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

Comparison of Postoperative Knee Alignment to Planned Alignment Using Two Implant Types and a Novel Robotic Platform in Total Knee Replacement - A Randomized Controlled Trial

Status
Recruiting
Phases
Unknown
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT07777757
Acronym
CAPTAIN
Enrollment
100
Registered
2026-08-20
Start date
2026-03-18
Completion date
2028-12-31
Last updated
2026-08-21

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Knee Osteoarthristis

Keywords

Total Knee Replacement, Robotic-Assisted Surgery, Knee Alignment, Knee Osteoarthritis

Brief summary

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.

Detailed description

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.

Interventions

DEVICEAttune Total Knee Implant

The Attune Total Knee Implant is a commercially available prosthetic knee system used in total knee replacement surgery. It is designed to provide stability and natural knee motion. In this study, it is used in conjunction with the KUNWU® Robotic Surgical System for implant positioning and bone resection guidance.

DEVICEPersona Total Knee Implant

The Persona Total Knee Implant is a commercially available prosthetic knee system used in total knee replacement surgery. It is designed to provide personalized fit and function. In this study, it is used in conjunction with the KUNWU® Robotic Surgical System for implant positioning and bone resection guidance.

Sponsors

The University of Hong Kong
Lead SponsorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
DOUBLE (Subject, Outcomes Assessor)

Masking description

Investigators are blinded to implant allocation except for the operating surgeon, who cannot be blinded due to the inherent differences in implant instrumentation and design. Participants and outcomes assessors remain blinded throughout the study. The allocation sequence is concealed using sequentially numbered, opaque, sealed envelopes.

Eligibility

Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No

Inclusion criteria

* Adults aged 18 years and older. * Diagnosis of symptomatic knee osteoarthritis requiring total knee replacement. * Ability to give informed consent. * Feasibility of using the two types of implants

Exclusion criteria

\- Severe radiographic knee OA (Kellgren-Lawrence grade 4) or severe knee pain (VAS\>80mm/100 mm) that could not tolerate further conservative management

Design outcomes

Primary

MeasureTime frameDescription
Change in Knee Alignment from Preoperative Plan to Postoperative OutcomeBaseline (preoperative CT) and immediate postoperative period (postoperative CT)Knee alignment will be assessed using the Hip-Knee-Ankle (HKA) angle and the Coronal Plane Alignment of the Knee (CPAK) classification. CPAK is derived from the Medial Proximal Tibial Angle (MPTA) and Lateral Distal Femoral Angle (LDFA), measured on CT scans. Postoperative alignment will be compared to the preoperative planned alignment to determine the accuracy of the robotic system in executing the surgical plan.

Secondary

MeasureTime frameDescription
Pain assessment using the Visual Analog Scale (VAS)Baseline (preoperative), 6 weeks, 3 months, 6 months, 12 months, and 24 months postoperativelyPain intensity will be assessed using the Visual Analog Scale (VAS), a 100-mm horizontal line ranging from 0 (no pain) to 100 (worst imaginable pain). Participants will be asked to mark their current level of knee pain on the scale. The VAS is a validated and widely used instrument for assessing pain in patients with knee osteoarthritis and following total knee replacement.
Functional assessment using the Forgotten Joint Scores (FJS) and Knee injury and Osteoarthritis Outcome Score, Junior (KOOS, JR)Baseline (preoperative), 6 weeks, 3 months, 6 months, 12 months, and 24 months postoperativelyFunctional outcomes will be assessed using two validated, patient-reported instruments. The Forgotten Joint Score (FJS) evaluates the patient's ability to forget about their replaced joint during daily activities, with higher scores indicating better awareness and function. The Knee Injury and Osteoarthritis Outcome Score, Junior (KOOS, JR) is a short-form, joint-specific tool that assesses pain, symptoms, and function related to knee osteoarthritis. Both instruments will be administered to evaluate patient-reported functional recovery following total knee replacement.
Quality of life measured by the Short-Form-12 health surveyBaseline (preoperative), 6 weeks, 3 months, 6 months, 12 months, and 24 months postoperativelyHealth-related quality of life will be assessed using the Short-Form-12 (SF-12) Health Survey, a validated 12-item questionnaire that measures physical and mental health components. The SF-12 provides a summary of overall well-being and is widely used in orthopedic outcomes research. It consists of 12 questions covering eight domains of health, including physical functioning, role limitations due to physical health, bodily pain, general health, vitality, social functioning, role limitations due to emotional problems, and mental health.
Complications : Documenting any intraoperative or postoperative complications, including infection, dislocation, and need for revision surgeryIntraoperative (day of surgery) and postoperative at 6 weeks, 3 months, 6 months, 12 months, and 24 monthsAll intraoperative and postoperative complications will be documented throughout the study period. Documented events will include, but are not limited to, infection (superficial or deep), wound dehiscence, periprosthetic fracture, dislocation or instability, implant loosening, neurovascular injury, deep vein thrombosis, pulmonary embolism, stiffness requiring manipulation under anesthesia, and need for revision surgery. Adverse events will be graded for severity and assessed for their relationship to the surgical procedure or implant. All serious adverse events will be reported to the HKU/HA HKW Institutional Review Board within 24 hours.
Cost-Effectiveness : Analysis of hospital costs, length of stay, and follow-up care.Hospital discharge and 24 months postoperativelyCost-effectiveness will be evaluated by analyzing direct medical costs associated with each implant group. Cost parameters will include implant costs, operating theater time, anesthetic services, hospital length of stay, inpatient rehabilitation, outpatient follow-up visits, and any additional healthcare utilization related to complications or revision surgeries. Total costs will be compared between the Attune and Persona groups to assess the economic impact of implant choice on overall healthcare resource utilization.

Countries

Hong Kong

Contacts

CONTACTChun Man Lawrence Prof. Lau, MBChB, MRCSEd, FRCSEd(Orth), F
laucml@hku.hk92646862
CONTACTKejing Eunice Ms. Xiao, Master
eunice7@hku.hk54845721

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Aug 22, 2026