Stacked-Cone Constructs for Extensive Tibial and/or Femoral Bone Loss in Complex Primary and Revision TKA: A Multicenter Analysis of 84 Cases.

Abstract

Stacked metaphyseal cone constructs can be used to address extensive metaphyseal and metadiaphyseal bone loss encountered during complex primary or revision total knee arthroplasty (TKA). Our study reports the 5-year outcomes of a multicenter cohort of stacked-cone constructs used to manage extensive bone loss encountered during primary or revision TKA. A retrospective review was conducted to identify patients who underwent primary or revision TKA with tibial and/or femoral stacked-cone constructs between July 2016 and September 2025 at 4 tertiary academic institutions. Demographic, operative, clinical, and radiographic data were obtained and analyzed. Five-year implant survivorship free from all-cause reoperation, all-cause revision, and stacked-cone construct revision for aseptic loosening was analyzed using Kaplan-Meier estimation. Eighty-four cases with a mean patient age of 67.3 years and a mean follow-up of 20.85 months were identified. Five-year survivorship was 56.5% (95% confidence interval [CI], 22.7% to 78.3%) free from all-cause reoperation, 65.2% (95% CI, 25.8% to 87.1%) free from all-cause revision, and 91.7% (95% CI, 52.5% to 99.8%) free from stacked-cone construct revision for aseptic loosening. Stacked-cone revision due to aseptic loosening was performed on the tibial side in 1 case (1.2%) at 3.6 years following the index surgery. Five other stacked cones were revised for periprosthetic joint infection (4 all femoral stacked-cone cases) and tibial implant fracture (1 tibial stacked-cone case). Stacked-cone constructs demonstrated excellent 5-year survivorship free from aseptic loosening. However, all-cause reoperations and revisions were common in this cohort, reflecting the complex nature of this patient population. Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.