Efficacy and Safety of NAVIO

Study Overview
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Brief Summary
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The goal of the study is to compare the efficacy, safety and costs of the NAVIO™ system with the conventional intramedullary alignment guide for total knee replacement in a clinical setting. The hypothesis is that total knee arthroplasty (TKA) with the use of NAVIO™ is at least as efficient and safe as TKA with the use of conventional intramedullary alignment guiding.

Official Title
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Comparison of Clinical Outcome and Alignment of NAVIO Total Knee Arthroplasty and Conventional Total Knee Arthroplasty A Prospective, Randomized, Controlled, Single Blind Study

Conditions
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Osteoarthritis, Knee

Intervention / Treatment
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* Procedure: total knee arthroplasty
* Radiation: CT scan


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Painful and disabled knee joint resulting from osteoarthritis where one or more compartments are involved, as assessed by X-ray High need to obtain pain relief and improve function Above 18 years old Able and willing to follow instructions Informed consent Exclusion Criteria: Active infection in knee General infection Failure of previous joint replacement Post-operative or post traumatic malalignment of the knee/leg Pregnancy Not able or willing to undergo CT-scan

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Conventional total knee arthroplasty<br>conventional total knee arthroplasty with standard intramedullary alignment guide | Procedure: total knee arthroplasty<br>* total knee arthroplasty<br>Radiation: CT scan<br>* The first 52 participants will recieve a pre- and postoperative CT scan of the hip, knee and ankle.<br>|
| Active Comparator: NAVIO total knee arthroplasty<br>NAVIO assisted total knee arthroplasty | Procedure: total knee arthroplasty<br>* total knee arthroplasty<br>Radiation: CT scan<br>* The first 52 participants will recieve a pre- and postoperative CT scan of the hip, knee and ankle.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Difference in planned and achieved alignment in degrees based on CT scan pre- and postoperatively (first 52 participants) | Difference in preoperatively planned and postoperatively achieved alignment of both the femoral and tibial component of the prosthesis in the frontal, sagittal and coronal plane. Deviations (in degrees varus/valgus, flexion extension, and internal/external rotation) from calculated positions (of both components) to bony anatomic landmarks, used by NAVIO to align the prosthesis, will be obtained. | within 6 weeks pre-surgery and 6 weeks post-surgery | 
| Difference in planned and achieved mechanical axis in degrees based on CT scan pre- and postoperatively (first 52 participants) | Preoperatively planned and postoperatively achieved mechanical axis of the operated leg. The mechanical axis is defined as the angle between a line from the centre of rotation of the hip to the centre of the femoral component and a line from the centre of the tibial plateau to the centre of the ankle. | within 6 weeks pre-surgery and 6 weeks post-surgery | 
| Difference in percentage of outliers of alignment on CT scan pre- and postoperatively (first 52 participants) | Percentage of outliers in alignment (defined as > 3 degrees deviation from positions calculated by software) of the femoral and tibial components in frontal, sagittal and transverse plane. | within 6 weeks pre-surgery and 6 weeks post-surgery | 
| Difference in percentage of outliers of mechanical axis based on CT scan pre- and postoperatively (first 52 participants) | Percentage of outliers (defined as > 3 degrees deviation from neutral) in mechanical axis of the of the operated leg. The mechanical axis is defined as the angle between a line from the centre of rotation of the hip to the centre of the femoral component and a line from the centre of the tibial plateau to the centre of the ankle. | within 6 weeks pre-surgery and 6 weeks post-surgery | 
| Mean change in the visual analogue scale scores | Comparison is made between the two study arms, a higher visual analogue pain score means a worse outcome | within 6 weeks preoperative, 24 hours post-surgery, day of discharge, 6 weeks post-surgery, 3 months post-surgery, 1 year post-surgery, 2 years post-surgery, 5 years post-surgery, 10 years post-surgery | 
