Comparison of Mobile-Bearing and Fixed-Bearing All-Polyethylene Tibia Total Knee Designs

Study Overview
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Brief Summary
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This study will be designed to compare prospectively, in a randomized fashion, the clinical, functional, and radiographic results of a nonmodular (all-polyethylene tibi/AP) fixed-bearing posterior cruciate substituting design with a modular posterior cruciate substituting rotating platform (RP) design for total knee arthroplasty. Comparing these two designs will afford the investigators information in the following areas: Does a RP design offer improvement in range of motion over a AP design? Does a RP design have improved wear characteristics over a nonmodular AP design? Is there a clear clinical advantage to the RP design that justifies its increased cost? Answering these questions will allow surgeons to use RP designs appropriately in different demand populations. This study was designed to address the questions of whether an RP design offers improvement in ROM, Knee Society scores, Western Ontario and McMaster Universities Index of Osteoarthritis (WOMAC) scores, selected Medical Outcomes Short-Form Health Survey Short Form-36 (SF-36) scores or radiographic measures, over an APT design. The investigators' primary hypothesis was that there would be no difference in these outcome measures at a minimum two year followup. A secondary hypothesis based on the anticipated long-term followup of this group was that there would be no difference in implant survival.

Official Title
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A Randomized Prospective Comparison of Mobile-Bearing and Fixed-Bearing (All-Polyethylene Tibia) Cruciate-Substituting Total Knee Arthroplasty (TKA) Designs

Conditions
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Osteoarthritis, Knee

Intervention / Treatment
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* Procedure: TKA surgery with the rotating platform mobile-bearing knee design
* Procedure: TKA surgery with the all-polyethylene tibia knee design


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: generally accepted clinical and radiographic criteria for primary total knee arthroplasty Exclusion Criteria: substantial angular deformity or bony deformity requiring structural grafting or modular augmentation were excluded at the discretion of the principle investigator patients whose mental function precluded them from responding to our standard questionnaires

Ages Eligible for Study
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Minimum Age: 60 Years
Maximum Age: 85 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
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: rotating-platform design TKA<br>patients who were randomized to receive the rotating platform mobile-bearing TKA design | Procedure: TKA surgery with the rotating platform mobile-bearing knee design<br>* Depuy Sigma RP rotating platform design<br>|
| Active Comparator: all-polyethylene tibia design TKA<br>patients who were randomized to receive the all-polyethylene tibial component design | Procedure: TKA surgery with the all-polyethylene tibia knee design<br>* Depuy Sigma fixed-bearing design with all-polyethylene tibia<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Knee Postoperative Range of Motion (ROM) at 2 Years | range of motion of the knee postoperatively at 2 years | 2 years | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Survival of the Implants to Subject Death or Implant Removal |  | 10 or more years | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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knee arthritis, total knee arthroplasty, total knee replacement, mobile bearing design, all-polyethylene tibia