Avascular Necrosis of the Medial Femoral Condyle, Osteoarthritis, Knee
Conditions
Brief summary
The objective of this clinical investigation is to evaluate the safety and effectiveness of the Oxford® Cementless Partial Knee System. The Oxford® Cementless Partial Knee System is intended to help the patients diagnosed with osteoarthritis or avascular necrosis gain mobility and decrease pain. All of the risks common to a conventional joint replacement are possible with this device as certain risks are associated with any invasive procedures. The study is designed to document and compare the clinical and radiographic results of the Oxford® Cementless Partial Knee System to those of the cemented Oxford® Partial Knee System (control treatment).
Detailed description
Prospectively controlled, randomized Investigational study. Patients are asked to come in pre-operatively, surgery, 6 weeks, 6 months, 1 year, 2 years and annually until the last patient reaches their 2 year visit. Product has not been cleared for use.
Interventions
DEVICEOxford Cementless Partial Knee
Oxford Partial Knee applied without bone cement.
DEVICEOxford Cemented Partial Knee
Oxford Partial Knee applied with bone cement.
Sponsors
Zimmer Biomet
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
SINGLE (Subject)
Eligibility
Sex/Gender
ALL
Age
21 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* Patients with a preoperative Knee Society Assessment Score of \<70 * Patients undergoing primary partial knee arthroplasty as unilateral arthroplasty or bilateral arthroplasty, simultaneously or otherwise * Patients diagnosed with osteoarthritis or avascular necrosis limited to the medial compartment of the operative knee joint * Male or female patients who are at least 21 years of age at the time of surgery * Patients with full thickness cartilage loss, with or without bone loss in the medial compartment * Patients with functionally intact Anterior Cruciate Ligament (ACL) and Posterior Cruciate Ligament (PCL) * Patients who needs to obtain relief of pain and/or improved function in their knee * Patients with fixed flexion deformity \<15 degrees * Patients who are able to follow postoperative care instructions * Patients who are willing and able to return for scheduled follow-up evaluations * Patients in which natural alignment can be restored * Patients who have completed a valid, Institutional Review Board (IRB) approved Informed Consent Form * Patients with child-bearing potential who voluntarily agree to prevent pregnancy for 2 years following device implantation
Exclusion criteria
* Patients with a preoperative Knee Society Assessment Score of greater than or equal to 70 * Patients in which the device would be used to revise a failed prosthesis * Patients who are less than 21 years of age, at the time of surgery * Disease or damage to the lateral part of the knee that in the investigator's opinion contraindicates a partial knee replacement * Patients diagnosed with rheumatoid arthritis or other forms of inflammatory joint disease * Patients diagnosed with a failed upper tibial osteotomy in the operative knee * Patients diagnosed with post-traumatic arthritis after tibial plateau fracture * Patients who have had a patellectomy * Patients with a flexion deformity \> 15 degrees * Patients with a fixed varus deformity \> 15 degrees * Patients who have rapid joint destruction, marked bone loss or bone resorption apparent on roentgenogram * Patients with a fused knee on operative side(s) * Patients who have active or suspected infection, local or systemic that, in the opinion of the investigator, may put patients at undue risk * Patients with pre-existing condition(s) that may interfere with the survival of the implants or their outcomes, including: * Sickle Cell Anemia * Lower extremity muscular atrophy * Neuromuscular disease * Vascular insufficiency * Metabolic Disorders which impair bone formation * Paget's Disease * Charcot's Disease * Osteomalacia * Severe Osteoporosis * Patients with clinical conditions that may limit follow-up (in the opinion of the investigator) including: * Immunocompromised conditions (i.e. HIV) * Hepatitis * Tuberculosis * Neoplastic disease such as cancer of the prostate, lung, stomach, cervix, etc. * Chronic renal failure * Organ transplant (i.e. heart, liver, lung, etc.) recipients * Known disease process that in the opinion of the investigator may limit long term (4 year) follow-up (i.e. multiple sclerosis, leukemia, lymphoma, etc.) * Patients diagnosed with Parkinson's or Alzheimer's Disease * Patients who have had an above-knee amputation in the contralateral leg * Instability or deformity of the ligaments and/or surrounding soft tissue, which would preclude stability of the prostheses * Patients with a known metal allergy * Prisoners or, individuals who are known to be abusing drugs or alcohol or are mentally incompetent * Patients who have received systemic steroids within the past 6 months or steroid injections into the affected knee within the previous 6 weeks prior to enrollment * Patients who are pregnant * Patients with severe valgus or varus knees (valgus or varus angulation of more than 20 degrees) where collateral ligament, iliotibial band, or popliteal release is required * Patients who refuse to sign the IRB approved Informed Consent Form * Participation in an interventional clinical research study procedure, other than a bilateral knee arthroplasty in this study, within the past 12 months * Patients with a history of osteomyelitis or sepsis of the index knee * Patients who require patellar resurfacing * Patients who are not skeletally mature * Patients who have had a total hip replacement procedure \< 18 months prior to entering the study * Patients who have had a contralateral non-study knee replacement procedure \< 18 months prior to entering the study * Patients who are found intraoperatively to have inadequate bone stock or other conditions that contraindicate a partial knee replacement
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Radiographic Success | 2 years | This is a binary endpoint in which a knee is either a success or failure. To obtain a successful radiographic endpoint, a knee must meet the following criteria at the 22+ month interval. 1. Absence of osteolysis 2. No migration/subsidence of any femoral or tibial component 3. Absence of fractured component Conversely, a radiographic failure is defined as follows: 1. Presence of osteolysis defined as a radiolucency that is both progressive and is greater than 3 mm at its maximum interface in two or more contiguous zones OR a bony destructive lesion that is progressive in nature. 2. Migration/subsidence of any femoral or tibial component defined as a component migration/subsidence of \> 3 mm as compared to 6 week radiographs. 3. A component fracture |
