Stacked Cone Constructs for the Treatment of Extensive Tibial Bone Loss in Revision Total Knee Arthroplasty

Background: Highly porous metaphyseal cones have emerged as a promising fixation strategy to address extensive proximal tibial bone loss in the multiply revised knee. Despite a paucity of literature regarding stacked cone constructs, they have gained popularity. This study reports on the early outcomes of stacked tibial cone constructs that are used during revision total knee arthroplasty (TKA). Methods: A single-institution retrospective observational study was performed to identify patients who had been treated with a stacked cone construct during revision TKA between January 2010 and December 2022. Demographic, operative, clinical, and radiographic data were collected and assessed. Kaplan-Meier estimates were used to assess survival with all-cause reoperation, tibial-sided revision, and radiographic loosening as end points. In total, 22 stacked cone constructs were identified: 15 (68.2%) of the patients were men; the demographics included a mean age of 64.1 years (range, 42.8 to 87.8 years), a body mass index of 34.2 kg/m 2 (range, 20.4 to 51.9 kg/m 2 ), a median of 4 prior surgeries (range, 1 to 12 prior surgeries), and a mean follow-up of 22.6 months (range, 6.8 to 79.1 months). Results: Twenty patients received 2-cone constructs, and 2 patients received 3-cone constructs. Patients received the stacked cone constructs during revision TKA for the following indications: periprosthetic joint infection (n = 11), aseptic loosening (n = 9), tibial stem pain (n = 1), and periprosthetic fracture (n = 1). At a median time of 2.9 months (range, 0.4 to 37.3 months), 5 patients underwent reoperation for the following indications: extensor mechanism failure (n = 2), femoral component loosening (n = 1), superficial wound dehiscence (n = 1), and postoperative hematoma (n = 1). At the 3-year follow-up, no patients had undergone revision for tibial component loosening (1 patient had radiographic evidence of loosening at the 15-month follow-up but did not undergo revision). Conclusions: Stacked cone constructs are a viable option during revision TKA when extensive metaphyseal bone loss is encountered. Level of Evidence: Therapeutic Level IV . See Instructions for Authors for a complete description of levels of evidence.