Medacta GMK Sphere® Multicenter Post-Market Outcomes Study

Study Overview
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Brief Summary
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This study is to average Forgotten Knee Score (FJS) of those patients receiving the Medacta GMK Sphere® knee at the two and five year time points. 70 subjects, enrolled at the data coordinating center in Medacta GMK Sphere® vs Posterior Stabilized study (WIRB Pro Num: 20141994) and randomized to the Sphere arm, will have their data utilized for this study.

Official Title
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Medacta GMK Sphere® Medial Pivot, Cruciate Substituting Multicenter, Post-Market Outcomes Study

Conditions
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Osteoarthritis

Intervention / Treatment
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* Device: Medacta GMK Sphere® Medial Knee Prosthesis


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients willing to sign the informed consent Patients able to comply with follow-up requirements including postoperative weight bearing restrictions and self evaluations. Male and non-pregnant female patients ages 21 - 80 years of age at the time of surgery. Patients requiring a primary total knee replacement. Patients with a diagnosis of osteoarthritis (OA), traumatic arthritis (TA), or avascular necrosis (AVN). Patients with intact collateral ligaments. Exclusion Criteria: Patients with inflammatory arthritis. Patients that are morbidly obese, body mass index (BMI) > 40. Patients with a history of total or unicompartmental reconstruction of the affected joint. Patients that have had a high tibial osteotomy or femoral osteotomy. Patients with neuromuscular or neurosensory deficiency, which would limit the ability to assess the performance of the device. Patients with a systemic or metabolic disorder leading to progressive bone deterioration. Patients that are immunologically compromised, or receiving chronic steroids (> 30 days). Patients bone stock is compromised by disease or infection, which cannot provide adequate support and/or fixation to the prosthesis. Patients with knee fusion to the affected joint. Patients with an active or suspected latent infection in or about the knee joint. Patients that are prisoners.

Ages Eligible for Study
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Minimum Age: 21 Years
Maximum Age: 80 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Other: Medacta GMK Sphere® Knee Prosthesis<br>All subjects enrolled will receive the Medacta GMK Sphere® Medial Knee Prosthesis | Device: Medacta GMK Sphere® Medial Knee Prosthesis<br>* There is no consensus within the Arthroplasty community as to whether a traditional post and cam-style Posterior Stabilized total knee device is superior to a medial-pivot, more congruent device. However, the majority of surgeons seem to prefer the former, though there is a minority that uses the latter device with great success. To date, there have been few prospective trials directly comparing these devices, and none with the latest generation of Total Knee Arthroplasty implants. Almost all such studies have been retrospective and/or utilizing older generation devices.<br>* Other names: Total Knee Prosthesis;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Evaluate the change in Forgotten Knee Scores (FJS) of those patients receiving the Medacta GMK Sphere from baseline to years 2 and 5 post-operatively. | Knee function-patients ability to forget the artificial joint in everyday life. | Baseline, 2 and 5 year time points | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Total Knee Society Score (KSS) | Total Knee Society score questionnaire to assess pain and function | Pre-operative, 6 weeks, 3-6 months, 1,2,3,4 and 5 years. | 
| Krackow Activity Scale (KAS) | The Krackow Activity Scale (KAS) lower extremity activity scale. | Pre-operative, 6 weeks, 3-6 months, 1,2,3,4 and 5 years | 
| Radiographic Analysis |  | Pre-operative, 6 weeks, 3-6 months, 1,2,3,4 and 5 years | 
| AP long standing X-ray | Determine degree of Varus or Valgus | Pre-operative and 6 weeks | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Total Knee Replacement, Total Knee Arthroplasty