Outcomes and Challenges of Optimal Fixation Selection for Metaphyseal Fixation Techniques in Revision Knee Arthroplasty According to Bone Defects: A Systematic Review.

Revision total knee arthroplasty (rTKA) is often complicated by metaphyseal bone loss, requiring stable fixation techniques to restore function and alignment. Metaphyseal sleeves and cones have shown promising clinical outcomes, particularly in cases of severe bone defects. However, no gold standard therapy has been established. Therefore, this review aimed to evaluate and compare the clinical and radiological outcomes of metaphyseal sleeves and cones in rTKA, considering the severity of bone defects and related complications. This systematic review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Thirteen studies published between 2004 and 2024 were included, evaluating clinical and radiological outcomes of metaphyseal sleeves and cones across varying Anderson Orthopaedic Research Institute (AORI) defect classifications. Metaphyseal sleeves demonstrated a 100% survival rate over five years across multiple studies, while metaphyseal cones showed a survivorship rate of 91 91%. Both techniques demonstrated satisfactory functional recovery, although outcome measurement tools varied across studies, such as the Knee Society Score (KSS), which showed progressive improvement in most patients in both groups. Sleeves were associated with a higher incidence of intraoperative fractures (3.7%), whereas cones required more re-revision surgeries (5.33%), often due to issues with cement fixation. Both metaphyseal sleeves and cones provided effective fixation in rTKA. Neither method proved universally superior; the choice should be tailored to the severity of the defect and individual patient factors to balance durability, risk, and clinical outcome.