| Absence of Revision/Removal/Unanticipated Adverse Device Effect (UADE) | 2 Years | This is a binary endpoint in which a knee is either a success or failure. To obtain a successful result, a knee must reach the 2 year upper window limit with the device intact and without a component revision/removal or a UADE. |
| The Knee Society Assessment Score | 2 Years | The Knee Society Assessment Score judges the parameters of pain, stability, and range of motion and flexion contracture, extension lag, and misalignment are deductions. The minimum score is 0 and maximum is 100, higher scores meaning a better outcome. |
| The Knee Society Function Score | 2 Year | The Knee Society Function Score considers walking distance and stair climbing, with deductions for walking aids. The minimum score is 0 and maximum is 100, higher scores meaning a better outcome. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Oxford Knee Score | Pre-operation (baseline), 6 weeks, 6 months, and annually thereafter until study completion | * 12-item self-report measure containing questions regarding the patient's pain and level of function * The scoring system ranges from 0-4 on each question with 4 representing maximum function and 0 representing poorest function. * Using this scale, the lowest, worst score is a 0, and the highest, best score is 48. * The OKS has 2 subscales: 1. Pain 2. Function The pain component score (OKS-PCS) consists of items 2, 3, 7, 11 and 12, and the functional component score consists of items 1, 4, 5, 6, 8, 9, and 10. |
| Knee Society Assessment Score | Pre-operation (baseline), 6 weeks, 6 months, and annually thereafter until study completion | The Knee Society Assessment Score judges the parameters of pain, stability, and range of motion and flexion contracture, extension lag, and misalignment are deductions. The minimum score is 0 and maximum is 100, higher scores meaning a better outcome. |
| Patient Assessment of Satisfaction | 6 weeks, 6 months, and annually thereafter until study completion | At each postoperative assessment using the Analysis Windows, patients were asked to indicate their level of satisfaction with the operated knee. The potential outcomes were Very Satisfied, Satisfied, Uncertain and Unsatisfied. |
| Number of Knees Which Met the Criteria for Radiographic Success | Pre-operation (baseline), 6 weeks, 6 months, 1y, 3y, 4y, 5y, 6y, 7y | This is a binary endpoint in which a knee is either a success or failure. To obtain a successful radiographic endpoint, a knee must meet the following criteria at the 22+ month interval. 1. Absence of osteolysis 2. No migration/subsidence of any femoral or tibial component 3. Absence of fractured component Conversely, a radiographic failure is defined as follows: 1. Presence of osteolysis defined as a radiolucency that is both progressive and is greater than 3 mm at its maximum interface in two or more contiguous zones OR a bony destructive lesion that is progressive in nature. 2. Migration/subsidence of any femoral or tibial component defined as a component migration/subsidence of \> 3 mm as compared to 6 week radiographs. 3. A component fracture |
| Knee Society Score Assessment for Bilateral Subjects | Pre-operation (baseline), 6 weeks, 6 months, and annually thereafter until study completion | The Knee Society Assessment Score judges the parameters of pain, stability, and range of motion and flexion contracture, extension lag, and misalignment are deductions. The minimum score is 0 and maximum is 100, higher scores meaning a better outcome. |
| Knee Society Function Score at All Timepoints | Pre-operation (baseline), 6 weeks, 6 months, and annually thereafter until study completion | The Knee Society Function Score considers walking distance and stair climbing, with deductions for walking aids. The minimum score is 0 and maximum is 100, higher scores meaning a better outcome. |
| Knee Society Function Score for Bilateral Subjects | Pre-operation (baseline), 6 weeks, 6 months, and annually thereafter until study completion | The Knee Society Function Score considers walking distance and stair climbing, with deductions for walking aids. The minimum score is 0 and maximum is 100, higher scores meaning a better outcome. |
Countries
United States
Participant flow
Pre-assignment details
ELK1078R - bilateral subject was randomized to Investigational arm and received the Cementless device during the initial surgery. During the contralateral surgery, the cemented keel saw was used therefore, the Control device was implanted. Because this subject was randomized to Investigational and received 1 control knee, the investigational count in the participant flow is off by 1. A row was added with a note for this subject.
Participants by arm
| Arm | Count |
|---|---|
| Oxford Cementless Partial Knee Oxford Partial Knee implanted WITHOUT bone cement.
Oxford Cementless Partial Knee: Oxford Partial Knee applied without bone cement. | 207 |
| Oxford Cementless Partial Knee Oxford Partial Knee implanted WITHOUT bone cement.
Oxford Cementless Partial Knee: Oxford Partial Knee applied without bone cement. | 241 |
| Oxford Cemented Partial Knee Oxford Partial Knee applied WITH bone cement.
Oxford Cemented Partial Knee: Oxford Partial Knee applied with bone cement. | 113 |
| Oxford Cemented Partial Knee Oxford Partial Knee applied WITH bone cement.
Oxford Cemented Partial Knee: Oxford Partial Knee applied with bone cement. | 137 |
| Total | 698 |
Withdrawals & dropouts
| Period | Reason | FG000 | FG001 |
|---|---|---|---|
| Overall Study | Death | 0 | 1 |
| Overall Study | ELK1078R: bilateral subject randomized to investigational, 2nd knee was cemented. | 1 | 0 |
| Overall Study | Lost to Follow-up | 21 | 13 |
| Overall Study | Protocol Violation | 32 | 19 |
| Overall Study | Withdrawal by Subject | 1 | 2 |
Baseline characteristics
| Characteristic | Oxford Cemented Partial Knee | Total | Oxford Cementless Partial Knee |
|---|---|---|---|
| Age, Continuous | 66.4 years STANDARD_DEVIATION 8.5 | 66.04 years STANDARD_DEVIATION 8.61 | 65.8 years STANDARD_DEVIATION 8.7 |
| Race and Ethnicity Not Collected | — | 0 Participants | — |
| Region of Enrollment United States | 113 Participants | 320 Participants | 207 Participants |
| Sex: Female, Male Female | 54 Participants | 135 Participants | 81 Participants |
| Sex: Female, Male Male | 59 Participants | 185 Participants | 126 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | 3 / 207 | 9 / 114 |
| other Total, other adverse events | 114 / 207 | 53 / 114 |
| serious Total, serious adverse events | 17 / 207 | 10 / 114 |
Outcome results
Primary
Absence of Revision/Removal/Unanticipated Adverse Device Effect (UADE)
This is a binary endpoint in which a knee is either a success or failure. To obtain a successful result, a knee must reach the 2 year upper window limit with the device intact and without a component revision/removal or a UADE.
