Metaphyseal cone in revision total knee arthroplasty - A retrospective review

Abstract

Introduction: Metaphyseal cone has emerged recently to be an effective tool in managing metaphyseal bone defect in revision total knee arthroplasty (TKA). We aim to review clinical and radiological outcomes of metaphyseal cone in our hospital. Materials and Methods: We retrospectively reviewed 17 patients (age 70.1 ± 9.2 years; 5 male and 12 female) who had undergone revision TKA using metaphyseal cone (Triathlon Tritanium Cone Augments, with the Triathlon Total Stabilizer Knee System, Stryker) during the period of August 2017 to January 2020. The mean follow-up period was 22 months. We investigated their demographics (age, gender, ASA class, comorbidities, indication), surgical factors (bone defect according to the Anderson Orthopaedic Research Institute (AORI) classification, tibial/femoral cone, implant size and shape), clinical outcomes (end-of-stem pain, Knee Society knee score, infection, revision surgery), as well as radiological outcomes (osteointegration, fracture, radiolucency, aseptic loosening). Results: In total, 15 tibial and two femoral cones were used. Surgical indications were periprosthetic joint infection (10 of 17), aseptic loosening (4 of 17) and others (3 of 17). All of the bone defects were classified as class II A/B by the AORI classification. There were two cases of intraoperative femoral fracture during femoral cone press-fit. There was no infection or revision surgery. Radiologically, osteointegration was seen in all cases except one case of aseptic loosening. Discussion and Conclusion: Metaphyseal cone is useful in managing bone defect in revision total knee arthroplasty, with promising short-term clinical and radiological outcomes. Precautions should be taken when using cone in patients with small body build.