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

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.

Study Overview

• Status: Completed
• Conditions: Osteoarthritis; Traumatic Arthritis; Avascular Necrosis of the Femoral Condyle; Moderate Varus; Valgus; Flexion Deformities
• Intervention / Treatment: Device: NexGen LPS-Flex Mobile Bearing Knee

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.

• Study Type: Interventional
• Enrollment (Actual): 266
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Florida
    • Tamarac, Florida, United States, 33321
      • Phoenix Clinical Research
  • Michigan
    • Auburn Hills, Michigan, United States, 48236-2776
      • Advanced Orthopaedics
  • Tennessee
    • Knoxville, Tennessee, United States, 37923
      • Tennessee Orthopaedic Foundation for Education and Research

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: ADULT; OLDER_ADULT; CHILD
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: All

Description

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 Plan

How is the study designed?

Design Details

• Primary Purpose: TREATMENT
• Allocation: NON_RANDOMIZED
• Interventional Model: SINGLE_GROUP
• Masking: NONE

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
EXPERIMENTAL: Post-Approval Study Group (Group 2); 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; Total Knee Replacement; Other Names: Mobile bearing knee
EXPERIMENTAL: Investigational Device Exemption Group (Group 1); 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; Total Knee Replacement; Other Names: Mobile bearing knee

What is the study measuring?

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

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Radiographic analysis	Independent radiographic review will be performed on all required post-operative follow-up intervals for both Group 1 & Group 2. Findings will be captured on the Independent Radiographic Evaluation form.	Group 1: annual visits for a total of 5 years; Group 2: Pre-op, 6 week, 6 month and annual for a total of 5 years

Collaborators and Investigators

• Sponsor: Zimmer Biomet

Study record dates

Study Major Dates

• Study Start (ACTUAL): April 1, 2009
• Primary Completion (ACTUAL): June 1, 2020
• Study Completion (ACTUAL): June 1, 2021

Study Registration Dates

• First Submitted: February 26, 2009
• First Submitted That Met QC Criteria: February 27, 2009
• First Posted (ESTIMATE): March 3, 2009

Study Record Updates

• Last Update Posted (ESTIMATE): February 14, 2023
• Last Update Submitted That Met QC Criteria: January 18, 2023
• Last Verified: January 1, 2023

More Information

Terms related to this study

• Keywords: osteoarthritis; total knee replacement; arthritis; avascular necrosis; TKA; degenerative knee disease
• Additional Relevant MeSH Terms: Pathologic Processes; Joint Diseases; Musculoskeletal Diseases; Rheumatic Diseases; Arthritis; Osteoarthritis; Necrosis
• Other Study ID Numbers: 07-100 (Dana-Farber Cancer Institute)

Drug and device information, study documents

• Studies a U.S. FDA-regulated device product: Yes