Time frame: 2 Years
Population: The analysis was performed on the per protocol population who had an evaluation at the 2+ year follow up interval. The analysis is at the knee level, not participant level (bilateral participants included as two individual knees).
| Arm | Measure | Category | Value (COUNT_OF_UNITS) |
|---|---|---|---|
| Oxford Cementless Partial Knee | Absence of Revision/Removal/Unanticipated Adverse Device Effect (UADE) | Successful | 203 knees |
| Oxford Cementless Partial Knee | Absence of Revision/Removal/Unanticipated Adverse Device Effect (UADE) | Failures | 13 knees |
| Oxford Cemented Partial Knee | Absence of Revision/Removal/Unanticipated Adverse Device Effect (UADE) | Successful | 119 knees |
| Oxford Cemented Partial Knee | Absence of Revision/Removal/Unanticipated Adverse Device Effect (UADE) | Failures | 3 knees |
Primary
Radiographic Success
This is a binary endpoint in which a knee is either a success or failure. To obtain a successful radiographic endpoint, a knee must meet the following criteria at the 22+ month interval. 1. Absence of osteolysis 2. No migration/subsidence of any femoral or tibial component 3. Absence of fractured component Conversely, a radiographic failure is defined as follows: 1. Presence of osteolysis defined as a radiolucency that is both progressive and is greater than 3 mm at its maximum interface in two or more contiguous zones OR a bony destructive lesion that is progressive in nature. 2. Migration/subsidence of any femoral or tibial component defined as a component migration/subsidence of \> 3 mm as compared to 6 week radiographs. 3. A component fracture
Time frame: 2 years
Population: The analysis was performed on the per protocol population who had a radiographic assessment at the 2+ year follow up interval. The analysis is at the knee level, not participant level (bilateral participants included as two individual knees).
| Arm | Measure | Category | Value (COUNT_OF_UNITS) |
|---|---|---|---|
| Oxford Cementless Partial Knee | Radiographic Success | Successful | 198 knees |
| Oxford Cementless Partial Knee | Radiographic Success | Failure | 13 knees |
| Oxford Cemented Partial Knee | Radiographic Success | Successful | 112 knees |
| Oxford Cemented Partial Knee | Radiographic Success | Failure | 3 knees |
Primary
The Knee Society Assessment Score
The Knee Society Assessment Score judges the parameters of pain, stability, and range of motion and flexion contracture, extension lag, and misalignment are deductions. The minimum score is 0 and maximum is 100, higher scores meaning a better outcome.
Time frame: 2 Years
Population: The analysis was performed on the per protocol population who completed the The Knee Society Assessment Score at the 2+ year follow up interval.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Oxford Cementless Partial Knee | The Knee Society Assessment Score | 95.6 score on a scale | Standard Deviation 8.3 |
| Oxford Cemented Partial Knee | The Knee Society Assessment Score | 95.5 score on a scale | Standard Deviation 7 |
Primary
The Knee Society Function Score
The Knee Society Function Score considers walking distance and stair climbing, with deductions for walking aids. The minimum score is 0 and maximum is 100, higher scores meaning a better outcome.
Time frame: 2 Year
Population: The analysis was performed on the per protocol population who completed the The Knee Society Function Score at the 2+ year follow up interval.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Oxford Cementless Partial Knee | The Knee Society Function Score | 89.4 score on a scale | Standard Deviation 14.4 |
| Oxford Cemented Partial Knee | The Knee Society Function Score | 89.7 score on a scale | Standard Deviation 14.1 |
Secondary
Knee Society Assessment Score
The Knee Society Assessment Score judges the parameters of pain, stability, and range of motion and flexion contracture, extension lag, and misalignment are deductions. The minimum score is 0 and maximum is 100, higher scores meaning a better outcome.
