Arthroplasty, Replacement, Knee
Conditions
Keywords
Knee
Brief summary
The purpose of this study is to evaluate the clinical outcomes (range of motion, pain, function, radiographic stability, and health related quality of life) of patients receiving the Triathlon® Posterior Stabilized (PS) Total Knee System. These outcomes will be evaluated using pre-operative scores and comparing them to post-operative scores in addition to being compared with cases who received the Scorpio® PS implant.
Detailed description
The Triathlon® Posteriorly Stabilized (PS) Total Knee System components are for use in cemented total knee arthroplasty for painful, disabling joint disease of the knee resulting from non-inflammatory degenerative joint disease (including osteoarthritis, traumatic arthritis or avascular necrosis) or rheumatoid arthritis (excluded from this study according to protocol). The components are designed to improve range of motion (ROM) and stability. This study serves to demonstrate that subjects have reduced pain, increased ROM and improved stability following implantation with the Triathlon® PS Total Knee System.
Interventions
DEVICETriathlon® PS Total Knee System
Triathlon® PS Total Knee system
Sponsors
Stryker Orthopaedics
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
TREATMENT
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
21 Years to 80 Years
Healthy volunteers
No
Inclusion criteria
1. The subject is a male or non-pregnant female 21-80 years of age at the time of enrollment. 2. The subject requires a primary cemented total knee replacement. 3. The subject has a diagnosis of osteoarthritis (OA), traumatic arthritis (TA), or avascular necrosis (AVN). 4. The subject has intact collateral ligaments. 5. The subject has signed the IRB approved, study specific Informed Patient Consent Form. 6. The subject is willing and able to comply with postoperative scheduled clinical and radiographic evaluations and rehabilitation.
Exclusion criteria
1. The subject has inflammatory arthritis. 2. The subject is morbidly obese, BMI \> 40. 3. The subject has a history of total or unicompartmental reconstruction of the affected joint. 4. The subject has had a high tibial osteotomy or femoral osteotomy. 5. The subject has a neuromuscular or neurosensory deficiency that would limit the ability to assess the performance of the device. 6. The subject has a systemic or metabolic disorder leading to progressive bone deterioration. 7. The subject is immunologically suppressed, or receiving chronic steroids (\>30 days duration). 8. The subject's bone stock is compromised by disease or infection and cannot provide adequate support and/or fixation to the prosthesis. 9. The subject has had a knee fusion at the affected joint. 10. The subject has an active or suspected latent infection in or about the knee joint. 11. The subject is a prisoner.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Range of Motion | 2 years | The primary outcome of this study is to compare active range of motion values for the Triathlon PS Total Knee System. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Radiographic Outcome | 1,2 and 5 years | Radiographic success/failure at 1, 2, and 5-year visits will be assessed. Radiographic failure is defined as a score of 10 or greater according to the Knee Society Roentgenographic Scoring System, regardless of symptoms. A migrating or shifting prosthesis with or without the disappearance of radiolucent lines is also a failure regardless of score. |
| Patient Outcome Lower-Extremity Activity Scale | 1,2,3,4 and 5 years | The Lower-Extremity Activity Scale (LEAS) score at 1, 2, 3, 4 and 5-year intervals will be compared at each post-surgery visit with baseline to see if any improvement is seen for each time point.The LEAS is completed by the participant to assess activity level. Activity levels were ordered in terms of intensity from 1 to 18, with 18 indicating the highest activity level. A level of 1 indicated that the subject was confined to bed all day while a level of 18 indicated that the subject was up and about at will inside and outside of the house, and also participated in vigorous physical activity, such as competitive level sports, on a daily basis. |
