Survivorship of Cemented Versus Cementless Metal on Metal Hip Resurfacing: A Match-Cohort Analysis at Minimum 5 Years.

Abstract

Background: One of the most common causes of failure after metal-on-metal hip resurfacing (MoM HR) remains femoral neck fracture and aseptic loosening of the femoral component. The purpose of this study was to compare the survivorship of cemented and cementless femoral fixation metal on metal hip resurfacing.

Methods: Five-hundred ninety patients' MoM HR performed through the Hueter-anterior approach with a minimum 5-year (mean age 50 years, body mass index (BMI) 29, 555 men and 35 women) follow-up were reviewed. One hundred and forty-three cementless (mean age 50 years, mean BMI 29, 136 men and 7 women) and 143 cemented MoM HR (mean age 52 years, mean BMI 29, 136 men and 7 women) were matched on age, sex, and BMI. Overall failures, femoral failures, adverse events, and complications were assessed. Acetabular cup inclination, neck-shaft angle (NSA), stem-shaft angles (SSA), Δ NSA-SSA, and neck narrowing were recorded.

Results: Survivorship was 91% at a mean follow-up of 8.2 years (range 5-19). There were 14 failures (10% rate) in the cemented group and 12 failures (8% failure rate) in the cementless group (p > 0.05) with men at 92.7% and women at 74.9% (p = 0.019). In the male group, using isolated femoral reasons for revision survivorship was 96.5% for the cemented group and 98% for the cementless group (p > 0.05). Neck narrowing more than 10% was present in 11 patients (8%) in the cemented group and in 3 patients (2%) in the cementless group (p < 0.01). No significant correlation was found between any radiological parameter and the risk of failure.

Conclusion: Both cementless and cemented MoM HR are associated with excellent survivorship, especially in men with cementless fixation having a lower incident of neck narrowing.