A Trial of Mechanical Axis vs Kinematic Alignment in Total Knee Replacement

Study Overview
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Brief Summary
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This is a prospective, randomized, longitudinal study of the clinical outcomes of osteoarthritis patients treated by two different alignment philosophies for total knee replacement. In this study ShapeMatch® cutting guides will be compared to the conventional approach.

Official Title
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A Prospective, Randomized, Controlled Trial of Mechanical Axis vs Kinematic Alignment in TKR - With a Follow-up, Longitudinal Study of the Clinical and Radiographic Outcomes

Conditions
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Arthroplasties, Knee Replacement

Intervention / Treatment
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* Device: OtisMed® ShapeMatch® Technology
* Device: Stryker Precision Knee Navigation
* Procedure: Total Knee Replacement
* Device: Stryker Triathlon® Total Knee System


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: The patient is a male or non-pregnant female between the ages of 40-80 years. The patient requires a primary total knee replacement and is indicated for computer-assisted surgery. Patient is deemed appropriate for a cruciate retaining knee replacement. The patient has a primary diagnosis of osteoarthritis (OA). The patient has intact collateral ligaments. The patient is able to undergo MRI scanning of the affected limb. The patient has signed the study specific, ethics-approved, Informed Consent document. The patient is willing and able to comply with the specified pre-operative and post-operative clinical and radiographic evaluations. Exclusion Criteria: The patient has a history of total, unicompartmental reconstruction or fusion of the affected joint. Patient has had a previous osteotomy around the knee. The patient is morbidly obese (BMI ≥ 40). The patient has a deformity which will require the use of stems, wedges or augments in conjunction with the Triathlon Total Knee System. The patient has a varus/valgus malalignment ≥ 15° (relative to mechanical axis). The patient has a fixed flexion deformity ≥ 15°. The patient has a neuromuscular or neurosensory deficiency, which would limit the ability to assess the performance of the device. The patient has a systemic or metabolic disorder leading to progressive bone deterioration. The patient is immunologically suppressed or receiving steroids in excess of normal physiological requirements. Patient has a cognitive impairment, an intellectual disability or a mental illness. The patient is pregnant. The patient has metal hardware present in the region of the hip, knee or ankle (as this is known to create geometrical distortion in the region of the implant). The patient has any known contraindications for undergoing assessment by MRI (e.g. ferrous implants, metallic clips, magnetically activated implanted devices such as cardiac pacemakers, etc).

Ages Eligible for Study
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Minimum Age: 40 Years
Maximum Age: 80 Years


