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Knee OsteoarthristisCAPTAINNCT07777757

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

A study testing Attune Total Knee Implant and Persona Total Knee Implant in people with Knee Osteoarthristis, run by The University of Hong Kong at 1 site in Hong Kong.

Recruiting

Looking for participants now. Contact the study team or a site below to ask about taking part.

Sites and contacts
Official record
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Trial 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. Read more about this study

Who is it for?
Ages 18 years and older
Conditions the study is for
Knee Osteoarthristis
What is being tested?
Attune Total Knee Implant and Persona Total Knee Implant
Type of treatment
Medical device
Could I receive a placebo?
No, everyone receives an active treatment
How many people
100 participants
Where
1 siteHong Kong
Study dates
18 Mar 2026to 31 Dec 2028
Phase
Interventional
Are there results?
Not yet: the study is under way

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 years and older
  • All sexes
  • No healthy volunteers
  • Adult, Older adult

Who may be able to join

  • 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

Who cannot join

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

Trial locations and contacts

1 site in 1 country. Contact the study team or a site near you to ask about taking part.

Chun Man Lawrence Prof. Lau, MBChB, MRCSEd, FRCSEd(Orth), F contact

92646862

laucml@hku.hk

Kejing Eunice Ms. Xiao, Master contact

54845721

eunice7@hku.hk

Hong Kong1 site, 1 recruiting
  • The Duchess of Kent Children's Hospital at Sandy Bay

    Hong Kong, Sandy Bay, 999077

    Chun Man Lawrence Prof. Lau, MBChB, MRCSEd, FRCSEd(Orth), F, 92646862, laucml@hku.hk

    Kejing Eunice Ms Xiao, Master, 54845721, eunice@hku.hk

    Recruiting

Other trials in Hong Kong

About this study

Official title: 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

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.

Read more

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.

Read the 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.

Being tested
Attune Total Knee Implant, Persona Total Knee Implant
Keywords
Total Knee Replacement, Robotic-Assisted Surgery, Knee Alignment, Knee Osteoarthritis
Medical subject headings
Osteoarthritis, Knee

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Attune Total Knee ImplantDevice

    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.

  • Persona Total Knee ImplantDevice

    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.

Study groups in NCT07777757
Study groupRoleWhat they receive
Attune Implant GroupExperimentalParticipants in this arm will undergo total knee replacement surgery using the KUNWU® Robotic Surgical System with the Attune total knee implant. The surgical procedure, including preoperative CT-based planning and intraoperative robotic guidance, is standardized across both arms.
Receives: Device: Attune Total Knee Implant
Persona Implant GroupExperimentalParticipants in this arm will undergo total knee replacement surgery using the KUNWU® Robotic Surgical System with the Persona total knee implant. The surgical procedure, including preoperative CT-based planning and intraoperative robotic guidance, is standardized across both arms.
Receives: Device: Persona Total Knee Implant

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Change in Knee Alignment from Preoperative Plan to Postoperative Outcome

    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.

    Measured: Baseline (preoperative CT) and immediate postoperative period (postoperative CT)

Secondary outcomes (5)
  1. Pain assessment using the Visual Analog Scale (VAS)

    Pain 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.

    Measured: Baseline (preoperative), 6 weeks, 3 months, 6 months, 12 months, and 24 months postoperatively

  2. Functional assessment using the Forgotten Joint Scores (FJS) and Knee injury and Osteoarthritis Outcome Score, Junior (KOOS, JR)

    Functional 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.

    Measured: Baseline (preoperative), 6 weeks, 3 months, 6 months, 12 months, and 24 months postoperatively

  3. Quality of life measured by the Short-Form-12 health survey

    Health-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.

    Measured: Baseline (preoperative), 6 weeks, 3 months, 6 months, 12 months, and 24 months postoperatively

  4. Complications : Documenting any intraoperative or postoperative complications, including infection, dislocation, and need for revision surgery

    All 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.

    Measured: Intraoperative (day of surgery) and postoperative at 6 weeks, 3 months, 6 months, 12 months, and 24 months

  5. Cost-Effectiveness : Analysis of hospital costs, length of stay, and follow-up care.

    Cost-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.

    Measured: Hospital discharge and 24 months postoperatively

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted20 Aug 2026
  2. Study start18 Mar 2026
  3. Primary completion30 Sep 2028 (estimated)
  4. Study completion31 Dec 2028 (estimated)

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase N/A
Primary purpose
Treatment
Allocation
Randomised
Intervention model
Parallel groups
Masking
Double blind
Who is masked
Participant, Outcomes assessor
Enrolment
100 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT07777757
Sponsor's protocol ID
UW 25-413
Acronym
CAPTAIN
Status last verified
Aug 2026
First submitted
17 Aug 2026
Last updated
21 Aug 2026
Results posted
No
Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
No: Individual participant data (IPD) will not be shared with other researchers due to institutional data protection policies and patient confidentiality requirements. Access to study data will be restricted to the principal investigator and designated study team members for the purposes of data analysis and publication. All data will be stored in a password-protected computer and retained for 5 years after study completion, after which it will be destroyed in accordance with the protocol.

Questions about this trial

What is this clinical trial studying?

A study testing Attune Total Knee Implant and Persona Total Knee Implant in people with Knee Osteoarthristis, run by The University of Hong Kong at 1 site in Hong Kong.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 4 inclusion and 1 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: looking for participants now, as of the sponsor's last update on 21 Aug 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in Hong Kong. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

This study is still under way. Results are not available in the source record yet.

How can a doctor refer a patient or contact the research team?

Contact Chun Man Lawrence Prof. Lau, MBChB, MRCSEd, FRCSEd(Orth), F (92646862, laucml@hku.hk), or a site near the patient. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Change in Knee Alignment from Preoperative Plan to Postoperative Outcome (time frame: Baseline (preoperative CT) and immediate postoperative period (postoperative CT)). It is what the study was designed to measure, not a finding.

Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 21 Aug 2026.

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