Avascular Necrosis of the Femoral Condyle, Flexion Deformities, Moderate Varus, Osteoarthritis, Traumatic Arthritis, Valgus
Conditions
Keywords
arthritis, osteoarthritis, degenerative knee disease, avascular necrosis, total knee replacement, TKA
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.
Interventions
DEVICENexGen LPS-Flex Mobile Bearing Knee
Total Knee Replacement
Sponsors
Zimmer Biomet
Study design
Allocation
NON_RANDOMIZED
Intervention model
SINGLE_GROUP
Primary purpose
TREATMENT
Masking
NONE
Eligibility
Sex/Gender
ALL
Healthy volunteers
Yes
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.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| 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 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 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 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 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 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 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. |
Countries
United States
Participant flow
Recruitment details
Cases were enrolled into a short-term study (5 years) and consisted of cases eligible to receive the LPS-Flex Mobile Bearing Knee implanted by an orthopedic surgeons experienced in primary total knee replacement. Subjects who had one operative knee were in the Unilateral Group and subjects who had two operative knees were in the Bilateral Group. These subjects are considered Group 2 per the study protocol.
Pre-assignment details
All cases in Group 1 per the protocol (subjects in the previous IDE study who were eligible to participate in the PAS) have study completed and are not included in these results. A final report for Group 1 was previously approved by FDA on June 29, 2016. Since 2016, only data from Group 2 subjects (PAS Group) was reported to FDA and are applicable to this clinicatrials.gov record.
Participants by arm
| Arm | Count |
|---|---|
| LPS Flex Mobile Uniliteral (Group 2) Cases were enrolled into a short-term study (5 years) and consisted of cases eligible to receive the LPS-Flex Mobile Bearing Knee implanted by an orthopedic surgeon experienced in primary total knee replacement. Subjects who were implanted with the study device in one knee were in the Unilateral Group. | 106 |
| LPS Flex Mobile Bilateral (Group 2) Cases were enrolled into a short-term study (5 years) and consisted of cases eligible to receive the LPS-Flex Mobile Bearing Knee implanted by an orthopedic surgeon experienced in primary total knee replacement. Subjects who were implanted with the study device in two knees were in the Bilateral Group. | 14 |
| LPS Flex Fixed (Group 1) Subjects in this group received the LPS-Flex Fixed Bearing Knee implanted by an orthopedic surgeon experienced in primary total knee replacement in one knee and were enrolled in a previous Investigational Device Exemption study. | 77 |
| LPS Flex Mobile (Group 1) Subjects in this group received the LPS Flex Mobile Bearing Knee implanted by an orthopedic surgeon experienced in primary total knee replacement in one knee and were enrolled in a previous Investigational Device Exemption study. | 69 |
| Total | 266 |
Withdrawals & dropouts
| Period | Reason | FG000 | FG001 | FG002 | FG003 |
|---|---|---|---|---|---|
| Overall Study | Adverse Event | 6 | 1 | 1 | 3 |
| Overall Study | Death | 7 | 0 | 1 | 1 |
| Overall Study | Lost to Follow-up | 18 | 5 | 21 | 21 |
| Overall Study | Physician Decision | 10 | 0 | 0 | 0 |
Baseline characteristics
| Characteristic | LPS Flex Mobile Uniliteral (Group 2) | Total | LPS Flex Mobile (Group 1) | LPS Flex Fixed (Group 1) | LPS Flex Mobile Bilateral (Group 2) |
|---|---|---|---|---|---|
| Age, Continuous | 65.8 Years | 65.4 Years | 62.5 Years | 61.4 Years | 62.4 Years |
| Race (NIH/OMB) American Indian or Alaska Native | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Asian | 1 Participants | 2 Participants | 0 Participants | 1 Participants | 0 Participants |
| Race (NIH/OMB) Black or African American | 12 Participants | 18 Participants | 1 Participants | 5 Participants | 0 Participants |
| Race (NIH/OMB) More than one race | 2 Participants | 7 Participants | 2 Participants | 1 Participants | 2 Participants |
| Race (NIH/OMB) Native Hawaiian or Other Pacific Islander | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Unknown or Not Reported | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) White | 91 Participants | 239 Participants | 66 Participants | 70 Participants | 12 Participants |
| Region of Enrollment United States | 106 participants | 266 participants | 69 participants | 77 participants | 14 participants |
| Sex: Female, Male Female | 68 Participants | 171 Participants | 40 Participants | 51 Participants | 12 Participants |
| Sex: Female, Male Male | 38 Participants | 95 Participants | 29 Participants | 26 Participants | 2 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk | EG002 affected / at risk | EG003 affected / at risk |
|---|---|---|---|---|
| deaths Total, all-cause mortality | 7 / 106 | 0 / 14 | 1 / 77 | 1 / 69 |
| other Total, other adverse events | 82 / 106 | 14 / 14 | 64 / 77 | 14 / 69 |
| serious Total, serious adverse events | 17 / 106 | 0 / 14 | 8 / 77 | 5 / 69 |
Outcome results
Primary
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.
