New Robotic Knee Surgery: Does Implant Type Affect Alignment Accuracy?

Overview

Total knee replacement is a common surgery for patients with severe knee arthritis. To improve surgical accuracy, surgeons now use robotic systems to help plan and perform the procedure. A new robotic system called KUNWU® has been developed in Hong Kong. Unlike many other systems, it allows surgeons to choose from different brands of knee implants. This study is a randomized controlled trial. It will compare two different types of knee implants (Attune and Persona) used together with the KUNWU® robotic system. The main goal is to see how accurately the robotic system helps achieve the knee alignment that was planned before surgery. Alignment refers to the straightness and balance of the knee joint after the implant is placed. Participants will be adults with knee osteoarthritis who need a total knee replacement. They will be randomly assigned to receive either the Attune or Persona implant. All surgeries will be performed using the KUNWU® robotic system. Participants will have CT scans before and after surgery, and X-rays will be taken at regular follow-up visits over 24 months. Clinical assessments, including pain and function scores, will also be collected at various time points. The study will take place at the Department of Orthopaedics \& Traumatology, The Duchess of Kent Children's Hospital (DKCH). A total of 100 participants will be recruited. The study will run for approximately 36 months, with recruitment lasting 12 months and follow-up continuing for 24 months. The results will help determine whether the new robotic system can consistently achieve the planned alignment regardless of which implant is used. This information may help surgeons make better decisions about implant selection and robotic surgery in the future.

This is a single-center, prospective, double-blinded, randomized controlled trial (RCT) conducted at the Department of Orthopaedics \& Traumatology, The Duchess of Kent Children's Hospital (DKCH), Hong Kong. The study aims to evaluate the accuracy of postoperative knee alignment relative to preoperative planning when using two different commercially available total knee arthroplasty (TKA) implant systems (Attune and Persona) in conjunction with a novel CT-based robotic surgical system (KUNWU® Robotic Surgical System, Yuanhua Robotics, Perception \& AI Technologies Limited, Hong Kong). Randomization and Blinding Eligible participants will be randomized in a 1:1 ratio to receive either the Attune or Persona implant using a computer-generated randomization sequence. Allocation concealment will be maintained using sequentially numbered, opaque, sealed envelopes. The study is double-blinded: participants and outcome assessors will be blinded to implant allocation. The operating surgeon cannot be blinded due to the inherent differences in implant instrumentation and design. Surgical Procedure All surgeries will be performed by a single surgical team using the KUNWU® robotic system. Preoperative planning will be based on CT-derived 3D models of the patient's knee joint, allowing for individualized determination of implant size, positioning, and alignment targets. Intraoperatively, the robotic system provides real-time haptic feedback and bone resection guidance to execute the preoperative plan. The choice of implant (Attune or Persona) is the only variable; all other aspects of the surgical procedure, including approach, soft tissue balancing, and postoperative rehabilitation protocol, will be standardized across both groups. Assessments and Follow-up Schedule Participants will undergo a series of clinical and radiological assessments at specified time points throughout the study. Imaging Assessments: Computed Tomography (CT) scans will be performed preoperatively and once postoperatively to assess knee alignment. Standard X-rays will be taken preoperatively, and at 3 months, 6 months, 12 months, and 24 months postoperatively. Clinical Assessments: All clinical outcome assessments will be administered by a blinded assessor. Assessments will take place preoperatively, and at 6 weeks, 3 months, 6 months, 12 months, and 24 months postoperatively. The following validated instruments will be used: Pain Assessment: Visual Analog Scale (VAS) for pain Functional Assessment: Forgotten Joint Score (FJS) and Knee Injury and Osteoarthritis Outcome Score, Junior (KOOS, JR) Quality of Life Assessment: Short-Form-12 (SF-12) health survey Safety Monitoring: All intraoperative and postoperative complications, including but not limited to infection, dislocation, and need for revision surgery, will be documented throughout the follow-up period. Length of hospital stay and cost-effectiveness data will also be collected. Summary of Assessment Schedule: In summary, CT scans are performed twice (preoperatively and postoperatively), while X-rays are performed at five time points (preoperatively, 3 months, 6 months, 12 months, and 24 months). Clinical outcome assessments using VAS, FJS, KOOS, JR, and SF-12 are conducted at six time points (preoperatively, 6 weeks, 3 months, 6 months, 12 months, and 24 months). Complications are monitored at all postoperative visits from 6 weeks through 24 months.