Arthroplasty, Replacement, Knee
Conditions
Keywords
Osteoarthritis, Post-traumatic arthritis
Brief summary
The purpose of this study is to compare the 10-year Knee Society Score (KSS) functional results of the Triathlon PKR Unicondylar Knee to the 10-year Knee Society Score (KSS) functional results of the Triathlon Cruciate Retaining (CR) Total Knee.
Interventions
DEVICETriathlon PKR
Triathlon PKR is a unicondylar knee resurfacing system designed to replace a single osteoarthritic compartment of a patient's natural knee.
Sponsors
Stryker Orthopaedics
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
TREATMENT
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
21 Years to 75 Years
Healthy volunteers
No
Inclusion criteria
* The subject is a male or non-pregnant female 21-75 years of age at the time of enrollment. * The subject requires a primary cemented unicompartmental knee replacement. * The subject has a diagnosis of osteoarthritis (OA) or posttraumatic arthritis (TA). * The subject has clinically intact cruciate and collateral ligaments and no ligamentous instability is present. * The subject has less than 10 degrees of flexion contracture and greater than 90 degrees of flexion. * The subject's preoperative mechanical alignment is less than 15 degrees of varus and 15 degrees of valgus. * The subject has signed the Institutional Review Board (IRB) approved study specific Informed Patient Consent Form. * The subject is willing and able to comply with postoperative scheduled clinical and radiographic evaluations and rehabilitation.
Exclusion criteria
* The subject has inflammatory arthritis or avascular necrosis(AVN). * The subject is obese, BMI \> 35. * The subject has a history of total or unicompartmental (contralateral compartment and/or patellofemoral joint) reconstruction of the affected joint. * The subject has a history of anterior cruciate ligament (ACL) reconstruction. * The subject has had a high distal femoral, or proximal tibial osteotomy. * The subject has a mental, neuromuscular or neurosensory disorder, which would create an unacceptable risk of prosthesis instability, prosthesis fixation failure, or complications in post-operative care and/or limit the ability to assess the performance of the device. * The subject has a systemic or metabolic disorder leading to progressive bone deterioration that the surgeon feels would affect the overall outcome of the study. * The subject is immunologically suppressed, or is receiving chronic steroids (\>30 days duration). * The subject has a known sensitivity to device materials. * The subject's bone stock is compromised by disease and/or infection which cannot provide adequate support and/or fixation to the prosthesis. * The subject's bone stock is compromised by a prior implantation which cannot provide adequate support and/or fixation to the prosthesis. * The subject has an active or suspected latent infection in or about the knee joint. * The subject is a prisoner.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Investigation of Clinical Performance and Patient Outcome With the Functional Knee Society Score (KSS). | 10 years | The Knee Society Score (KSS) consists of two distinct sub-scores: one for pain, range of motion, joint stability and alignment (Pain/Motion KSS) and one for distance walked, stair climbing and walking aids (Functional KSS). This outcome measure was only for the KSS Function Score at 10-years. The KSS Function score subscale is 0-100, with 100 representing a better outcome. Although the specific scores are not distinguished as excellent, good, fair, or poor, a higher value represents a better outcome. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| 10-years Kaplan Meier Survival Analysis | 10-years | For the purpose of this study the Kaplan-Meier survival curves are a statistical method to estimate the survival function from lifetime data of a knee replacement after treatment. Survivorship is defined as a percentage of knees free of any component revision for any reason. |
Countries
Germany, Italy, Sweden, United States
Participant flow
Recruitment details
There were 112 knees in 111 patients that were enrolled in the study (one bilateral case).
Pre-assignment details
Of the 111 participants enrolled, there were 23 cases that were censored due to not having the study device, surgery canceled or an inclusion exclusion violation. Therefore, 89 knees in 88 participants are followed who did receive the study device and met protocol criteria. Those applicable data are reflected in this record.
Participants by arm
| Arm | Count |
|---|---|
| Triathlon PKR All subjects enrolled will receive the Triathlon PKR device.
Triathlon PKR: Triathlon PKR is a unicondylar knee resurfacing system designed to replace a single osteoarthritic compartment of a patient's natural knee. | 88 |
| Total | 88 |
Withdrawals & dropouts
| Period | Reason | FG000 |
|---|---|---|
| Overall Study | Adverse Event | 5 |
| Overall Study | Censored because of Inclusion/exclusion violation | 7 |
| Overall Study | Censored because study device was not implanted | 14 |
| Overall Study | Censored because surgery not done | 2 |
| Overall Study | Death | 1 |
| Overall Study | Lost to Follow-up | 6 |
| Overall Study | Sponsor terminated early | 49 |
| Overall Study | Withdrawal by Subject | 14 |
Baseline characteristics
| Characteristic | Triathlon PKR |
|---|---|
| Age, Continuous | 61.83 years |
| Race (NIH/OMB) American Indian or Alaska Native | 1 Participants |
| Race (NIH/OMB) Asian | 1 Participants |
| Race (NIH/OMB) Black or African American | 0 Participants |
| Race (NIH/OMB) More than one race | 0 Participants |
| Race (NIH/OMB) Native Hawaiian or Other Pacific Islander | 0 Participants |
| Race (NIH/OMB) Unknown or Not Reported | 0 Participants |
| Race (NIH/OMB) White | 86 Participants |
| Sex: Female, Male Female | 39 Participants |
| Sex: Female, Male Male | 49 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | 0 / 89 | 1 / 88 |
| other Total, other adverse events | 26 / 89 | 0 / 88 |
| serious Total, serious adverse events | 11 / 89 | 20 / 88 |
Outcome results
Primary
Investigation of Clinical Performance and Patient Outcome With the Functional Knee Society Score (KSS).
The Knee Society Score (KSS) consists of two distinct sub-scores: one for pain, range of motion, joint stability and alignment (Pain/Motion KSS) and one for distance walked, stair climbing and walking aids (Functional KSS). This outcome measure was only for the KSS Function Score at 10-years. The KSS Function score subscale is 0-100, with 100 representing a better outcome. Although the specific scores are not distinguished as excellent, good, fair, or poor, a higher value represents a better outcome.
Time frame: 10 years
Population: Due to early study termination the primary outcome was only reached for a minimal number of participants (12) reaching 10 years. These only included prospective cases. No retrospective cases reached the 10-year time interval.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Triathlon PKR Unicompartmental Knee | Investigation of Clinical Performance and Patient Outcome With the Functional Knee Society Score (KSS). | 98.33 units on a scale | Standard Deviation 5.77 |
Secondary
10-years Kaplan Meier Survival Analysis
For the purpose of this study the Kaplan-Meier survival curves are a statistical method to estimate the survival function from lifetime data of a knee replacement after treatment. Survivorship is defined as a percentage of knees free of any component revision for any reason.
Time frame: 10-years
Population: This primary outcome measure at 10 years is a statistical estimation based on 80 prospective knees as per the protocol.
| Arm | Measure | Value (NUMBER) |
|---|---|---|
| Triathlon PKR Unicompartmental Knee | 10-years Kaplan Meier Survival Analysis | 91.35 percentage of knees |