Time frame: Pre-operation (baseline), 6 weeks, 6 months, and annually thereafter until study completion
Population: The analysis was performed on the per protocol population who completed the The Knee Society Assessment Score at each follow-up timepoint. The analysis is at the knee level, not participant level (bilateral participants included as two individual knees). The Overall Number of Participants Analyzed is the number of study participants pre-operatively; the Overall Number of Units Analyzed refers to the number of knees with data available for analysis at each follow-up timepoint.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Oxford Cementless Partial Knee | Knee Society Assessment Score | 1 Year | 94.1 score on a scale | Standard Deviation 9.5 |
| Oxford Cementless Partial Knee | Knee Society Assessment Score | 6 Week | 86.5 score on a scale | Standard Deviation 13.7 |
| Oxford Cementless Partial Knee | Knee Society Assessment Score | 2 Year | 95.5 score on a scale | Standard Deviation 8.5 |
| Oxford Cementless Partial Knee | Knee Society Assessment Score | 5 Year | 95 score on a scale | Standard Deviation 9.1 |
| Oxford Cementless Partial Knee | Knee Society Assessment Score | 3 Year | 95.2 score on a scale | Standard Deviation 8.7 |
| Oxford Cementless Partial Knee | Knee Society Assessment Score | Pre-op | 43.2 score on a scale | Standard Deviation 11 |
| Oxford Cementless Partial Knee | Knee Society Assessment Score | 6 Month | 93.5 score on a scale | Standard Deviation 10.3 |
| Oxford Cementless Partial Knee | Knee Society Assessment Score | 6 Year | 92.8 score on a scale | Standard Deviation 13.3 |
| Oxford Cementless Partial Knee | Knee Society Assessment Score | 4 Year | 95.3 score on a scale | Standard Deviation 8.6 |
| Oxford Cemented Partial Knee | Knee Society Assessment Score | 6 Year | 93.6 score on a scale | Standard Deviation 11.2 |
| Oxford Cemented Partial Knee | Knee Society Assessment Score | 6 Week | 87 score on a scale | Standard Deviation 12.8 |
| Oxford Cemented Partial Knee | Knee Society Assessment Score | 4 Year | 94.2 score on a scale | Standard Deviation 8.8 |
| Oxford Cemented Partial Knee | Knee Society Assessment Score | 6 Month | 94.2 score on a scale | Standard Deviation 8.3 |
| Oxford Cemented Partial Knee | Knee Society Assessment Score | 1 Year | 95 score on a scale | Standard Deviation 9.3 |
| Oxford Cemented Partial Knee | Knee Society Assessment Score | 2 Year | 95.6 score on a scale | Standard Deviation 6.9 |
| Oxford Cemented Partial Knee | Knee Society Assessment Score | 3 Year | 94.4 score on a scale | Standard Deviation 9.9 |
| Oxford Cemented Partial Knee | Knee Society Assessment Score | 5 Year | 94.4 score on a scale | Standard Deviation 10.3 |
| Oxford Cemented Partial Knee | Knee Society Assessment Score | Pre-op | 45 score on a scale | Standard Deviation 11 |
Secondary
Knee Society Function Score at All Timepoints
The Knee Society Function Score considers walking distance and stair climbing, with deductions for walking aids. The minimum score is 0 and maximum is 100, higher scores meaning a better outcome.
Time frame: Pre-operation (baseline), 6 weeks, 6 months, and annually thereafter until study completion
Population: The analysis was performed on the per protocol population who completed the The Knee Society Assessment Score at each follow-up. The analysis is at the knee level, not participant level (bilateral participants included as two individual knees). The Overall Number of Participants Analyzed is the number of study participants pre-operatively; the Overall Number of Units Analyzed refers to the number of knees with data available for analysis at each follow-up timepoint.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Oxford Cementless Partial Knee | Knee Society Function Score at All Timepoints | 4 Year | 87.1 score on a scale | Standard Deviation 17.1 |
| Oxford Cementless Partial Knee | Knee Society Function Score at All Timepoints | 1 Year | 87.9 score on a scale | Standard Deviation 15.9 |
| Oxford Cementless Partial Knee | Knee Society Function Score at All Timepoints | 6 Week | 65.4 score on a scale | Standard Deviation 20.4 |
| Oxford Cementless Partial Knee | Knee Society Function Score at All Timepoints | 2 Year | 89.9 score on a scale | Standard Deviation 13 |
| Oxford Cementless Partial Knee | Knee Society Function Score at All Timepoints | Pre-op | 58.1 score on a scale | Standard Deviation 16 |
| Oxford Cementless Partial Knee | Knee Society Function Score at All Timepoints | 3 Year | 88.5 score on a scale | Standard Deviation 15 |
| Oxford Cementless Partial Knee | Knee Society Function Score at All Timepoints | 5 Year | 86.7 score on a scale | Standard Deviation 17.4 |
| Oxford Cementless Partial Knee | Knee Society Function Score at All Timepoints | 6 Year | 83.2 score on a scale | Standard Deviation 19.7 |
| Oxford Cementless Partial Knee | Knee Society Function Score at All Timepoints | 6 Month | 86 score on a scale | Standard Deviation 15.3 |
| Oxford Cemented Partial Knee | Knee Society Function Score at All Timepoints | 6 Year | 85.7 score on a scale | Standard Deviation 17.9 |
| Oxford Cemented Partial Knee | Knee Society Function Score at All Timepoints | 4 Year | 90 score on a scale | Standard Deviation 11.1 |
| Oxford Cemented Partial Knee | Knee Society Function Score at All Timepoints | 5 Year | 85.6 score on a scale | Standard Deviation 15.2 |
| Oxford Cemented Partial Knee | Knee Society Function Score at All Timepoints | Pre-op | 57.7 score on a scale | Standard Deviation 17.7 |
| Oxford Cemented Partial Knee | Knee Society Function Score at All Timepoints | 6 Week | 70.2 score on a scale | Standard Deviation 18.5 |
| Oxford Cemented Partial Knee | Knee Society Function Score at All Timepoints | 6 Month | 87.4 score on a scale | Standard Deviation 15.2 |
| Oxford Cemented Partial Knee | Knee Society Function Score at All Timepoints | 1 Year | 88 score on a scale | Standard Deviation 15.4 |
| Oxford Cemented Partial Knee | Knee Society Function Score at All Timepoints | 2 Year | 89.8 score on a scale | Standard Deviation 14 |
| Oxford Cemented Partial Knee | Knee Society Function Score at All Timepoints | 3 Year | 88.9 score on a scale | Standard Deviation 12.8 |
Secondary
Knee Society Function Score for Bilateral Subjects
The Knee Society Function Score considers walking distance and stair climbing, with deductions for walking aids. The minimum score is 0 and maximum is 100, higher scores meaning a better outcome.