Time frame: 10 year
Population: Only subjects with an evaluable endpoint at the applicable time frame interval were used to calculate the count of participants.
| Arm | Measure | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|
| LPS Flex Mobile Unilateral Group (Group 2) | Group 1 - Number of Subjects With Absence of Implant Revision | 75 Participants |
| LPS Flex Mobile Bilateral Group (Group 2) | Group 1 - Number of Subjects With Absence of Implant Revision | 68 Participants |
Primary
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.
Time frame: 10 year
Population: Only subjects with an evaluable endpoint at the applicable time frame interval were used to calculate the count of participants.
| Arm | Measure | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|
| LPS Flex Mobile Unilateral Group (Group 2) | Group 1 - Number of Subjects With Absence of Radiolucency/Bone Loss | 65 Participants |
| LPS Flex Mobile Bilateral Group (Group 2) | Group 1 - Number of Subjects With Absence of Radiolucency/Bone Loss | 62 Participants |
Primary
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.
Time frame: 10 year
Population: Only subjects with an evaluable endpoint at the applicable time frame interval were used to calculate the count of participants.
| Arm | Measure | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|
| LPS Flex Mobile Unilateral Group (Group 2) | Group 1 - Number of Subjects With Absence of Severe Knee-Related Complication | 75 Participants |
| LPS Flex Mobile Bilateral Group (Group 2) | Group 1 - Number of Subjects With Absence of Severe Knee-Related Complication | 67 Participants |
Primary
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.
Time frame: 4 year, 5 year, 6 year, 8 year, and 10 year
Population: Only subjects with an evaluable endpoint at each time frame interval were used to calculate mean and standard deviations.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| LPS Flex Mobile Unilateral Group (Group 2) | Group 1 - Total Knee Society Score (KSS) | 5 Year | 142.4 score on a scale | Standard Deviation 32.2 |
| LPS Flex Mobile Unilateral Group (Group 2) | Group 1 - Total Knee Society Score (KSS) | 8 Year | 164.8 score on a scale | Standard Deviation 31 |
| LPS Flex Mobile Unilateral Group (Group 2) | Group 1 - Total Knee Society Score (KSS) | 6 Year | 161.9 score on a scale | Standard Deviation 28.1 |
| LPS Flex Mobile Unilateral Group (Group 2) | Group 1 - Total Knee Society Score (KSS) | 10 Year | 166.6 score on a scale | Standard Deviation 25.5 |
| LPS Flex Mobile Unilateral Group (Group 2) | Group 1 - Total Knee Society Score (KSS) | 4 Year | 164.6 score on a scale | Standard Deviation 32.9 |
| LPS Flex Mobile Bilateral Group (Group 2) | Group 1 - Total Knee Society Score (KSS) | 10 Year | 170.8 score on a scale | Standard Deviation 29.3 |
| LPS Flex Mobile Bilateral Group (Group 2) | Group 1 - Total Knee Society Score (KSS) | 4 Year | 184.4 score on a scale | Standard Deviation 9.7 |
| LPS Flex Mobile Bilateral Group (Group 2) | Group 1 - Total Knee Society Score (KSS) | 5 Year | 142.6 score on a scale | Standard Deviation 41.3 |
| LPS Flex Mobile Bilateral Group (Group 2) | Group 1 - Total Knee Society Score (KSS) | 6 Year | 169.3 score on a scale | Standard Deviation 29.8 |
| LPS Flex Mobile Bilateral Group (Group 2) | Group 1 - Total Knee Society Score (KSS) | 8 Year | 172.0 score on a scale | Standard Deviation 26.9 |
Primary
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.
Time frame: 5 year
Population: Only subjects with an evaluable endpoint at the applicable time frame interval were used to calculate the count of participants.
| Arm | Measure | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|
| LPS Flex Mobile Unilateral Group (Group 2) | Group 2 - Number of Subjects With Absence of Implant Revision | 103 Participants |
| LPS Flex Mobile Bilateral Group (Group 2) | Group 2 - Number of Subjects With Absence of Implant Revision | 14 Participants |
Primary
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.
