Revision Hip Arthroplasty with a Single-Taper Cementless Conical Revision Stem: Clinical and Radiographic Assessment of 57 Implants.

Abstract

Background: The optimal stem design for revision hip arthroplasties is still controversial. A retrospective cohort study of revision hip arthroplasties performed using a single-taper cementless conical stem was designed, aiming to assess clinical outcomes, complications and survival rates, and radiological osseointegration, at a minimum follow-up of 2 years.

Methods: A retrospective observational cohort study was conducted on 57 femoral revision arthroplasties performed between 2004 and 2018 using a cementless monoblock conical tapered stem, with a minimum 2-year follow-up. Clinical outcomes were assessed using the Harris Hip Score (HHS). Radiographic evaluations included stem alignment, bone stock remodeling across Gruen zones, and osseointegration graded using 2 systems: Global Radiographic Score (a 5-scale index combining bone quality and osseointegration) and the Engh criteria (fixation classified as bone ingrowth, stable fibrous fixation, or unstable fixation). Kaplan-Meier survival analysis was also performed.

Results: At a mean follow-up of 6.0 ± 3.9 years, the mean HHS was 86.02 ± 9.73. The cumulative stem survival rate was 96.6% at 60 months and 120 months (implant survival: 96.6% and 89.7%, respectively). Bone stock improved across all Gruen zones, with significant increases in zones 1, 3, and 5. No radiolucent lines were found in 59.6% of proximal femurs and 93.0% of distal femurs. More than half of the stems (54.4%) achieved the maximum Global Radiographic Score (20 / 20), and 84.2% demonstrated bone ingrowth according to the Engh criteria.

Conclusions: The single-taper conical revision stem provided good clinical outcomes and reliable survival rates (96.6%) at 6 and 10 years, with 93% of cases exhibiting very good stem stability.