Time frame: Pre-operation (baseline), 6 weeks, 6 months, and annually thereafter until study completion
Population: The analysis was performed on the bilateral subjects in the per protocol population who had a Knee Society Function Score at each follow-up timepoint. The analysis is at the knee level, not participant level (bilateral participants included as two individual knees). The Overall Number of Participants Analyzed is the number of study participants pre-operatively; the Overall Number of Units Analyzed refers to the number of knees with data available for analysis at each follow-up timepoint.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Oxford Cementless Partial Knee | Knee Society Function Score for Bilateral Subjects | 5 Year | 90 score on a scale | Standard Deviation 10.3 |
| Oxford Cementless Partial Knee | Knee Society Function Score for Bilateral Subjects | 4 Year | 90.7 score on a scale | Standard Deviation 13.2 |
| Oxford Cementless Partial Knee | Knee Society Function Score for Bilateral Subjects | Pre-op | 60.1 score on a scale | Standard Deviation 15.8 |
| Oxford Cementless Partial Knee | Knee Society Function Score for Bilateral Subjects | 6 Week | 65.8 score on a scale | Standard Deviation 20.3 |
| Oxford Cementless Partial Knee | Knee Society Function Score for Bilateral Subjects | 6 Month | 84.5 score on a scale | Standard Deviation 16 |
| Oxford Cementless Partial Knee | Knee Society Function Score for Bilateral Subjects | 1 Year | 85.3 score on a scale | Standard Deviation 16.5 |
| Oxford Cementless Partial Knee | Knee Society Function Score for Bilateral Subjects | 2 Year | 88.6 score on a scale | Standard Deviation 13 |
| Oxford Cementless Partial Knee | Knee Society Function Score for Bilateral Subjects | 3 Year | 89.3 score on a scale | Standard Deviation 14.8 |
| Oxford Cementless Partial Knee | Knee Society Function Score for Bilateral Subjects | 6 Year | 82.2 score on a scale | Standard Deviation 18.6 |
| Oxford Cementless Partial Knee | Knee Society Function Score for Bilateral Subjects | 7 Year | 60 score on a scale | Standard Deviation 0 |
| Oxford Cemented Partial Knee | Knee Society Function Score for Bilateral Subjects | 3 Year | 93.3 score on a scale | Standard Deviation 8.4 |
| Oxford Cemented Partial Knee | Knee Society Function Score for Bilateral Subjects | 6 Year | 100 score on a scale | Standard Deviation 0 |
| Oxford Cemented Partial Knee | Knee Society Function Score for Bilateral Subjects | 4 Year | 96.1 score on a scale | Standard Deviation 6.1 |
| Oxford Cemented Partial Knee | Knee Society Function Score for Bilateral Subjects | 1 Year | 86.8 score on a scale | Standard Deviation 16.1 |
| Oxford Cemented Partial Knee | Knee Society Function Score for Bilateral Subjects | Pre-op | 56.3 score on a scale | Standard Deviation 19.3 |
| Oxford Cemented Partial Knee | Knee Society Function Score for Bilateral Subjects | 5 Year | 90.8 score on a scale | Standard Deviation 13.2 |
| Oxford Cemented Partial Knee | Knee Society Function Score for Bilateral Subjects | 6 Week | 72 score on a scale | Standard Deviation 15.3 |
| Oxford Cemented Partial Knee | Knee Society Function Score for Bilateral Subjects | 2 Year | 92.4 score on a scale | Standard Deviation 10.5 |
| Oxford Cemented Partial Knee | Knee Society Function Score for Bilateral Subjects | 6 Month | 88.8 score on a scale | Standard Deviation 14.7 |
Secondary
Knee Society Score Assessment for Bilateral Subjects
The Knee Society Assessment Score judges the parameters of pain, stability, and range of motion and flexion contracture, extension lag, and misalignment are deductions. The minimum score is 0 and maximum is 100, higher scores meaning a better outcome.
Time frame: Pre-operation (baseline), 6 weeks, 6 months, and annually thereafter until study completion
Population: The analysis was performed on the bilateral subjects in the per protocol population who had a Knee Society Assessment Score at each follow-up timepoint. The analysis is at the knee level, not participant level (bilateral participants included as two individual knees). The Overall Number of Participants Analyzed is the number of study participants pre-operatively; the Overall Number of Units Analyzed refers to the number of knees with data available for analysis at each follow-up timepoint.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Oxford Cementless Partial Knee | Knee Society Score Assessment for Bilateral Subjects | Preop | 43.4 score on a scale | Standard Deviation 10.7 |
| Oxford Cementless Partial Knee | Knee Society Score Assessment for Bilateral Subjects | 3 Year | 96.2 score on a scale | Standard Deviation 6.1 |
| Oxford Cementless Partial Knee | Knee Society Score Assessment for Bilateral Subjects | 1 Year | 94.1 score on a scale | Standard Deviation 8.6 |
| Oxford Cementless Partial Knee | Knee Society Score Assessment for Bilateral Subjects | 4 Year | 96.4 score on a scale | Standard Deviation 6 |
| Oxford Cementless Partial Knee | Knee Society Score Assessment for Bilateral Subjects | 6 Week | 86.6 score on a scale | Standard Deviation 14.5 |
| Oxford Cementless Partial Knee | Knee Society Score Assessment for Bilateral Subjects | 5 Year | 92.8 score on a scale | Standard Deviation 13.3 |
| Oxford Cementless Partial Knee | Knee Society Score Assessment for Bilateral Subjects | 2 Year | 95.7 score on a scale | Standard Deviation 8.6 |
| Oxford Cementless Partial Knee | Knee Society Score Assessment for Bilateral Subjects | 6 Year | 91.4 score on a scale | Standard Deviation 9.9 |