| Patient Outcome Knee Society Score | 1,2 and 5 years | The Knee Society Scores (KSS) at 1, 2, and 5-year visits will be compared. Additionally, comparison of scores at each post-surgery visit with baseline will be tested to see if any improvement is seen at each time point. The Knee Society Clinical Rating System is comprised of two distinct sub-scores: one for pain, ROM and joint stability, and one for functional parameters. Sub-scores range from a potential minimum score of 0 to a maximum score of 100 points. Although the specific scores are not distinguished as excellent, good, fair, or poor, a higher value represents a better outcome. |
| Patient Outcome SF-36 | 1,2,3,4 and 5 years | The SF-36 score at 1, 2, 3, 4 and 5-year visits will be compared at each post-surgery visit with baseline to see if any improvement is seen for each time point.The SF-36 includes a physical component and a mental component and is completed by the participant. Physical component and mental component scores were calculated on a scale ranging from 0 to 100. Low values represented a poor health state and high values represented a good health state. |
| Patient Outcome WOMAC | 5 years | The Western Ontario and McMaster Osteoarthritis Index (WOMAC) scores at 1, 2, 3, 4 and 5-year visits will be compared between groups, when data is available. Additionally, comparison of scores at each post-surgery visit with baseline will be tested to see if any improvement is seen for each time point. The WOMAC collects information specific to osteoarthritis outcomes. The questionnaire uses a visual analog scale for pain, measuring factors of general pain, stiffness, and physical findings. Pain is scored from 0 to 100 for each set of factors, with 0 indicating no pain and 100 indicating extreme pain. Total WOMAC scores range from 0 to 300. Lower values represent better outcomes. Data for the WOMAC is only available at the 5 year interval due to typographical errors noted on earlier interval forms rendering them invalid for comparison. |
Countries
United States
Participant flow
Pre-assignment details
409 participants/500 knees enrolled - 55 participants/65 knees censored = 354 participants/435 knees followed.
Participants by arm
| Arm | Count |
|---|---|
| Triathlon® PS Total Knee System Participants who were not censored from analysis. | 351 |
| Total | 351 |
Withdrawals & dropouts
| Period | Reason | FG000 |
|---|---|---|
| Overall Study | Death | 5 |
| Overall Study | Lost to Follow-up | 8 |
| Overall Study | No 2 yr ROM data | 35 |
| Overall Study | Revised study component by 2 yr visit | 8 |
| Overall Study | Site Termination by the 2 yr visit | 16 |
| Overall Study | Surgery Cancelled | 9 |
| Overall Study | Termination due to language issue | 2 |
| Overall Study | Withdrawal by Subject | 34 |
Baseline characteristics
| Characteristic | Triathlon® PS Total Knee System |
|---|---|
| Age, Continuous | 65.12 years STANDARD_DEVIATION 8.59 |
| Gender Female | 200 Participants |
| Gender Male | 151 Participants |
| Region of Enrollment United States | 351 participants |
Adverse events
| Event type | EG000 affected / at risk |
|---|---|
| deaths Total, all-cause mortality | — / — |
| other Total, other adverse events | 194 / 354 |
| serious Total, serious adverse events | 86 / 354 |
Outcome results
Primary
Range of Motion
The primary outcome of this study is to compare active range of motion values for the Triathlon PS Total Knee System.
Time frame: 2 years
Population: Participants can have both knees replaced. Range of motion is measured for each knee, as such the number of knees evaluated can be greater than the number of participants.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Triathlon® PS Total Knee System | Range of Motion | 124 degrees | Standard Deviation 9.98 |
Secondary
Patient Outcome Knee Society Score
The Knee Society Scores (KSS) at 1, 2, and 5-year visits will be compared. Additionally, comparison of scores at each post-surgery visit with baseline will be tested to see if any improvement is seen at each time point. The Knee Society Clinical Rating System is comprised of two distinct sub-scores: one for pain, ROM and joint stability, and one for functional parameters. Sub-scores range from a potential minimum score of 0 to a maximum score of 100 points. Although the specific scores are not distinguished as excellent, good, fair, or poor, a higher value represents a better outcome.
