Evaluation of Triathlon - A New Total Knee Prosthesis System - RSA Triathlon Standard vs. Short Keel

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 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. The evaluation is carried out by a prospective randomised RSA-study with Triathlon Standard vs. Short Keel.

Official Title
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Evaluation of Triathlon - A New Total Knee Prosthesis System - RSA Triathlon Standard vs. Short Keel

Conditions
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Arthroplasty, Replacement, Knee

Intervention / Treatment
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* Device: Triathlon Standard Keel
* Device: Triathlon Short Keel


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients suffering exclusively from OA, Stage II-V [Ahlbäck-Traumascore, 1968 391] 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: Triathlon Standard Keel<br>Triathlon Cruciate Retaining knee (CR) with a tibial keel of standard length randomised against Triathlon Cruciate Retaining knee (CR) with a tibial part with a short keel, both system will be used with cemented fixation. The short tibial keel is thought to facilitate the surgery due to easier access and better positioning possibilities. This study is aimed to evaluate if the short tibial keel will have equal fixation and migration properties as the standard keel. | Device: Triathlon Standard Keel<br>* Implantation of Knee Prosthesis<br>|
| Active Comparator: Triathlon Short Keel<br>Triathlon Cruciate Retaining knee (CR) with a tibial keel of standard length randomised against Triathlon Cruciate Retaining knee (CR) with a tibial part with a short keel, both system will be used with cemented fixation. The short tibial keel is thought to facilitate the surgery due to easier access and better positioning possibilities. This study is aimed to evaluate if the short tibial keel will have equal fixation and migration properties as the standard keel. | Device: Triathlon Short Keel<br>* Implantation of Knee Prosthesis<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Assessment of fixation and stability of the Triathlon total knee prosthesis by Roentgen Stereophotogrammetric Analysis (RSA) | Assessment of fixation and stability of the Triathlon total knee prosthesis by Roentgen Stereophotogrammetric as a predictor of late mechanical loosening. | 10 years follow-up | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Investigation of patient outcome with radiographic analysis | Plain radiographs will be obtained for assessment of fixation of the device. | 3 months, 1, 2, 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. | pre-operative, 3 months, 1, 2, 5, 7 and 10 years | 
| Investigation of clinical performance and patient outcome with KOOS patient questionnaire | KOOS (Knee injury and osteoarthritis outcome score) consists of 5 subscales: Pain, other symptoms, function in daily living, function in sport and recreation 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). | 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 (EuroQuol-5 dimension) health questionnaire provides a simple descriptive profile and a single index value for health status. | pre-operative, 3 months, 1, 2, 5, 7 and 10 years |