| Oxford Cementless Partial Knee | Knee Society Score Assessment for Bilateral Subjects | 6 Month | 93.7 score on a scale | Standard Deviation 10.9 |
| Oxford Cemented Partial Knee | Knee Society Score Assessment for Bilateral Subjects | 6 Year | 100 score on a scale | Standard Deviation 0 |
| Oxford Cemented Partial Knee | Knee Society Score Assessment for Bilateral Subjects | 6 Week | 87.7 score on a scale | Standard Deviation 12.5 |
| Oxford Cemented Partial Knee | Knee Society Score Assessment for Bilateral Subjects | Preop | 46.0 score on a scale | Standard Deviation 11.7 |
| Oxford Cemented Partial Knee | Knee Society Score Assessment for Bilateral Subjects | 6 Month | 95.6 score on a scale | Standard Deviation 5 |
| Oxford Cemented Partial Knee | Knee Society Score Assessment for Bilateral Subjects | 1 Year | 95.3 score on a scale | Standard Deviation 7.4 |
| Oxford Cemented Partial Knee | Knee Society Score Assessment for Bilateral Subjects | 2 Year | 95.4 score on a scale | Standard Deviation 6.4 |
| Oxford Cemented Partial Knee | Knee Society Score Assessment for Bilateral Subjects | 3 Year | 92.5 score on a scale | Standard Deviation 11.8 |
| Oxford Cemented Partial Knee | Knee Society Score Assessment for Bilateral Subjects | 4 Year | 92.9 score on a scale | Standard Deviation 7.2 |
| Oxford Cemented Partial Knee | Knee Society Score Assessment for Bilateral Subjects | 5 Year | 92.8 score on a scale | Standard Deviation 10 |
Secondary
Number of Knees Which Met the Criteria for Radiographic Success
This is a binary endpoint in which a knee is either a success or failure. To obtain a successful radiographic endpoint, a knee must meet the following criteria at the 22+ month interval. 1. Absence of osteolysis 2. No migration/subsidence of any femoral or tibial component 3. Absence of fractured component Conversely, a radiographic failure is defined as follows: 1. Presence of osteolysis defined as a radiolucency that is both progressive and is greater than 3 mm at its maximum interface in two or more contiguous zones OR a bony destructive lesion that is progressive in nature. 2. Migration/subsidence of any femoral or tibial component defined as a component migration/subsidence of \> 3 mm as compared to 6 week radiographs. 3. A component fracture
Time frame: Pre-operation (baseline), 6 weeks, 6 months, 1y, 3y, 4y, 5y, 6y, 7y
Population: The analysis was performed on the per protocol population had a radiographic assessment at each follow-up timepoint. The analysis is at the knee level, not participant level (bilateral participants included as two individual knees). The Overall Number of Participants Analyzed is the number of study participants at 6 weeks; the Overall Number of Units Analyzed refers to the number of knees with data available for analysis at each follow-up timepoint.
| Arm | Measure | Group | Value (COUNT_OF_UNITS) |
|---|---|---|---|
| Oxford Cementless Partial Knee | Number of Knees Which Met the Criteria for Radiographic Success | 7 Year | 1 Knees |
| Oxford Cementless Partial Knee | Number of Knees Which Met the Criteria for Radiographic Success | 1 Year | 208 Knees |
| Oxford Cementless Partial Knee | Number of Knees Which Met the Criteria for Radiographic Success | 2 Year | 180 Knees |
| Oxford Cementless Partial Knee | Number of Knees Which Met the Criteria for Radiographic Success | 3 Year | 147 Knees |
| Oxford Cementless Partial Knee | Number of Knees Which Met the Criteria for Radiographic Success | 5 Year | 63 Knees |
| Oxford Cementless Partial Knee | Number of Knees Which Met the Criteria for Radiographic Success | 6 Year | 23 Knees |
| Oxford Cementless Partial Knee | Number of Knees Which Met the Criteria for Radiographic Success | 6 Week | 235 Knees |
| Oxford Cementless Partial Knee | Number of Knees Which Met the Criteria for Radiographic Success | 6 Month | 208 Knees |
| Oxford Cementless Partial Knee | Number of Knees Which Met the Criteria for Radiographic Success | 4 Year | 99 Knees |
| Oxford Cemented Partial Knee | Number of Knees Which Met the Criteria for Radiographic Success | 6 Month | 115 Knees |
| Oxford Cemented Partial Knee | Number of Knees Which Met the Criteria for Radiographic Success | 5 Year | 32 Knees |
| Oxford Cemented Partial Knee | Number of Knees Which Met the Criteria for Radiographic Success | 1 Year | 113 Knees |
| Oxford Cemented Partial Knee | Number of Knees Which Met the Criteria for Radiographic Success | 6 Week | 129 Knees |
| Oxford Cemented Partial Knee | Number of Knees Which Met the Criteria for Radiographic Success | 2 Year | 103 Knees |
| Oxford Cemented Partial Knee | Number of Knees Which Met the Criteria for Radiographic Success | 4 Year | 49 Knees |
| Oxford Cemented Partial Knee | Number of Knees Which Met the Criteria for Radiographic Success | 3 Year | 79 Knees |
| Oxford Cemented Partial Knee | Number of Knees Which Met the Criteria for Radiographic Success | 6 Year | 14 Knees |
Secondary
Oxford Knee Score
* 12-item self-report measure containing questions regarding the patient's pain and level of function * The scoring system ranges from 0-4 on each question with 4 representing maximum function and 0 representing poorest function. * Using this scale, the lowest, worst score is a 0, and the highest, best score is 48. * The OKS has 2 subscales: 1. Pain 2. Function The pain component score (OKS-PCS) consists of items 2, 3, 7, 11 and 12, and the functional component score consists of items 1, 4, 5, 6, 8, 9, and 10.
