Clinical Trial Details
— Status: Completed
Administrative data
| NCT number |
NCT05987839 |
| Other study ID # |
robotTKARCT |
| Secondary ID |
|
| Status |
Completed |
| Phase |
N/A
|
| First received |
|
| Last updated |
|
| Start date |
November 1, 2022 |
| Est. completion date |
June 30, 2023 |
Study information
| Verified date |
July 2023 |
| Source |
Peking University Third Hospital |
| Contact |
n/a |
| Is FDA regulated |
No |
| Health authority |
|
| Study type |
Interventional
|
Clinical Trial Summary
Purpose: A robotic system was recently introduced to improve prosthetic alignment during
total knee arthroplasty (TKA). The purpose of this multicenter prospective randomized
controlled trial (RCT) study was to determine whether robotic-arm-assisted TKA improves the
clinical and radiological outcomes in patients compared to conventional TKA.
Methods: One hundred and thirty patients who underwent primary TKA were enrolled in this
prospective, multicenter RCT conducted in 3 hospitals. Five patients were lost to follow-up
at 6 weeks after surgery. Therefore, 125 patients (63 in the intervention group and 62 in the
control group) remained in the final analysis. The primary outcome was the rate of patients
whose mechanical axis of the femur was less than 3° deviated from the mechanical axis of the
tibia evaluated by full-length weight-bearing X-rays of the lower limb at 6 weeks
postoperatively. Secondary outcomes will include operation times, 6-week postoperative
functional outcomes evaluated by the American Knee Society Score (KSS) and the Western
Ontario and McMaster Universities Osteoarthritis Index (WOMAC), SF-36, adverse events (AEs)
and serious adverse events (SAEs).
Hypothesis: Robotic-arm-assisted TKA is safe and effective as demonstrated in this trial.
Description:
2. Materials and methods 2.1 Study design Our study was a prospective, multicenter and
randomized controlled trial that was approved by the Institutional Review Board of Peking
University Third Hospital (IRB # 2022-134-02), the First Affiliated Hospital of Shandong
First Medical University (IRB # 2022-QX-S003-01) and Chifeng Municipal Hospital (IRB #
2022-LLSCGVK4-101-06). All patients had provided written informed consent.
2.2 Patient recruitment From November 2022 to May 2023, a total of 130 patients were
randomized into two groups - 65 patients underwent robotic-assisted TKA and 65 underwent
conventional TKA. The inclusion criteria were as follows: older than 18 years old and younger
than 80 years old with knee osteoarthritis undergoing primary and unilateral TKA; after
receiving both an oral and a written explanation of the study protocol, they provided written
informed consent that they were willing to complete all of the assessments and potential
interventions. The exclusion criteria were as follows: patients with infection, severe
systemic disease (severe diabetes, severe osteoporosis, severe muscle loss, etc.),
neuromuscular dysfunction of lower limbs, who are allergic to metal implants, participated in
other clinical studies, whose knee joint has been fused for a long time without pain or
deformity, unable to tolerate surgery on a systemic assessment, women who are pregnant or
breastfeeding, or who expect to give birth during the clinical period, and there are other
factors that affect the efficacy of observation in this study. All operations were performed
by experienced surgeons for the conventional and robotic-assisted groups at three hospitals.
All patients who underwent TKA with the robotic-assisted or conventional operations underwent
the radiologic and clinical assessment.
Main effectiveness evaluation index The main evaluation index of the knee navigation and
positioning system clinical trial was the proportion of subjects whose mechanical axis of the
femoris deviated from the mechanical axis of the tibia by ≤3° on the full-length lower
extremity weight-bearing X-ray at 6 weeks (±2 weeks) after surgery.
X-ray shooting requirements: Full-length weight-bearing X-ray of both lower limbs, that is,
X-ray of both lower limbs including hip joint, full length of femur, knee joint, full length
of tibia and fibula and ankle joint taken by the patient in the standing state. Key points:
The patient stands upright on the camera frame, the back is close to the camera frame, the
hands naturally droop, the knee joint is as straight as possible, the feet are the same width
as the shoulders, and the internal rotation is about 15°, so that the small head of the
fibula overlaps with the tibia nearly one-third, and the patella is pointed vertically in
front.
The lower limb force line was evaluated by non-surgeon.
1. Measurement method of mechanical shaft of femur:
The mechanical axis of the femur is the line from the center of the proximal joint
(center of the hip joint) to the center of the distal joint (center of the knee joint).