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: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: OtisMed® ShapeMatch® with Triathlon<br>Participants randomised to the Intervention Group will undergo Total Knee Replacement (TKR) with the Stryker Triathlon® Total Knee System and OtisMed® ShapeMatch® Technology with the goal of kinematic alignment (re-aligning the limb to its pre-disease kinematic alignment). | Device: OtisMed® ShapeMatch® Technology<br>* The appropriate Stryker ShapeMatch® Cutting Guides will be used to guide the surgeons bone resections. The surgeon will implant the knee prostheses following the surgical protocol for Triathlon® Knee System with OtisMed® ShapeMatch® Technology<br>Procedure: Total Knee Replacement<br> <br> Device: Stryker Triathlon® Total Knee System<br>* Prosthetic components to be implanted including Triathlon® Cruciate Retaining (CR) Total Knee System (cemented), including Femoral Component and Primary Tibial Baseplate; Triathlon® Cruciate Substituting (CS) X3® polyethylene insert; Triathlon® X3 Patella (asymmetric) - treated selectively by surgeon.<br>|
| Active Comparator: Stryker Precision Knee Navigation<br>Participants randomised to the Control Group will undergo Total Knee Replacement (TKR) with the Stryker Triathlon® Total Knee System guided by Stryker Precision Knee Navigation with the goal of neutral alignment to the mechanical axis. This is the standard method for TKR with Triathlon® Knee System and this group will serve as a control reference for the intervention group. | Device: Stryker Precision Knee Navigation<br>* Stryker PrecisioN Knee (4.0) Navigation System, comprising of computer hardware and software and associated instrumentation, will be used for intra-operative alignment and orientation of implant. Navigation trackers will be secured to the femur and tibia and registration of the limb will be undertaken according to the PrecisioN Knee System surgical technique.Femoral and tibial resections, followed by device implantation, will be performed according to the Triathlon Knee System Surgical Protocol.<br>Procedure: Total Knee Replacement<br> <br> Device: Stryker Triathlon® Total Knee System<br>* Prosthetic components to be implanted including Triathlon® Cruciate Retaining (CR) Total Knee System (cemented), including Femoral Component and Primary Tibial Baseplate; Triathlon® Cruciate Substituting (CS) X3® polyethylene insert; Triathlon® X3 Patella (asymmetric) - treated selectively by surgeon.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Oxford Knee Score | To demonstrate, through calculation of Oxford Knee Score (OKS) post operatively, that total knee replacement (TKR) performed using the ShapeMatch® Cutting Guide provides improvement from preoperative levels of patient pain and function comparable to the improvement obtained with TKR performed using computer-assisted Navigation. Oxford Knee Scores will be calculated pre-operatively and at 6 weeks, 6 months, 12 months, 2 years and 5 years. The OKS is a participant completed 12 question form on activities of daily living that assess function and pain. Scores can range from 0 to 48 with lower scores indicating a poor outcome and higher scores indicating a more satisfactory joint outcome. | Preoperatively, 6-week, 6-months, 12 months, 2 years and 5 years postoperatively | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Cost Effectiveness: Total Duration of Operating Procedure (Anaesthetic Time and Skin-to-skin Incision Time) | Skin to skin time is the time in minutes from initial skin incision to skin closure. Anaesthesia time is the time in minutes that anaesthesia administration is started to the time it is stopped. Data for anaesthesia time is not available due to an error on the original case report form that did not correctly capture anaesthesia time. | Intraoperative - participants were followed for the duration of the operation, an average of 1 hour and 50 minutes. | 
| Cost Effectiveness: Wound Length | To compare the cost-effectiveness and cost-utility of the procedure between the ShapeMatch® Cutting Guide group and the computer-assisted Navigation control group the surgical incision length is reported in mm. | Intraoperative - participants were followed for the duration of the operation, an average of 1 hour and 50 minutes. | 
| Cost Effectiveness: Cost of Consumable Items Used During Operating Procedure | To compare the cost-effectiveness and cost-utility of the procedure between the ShapeMatch® Cutting Guide group and the computer-assisted Navigation control group. The data for the cost of consumable items used during the operating procedure is not available. Due to limited site resources, a decision was made not to collect this secondary outcome measure data. | Intraoperative - participants were followed for the duration of the operation, an average of 1 hour and 50 minutes. | 
| Cost Effectiveness: Length of Stay in Hospital | To compare the cost-effectiveness and cost-utility of the procedure between the ShapeMatch® Cutting Guide group and the computer-assisted Navigation control group the length of stay in number of days spent in the hospital is reported.. | 14 days | 
| Cost Effectiveness: Quality-adjusted Life-years (QALYs) From EQ-5D-3L | A quality-adjusted life-year (QALY) takes into account both the quantity and quality of life generated by healthcare interventions. It is the arithmetic product of life expectancy and a measure of the quality of the remaining life-years. A QALY places a weight on time in different health states. A year of perfect health is worth 1 and a year of less than perfect health is worth less than 1. Death is considered to be equivalent to 0; however,some health states may be considered worse than death and have negative scores. | 12 months | 
| Knee Pain | Pain at rest and pain during mobilization was measured using a 10 centimeter Visual Analogue Scale (VAS). Participants are asked to indicate their level of pain with 0 being no pain and 10 being the worst pain. | Preoperatively, 6-week, 6-months,12 months, 2 years and 5 years postoperatively | 
| The Western Ontario and McMaster Universities Arthritis Index (WOMAC) | The WOMAC is completed by the participant and measures five items for pain (score range 0-100), two for stiffness (score range 0-100), and 17 for functional limitation (score range 0-100). The total score is the sum of these three categories. | Preoperatively, 6-week, 6-months,12 months, 2 years and 5 years postoperatively | 
| Health-related Quality of Life (EQ-5D-3L) | The EQ-5D-3L descriptive system comprises the following 5 dimensions: mobility, self-care, usual activities, pain/discomfort and anxiety/depression. Each dimension has 3 levels: no problems, some problems, extreme problems. The participant is asked to indicate his/her health state by indicating the most appropriate level for each of the 5 dimensions. Responses may be converted into a single summary index by applying a formula that essentially attaches values (also called weights) to each of the levels in each dimension. The index can be calculated by deducting the appropriate weights from 1= the value for full health. The EQ VAS records the participant's self-rated health on a vertical, visual analogue scale where the endpoints are labelled from 100 ='Best imaginable health state' to 0= 'Worst imaginable health state'. | Preoperatively, 6-week, 6-month and 12 month visits, 2 years and 5 years | 
| The Forgotten Joint Score (FJS-12) | The Forgotten Joint Score (FJS) is a 12 question form that asks the patient their level of awareness of their artificial joint in 12 scenarios commonly encountered in daily life. Scores can range from 0 to 100 with a higher score indicating a better outcome (high degree of forgetting the joint in everyday life). | 6 week, 6 month, 12 month , 2 years and 5 years visits | 
| The International Knee Society Score (IKSS) | The Knee Society Clinical Rating System is comprised of two distinct sub-scores: one for pain, range of motion (ROM) and joint stability, and one for functional parameters. Sub-scores range from a minimum score of 0 to a maximum of 100 points. Although the specific scores are not distinguished as excellent, good, fair, or poor, a higher value represents a better outcome. | Preoperatively, 6-week, 6-months,12 months, 2 years and 5 years postoperatively | 
| Perth CT Protocol | The Perth CT protocol is a comprehensive assessment of total knee replacement (TKR) component position and orientation. The alignment of the TKR components is measured against the mechanical axis and the transepicondylar axis of the lower extremity. The posted data represents the mean angle between the femoral component and mechanical axis of the femur, the angle between tibial component and mechanical axis of the tibia, the tibial component slope relative to the sagittal mechanical axis, and the femoral component rotation relative to surgical epicondylar axis (positive value=external rotation). For all degree values posted a positive (+) value= valgus and a negative (-) value = varus. | 3 months |