Time frame: Pre-operation (baseline), 6 weeks, 6 months, and annually thereafter until study completion
Population: The analysis was performed on the per protocol population who completed the Oxford Knee Score at each follow-up timepoint. The analysis is at the knee level, not participant level (bilateral participants included as two individual knees). The Overall Number of Participants Analyzed is the number of study participants pre-operatively; the Overall Number of Units Analyzed refers to the number of knees with data available for analysis at each follow-up timepoint.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Oxford Cementless Partial Knee | Oxford Knee Score | Pre-op | 23.7 score on a scale | Standard Deviation 8.1 |
| Oxford Cementless Partial Knee | Oxford Knee Score | 6 Week | 32.4 score on a scale | Standard Deviation 7.8 |
| Oxford Cementless Partial Knee | Oxford Knee Score | 6 Month | 41.8 score on a scale | Standard Deviation 5.8 |
| Oxford Cementless Partial Knee | Oxford Knee Score | 1 Year | 42.9 score on a scale | Standard Deviation 6.3 |
| Oxford Cementless Partial Knee | Oxford Knee Score | 3 Year | 44.6 score on a scale | Standard Deviation 7.7 |
| Oxford Cementless Partial Knee | Oxford Knee Score | 4 Year | 44.3 score on a scale | Standard Deviation 5.3 |
| Oxford Cementless Partial Knee | Oxford Knee Score | 6 Year | 41.3 score on a scale | Standard Deviation 8.5 |
| Oxford Cementless Partial Knee | Oxford Knee Score | 5 Year | 43.7 score on a scale | Standard Deviation 5.9 |
| Oxford Cementless Partial Knee | Oxford Knee Score | 7 Year | 44 score on a scale | Standard Deviation 0 |
| Oxford Cementless Partial Knee | Oxford Knee Score | 2 Year | 44.5 score on a scale | Standard Deviation 4.5 |
| Oxford Cemented Partial Knee | Oxford Knee Score | Pre-op | 24.9 score on a scale | Standard Deviation 7.6 |
| Oxford Cemented Partial Knee | Oxford Knee Score | 6 Year | 44.1 score on a scale | Standard Deviation 7.1 |
| Oxford Cemented Partial Knee | Oxford Knee Score | 6 Week | 34.5 score on a scale | Standard Deviation 7 |
| Oxford Cemented Partial Knee | Oxford Knee Score | 4 Year | 45 score on a scale | Standard Deviation 5.9 |
| Oxford Cemented Partial Knee | Oxford Knee Score | 5 Year | 45.3 score on a scale | Standard Deviation 4.9 |
| Oxford Cemented Partial Knee | Oxford Knee Score | 1 Year | 43.5 score on a scale | Standard Deviation 5.7 |
| Oxford Cemented Partial Knee | Oxford Knee Score | 2 Year | 44.9 score on a scale | Standard Deviation 3.9 |
| Oxford Cemented Partial Knee | Oxford Knee Score | 6 Month | 42.4 score on a scale | Standard Deviation 6.1 |
| Oxford Cemented Partial Knee | Oxford Knee Score | 3 Year | 44.6 score on a scale | Standard Deviation 6.2 |
Secondary
Patient Assessment of Satisfaction
At each postoperative assessment using the Analysis Windows, patients were asked to indicate their level of satisfaction with the operated knee. The potential outcomes were Very Satisfied, Satisfied, Uncertain and Unsatisfied.
Time frame: 6 weeks, 6 months, and annually thereafter until study completion
Population: This analysis is done at the knee-level, not participant level. Bilateral participants were allowed in the study. The Overall Number of Participants Analyzed is the number of study subjects analyzed (some with unilateral and some with bilateral knees); the Overall Number of Units Analyzed refers to the number of knees analzyed. Also, not every participant returned for every follow-up visit. The Number Analyzed in each row/visit below shows the number of knees analyzed at each follow-up.
| Arm | Measure | Group | Category | Value (COUNT_OF_UNITS) |
|---|---|---|---|---|
| Oxford Cementless Partial Knee | Patient Assessment of Satisfaction | 7 Years | Unsatisfied | 0 Knees |
| Oxford Cementless Partial Knee | Patient Assessment of Satisfaction | 1 Year | Very Satisfied | 156 Knees |
| Oxford Cementless Partial Knee | Patient Assessment of Satisfaction | 6 Years | Unsatisfied | 0 Knees |
| Oxford Cementless Partial Knee | Patient Assessment of Satisfaction | 6 Week | Satisfied | 60 Knees |
| Oxford Cementless Partial Knee | Patient Assessment of Satisfaction | 6 Month | Very Satisfied | 166 Knees |
| Oxford Cementless Partial Knee | Patient Assessment of Satisfaction | 1 Year | Satisfied | 38 Knees |
| Oxford Cementless Partial Knee | Patient Assessment of Satisfaction | 1 Year | Uncertain | 8 Knees |
| Oxford Cementless Partial Knee | Patient Assessment of Satisfaction | 3 Years | Very Satisfied | 143 Knees |
| Oxford Cementless Partial Knee | Patient Assessment of Satisfaction | 4 Years | Unsatisfied | 0 Knees |
| Oxford Cementless Partial Knee | Patient Assessment of Satisfaction | 5 Years | Very Satisfied | 53 Knees |
| Oxford Cementless Partial Knee | Patient Assessment of Satisfaction | 7 Years | Very Satisfied | 1 Knees |
| Oxford Cementless Partial Knee | Patient Assessment of Satisfaction | 6 Week | Very Satisfied | 151 Knees |
| Oxford Cementless Partial Knee | Patient Assessment of Satisfaction | 6 Week | Uncertain | 23 Knees |
| Oxford Cementless Partial Knee | Patient Assessment of Satisfaction | 6 Week | Unsatisfied | 3 Knees |
| Oxford Cementless Partial Knee | Patient Assessment of Satisfaction | 6 Month | Satisfied | 35 Knees |
| Oxford Cementless Partial Knee | Patient Assessment of Satisfaction | 6 Month | Uncertain | 19 Knees |