The central point of the hip joint is located in the central point of the femoral head
circle, and the Mose circle is used to determine the central point of the femoral head.
When determining the central point of the knee joint, the apex of the femoral
intercondylar fossa was used as the central point of the knee joint, without measuring
the width of bone tissue or soft tissue.
2. Measurement method of tibial mechanical axis:
The mechanical axis of the tibia is the line from the center of the proximal joint
(center of the knee joint) to the center of the distal joint (center of the ankle
joint).
The central point of the knee joint is located in the center of the tibial plateau.
Measure the midpoint of the talus width to determine the ankle joint center point.
3. Measurement method of the medial Angle between the mechanical axis of femur and the
mechanical axis of tibia:
The medial Angle between the mechanical axis of femur and the mechanical axis of tibia is the
hip knee ankle Angle (HKA).
Criteria: After measurement, the Angle of HKA does not exceed 180°±3°, and it is regarded as
an example of compliance with the mechanical shaft deviation Angle ≤3°. The proportion of
subjects in the experimental group and the control group whose mechanical axis deviation
Angle was ≤3° on the full-length lower extremity weight-bearing X-ray film 6 weeks (±2 weeks)
after surgery was calculated.
Secondary effectiveness evaluation index
1. Operation time The operation time of control group was from the establishment of
surgical incision to the end of skin suture. The operation start time of the
experimental group was the first time when the equipment started to work and the
surgical incision was established, and the operation end time was the end time of skin
suture.
2. KSS score The knee society score (KSS) is one of the most commonly used scores to
evaluate knee function. This method is to evaluate the patient's knee joint and its
function in two aspects according to the particularity of joint replacement surgery
through the evaluator interview and physical examination, that is, to obtain the
information of joint anatomy, biomechanics and other aspects, and to understand the
patient's functional recovery. Knee joint evaluation is to evaluate the impact of
surgery on the joint and the recovery of the joint after surgery, such as: joint pain,
joint range of motion, ligament stability, muscle strength, bone alignment, contracture
deformity; Functional assessments include activities of daily living, walking ability,
going up and down stairs, and the need for AIDS. Subjects and subjects were evaluated by
KSS scale.
3. WOMAC score This score is used to assess the severity of arthritis and its therapeutic
effectiveness based on the patient's relevant signs and symptoms. The structure and
function of the knee joint were evaluated by pain, stiffness and joint function. The
functional description of the knee joint was mainly for the lower limbs. You can use the
entire system or pick a part of it when you use it. In terms of content, this rating
scale assesses the structure and function of the knee joint from the three aspects of
pain, stiffness, and joint function, with a total of 24 items, including the basic
symptoms and signs of the entire joint. The pain part had five items, the stiffness part
had two items, and the joint function part had 17 items. The reliability, validity and
sensitivity of the assessment of the knee joint were objectively evaluated by the WOMAC
scoring scale.
4. SF-36 Health questionnaire The SF-36 Health Survey is a universal measurement scale
developed by the Medical Outcomes Study (MOS). It consists of 36 entries covering eight
areas: physical function, physical role, physical pain, general health, vitality, social
function, emotional role, and mental health. It is widely used in the measurement of the
quality of life of the general population, the evaluation of clinical trial effect and
the evaluation of health policy.
Safety evaluation
1. Incidence of adverse events Adverse events were collected and recorded throughout the
clinical trial, and the incidence rate was calculated.
2. Incidence of serious adverse events Serious adverse events were collected and recorded
throughout the clinical trial, and the incidence rate was calculated.
Statistical analysis and sample size calculation The description of quantitative indicators
will calculate the mean, standard deviation, median, minimum, maximum, lower quartile, upper
quartile, and qualitative indicators describe the frequency and frequency of each type. The
comparison of two groups of general conditions will be analyzed by appropriate methods
according to the type of indicators. Group t test or Wilcoxon rank sum test will be used for
comparison between groups of quantitative data, U-test, chi-square test or Fisher exact
probability method will be used for qualitative data, and Wilcoxon rank sum test will be used
for rank data.
Test level α=0.025 (unilateral), according to β=0.2 to calculate the test grasp, the ratio of
test group and control group is 1:1. According to the results of efficacy analysis, the
required sample size was calculated to be 55 cases, and the sample size was expanded to 65
cases considering the 15% shedding rate. The experimental group and the control group
completed 65 subjects each.
