Abstract
BACKGROUND: Metaphyseal fixation with modern cones or sleeves is often necessitated in revision total knee arthroplasty (rTKA). Survivorship and outcomes data, particularly of novel systems, are limited. This study aims to report the early outcomes and survivorship of a series of rTKA patients receiving a specific tibial or femoral cone. MATERIALS AND METHODS: A retrospective review of a prospectively collected internal database was conducted for all rTKA patients with a specific metaphyseal cone (ATTUNE, Johnson & Johnson MedTech, Warsaw, Indiana, United States) at a minimum three-month follow-up. Data collected included demographics (age, sex, body mass index (BMI)), postoperative outcomes (length of stay, 30- and 90-day readmissions, complications, reoperations), radiographic subsidence, and Knee Injury and Osteoarthritis Outcome Score for Joint Replacement (KOOS JR) scores preoperatively as well as three months postoperatively. P-values were obtained by t-tests and assessed as significant if p<0.05. RESULTS: A total of 24 patients were identified with the following revision indications: mechanical loosening (n=9; 37.5%), infection (n=8; 33.3%), instability (n=6; 25%), and arthrofibrosis (n=1; 4.2%). The mean follow-up was 9.3 months. Thirteen tibial cones (54.2%) and 11 (45.8%) femoral cones were implanted. A semi-constrained prosthesis was used in 22 cases, and a hinged prosthesis was used in two cases. The reoperation-free survivorship was 100%. Twelve patients (50%) had two or more postoperative X-rays, and the average subsidence was ≤0.5 mm in both femoral and tibial cone cohorts. One intraoperative complication and two postoperative complications occurred, all unrelated to the tibial cone construct. Statistically significant improvements to the KOOS JR (p<0.001) were observed at three months. CONCLUSIONS: The early short-term outcomes of this novel metaphyseal cone construct are promising, with a 100% survivorship free from reoperation and no complications attributable to the device. Further follow-up is required to determine the long-term durability of these metaphyseal fixation devices.