Imageless Navigation Versus Image-Based Navigation in Robotic-Assisted Total Knee Arthroplasty for Knee Osteoarthritis

Outcomes of Robotic-Assisted Total Knee Arthroplasty With Imageless Navigation Versus Image-Based Navigation: A Randomised, Single-Blinded, Non-Inferiority Trial

The goal of this clinical trial is to learn if imageless navigation is not inferior to image-based navigation in robotic-assisted total knee arthroplasty (RA-TKA) for treating patients with knee osteoarthritis.

The main questions the study aims to answer are:

1. Does imageless procedure provide functional results comparable to those of image-based navigation?
2. Are there differences in postoperative complications patients may experience after RA-TKA with imageless and image-based navigation? Researchers will compare imageless navigation with image-based navigation used in total knee arthroplasty to assess whether imageless navigation is comparable for the treatment of knee osteoarthritis.

Participants will:

1. Answer survey questions about knee pain and function before RA-TKA.
2. Undergo RA-TKA with imageless navigation or image-based navigation.
3. Visit the Clinic after 6 months and 12 months after surgery for checkups and to answer the same survey questions about postoperative knee pain and function.

Study Overview

• Status: Not yet recruiting
• Conditions: Total Knee Arthroplasty (TKA); Osteoarthritis (OA) of the Knee; Knee Pain Arthritis; Robotic Assisted Arthroplasty
• Intervention / Treatment: Procedure: Imageless Robotic-Assisted Total Knee Arthroplasty; Procedure: Image-based Robotic-Assisted Total Knee Arthroplasty

Detailed Description

The trial will include patients with end-stage osteoarthritis, qualified for Robotic-Assisted Total Knee Arthroplasty (RA-TKA). For each patient, a full-length standing radiograph will be taken with designated sensors. Based on these, a three-dimensional model of the knee joint will be generated, enabling preoperative planning and intraoperative navigation in the image-based mode. Patients who meet the criteria and provide informed consent will be included in the study. Immediately before surgery, patients will be randomly assigned by a computer programme to either the experimental or control group in a 1:1 ratio, remaining blinded to the chosen method. In the experimental group, RA-TKA will be performed using imageless navigation, whereas in the control group, it will be performed using image-based navigation. In both groups, the procedure will be performed by experienced specialists with several years of experience, according to a standardized protocol: a medial parapatellar approach with restricted kinematic alignment, using a medial congruent knee implant.

The total number of patients included in the study is planned to be 146, with 73 in the experimental group and 73 in the control group. The group size was calculated based on a power analysis; power level: 80%, significance level: α=0.05, minimal clinically important difference: 5 points on the Oxford Knee Score (OKS), standard deviation: 10 points on the OKS. The study's dropout rate is estimated at 15%.

Radiologic imaging, survey responses, and intraoperative records will be stored on physical disks and paper, as well as in a secure cloud-based database. All other records will be stored digitally only. Registry data will be compared with external data sources (medical records) every 6 months to assess their accuracy and completeness. A Linear Mixed-Effects Model will be used to account for correlation between OKS measurements in the same patient. Both Per-Protocol and Intention-to-Treat analyses will be reported. For comparing continuous variables, a t-test (if normally distributed) or a Mann-Whitney U test (if skewed) will be used. Categorical variables will be compared with Fisher's Exact Test or the Chi-squared test. A cost-minimization analysis will be conducted using economic data.

• Study Type: Interventional
• Enrollment (Estimated): 146
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Paweł Kasprzak, MD; Phone Number: +48 22 50 21 514; Email: pawel.kasprzak@wum.edu.pl

Study Locations

• Poland
  • Mazovian
    • Warsaw, Mazovian, Poland, 02-005
      • Department of Orthopedics and Locomotor Traumatology, Medical University of Warsaw
      • Contact: Paweł Kasprzak, MD; Phone Number: +48 22 50 21 514; Email: pawel.kasprzak@wum.edu.pl
      • Principal Investigator: Paweł Łęgosz, MD, Professor
      • Principal Investigator: Łukasz Pulik, MD, PhD
      • Principal Investigator: Paweł Kasprzak, MD

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

1. Symptomatic, radiologically confirmed advanced osteoarthritis of the knee.
2. Patients referred for primary robotic-assisted total knee arthroplasty.
3. Patients in whom a correctly performed radiograph with designated sensors has confirmed the possibility of performing robotic-assisted total knee arthroplasty with image-based navigation.
4. Patients capable of giving informed consent to participate in the study and willing to attend all follow-up visits.