Time frame: 1,2 and 5 years
Population: Maximum number of knees evaluated at any interval.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Triathlon® PS Total Knee System | Patient Outcome Knee Society Score | Pain/Motion 1 Yr (N=335) | 93.77 units on a scale | Standard Deviation 9.03 |
| Triathlon® PS Total Knee System | Patient Outcome Knee Society Score | Pain/Motion 1 Yr difference from Baseline (N=333) | 57.36 units on a scale | Standard Deviation 16.8 |
| Triathlon® PS Total Knee System | Patient Outcome Knee Society Score | Function 1 Yr (N=340) | 86.26 units on a scale | Standard Deviation 15.5 |
| Triathlon® PS Total Knee System | Patient Outcome Knee Society Score | Function 1 Yr difference from Baseline (N=340) | 30.99 units on a scale | Standard Deviation 17.43 |
| Triathlon® PS Total Knee System | Patient Outcome Knee Society Score | Pain/Motion 2 Yr (N=281) | 93.96 units on a scale | Standard Deviation 8.45 |
| Triathlon® PS Total Knee System | Patient Outcome Knee Society Score | Pain/Motion 2 Yr difference from Baseline (N=279) | 57.76 units on a scale | Standard Deviation 17.2 |
| Triathlon® PS Total Knee System | Patient Outcome Knee Society Score | Function 2 Yr (N=284) | 87.38 units on a scale | Standard Deviation 16.4 |
| Triathlon® PS Total Knee System | Patient Outcome Knee Society Score | Function 2 Yr difference from Baseline (N=284) | 32.55 units on a scale | Standard Deviation 18.89 |
| Triathlon® PS Total Knee System | Patient Outcome Knee Society Score | Pain/Motion 5 Yr (N=230) | 94.61 units on a scale | Standard Deviation 7.62 |
| Triathlon® PS Total Knee System | Patient Outcome Knee Society Score | Pain/Motion 5 Yr difference from Baseline (N=229) | 58.56 units on a scale | Standard Deviation 16.35 |
| Triathlon® PS Total Knee System | Patient Outcome Knee Society Score | Function 5 Yr (N=232) | 82.07 units on a scale | Standard Deviation 20.74 |
| Triathlon® PS Total Knee System | Patient Outcome Knee Society Score | Function 5 Yr difference from Baseline (N=232) | 27.33 units on a scale | Standard Deviation 22.59 |
Comparison: KSS Pain/Motion and Function Score comparison from pre-op to 1, 2 and 5 yearp-value: <0.0001t-test, 2 sided
Secondary
Patient Outcome Lower-Extremity Activity Scale
The Lower-Extremity Activity Scale (LEAS) score at 1, 2, 3, 4 and 5-year intervals will be compared at each post-surgery visit with baseline to see if any improvement is seen for each time point.The LEAS is completed by the participant to assess activity level. Activity levels were ordered in terms of intensity from 1 to 18, with 18 indicating the highest activity level. A level of 1 indicated that the subject was confined to bed all day while a level of 18 indicated that the subject was up and about at will inside and outside of the house, and also participated in vigorous physical activity, such as competitive level sports, on a daily basis.
Time frame: 1,2,3,4 and 5 years
Population: Maximum number of knees available at any interval.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Triathlon® PS Total Knee System | Patient Outcome Lower-Extremity Activity Scale | LEAS 1 Year (N=339) | 11.22 units on a scale | Standard Deviation 2.62 |
| Triathlon® PS Total Knee System | Patient Outcome Lower-Extremity Activity Scale | LEAS 1 Year difference from Baseline (N=339) | 1.97 units on a scale | Standard Deviation 2.84 |
| Triathlon® PS Total Knee System | Patient Outcome Lower-Extremity Activity Scale | LEAS 2 Year (N=291) | 11.04 units on a scale | Standard Deviation 2.63 |
| Triathlon® PS Total Knee System | Patient Outcome Lower-Extremity Activity Scale | LEAS 2 Year difference from Baseline (N=291) | 1.86 units on a scale | Standard Deviation 2.98 |