| Mean change in the American Knee Society Score | in a total of 50 points, stability, 25 points, and range of motion, 25 points. The maximum score of 100 points . Comparison is made between the two study arms. A higher American Knee Society Score means a better outcome | within 6 weeks preoperative, 3 months post-surgery, 1 year post-surgery, 2 years post-surgery, 5 years post-surgery, 10 years post-surgery | 
| Mean change in the Oxford Knee Score | Comparison is made between the two study arms, score between 0 and 48. Better score means better outcome | within 6 weeks preoperative, 3 months post-surgery, 1 year post-surgery, 2 years post-surgery, 5 years post-surgery, 10 years post-surgery | 
| Mean change in the Lower Extremities Activity scale | Comparison is made between the two study arms, score between 0 and 80. The minimal clinically important difference is 9 scale points. The lower the score the greater the disability. | within 6 weeks preoperative, day of discharge, 6 weeks post-surgery, 3 months post-surgery, 1 year post-surgery, 2 years post-surgery, 5 years post-surgery, 10 years post-surgery | 
| Mean change in the The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) | Comparison is made between the two study arms. Five items for pain (score range 0-20), two for stiffness (score range 0-8), and 17 for functional limitation (score range 0-68). The higher the score, the poorer the function | within 6 weeks preoperative, 3 months post-surgery, 1 year post-surgery, 2 years post-surgery, 5 years post-surgery, 10 years post-surgery | 
| Difference in mechanical axis of the prosthesis between the two study arms based on Long-leg X-rays | Post-operative (at 6 week visit) the baseline mechanical axis will be measured as the angle between a line connecting the center of the femoral head with the center of the knee and the line connecting the center of the knee with the center of the ankle. | within 6 weeks preoperative, 6 weeks post-surgery, 1 year post-surgery, 5 years post-surgery, 10 years post-surgery | 
| Difference in positioning of the prosthesis between the two study arms based on Long-leg X-rays | In order to measure positioning of the prosthesis (coronal alignment), long-leg, weight-bearing, standing anteroposterior and lateral X-rays will be made | within 6 weeks preoperative, 6 weeks post-surgery, 1 year post-surgery, 5 years post-surgery, 10 years post-surgery | 
| Difference in wear between the two study arms based on Long-leg X-rays | In the long term, wear can be roughly measured by measuring again the mechanical axis of the leg and comparing this with baseline mechanical axis and by measuring the distance between medial and lateral femoral condyles and medial and lateral tibial platform respectively. | within 6 weeks preoperative, 6 weeks post-surgery, 1 year post-surgery, 5 years post-surgery, 10 years post-surgery | 
| Significant difference in length of hospital stay between the two study arms | Length of hospital stay (in days) will be registered for both groups. | 1 day of discharge from the hospital | 
| Operation Time | Compare the duration of surgery between the two study arms | intraoperative (Time will be recorded from the moment of incision until bandage is being placed) | 
| Significant difference in blood loss between study arms | Blood loss will be measured intra-operatively and up to 24 hours post-operatively. The amount of rinsing liquid will be subtracted from the total amount collected in the suction device to obtain the amount (ml) of intra-operative blood loss. The weight of grids and compresses will be measured post-operatively and dry weight will be subtracted from this value to obtain blood loss not collected in the suction device (1mg = 1ml). On day 2 post-operative, Hb and Ht will obtained. | Intra-operatively until 24 hours post-surgery. . | 
| Difference in adverse events | Complication registration will be done throughout the entire study period | through study completion, an average of 10 years | 
| Difference in frequency of infection | When infection is present, this will be noted on the complication registry form and appropriate action will be taken. Distinction will be made between superficial infections and deep infections. | through study completion, an average of 10 years | 
| Difference in frequency of trombo-embolic complications | Attention will be focused on clinical signs of deep vein thrombosis and pulmonary embolism. | through study completion, an average of 10 years | 
| Difference in frequency of wound problems | Persistent wound leakage will be registered. Persistent leakage is defined as leakage lasting 5 days after surgery. | From day of surgery until 5 days post-surgery | 
| Difference in frequency of loosening | Loosening of tibial or femoral components of the prosthesis as seen on X-ray. | through study completion, an average of 10 years. |