Retrospective Study
Copyright ©The Author(s) 2024. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Orthop. Feb 18, 2024; 15(2): 118-128
Published online Feb 18, 2024. doi: 10.5312/wjo.v15.i2.118
Mid-term outcomes of a kinematically designed cruciate retaining total knee arthroplasty
Jonathan L Katzman, Akram A Habibi, Muhammad A Haider, Casey Cardillo, Ivan Fernandez-Madrid, Morteza Meftah, Ran Schwarzkopf
Jonathan L Katzman, Akram A Habibi, Muhammad A Haider, Casey Cardillo, Ivan Fernandez-Madrid, Morteza Meftah, Ran Schwarzkopf, Department of Orthopedic Surgery, Division of Adult Reconstructive Surgery, NYU Langone Orthopedic Hospital, NYU Langone Health, New York, NY 10010, United States
Author contributions: All authors contributed to the study conception and design; Material preparation, data collection and analysis were performed by Katzman JL, Habibi AA, Haider MA, Cardillo C, Fernandez-Madrid I, Meftah M, Schwarzkopf R; The first draft of the manuscript was written by Katzman JL and Habibi AA; Haider MA, Cardillo C, Fernandez-Madrid I, Meftah M, and Schwarzkopf R wrote, reviewed, and revised parts of the manuscript; All authors read and approved the final manuscript.
Institutional review board statement: The study was reviewed and approved by the NYU Langone Institutional Review Board, No. i17-01223.
Informed consent statement: Waiver of informed consent.
Conflict-of-interest statement: Morteza Meftah reports financial relationships with multiple companies including CAIRA Surgical (Stock or stock Options), Conformis (Paid consultant), Constance (Stock or stock Options), Innomed (IP royalties), Intellijoint (Paid consultant) and involvement with the following organizations ISTA (Board or committee member) and Orthopedics (Editorial or governing board). Ran Schwarzkopf discloses financial relationships with Gauss Surgical (Stock or stock Options), Intellijoint (Paid consultant; Stock or stock Options), PSI (Stock or stock Options), Smith & Nephew (IP royalties; Paid consultant; Research support), and Zimmer (Paid consultant) and oganizational associations with AAOS (Board or committee member), American Association of Hip and Knee Surgeons (Board or committee member), Arthroplasty Today (Editorial or governing board), and Journal of Arthroplasty (Editorial or governing board). The remaining authors, Jonathan L. Katzman, Akram A. Habibi, Muhammad A. Haider, Casey Cardillo, and Ivan Fernandez-Madrid, have nothing to disclose.
Data sharing statement: The data presented in this retrospective study were obtained following approval from the Institutional Review Board (IRB) (i17-01223) which granted permission for the use of anonymized patient information without individual consent. The retrospective nature of this study involved the analysis of de-identified retrospective data, ensuring anonymity and minimizing the risk of identification. As such, no explicit consent from each patient was obtained due to the retrospective design and the anonymization process. The IRB approval ensures compliance with ethical guidelines and regulations regarding data use and protection. For data sharing purposes, the presented data, while anonymized, are available upon request to qualified researchers, subject to appropriate ethical approvals and data sharing agreements.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See:
Corresponding author: Ran Schwarzkopf, MD, MSc, Professor, Department of Orthopedic Surgery, Division of Adult Reconstructive Surgery, NYU Langone Orthopedic Hospital, NYU Langone Health, 301 East 17th Street, Suite 1402, New York, NY 10010, United States.
Received: October 13, 2023
Peer-review started: October 13, 2023
First decision: December 7, 2023
Revised: December 15, 2023
Accepted: January 9, 2024
Article in press: January 9, 2024
Published online: February 18, 2024
Research background

This study investigates the effectiveness of a specialized knee implant in improving patient outcomes. Focusing on a kinematically designed cruciate retaining (CR) total knee replacement, the research explores its mid-term clinical performance and patient-reported outcomes. It addresses a gap in the existing literature by assessing the implant’s impact on patient satisfaction, functional improvement, and complications, emphasizing the need for comprehensive evaluation of specific implant designs to enhance total knee arthroplasty (TKA) procedures. Every novel implant should be evaluated and early and mid-term reports should be published in order to single out low performing implants and limit the effect on the public.

