A Study to Compare the NexGen LPS and LPS-Flex Knee Implants

Study Overview
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Brief Summary
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The purpose of this study is to test for significant differences in functional outcomes obtained by using a NexGen LPS versus a NexGen LPS-Flex knee implant. Specifically, it is predicted that an increase in postoperative range of motion will be experienced by patients treated with the NexGen LPS-Flex knee implant.

Detailed Description
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This study will compare the clinical results of the NexGen LPS femoral component with the higher flexion potential of the NexGen LPS-Flex femoral component in all patients with degenerative joint disease that require total knee arthroplasty. The primary variable of interest is postoperative range of motion achieved with the two devices, which are implanted with slightly different surgical techniques in patients who may also be subjected to different rehabilitation programs depending on the device they are assigned.

Official Title
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Prospective Randomized Multicenter Study of NexGen LPS-Flex Knee

Conditions
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Total Knee Arthroplasty, Osteoarthritis

Intervention / Treatment
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* Device: NexGen LPS-Flex Fixed Bearing Knee
* Device: NexGen Legacy Posterior Stabilized Knee


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age, 21-80 years Sex, Males and females will be included BMI less than or equal to 39 and calf-thigh less than or equal to 90 degrees Stable health, the patient would be able to undergo surgery and participate in the follow-up program based on physical examination and medical history. Patient is willing and able to cooperate in follow-up therapy. Patient exhibits preoperative radiographic evidence of joint degeneration consistent with TKA that cannot be treated in non-operative fashion. Patient has stable and functional collateral ligaments. Patient has potential to perform higher than average range of motion activities. Operative side range of motion flexion greater than or equal to 90 degrees. Severe knee pain and disability due to degenerative joint disease. Patient or patient's legal representative has signed the Informed Consent form. Exclusion Criteria: Previous history of infection in the affected joint. Previously failed knee endoprosthesis of any kind. Charcot joint disease or other severe neurosensory deficits. Previous patellectomy. Patient is skeletally immature. Grossly insufficient femoral or tibial bone stock. Patient is pregnant. Varus or valgus deformity greater than 20 degrees. Fixed flexion deformity greater than 15 degrees. Previous high tibial osteotomy. Previous femoral osteotomy. Patient is a poor compliance risk - currently treated for ethanol or drug abuse, physical or mental handicap, etc. Loss of musculature or absence of musculoligamentous supporting structures required for adequate soft tissue balance.

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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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: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: 1<br>Study arm will consist of patients that are treated with the NexGen LPS-Flex Fixed Bearing Knee. | Device: NexGen LPS-Flex Fixed Bearing Knee<br>* NexGen LPS-Flex Fixed Bearing femoral component<br>* Other names: LPS-Flex Knee;|
| Active Comparator: 2<br>Study arm will consist of patients that are treated with the NexGen Legacy Posterior Stabilized Knee. | Device: NexGen Legacy Posterior Stabilized Knee<br>* NexGen Legacy Posterior Stabilized femoral component<br>* Other names: LPS Knee;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Postoperative Range of Motion (ROM) | Postoperative ROM was calculated by taking the measurement of patient flexion minus the measurement of patients' extension. | 6 Weeks to 2 Years Post-op, based on on the intervals listed | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Return to Function (RtF) Via Knee Society Score (Modified) | Scores were calculated from responses on a modified Knee Society Score by the enrolled subjects for the stated visit intervals. Grading for the Knee Society Score is based on a scale from 0-100 and results are established follows: 80-100 =Excellent; 70-79 = Good; 60-69 = Fair; and Below 60 = Poor. | 6 Weeks to 2 Years Post-op, based on on the intervals listed | 

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