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

Not Applicable

Completed

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

Interventions: Device: NexGen LPS-Flex Mobile Bearing Knee

Registration Number: NCT00854295

Lead Sponsor: Zimmer Biomet

Brief Summary: 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: 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.

Recruitment & Eligibility

Status: COMPLETED

Sex: All

Target Recruitment: 266

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.

Study & Design

Study Type: INTERVENTIONAL

Study Design: SINGLE_GROUP

Arm && Interventions

Group	Intervention	Description
Investigational Device Exemption Group (Group 1)	NexGen LPS-Flex Mobile Bearing Knee	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.
Post-Approval Study Group (Group 2)	NexGen LPS-Flex Mobile Bearing Knee	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.

Primary Outcome Measures

Name	Time	Method
Group 1 - Total Knee Society Score (KSS)	4 year, 5 year, 6 year, 8 year, and 10 year	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.
Group 1 - Number of Subjects With Absence of Implant Revision	10 year	Revision is defined as "No intended, actual, or planned removal of any component of the knee system."
Group 2 - Total Knee Society Score (KSS)	Pre-op, 6 week, 6 month, 1 year, 2 year, 3 year, 4 year, and 5 year	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.
Group 1 - Number of Subjects With Absence of Radiolucency/Bone Loss	10 year	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."
Group 2 - Number of Subjects With Absence of Severe Knee-Related Complication	5 year	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.
Group 2 - Number of Subjects With Absence of Radiolucency/Bone Loss	5 year	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."
Group 2 - Number of Subjects With Absence of Implant Revision	5 year	Revision is defined as "No intended, actual, or planned removal of any component of the knee system."
Group 1 - Number of Subjects With Absence of Severe Knee-Related Complication	10 year	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.

Secondary Outcome Measures

Name	Time	Method

Trial Locations

Locations (3): Phoenix Clinical Research
🇺🇸
Tamarac, Florida, United States
Advanced Orthopaedics
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Auburn Hills, Michigan, United States
Tennessee Orthopaedic Foundation for Education and Research
🇺🇸
Knoxville, Tennessee, United States