Exclusion Criteria:

1. No informed consent for the surgery.
2. No informed consent for taking part in the study.
3. Pregnancy.
4. Active infections.
5. Diagnosed comorbidities: autoimmune arthritis, malignant tumors, serious neurological disorders affecting a reliable functional outcome measurement (e.g., severe stroke, severe Parkinson's disease).

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Imageless Robotic Navigation	Procedure: Imageless Robotic-Assisted Total Knee Arthroplasty; Patients undergoing Robotic-Assisted Total Knee Arthroplasty with Imageless Navigation
Active Comparator: Image-based Robotic Navigation	Procedure: Image-based Robotic-Assisted Total Knee Arthroplasty; Patients undergoing Robotic-Assisted Total Knee Arthroplasty with Image-based Navigation

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Patient-Reported Outcome Measures assessed with the Oxford Knee Score	Zero is equivalent to the worst possible function of the joint and 48 indicates the best achievable function.	Survey taken right before surgery, at 6 months, and at 12 months after surgery.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Number of Participants achieving a planned postoperative limb alignment	The percentage of patients within ±3 degrees of the preoperative target.	From enrollment to 12 months after surgery.
Postoperative radiographic results	Hip-Knee-Ankle angle, mechanical axis deviation, coronal femoral component angle, sagittal femoral tilt/flexion, femoral component rotation, coronal tibial component angle, posterior tibial slope, patellar tilt, all measured in degrees.	From enrollment to 12 months after surgery.
Postoperative pain assessed with a VAS scale	Zero is equivalent to no pain and 10 indicates the worst possible pain.	Survey taken right before surgery, at 6 months, and at 12 months after surgery.
Time of the surgical procedure	Duration of the surgical procedure in total and for each stage measured in minutes.	From the beginning to the end of the surgical procedure.
Estimation of perioperative blood loss	Intra-operative blood loss estimation by measuring the blood volume accumulated in suction bottles in milliliters, taking into account the volume of saline solution used during the surgery.	Immediately after the end of the surgery.
Difference between preoperative and postoperative hemoglobin levels	Hemoglobin levels will be obtained from samples taken at different times before and after surgery.	Hemoglobin levels will be measured within 2 weeks before surgery, as well as 24, 48 and 72 hours after surgery.
Postoperative complications	The percentage of cases with reported postoperative complications, such as: bleeding, wound complication, thromboembolic disease, neural deficit, vascular injury, ligament injury, instability, malalignment, stiffness, periprosthetic joint infection, periprosthetic fracture, extensor mechanism disruption, dislocation, bearing surface wear, osteolysis, implant loosening, revision, death.	From enrollment to 12 months after surgery.
Costs required for preoperative planning	Costs of all preoperative imaging and procedures necessary to plan imageless and image-based robotic navigation.	From one month before enrollment to 12 months after surgery.
Time required for preoperative planning	Time required to prepare all preoperative imaging and procedures necessary to plan imageless and image-based robotic navigation.	From one month before enrollment to 12 months after surgery.

Collaborators and Investigators

• Sponsor: Medical University of Warsaw
• Investigators: Principal Investigator: Paweł Łęgosz, MD, Professor, Medical University of Warsaw; Principal Investigator: Łukasz Pulik, MD, PhD, Medical University of Warsaw; Principal Investigator: Paweł Kasprzak, MD, Medical University of Warsaw

Study record dates

Study Major Dates

• Study Start (Estimated): May 1, 2026
• Primary Completion (Estimated): January 1, 2029
• Study Completion (Estimated): January 1, 2029

Study Registration Dates

• First Submitted: March 30, 2026
• First Submitted That Met QC Criteria: April 7, 2026
• First Posted (Actual): April 13, 2026

Study Record Updates

• Last Update Posted (Actual): April 13, 2026
• Last Update Submitted That Met QC Criteria: April 7, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Keywords: Knee Osteoarthritis; Patient Reported Outcome Measures; Robotic-Assisted Total Knee Arthroplasty; Imageless Navigation; Image-based Navigation
• Additional Relevant MeSH Terms: Musculoskeletal Diseases; Arthritis; Joint Diseases; Rheumatic Diseases; Osteoarthritis; Osteoarthritis, Knee
• Other Study ID Numbers: KB/178/2025

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: De-identified study results will be disseminated in conference abstracts and peer-reviewed journal articles.
• IPD Sharing Time Frame: Within 12 months of the trial completion.
• IPD Sharing Access Criteria: Data and supporting information will be shared upon reasonable request to the Principal Investigator. After the Principal Investigator reviews and approves the applicant's request, de-identified information will be provided.
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; SAP

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No