Time frame: 5 year
Population: Only subjects with an evaluable endpoint at the applicable time frame interval were used to calculate the count of participants.
| Arm | Measure | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|
| LPS Flex Mobile Unilateral Group (Group 2) | Group 2 - Number of Subjects With Absence of Radiolucency/Bone Loss | 90 Participants |
| LPS Flex Mobile Bilateral Group (Group 2) | Group 2 - Number of Subjects With Absence of Radiolucency/Bone Loss | 14 Participants |
Primary
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.
Time frame: 5 year
Population: Only subjects with an evaluable endpoint at the applicable time frame interval were used to calculate the count of participants.
| Arm | Measure | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|
| LPS Flex Mobile Unilateral Group (Group 2) | Group 2 - Number of Subjects With Absence of Severe Knee-Related Complication | 105 Participants |
| LPS Flex Mobile Bilateral Group (Group 2) | Group 2 - Number of Subjects With Absence of Severe Knee-Related Complication | 14 Participants |
Primary
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.
Time frame: Pre-op, 6 week, 6 month, 1 year, 2 year, 3 year, 4 year, and 5 year
Population: Only subjects with an evaluable endpoint at each time frame interval were used to calculate mean and standard deviations.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| LPS Flex Mobile Unilateral Group (Group 2) | Group 2 - Total Knee Society Score (KSS) | 5 Year | 160.8 score on a scale | Standard Deviation 28.6 |
| LPS Flex Mobile Unilateral Group (Group 2) | Group 2 - Total Knee Society Score (KSS) | 1 Year | 159.2 score on a scale | Standard Deviation 28.1 |
| LPS Flex Mobile Unilateral Group (Group 2) | Group 2 - Total Knee Society Score (KSS) | 4 Year | 160.2 score on a scale | Standard Deviation 29.4 |
| LPS Flex Mobile Unilateral Group (Group 2) | Group 2 - Total Knee Society Score (KSS) | 2 Year | 159.2 score on a scale | Standard Deviation 32.2 |
| LPS Flex Mobile Unilateral Group (Group 2) | Group 2 - Total Knee Society Score (KSS) | 6 Week | 118.2 score on a scale | Standard Deviation 33 |
| LPS Flex Mobile Unilateral Group (Group 2) | Group 2 - Total Knee Society Score (KSS) | 3 Year | 161.1 score on a scale | Standard Deviation 27.3 |
| LPS Flex Mobile Unilateral Group (Group 2) | Group 2 - Total Knee Society Score (KSS) | Pre-op | 92.2 score on a scale | Standard Deviation 28.5 |
| LPS Flex Mobile Unilateral Group (Group 2) | Group 2 - Total Knee Society Score (KSS) | 6 Month | 148 score on a scale | Standard Deviation 29.7 |
| LPS Flex Mobile Bilateral Group (Group 2) | Group 2 - Total Knee Society Score (KSS) | 5 Year | 167.1 score on a scale | Standard Deviation 29.3 |
| LPS Flex Mobile Bilateral Group (Group 2) | Group 2 - Total Knee Society Score (KSS) | Pre-op | 78.5 score on a scale | Standard Deviation 29 |
| LPS Flex Mobile Bilateral Group (Group 2) | Group 2 - Total Knee Society Score (KSS) | 6 Week | 96.7 score on a scale | Standard Deviation 34 |
| LPS Flex Mobile Bilateral Group (Group 2) | Group 2 - Total Knee Society Score (KSS) | 6 Month | 130.4 score on a scale | Standard Deviation 51.5 |
| LPS Flex Mobile Bilateral Group (Group 2) | Group 2 - Total Knee Society Score (KSS) | 1 Year | 137.2 score on a scale | Standard Deviation 56.9 |
| LPS Flex Mobile Bilateral Group (Group 2) | Group 2 - Total Knee Society Score (KSS) | 2 Year | 149.4 score on a scale | Standard Deviation 34.7 |
| LPS Flex Mobile Bilateral Group (Group 2) | Group 2 - Total Knee Society Score (KSS) | 4 Year | 121.3 score on a scale | Standard Deviation 56.7 |
| LPS Flex Mobile Bilateral Group (Group 2) | Group 2 - Total Knee Society Score (KSS) | 3 Year | 147.3 score on a scale | Standard Deviation 45.3 |