see Table 4.