FEWER SUBSEQUENT REVISIONS WITH MODULAR DUAL-MOBILITY CONSTRUCTS THAN LARGE FEMORAL HEADS IN REVISION TOTAL HIP ARTHROPLASTIES AT TEN YEARS

Abstract

There is a paucity of mid-term data on modular dual-mobility (MDM) constructs versus large (≥40 mm) femoral heads (LFH) in revision total hip arthroplasties (THAs). The purpose of this study was to update our prior series at 10 years, with specific emphasis on survivorships free of re-revision for dislocation, any re-revision, and dislocation.We identified 300 revision THAs performed at a single tertiary care academic institution from 2011 to 2014. Aseptic loosening of the acetabular component (n=65), dislocation (n=59), and reimplantation as part of a two-stage exchange protocol (n=57) were the most common reasons for index revision. Dual-mobility constructs were used in 124 cases, and LFH were used in 176 cases. Mean age was 66 years, mean BMI was 31 kg/m2, and 45% were female. Mean follow-up was 7 years.The 10-year survivorship free of re-revision for dislocation was 97% in the MDM cohort and 91% in the LFH cohort with a significantly increased risk of re-revision for dislocation in the LFH cohort (HR 5.2; p=0.03). The 10-year survivorship free of any re-revision was 90% in the MDM cohort and 84% in the LFH cohort with a significantly increased risk of any re-revision in the LFH cohort (HR 2.5; p=0.04). The 10-year survivorship free of any dislocation was 92% in the MDM cohort and 87% in the LFH cohort. There was a trend towards an increased risk of any dislocation in the LFH cohort (HR 2.3; p=0.06).In this head-to-head comparison, revision THAs using MDM constructs had a significantly lower risk of re-revision for dislocation compared to LFH at 10 years. In addition, there was a trend towards lower risk of any dislocation.Level of Evidence: IV