BACKGROUND: 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.
METHODS: 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.
RESULTS: 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).
CONCLUSIONS: 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.
LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.
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