Early Clinical and Radiological Outcomes of a Novel Robotic TKA System (RA-TKA)

This study aimed to evaluate the early clinical and radiological outcomes of robot assisted total knee arthroplasty, and to determine the efficiency and safety of its bone resection and implant positioning of the novel robot system.

144 patients undergoing primary TKA were enrolled in this prospective, multicenter RCT conducted in 3 hospitals. The primary outcome was the rate of patients whose postoperative alignment was less than 3° deviated from the planned evaluated by full-length weight-bearing X-rays of the lower limb at 12 weeks postoperatively. Secondary outcomes will include coronal and sagittal alignment of the components, operation times, blood loss, 12-week range of motion(ROM), 12-week postoperative functional outcomes and satisfaction evaluated by the American Knee Society Score (KSS) and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and adverse events (AEs).

Study Overview

• Status: Completed
• Conditions: Robotic Surgery; Total Knee Anthroplasty
• Intervention / Treatment: Procedure: robotic-assisted TKA; Procedure: CI-TKA

• Study Type: Interventional
• Enrollment (Actual): 144
• Phase: Not Applicable

Contacts and Locations

Study Locations

• China
  • Beijing
    • Beijing, Beijing, China, 100191
      • Peking University Third Hospital

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

• Patients aged 18-85 years (including 18 and 85), regardless of gender;
• Patients scheduled for unilateral primary total knee arthroplasty based on the clinical judgment of the study physician;
• The subject or their guardian has been informed of the study, agrees to all terms of the trial, signs an informed consent form approved by the ethics committee, and agrees to participate in the trial.

Exclusion Criteria:

• The side scheduled for surgery has significant hip joint disease, such as substantial bone defects or severe limitations in joint mobility;
• Patients with active infections around the knee joint or systemic infections;
• Discontinuity or severe functional loss of the knee extensor mechanism, painless knee joint fusion, Charcot joint, poor surgical tolerance, or other conditions that may adversely affect surgical prognosis;
• Patients with contraindications for traditional TKA surgery;
• Pregnant or breastfeeding women;
• Patients known to have excessive alcohol consumption or substance abuse; Body mass index (BMI) > 35 kg/m²;
• Patients who have participated in other clinical trials within one month prior to signing the informed consent form;
• Patients with mental or intellectual disabilities that may affect clinical outcome evaluations;
• Patients deemed unsuitable for participation in this clinical trial by the investigator.

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
Experimental: RA TKA; Robotic-assisted TKA	Procedure: robotic-assisted TKA; Robotic-assisted TKA means that TKA surgery is operated with the guidance of robotic system.
Active Comparator: CI TKA; TKA with conventional instruments	Procedure: CI-TKA; TKA operated with conventional instruments

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
HKA outliers	the proportion of patients with a deviation of ≤ 3° between the mechanical axis (hip-knee-ankle angle, or HKA angle) measured from a full-length, frontal-view lower limb X-ray	12 weeks post-surgery

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
FFC angle	frontal femoral component (FFC) angle	12 weeks post-surgery
outliers of FFC angle	outliers of frontal femoral component (FFC) angle (>3 degree)	12 weeks post-surgery
FTC angle	frontal tibia component (FTC) angle	12 weeks post-surgery
outliers of FTC angle	outliers of frontal tibia component (FTC) angle (>3 degree)	12 weeks post-surgery
LFC angle	lateral femoral component (LFC) angle	12 weeks post-surgery
outliers of LFC angle	outliers of lateral femoral component (LFC) angle (>3 degree)	12 weeks post-surgery
LTC angle	lateral tibia component (LTC) angle	12 weeks post-surgery
outliers of LTC angle	outliers of lateral tibia component (LTC) angle (>3 degree)	12 weeks post-surgery
Surgical duration	In this study, surgical duration is defined as the time from the first incision to the completion of skin closure	During operation
Blood loss	Postoperative blood loss is calculated using the Gross formula in this study. The Gross equation was used to calculate the total blood loss (mL) as preoperative blood volume×(preoperative HCT level-postoperative HCT level).	3 days after surgery
ROM	ROM refers to the maximum passive range of knee motion	12 weeks post-surgery
Knee Society Score (KSS)	The KSS, developed by the American Knee Society, evaluates objective knee indicators, symptoms, patient satisfaction, patient expectations, and functional activities. A total score above 85 is considered excellent, 70-84 is good, 60-69 is fair, and below 60 is poor.	screening and 12 weeks post-surgery.
Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC)	The WOMAC measures knee function in terms of pain, stiffness, and physical function across 25 items. Pain is assessed with five items, stiffness with two items, and physical function with 18 items. Each item is scored from 0 to 4, with higher scores indicating more severe symptoms.	screening and 12 weeks post-surgery.
Incidence of adverse events and serious adverse events	Throughout the study, any adverse events that occurred were recorded, and the corresponding incidence was calculated. Similarly, any serious adverse events that occurred during the study were recorded, and the corresponding incidence was calculated.	Through study completion, an average of 12 weeks

Collaborators and Investigators

• Sponsor: Peking University Third Hospital

Study record dates

Study Major Dates

• Study Start (Actual): September 8, 2022
• Primary Completion (Actual): February 2, 2023
• Study Completion (Actual): May 13, 2024

Study Registration Dates

• First Submitted: October 6, 2024
• First Submitted That Met QC Criteria: October 10, 2024
• First Posted (Actual): October 15, 2024

Study Record Updates

• Last Update Posted (Actual): October 15, 2024
• Last Update Submitted That Met QC Criteria: October 10, 2024
• Last Verified: October 1, 2024

More Information

Terms related to this study

• Keywords: total knee arthroplasty; robot; clinical outcome; radiological; postoperative alignment
• Other Study ID Numbers: JUST-RA-TKA

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

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