| Triathlon® PS Total Knee System | Patient Outcome Lower-Extremity Activity Scale | LEAS 3 Year (N=266) | 11.15 units on a scale | Standard Deviation 2.87 |
| Triathlon® PS Total Knee System | Patient Outcome Lower-Extremity Activity Scale | LEAS 3 Year difference from Baseline (N=266) | 1.95 units on a scale | Standard Deviation 3.12 |
| Triathlon® PS Total Knee System | Patient Outcome Lower-Extremity Activity Scale | LEAS 4 Year (N=262) | 10.97 units on a scale | Standard Deviation 2.76 |
| Triathlon® PS Total Knee System | Patient Outcome Lower-Extremity Activity Scale | LEAS 4 Year difference from Baseline (N=262) | 1.87 units on a scale | Standard Deviation 3.03 |
| Triathlon® PS Total Knee System | Patient Outcome Lower-Extremity Activity Scale | LEAS 5 Year (N=244) | 11.02 units on a scale | Standard Deviation 2.93 |
| Triathlon® PS Total Knee System | Patient Outcome Lower-Extremity Activity Scale | LEAS 5 Year difference from Baseline (N=244) | 1.89 units on a scale | Standard Deviation 3.14 |
Comparison: LEAS score comparison from pre-op to 1, 2, 3, 4 and 5 yearsp-value: <0.0001t-test, 2 sided
Secondary
Patient Outcome SF-36
The SF-36 score at 1, 2, 3, 4 and 5-year visits will be compared at each post-surgery visit with baseline to see if any improvement is seen for each time point.The SF-36 includes a physical component and a mental component and is completed by the participant. Physical component and mental component scores were calculated on a scale ranging from 0 to 100. Low values represented a poor health state and high values represented a good health state.
Time frame: 1,2,3,4 and 5 years
Population: Maximum number of knees evaluated at any interval.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Triathlon® PS Total Knee System | Patient Outcome SF-36 | SF36 Physical Component 1 Yr (N=335) | 48.16 units on a scale | Standard Deviation 8.5 |
| Triathlon® PS Total Knee System | Patient Outcome SF-36 | SF36 Physical 1 Yr difference from Baseline(N=332) | 15.32 units on a scale | Standard Deviation 9.28 |
| Triathlon® PS Total Knee System | Patient Outcome SF-36 | SF36 Mental Component 1 Yr (N=335) | 55.21 units on a scale | Standard Deviation 8.02 |
| Triathlon® PS Total Knee System | Patient Outcome SF-36 | SF36 Mental 1Yr difference from Baseline(N=332) | 2.58 units on a scale | Standard Deviation 11.06 |
| Triathlon® PS Total Knee System | Patient Outcome SF-36 | SF36 Physical Component 2Yr (N=290) | 47.34 units on a scale | Standard Deviation 9.57 |
| Triathlon® PS Total Knee System | Patient Outcome SF-36 | SF36 Physical 2 Yr difference from Baseline(N=288) | 14.54 units on a scale | Standard Deviation 9.75 |
| Triathlon® PS Total Knee System | Patient Outcome SF-36 | SF36 Mental Component 2 Yr (N=290) | 55.04 units on a scale | Standard Deviation 8.1 |
| Triathlon® PS Total Knee System | Patient Outcome SF-36 | SF36 Mental 2Yr difference from Baseline(N=288) | 2.04 units on a scale | Standard Deviation 10.9 |
| Triathlon® PS Total Knee System | Patient Outcome SF-36 | SF36 Physical Component 3Yr (N=259) | 47.23 units on a scale | Standard Deviation 9.31 |
| Triathlon® PS Total Knee System | Patient Outcome SF-36 | SF36 Physical 3 Yr difference from Baseline(N=257) | 14.45 units on a scale | Standard Deviation 9.58 |
| Triathlon® PS Total Knee System | Patient Outcome SF-36 | SF36 Mental Component 3 Yr (N=259) | 54.30 units on a scale | Standard Deviation 9.68 |
| Triathlon® PS Total Knee System | Patient Outcome SF-36 | SF36 Mental 3 Yr difference from Baseline(N=257) | 1.93 units on a scale | Standard Deviation 11.06 |
| Triathlon® PS Total Knee System | Patient Outcome SF-36 | SF36 Physical Component 4 Yr (N=254) | 46.26 units on a scale | Standard Deviation 10.05 |
