Prospective Multicenter Post Approval Study of the LPS-Flex Mobile Bearing Knee

Study Overview
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Brief Summary
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The purpose of the study is to assess the long-term performance of the NexGen LPS-Flex Mobile Bearing Knee in the treatment of patients with severe knee pain or degenerative knee disease.

Detailed Description
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The NexGen LPS-FLex Mobile Bearing Knee received FDA approval for commercial distribution in the US on December 10, 2007. The approval was in accordance with a condition of approval to perform a 10-year post approval study to evaluate the longer-term safety and effectiveness of the LPS-Flex Mobile Bearing Knee. The post approval study will consist of patients from the investigational device exemption study arm (Group 1) as well as patients who are eligible for a total knee replacement and have been chosen to receive the LPS-Flex Mobile Knee (Group 2). Group 1 will be followed from 4 years through a total of 10 years from the date of surgery. Group 2 will be followed from pre-op through a total of 5 years from the date of surgery.

Official Title
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Prospective Multicenter Post Approval Study of the LPS-Flex Mobile Bearing Knee

Conditions
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Osteoarthritis, Traumatic Arthritis, Avascular Necrosis of the Femoral Condyle, Moderate Varus, Valgus, Flexion Deformities

Intervention / Treatment
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* Device: NexGen LPS-Flex Mobile Bearing Knee


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Osteoarthritis Primary and secondary traumatic arthritis Avascular necrosis of the femoral condyle Moderate varus, valgus, or flexion deformities (i.e. valgus/varus deformity of less than or equal to 15 degrees, fixed flexion deformity of less than or equal to 10 degrees) Exclusion Criteria: Previous history of infection in the affected joint and/or local/systemic infection that may affect the prosthetic joint Insufficient bone stock on femoral or tibial surfaces Skeletal immaturity Neuropathic arthropathy Osteoporosis or any loss of musculature or neuromuscular disease that compromises the affected limb A stable, painless arthrodesis in a satisfactory functional position Severe instability secondary to the absence of collateral integrity Total knee arthroplasty is contraindicated in patients who have rheumatoid arthritis (RA) and an ulcer of the skin or a history of recurrent breakdown of the skin because their risk of postoperative infection is greater. RA patient using steroids may also have increased risk of infection. Late infections in RA patients have been reported 24+ months postoperative. Patient is a poor compliance risk, i.e., history of ethanol or drug abuse, or mental handicap that would compromise patient compliance with respect to rehabilitation or follow-up Patient is not willing or able to give informed consent to participate in the follow-up program Patient is not willing to return for all scheduled follow-up appointments as defined by this protocol.
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: Non-Randomized
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Post-Approval Study Group (Group 2)<br>Subjects enrolled in a short-term study (5 years) consisted of cases eligible to receive the LPS-Flex Mobile Bearing Knee implanted by orthopedic surgeons experienced in primary total knee replacement. All Group 2 subjects, both unilateral and bilateral subjects, are in the same arm of the study. As part of the PAS study, these subjects were followed from Pre-operative to 5 years. | Device: NexGen LPS-Flex Mobile Bearing Knee<br>* Total Knee Replacement<br>* Other names: Mobile bearing knee;|
| Experimental: Investigational Device Exemption Group (Group 1)<br>Subjects who were implanted with either the LPS Flex Fixed Bearing Knee (control population) or the LPS Flex Mobile Bearing Knee device during the previous Investigational Device Exemption study. As part of the PAS study, these subjects were followed from 4 years to 10 years. | Device: NexGen LPS-Flex Mobile Bearing Knee<br>* Total Knee Replacement<br>* Other names: Mobile bearing knee;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Group 2 - Total Knee Society Score (KSS) | Total Knee Society Score is used to assess pain and function which is scored from 0 to 200 with lower scores being indicative of worse knee conditions and higher scores being indicative of better knee conditions. | Pre-op, 6 week, 6 month, 1 year, 2 year, 3 year, 4 year, and 5 year | 
| Group 2 - Number of Subjects With Absence of Radiolucency/Bone Loss | Independent radiographic was performed on all required post-operative follow-up intervals and a detailed report was provided at the completion of the study. Each case was expected to have anteroposterio (A/P) and lateral radiographs obtained at all postoperative assessments. An independent review of the radiographs was assessed for progressive radiolucencies over time. Per the protocol, radiographic outcomes are defined as An absence of subsidence of greater than or equal to 2 millimeters and an absence of both osteolysis and radiolucencies greater than or equal to 2 millimeters as determined by an independent radiographic reviewer. | 5 year | 
| Group 2 - Number of Subjects With Absence of Implant Revision | Revision is defined as No intended, actual, or planned removal of any component of the knee system. | 5 year | 
| Group 2 - Number of Subjects With Absence of Severe Knee-Related Complication | All severe knee-related complications are determined by each study investigator. A severe adverse event is any undesirable experience associated with the use of the implant in a patient that results in death, is life-threatening, requires hospitalization or prolongation of existing hospitalization, results in persistent or significant disability or incapacity, or is a birth defect. A knee-related complication is an adverse event that has been classified by the investigator to have a relation to the knee. | 5 year | 
| Group 1 - Total Knee Society Score (KSS) | Total Knee Society Score is used to assess pain and function which is scored from 0 to 200 with lower scores being indicative of worse knee conditions and higher scores being indicative of better knee conditions. | 4 year, 5 year, 6 year, 8 year, and 10 year | 
| Group 1 - Number of Subjects With Absence of Radiolucency/Bone Loss | Independent radiographic was performed on all required post-operative follow-up intervals and a detailed report was provided at the completion of the study. Each case was expected to have anteroposterio (A/P) and lateral radiographs obtained at all postoperative assessments. An independent review of the radiographs was assessed for progressive radiolucencies over time. Per the protocol, radiographic outcomes are defined as An absence of subsidence of greater than or equal to 2 millimeters and an absence of both osteolysis and radiolucencies greater than or equal to 2 millimeters as determined by an independent radiographic reviewer. | 10 year | 
| Group 1 - Number of Subjects With Absence of Implant Revision | Revision is defined as No intended, actual, or planned removal of any component of the knee system. | 10 year | 
| Group 1 - Number of Subjects With Absence of Severe Knee-Related Complication | All severe knee-related complications are determined by each study investigator. A severe adverse event is any undesirable experience associated with the use of the implant in a patient that results in death, is life-threatening, requires hospitalization or prolongation of existing hospitalization, results in persistent or significant disability or incapacity, or is a birth defect. A knee-related complication is an adverse event that has been classified by the investigator to have a relation to the knee. | 10 year | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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arthritis, osteoarthritis, degenerative knee disease, avascular necrosis, total knee replacement, TKA