| Oxford Cementless Partial Knee | Patient Assessment of Satisfaction | 6 Month | Unsatisfied | 2 Knees |
| Oxford Cementless Partial Knee | Patient Assessment of Satisfaction | 2 Years | Very Satisfied | 158 Knees |
| Oxford Cementless Partial Knee | Patient Assessment of Satisfaction | 2 Years | Satisfied | 27 Knees |
| Oxford Cementless Partial Knee | Patient Assessment of Satisfaction | 2 Years | Uncertain | 8 Knees |
| Oxford Cementless Partial Knee | Patient Assessment of Satisfaction | 2 Years | Unsatisfied | 1 Knees |
| Oxford Cementless Partial Knee | Patient Assessment of Satisfaction | 3 Years | Satisfied | 17 Knees |
| Oxford Cementless Partial Knee | Patient Assessment of Satisfaction | 3 Years | Uncertain | 4 Knees |
| Oxford Cementless Partial Knee | Patient Assessment of Satisfaction | 3 Years | Unsatisfied | 1 Knees |
| Oxford Cementless Partial Knee | Patient Assessment of Satisfaction | 4 Years | Very Satisfied | 89 Knees |
| Oxford Cementless Partial Knee | Patient Assessment of Satisfaction | 4 Years | Satisfied | 16 Knees |
| Oxford Cementless Partial Knee | Patient Assessment of Satisfaction | 4 Years | Uncertain | 2 Knees |
| Oxford Cementless Partial Knee | Patient Assessment of Satisfaction | 5 Years | Satisfied | 8 Knees |
| Oxford Cementless Partial Knee | Patient Assessment of Satisfaction | 5 Years | Uncertain | 3 Knees |
| Oxford Cementless Partial Knee | Patient Assessment of Satisfaction | 5 Years | Unsatisfied | 1 Knees |
| Oxford Cementless Partial Knee | Patient Assessment of Satisfaction | 6 Years | Very Satisfied | 24 Knees |
| Oxford Cementless Partial Knee | Patient Assessment of Satisfaction | 6 Years | Satisfied | 4 Knees |
| Oxford Cementless Partial Knee | Patient Assessment of Satisfaction | 6 Years | Uncertain | 2 Knees |
| Oxford Cementless Partial Knee | Patient Assessment of Satisfaction | 7 Years | Satisfied | 0 Knees |
| Oxford Cementless Partial Knee | Patient Assessment of Satisfaction | 7 Years | Uncertain | 0 Knees |
| Oxford Cementless Partial Knee | Patient Assessment of Satisfaction | 1 Year | Unsatisfied | 2 Knees |
| Oxford Cemented Partial Knee | Patient Assessment of Satisfaction | 1 Year | Uncertain | 3 Knees |
| Oxford Cemented Partial Knee | Patient Assessment of Satisfaction | 2 Years | Satisfied | 12 Knees |
| Oxford Cemented Partial Knee | Patient Assessment of Satisfaction | 6 Week | Very Satisfied | 95 Knees |
| Oxford Cemented Partial Knee | Patient Assessment of Satisfaction | 5 Years | Very Satisfied | 32 Knees |
| Oxford Cemented Partial Knee | Patient Assessment of Satisfaction | 6 Week | Satisfied | 27 Knees |
| Oxford Cemented Partial Knee | Patient Assessment of Satisfaction | 6 Week | Unsatisfied | 1 Knees |
| Oxford Cemented Partial Knee | Patient Assessment of Satisfaction | 2 Years | Uncertain | 3 Knees |
| Oxford Cemented Partial Knee | Patient Assessment of Satisfaction | 1 Year | Very Satisfied | 93 Knees |
| Oxford Cemented Partial Knee | Patient Assessment of Satisfaction | 6 Years | Very Satisfied | 13 Knees |
| Oxford Cemented Partial Knee | Patient Assessment of Satisfaction | 1 Year | Satisfied | 17 Knees |
| Oxford Cemented Partial Knee | Patient Assessment of Satisfaction | 2 Years | Unsatisfied | 1 Knees |
| Oxford Cemented Partial Knee | Patient Assessment of Satisfaction | 1 Year | Unsatisfied | 1 Knees |
| Oxford Cemented Partial Knee | Patient Assessment of Satisfaction | 5 Years | Satisfied | 0 Knees |
| Oxford Cemented Partial Knee | Patient Assessment of Satisfaction | 3 Years | Very Satisfied | 76 Knees |
| Oxford Cemented Partial Knee | Patient Assessment of Satisfaction | 3 Years | Satisfied | 3 Knees |
| Oxford Cemented Partial Knee | Patient Assessment of Satisfaction | 4 Years | Unsatisfied | 0 Knees |
| Oxford Cemented Partial Knee | Patient Assessment of Satisfaction | 6 Years | Uncertain | 0 Knees |
| Oxford Cemented Partial Knee | Patient Assessment of Satisfaction | 6 Years | Unsatisfied | 1 Knees |
| Oxford Cemented Partial Knee | Patient Assessment of Satisfaction | 3 Years | Uncertain | 3 Knees |
| Oxford Cemented Partial Knee | Patient Assessment of Satisfaction | 5 Years | Uncertain | 2 Knees |
| Oxford Cemented Partial Knee | Patient Assessment of Satisfaction | 3 Years | Unsatisfied | 1 Knees |
| Oxford Cemented Partial Knee | Patient Assessment of Satisfaction | 6 Week | Uncertain | 9 Knees |
| Oxford Cemented Partial Knee | Patient Assessment of Satisfaction | 6 Years | Satisfied | 0 Knees |
| Oxford Cemented Partial Knee | Patient Assessment of Satisfaction | 6 Month | Very Satisfied | 95 Knees |
| Oxford Cemented Partial Knee | Patient Assessment of Satisfaction | 4 Years | Very Satisfied | 51 Knees |
| Oxford Cemented Partial Knee | Patient Assessment of Satisfaction | 6 Month | Satisfied | 20 Knees |
| Oxford Cemented Partial Knee | Patient Assessment of Satisfaction | 5 Years | Unsatisfied | 0 Knees |
| Oxford Cemented Partial Knee | Patient Assessment of Satisfaction | 6 Month | Uncertain | 5 Knees |
| Oxford Cemented Partial Knee | Patient Assessment of Satisfaction | 4 Years | Satisfied | 1 Knees |
| Oxford Cemented Partial Knee | Patient Assessment of Satisfaction | 6 Month | Unsatisfied | 3 Knees |
| Oxford Cemented Partial Knee | Patient Assessment of Satisfaction | 2 Years | Very Satisfied | 100 Knees |
| Oxford Cemented Partial Knee | Patient Assessment of Satisfaction | 4 Years | Uncertain | 2 Knees |