| Triathlon® PS Total Knee System | Patient Outcome SF-36 | SF36 Physical 4 Yr difference from Baseline(N=253) | 13.58 units on a scale | Standard Deviation 10.54 |
| Triathlon® PS Total Knee System | Patient Outcome SF-36 | SF36 Mental 4 Yr difference from Baseline(N=253) | 1.93 units on a scale | Standard Deviation 10.88 |
| Triathlon® PS Total Knee System | Patient Outcome SF-36 | SF36 Physical Component 5 Yr (N=243) | 46.33 units on a scale | Standard Deviation 9.72 |
| Triathlon® PS Total Knee System | Patient Outcome SF-36 | SF36 Physical 5 Yr difference from Baseline(N=242) | 13.65 units on a scale | Standard Deviation 10.82 |
| Triathlon® PS Total Knee System | Patient Outcome SF-36 | SF36 Mental Component 5 Yr (N=243) | 54.82 units on a scale | Standard Deviation 7.97 |
| Triathlon® PS Total Knee System | Patient Outcome SF-36 | SF36 Mental 5 Yr difference from Baseline(N=242) | 2.25 units on a scale | Standard Deviation 11.06 |
| Triathlon® PS Total Knee System | Patient Outcome SF-36 | SF36 Mental Component 4 Yr (N=254) | 54.49 units on a scale | Standard Deviation 8.74 |
Comparison: SF-36 Physical score comparison from pre-op to 1, 2, 3, 4 and 5 yearsp-value: <0.0001t-test, 2 sided
Comparison: SF-36 Mental score comparison from pre-op to 1 yearp-value: <0.0001t-test, 2 sided
Comparison: SF-36 Mental score comparison from pre-op to 2 yearp-value: 0.0017t-test, 2 sided
Comparison: SF-36 Mental score comparison from pre-op to 3 yearp-value: 0.0055t-test, 2 sided
Comparison: SF-36 Mental score comparison from pre-op to 4 yearp-value: 0.005t-test, 2 sided
Comparison: SF-36 Mental score comparison from pre-op to 5 yearp-value: 0.0018t-test, 2 sided
Secondary
Patient Outcome WOMAC
The Western Ontario and McMaster Osteoarthritis Index (WOMAC) scores at 1, 2, 3, 4 and 5-year visits will be compared between groups, when data is available. Additionally, comparison of scores at each post-surgery visit with baseline will be tested to see if any improvement is seen for each time point. The WOMAC collects information specific to osteoarthritis outcomes. The questionnaire uses a visual analog scale for pain, measuring factors of general pain, stiffness, and physical findings. Pain is scored from 0 to 100 for each set of factors, with 0 indicating no pain and 100 indicating extreme pain. Total WOMAC scores range from 0 to 300. Lower values represent better outcomes. Data for the WOMAC is only available at the 5 year interval due to typographical errors noted on earlier interval forms rendering them invalid for comparison.
Time frame: 5 years
Population: The number of knees evaluated at 5 years.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Triathlon® PS Total Knee System | Patient Outcome WOMAC | 45.11 units on a scale | Standard Deviation 53.96 |
Secondary
Radiographic Outcome
Radiographic success/failure at 1, 2, and 5-year visits will be assessed. Radiographic failure is defined as a score of 10 or greater according to the Knee Society Roentgenographic Scoring System, regardless of symptoms. A migrating or shifting prosthesis with or without the disappearance of radiolucent lines is also a failure regardless of score.
Time frame: 1,2 and 5 years
Population: Maximum number of knees evaluable at any interval.
| Arm | Measure | Group | Value (NUMBER) |
|---|---|---|---|
| Triathlon® PS Total Knee System | Radiographic Outcome | Radiographic failure at 1 Yr (N=347 knees) | 1 knees |
| Triathlon® PS Total Knee System | Radiographic Outcome | Radiographic failure at 2 Yrs (N=282 knees) | 2 knees |
| Triathlon® PS Total Knee System | Radiographic Outcome | Radiographic failure at 5 Yrs (N=217 knees) | 3 knees |