Research motivation

The research motivation lies in the need to address existing challenges in knee arthroplasty, particularly regarding implant design and patient outcomes. We think it is important to have early and midterm reports of novel implants in order to catch early failures and limit usage of failing implants. Key issues, such as achieving optimal knee functionality, improving patient satisfaction, and minimizing postoperative complications, serve as the primary focus. Solving these problems is critical for advancing the field of orthopedics, guiding future research in enhancing implant technologies, refining surgical techniques, and ultimately enhancing the quality of life for individuals undergoing knee replacement surgeries.

Research objectives

The primary aim was to evaluate the short-term and mid-term clinical outcomes as well as patient-reported outcome measures associated with a kinematically designed CR TKA. Through comprehensive clinical assessments and patient reported outcome measures (PROMs), the study aimed to ascertain the efficacy, functional improvements, and patient satisfaction levels achieved with this specific TKA design. This study is significant in the field of orthopedics because it provides empirical evidence regarding the performance and patient-reported experiences related to this particular kinematic design, thereby informing future TKA approaches and enhancing patient care in the orthopedic field.

Research methods

In the conducted retrospective study, we analyzed a cohort of patients who had previously undergone CR TKA by collecting clinical and PROMs data from medical records to assess the short-term and mid-term outcomes. While the design of the study is well-established, the CR TKA implant analyzed is a novel, new device that has been introduced within the past decade and with little available published data on outcomes. Thus, this study will greatly assist surgeons who wish to make better-informed risk assessment when selecting this novel implant for their patients. As a result, this study is truly clinically relevant and innovative in the field of total joint arthroplasty.

Research results

Postoperative hospital stay averaged 2.1 d and most patients were discharged to home (92.5%). The 90 d emergency department visit rate was 7.1% and 90 d readmission rate was 1.2%. The overall revision-free survivorship rate was 98.4% with an average follow-up of 3.3 years. Significant improvements in patient-reported outcome measures [Knee Injury and Osteoarthritis Outcome Score for Joint Replacement (KOOS JR) and Patient-Reported Outcomes Measurement Information System (PROMIS®) scores] were observed at six months and further improvements at two-years postoperatively, indicating favorable surgical outcomes and patient satisfaction. This study contributes vital real-world data to the field of knee prosthetic design, showcasing a notably high revision-free survivorship rate of 98.4% over a 3.3-year average follow-up. However, challenges persist, notably in reducing the occurrences of complications like periprosthetic joint infections and addressing issues such as arthrofibrosis and aseptic loosening, which demand further investigation and targeted intervention strategies for improved patient care and long-term surgical success.

Research conclusions

New theories proposed: The study doesn’t explicitly mention proposing new theories, but it does contribute to the growing body of evidence supporting the effectiveness of kinematically designed CR TKA implants. The findings suggest that this implant design offers favorable clinical outcomes, low complication rates, and notable improvements in PROMs for patients undergoing primary TKA. New methods used: The study employed a retrospective, multi-surgeon design that gathered data from 255 knees over a period from March 2015 to July 2021. The research collected patient demographics, surgical details, clinical outcomes, and PROMs data through electronic medical records. It specifically utilized the KOOS JR and PROMIS® scores to assess patient-reported outcomes. Statistical analysis, including Independent Samples t-tests, was used to determine the significance of improvements in PROMs scores.

Research perspectives

Future research in this field should concentrate on extending long-term follow-up beyond the current mean of 3.3 years to evaluate sustained implant performance. A prospective study, tracking patients undergoing CR TKA from preoperative stages through long-term postoperative follow-up, could offer comprehensive insights into its performance, complications, and patient-reported outcomes, further solidifying its efficacy and addressing any evolving concerns in real-time. Comparative studies against existing TKA designs, assessment across diverse patient populations, and investigations into health economics and cost-effectiveness are essential for validating this implant design’s superiority, understanding its efficacy in varied demographics, and informing healthcare decisions. Additionally, biomechanical analyses to comprehend how the implant’s design influences joint mechanics could aid in further optimizing its performance and durability.