Evaluation of Triathlon - a New Total Knee Prosthesis System - Triathlon vs. Duracon

Study Overview
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Brief Summary
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The objective is to investigate the Clinical, Radiographic, Roentgen Stereophotogrammetric behaviour and patient outcome when using the Triathlon total knee prosthesis in a prospective randomized clinical trial.

Detailed Description
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The evaluation is carried out by a prospective randomised RSA-study with Triathlon cemented knee prosthesis versus Duracon cemented knee prosthesis.

Official Title
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Evaluation of Triathlon - a New Total Knee Prosthesis System. Prospective, Comparative, Randomised, Roentgen Stereophotogrammetric Analysis (RSA) Series

Conditions
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Arthroplasty, Replacement, Knee

Intervention / Treatment
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* Device: Cemented Triathlon total knee system
* Device: Duracon total knee system


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients suffering exclusively from osteo arthritis (OA), Stage II-V [Ahlbäck, 1968] will be operated. Patients requiring knee prosthesis, suitable for the use of Duracon and Triathlon knee system Patients who understand the conditions of the study and are willing and able to comply with the post-operative scheduled clinical and radiographical evaluations and the prescribed rehabilitation. Patients who signed the Ethics Committee approved Informed Consent Form prior to surgery. Exclusion Criteria: Previous major knee surgery Other significant disabling problems from the muscular-skeletal system than in the knees Obese patients where obesity is severe enough to affect subject's ability to perform activities of daily living (body mass index, kg/m2: BMI above 35). Patients with active or suspected infection. Patients with malignancy - active malignancy. Patients with severe osteoporosis, Paget's disease, renal osteodystrophy. Patients immunologically suppressed, or receiving steroids in excess of physiologic dose requirements. The patient has a neuromuscular or neurosensory deficit which would limit the ability to assess the performance of the device or the patient has a neurological deficit which interferes with the patient's ability to limit weight bearing or places an extreme load on the implant during the healing period. Female patients planning a pregnancy during the course of the study. Patients with systemic or metabolic disorders leading to progressive bone deterioration. Patients, who as judged by the surgeon, are mentally incompetent or are unlikely to be compliant with the prescribed post-operative routine and follow-up evaluation schedule. Patients with other severe concurrent joint involvements, which can affect their outcome. Patients with other concurrent illnesses, which are likely to affect their outcome such as sickle cell anaemia, systemic lupus erythematosus or renal disease requiring dialysis. Patients under the protection of law (e.g. guardianship).

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 85 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: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Cemented Triathlon total knee system<br>The Triathlon total knee system is the successor of the Duracon total knee system and was observed in a prospective randomised, parallel, double-blind study. | Device: Cemented Triathlon total knee system<br>* Orthopaedic implant<br>|
| Active Comparator: Cemented Duracon total knee system<br>The Duracon total knee system is the predecessor of the Triathlon total knee system and was observed in a prospective randomised, parallel, double-blind study. | Device: Duracon total knee system<br>* Orthopaedic implant<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Roentgen Stereophotogrammetric Analysis (RSA) | To compare the maximum total point motion (MTPM) of the Triathlon and Duracon tibial components at two years assessed by means of RSA. | 2 years | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Roentgen Stereophotogrammetric Analysis (RSA) | To compare the maximum total point motion (MTPM) of the Triathlon and Duracon tibial components by means of RSA. | 3 months, 1, 5, 7 and 10 years | 
| Investigation of Clinical Performance and Patient Outcome With KSS (Knee Society Score) | The Knee Society Clinical Rating System is comprised of two distinct sub-scores: one for pain, ROM and joint stability, and one for functional parameters. Sub-scores range from a potential minimum score of 0 to a maximum score of 100 points. Although the specific scores are not distinguished as excellent, good, fair, or poor, a higher value represents a better outcome. | [Time Frame: pre-operative, 3 months, 1, 2, 5, 7 and 10 years] | 
| Investigation of Clinical Performance and Patient Outcome With KOOS Patient Questionnaire | KOOS consists of 5 subscales; Pain, other Symptoms, Activities of Daily Living (ADL), Sport and Recreation Function (Sport/Rec) and knee-related Quality of Life (QOL). The previous week is the time period considered when answering the questions. Standardized answer options are given (5 Likert boxes) and each question is assigned a score from 0 to 4. A normalized score (100 indicating no symptoms and 0 indicating extreme symptoms) is calculated for each subscale. [taken from User Guide] http://www.koos.nu/ | pre-operative, 3 months, 1, 2, 5, 7 and 10 years | 
| Investigation of Clinical Performance and Patient Outcome With EQ-5D Patient Questionnaire | The EQ-5D is a subject-completed questionnaire designed to assess subject health state values. The EQ-5D consists of 2 areas; the EQ visual analogue scale (EQ VAS) and EQ-5D descriptive system. The EQ VAS collects health state values using a 20 cm visual analogue scale with the endpoints labeled best imaginable health state at the top and worst imaginable health state at the bottom, having numeric values of 100 to 0 respectively. The EQ-5D Time Trade-off (TTO) descriptive system comprises the following five dimensions: mobility, self-care, usual activities, pain/comfort and anxiety/depression. Each dimension has three levels: no problems, some problems and extreme problems, where an overall score of 1 represents full health. NOTE: While the protocol includes pre-operative, 3 months, and 1 year, this data was not collected. | pre-operative, 3 months, 1, 2, 5, 7 and 10 years | 
| Mean Operative Time | Skin to skin operative time | intra-operative | 
| Duration Hospital Stay |  | preoperative to discharge | 
| Blood Loss | Blood loss during surgery | intra-operative |