Comparison of Highly Cross-Linked and Conventional Polyethylene in Total Knee Arthroplasty

Study Overview
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Brief Summary
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To our knowledge, there has been no information on in vivo clinical results of posterior cruciate-substituting arthroplasties using highly cross-linked polyethylene. We evaluated whether the clinical and radiographic results, incidence of post fracture of the tibial polyethylene insert, failure of the locking mechanism of the tibial polyethylene insert, and the incidence of osteolysis would be similar between posterior cruciate-substituting total knee prostheses using conventional and highly cross-linked polyethylene.

Official Title
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Comparison of Highly Cross-Linked and Conventional Polyethylene in Posterior Cruciate-Substituting Total Knee Arthroplasty in the Same Patients

Conditions
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Osteoarthritis, Knee

Intervention / Treatment
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* Procedure: Total knee arthroplasty


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: osteoarthritis that was severe enough to warrant total knee arthroplasty after an adequate trial of nonoperative therapy, and the need for bilateral total knee arthroplasties Exclusion Criteria: inflammatory arthritis osteoarthritis of the hip causing pain or restricted mobility a foot or ankle disorder which limited walking dementia or a neurological disorder including a past history of stroke which affected mobility

Ages Eligible for Study
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Minimum Age: 20 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: Conventional<br>knee receiving Total knee arthroplasty with conventional polyethylene inserts | Procedure: Total knee arthroplasty<br>* Total knee arthroplasty with standard incision and approach, and cement fixation. Zimmer Nexgen posterior stabilized total knee implants are used.<br>|
| Experimental: Prolong<br>knee receiving total knee arthroplasty with highly cross linked polyethylene insert | Procedure: Total knee arthroplasty<br>* Total knee arthroplasty with standard incision and approach, and cement fixation. Zimmer Nexgen posterior stabilized total knee implants are used.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| knee society knee score | clinical evaluation of knee function by knee score. This knee score will be compared, between preoperative and the latest score, and between the latest scores of study and control group. | 3 months, 1 year, and yearly thereafter the operation, until 15 years after the operation | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| range of motion | this value will be compared between preoperative and the latest value, and between the latest value of study and control groups | preoperative, 3 months, 1 year, and yearly thereafter the operation until 15 years |