Osteoarthritis, Total Knee Arthroplasty
Conditions
Keywords
Total Knee Arthroplasty, Osteoarthritis, Knee
Brief summary
The purpose of this study is to test for significant differences in functional outcomes, specifically pre-operative ROM and post-operative ROM obtained by using a NexGen CR versus a NexGen CR-Flex knee implant. Specifically, it is predicted that an increase in post-operative range of motion will be experienced by patients treated with the NexGen CR-Flex knee implant.
Detailed description
This study will compare the clinical results of the NexGen CR femoral component with the higher flexion potential of the NexGen CR-Flex femoral component in all patients with degenerative joint disease that require total knee arthroplasty. The primary variable of interest is post-operative 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.
Interventions
DEVICENexGen CR-Flex Fixed Bearing Knee
NexGen CR-Flex Fixed Bearing femoral component
DEVICENexGen CR Knee
NexGen Complete Knee Solution Cruciate Retaining femoral component
Sponsors
Zimmer Biomet
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
SINGLE (Subject)
Eligibility
Sex/Gender
ALL
Age
21 Years to 80 Years
Healthy volunteers
No
Inclusion criteria
* Age, 21-80 years * Sex, Male and Females will be included * BMI less than or equal to 39 * Stable Health, the patient would be able to undergo surgery and participate in a follow-up program based on physical examination and medical history. * Patient is willing and able to cooperate in follow-up therapy. * Patient exhibits pre-operative radiographic evidenced of joint degeneration consistent with TKA that cannot be treated in non-operative fashion. * Patient has stable and functional posterior cruciate and 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 120 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.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Postoperative Range of Motion (ROM) | 24 Months | The subject will have the operative joint's range of motion/movement assessed through a series of exercises and bends. The assessor will measure how far the joint bends/moves in each direction by degrees. The measurements are taken at each visit interval and recorded. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Return to Function (RtF) Via Knee Scoiety Score (Modified) | 24 Months | 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 estabalished follows: 80-100 = Excellent; 70-79 = Good; 60-69 = Fair; and Below 60 = Poor. |
Countries
United States
Participant flow
Recruitment details
Patients were enrolled between 2004 and 2008 at a total of 15 sites throughout the USA
Participants by arm
| Arm | Count |
|---|---|
| CR Flex Fixed Bearing Knee Study arm will consist of patients that are treated with the NexGen CR-Flex Fixed Bearing Knee. | 87 |
| CR Standard Knee Study arm will consist of patients that are treated with the NexGen CR Knee. | 102 |
| Total | 189 |
Withdrawals & dropouts
| Period | Reason | FG000 | FG001 |
|---|---|---|---|
| Overall Study | Adverse Event | 26 | 34 |
| Overall Study | Death | 0 | 1 |
| Overall Study | Lost to Follow-up | 6 | 11 |
| Overall Study | Withdrawal by Subject | 3 | 8 |
Baseline characteristics
| Characteristic | CR Standard Knee | CR Flex Fixed Bearing Knee | Total |
|---|---|---|---|
| Age, Categorical <=18 years | 0 Participants | 0 Participants | 0 Participants |
| Age, Categorical >=65 years | 54 Participants | 50 Participants | 104 Participants |
| Age, Categorical Between 18 and 65 years | 48 Participants | 37 Participants | 85 Participants |
| Age Continuous | 65.7 years STANDARD_DEVIATION 8.5 | 66.8 years STANDARD_DEVIATION 8.5 | 66.2 years STANDARD_DEVIATION 189 |
| Region of Enrollment United States | 102 participants | 87 participants | 189 participants |
| Sex: Female, Male Female | 48 Participants | 53 Participants | 101 Participants |
| Sex: Female, Male Male | 54 Participants | 34 Participants | 88 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | — / — | — / — |
| other Total, other adverse events | 2 / 87 | 6 / 102 |
| serious Total, serious adverse events | 1 / 87 | 2 / 102 |
Outcome results
Primary
Postoperative Range of Motion (ROM)
The subject will have the operative joint's range of motion/movement assessed through a series of exercises and bends. The assessor will measure how far the joint bends/moves in each direction by degrees. The measurements are taken at each visit interval and recorded.
Time frame: 24 Months
Population: There was one case in the CR Standard Knee cohort where the Range of Motion was not complete. Therefore, the total number analyzed is 47 and not 48.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| CR Flex Fixed Bearing Knee | Postoperative Range of Motion (ROM) | 119.1 degrees | Standard Deviation 16.5 |
| CR Standard Knee | Postoperative Range of Motion (ROM) | 120.7 degrees | Standard Deviation 11.1 |
Secondary
Return to Function (RtF) Via Knee Scoiety 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 estabalished follows: 80-100 = Excellent; 70-79 = Good; 60-69 = Fair; and Below 60 = Poor.
Time frame: 24 Months
Population: There was one case in the CR Flex Fixed cohort and 3 in the CR Standard Knee cohort where the Return to Function was not complete. Therefore, the total number analyzed is 51 instead of 52 and 45 instead of 48 respectfully.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| CR Flex Fixed Bearing Knee | Return to Function (RtF) Via Knee Scoiety Score (Modified) | 80.9 units on a scale | Standard Deviation 18.8 |
| CR Standard Knee | Return to Function (RtF) Via Knee Scoiety Score (Modified) | 85.1 units on a scale | Standard Deviation 16.9 |