A novel knee implant for total knee arthroplasty meets expectations at 10 years. First long-term follow-up report of clinical outcomes and survivorship.

Abstract

Purpose: Achieving a "forgotten knee" after total knee arthroplasty (TKA) remains a primary goal in modern knee replacement surgery. Anatomic implant designs aim to replicate native knee anatomy and kinematics, potentially improving patient satisfaction and functional outcomes. This study evaluates the long-term clinical outcome and survivorship of the Persona Knee System at a minimum follow-up of 10 years.

Methods: 116 TKAs performed using the Persona Posterior Stabilised (PS) Knee System (Zimmer Biomet, Warsaw, Indiana, USA) between 2013 and 2014 at a high-volume orthopaedic centre were prospectively followed and retrospectively analysed. Clinical outcomes were assessed using patient-reported outcome measures (PROMs), including the Forgotten Joint Score-12 (FJS-12), Oxford Knee Score (OKS), and Western Ontario and McMaster Universities Arthritis Index (WOMAC). Implant survivorship was determined using Kaplan-Meier analysis, and complication rates were recorded.

Results: At a mean follow-up of 11.1 years, 116 knees were available for analysis. Patients were assessed clinically and radiographically at 1, 3 and 6 months postoperatively, and then annually, with a mean follow-up of 11.1 years. The mean FJS-12 was 69.52 (SD 12.21, range 15-88), indicating a high level of joint awareness reduction. The OKS and WOMAC scores significantly improved postoperatively, with mean final values of 38.63 (SD 7.99, range 7-48) and 25.29 (SD 16.97, range 4-91), respectively. Radiological analysis demonstrated accurate and stable implant positioning, with no progressive radiolucent lines in non-revised cases. Kaplan-Meier survival analysis showed a 95.7% (SD 1.9%) implant survival rate. The revision rate was 4.3%, with aseptic loosening and persistent painful prosthesis as the primary causes.

Conclusion: The anatomic design of the Persona Knee System provides excellent long-term clinical outcomes, high patient satisfaction, and sustained implant durability. Future research should further investigate patient-specific factors and surgical refinements to optimise long-term outcomes in TKA.

Level of evidence: Level III.