Osteoarthritis, Knee
Conditions
Keywords
Knee Arthroplasty, Unicompartmental, Fixation, Radiostereometric Analysis
Brief summary
Unicompartmental knee replacement for selected cases of osteoarthritis is less invasive than total knee replacement. It gives better range of movement; patients stay for shorter time in the hospital and have a more natural feel than total knee replacement. Usually, the implant is fixed in the bone using bone cement. However, there are potential disadvantages of using bone cement. The operation takes longer; cement can get squeezed out into the surrounding tissues and may interfere with function. To avoid these problems, the implant can be fixed without cement. Cementless components have a special coating to encourage bone in-growth and fixation. Although the investigators believe cementless fixation will be at least as good as cemented fixation, there is a risk that it could be worse and might result in loosening. The aim of this study is therefore to compare the outcome of cemented and cementless unicompartmental knee replacement.
Detailed description
Design: A prospective, randomised trial to compare the outcome of cemented and cementless unicompartmental knee replacement. Size: 40 subjects in total will be recruited with 20 in each arm. Methods: Patients will be recruited from the routine waiting list for unicompartmental knee replacement at the Nuffield Orthopaedic Centre. All subjects will have the procedure explained and be fully consented prior to the procedure. Randomisation: Patients will be randomly allocated to receive either a cemented or cementless Oxford Unicompartmental Knee Replacement. This will be performed using a randomisation program based on optimisation (Minim). Subjects will be stratified according to sex and age. Operation: All subjects will undergo the same surgical approach. 0.8mm Tantalum marker balls will be placed at standardised sites on the femur and tibia in all cases. All cemented components will be secured using the same cement. Cementless components have a hydroxy-appatite coating to facilitate bone ingrowth. Follow-up: All patients will be followed up at 0, 3, 6, 12, 24, 60, and 120 months with clinical and radiological assessment. Clinical assessment will involve documentation with the Oxford Knee Score. Patients will undergo radiostereometric analysis and fluoroscopy to study implant migration and occurence of radiolucency, respectively.
Interventions
DEVICECementless Oxford Unicompartmental Knee Arthroplasty
All patients will undergo the same surgical approach. 0.8mm diameter tantalum marker balls will be placed in the tibia and femur in all cases. Cementless components have a hydroxy-appatite coating to facilitate bone ingrowth. The cementless femoral component also has a smaller second peg, located anteriorly to the larger central peg that is also present of the cemented femoral component.
DEVICECemented Oxford Unicompartmental Knee Arthroplasty
All patients will undergo the same surgical approach. 0.8mm diameter tantalum marker balls will be placed in the tibia and femur in all cases. All cemented components will be secured using the same cement.
Sponsors
Oxford University Hospitals NHS Trust
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
SINGLE (Subject)
Intervention model description
Patients will be randomised to receive either a cementless or cemented Oxford Unicompartmental Knee Arthroplasty.
Eligibility
Sex/Gender
ALL
Age
30 Years to 80 Years
Healthy volunteers
No
Inclusion criteria
* Healthy Subjects with osteoarthritis of knee fulfilling the standard indications for an Oxford Unicompartmental Knee Replacement. * American Society of Anaesthesiologists (ASA) Score of 1 to 3.
Exclusion criteria
* Subjects with severe limiting systemic illness (i.e. ASA \> 3). * Subjects who are too large for radiostereometric analysis to be carried out. * Subjects who have had previous open surgery or anterior cruciate ligament (ACL) reconstruction on the same knee.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Radiostereometric Analysis Examination - Translations | Patients will be examined 3 months post surgery. | Patients will have weight-bearing stereoradiographs. These stereoradiographs will be analysed using model-based radiostereometric analysis which will allow the migration of the components relative to the bone to be determined. Three-dimensional translations will be measured in millimetres. The component position at the post-operative timepoint was used as the baseline for measurement of migration. Migration can be interpreted as: * X translation: Positive (+ve) = Medial; Negative (-ve) = Lateral * Y translation: Positive (+ve) = Superior; Negative (-ve) = Inferior * Z translation: Positive (+ve) = Anterior; Negative (-ve) = Posterior |
| Radiostereometric Analysis Examination - Rotations | Patients will be examined at 3 months post surgery. | Patients will have weight-bearing stereoradiographs. These stereoradiographs will be analysed using model-based radiostereometric analysis which will allow the migration of the components relative to the bone to be determined. Three-dimensional rotations will be measured in degrees.The component position at the post-operative timepoint was used as the baseline for measurement of migration. Migration can be interpreted as: \*For the Femoral Component\* X Rotation: Positive (+ve) = Increased Flexion; Negative (-ve) = Decreased Flexion Y Rotation: Positive (+ve) = Internal Rotation; Negative (-ve) = External Rotation Z Rotation: Positive (+ve) = Valgus; Negative (-ve) = Varus \*For the Tibial Component\* X Rotation: Positive (+ve) = Reduced Slope; Negative (-ve) = Increased Slope Y Rotation: Positive (+ve) = Internal Rotation; Negative (-ve) = External Rotation Z Rotation: Positive (+ve) = Valgus; Negative (-ve) = Varus |
| Clinical Assessment | Patients will be assessed pre-operatively. | Clinical assessment will involve documentation with the Oxford Knee Score. The score will be calculated on a scale of 0 (worst) to 48 (best). |
| Radiostereometric Analysis Examination - Maximum Total Point Motion | Patients will be examined at 3 months post surgery. | Patients will have weight-bearing stereoradiographs. These stereoradiographs will be analysed using model-based radiostereometric analysis which will allow the migration of the components relative to the bone to be determined. Maximum Total Point Motion (MTPM - defined as the length of the translation vector of the point of the component model that has migrated the most) will be measured in millimetres. |
| Radiographic Examination | Patients will be examined at 12 months post surgery. | Fluoroscopic imaging will be used to study the occurence of radiolucencies beneath the components. Anteroposterior radiographs will be analysed to assess the presence and position of radiolucencies. Radiolucencies will be graded as either 'no radiolucency present', 'partial radiolucency', or 'complete radiolucency'. |
Participant flow
Recruitment details
A consecutive series of patients awairing an Oxford Unicompartmental Knee Replacement (OUKR) were invited to participate in the study. Consenting participants received an OUKR between November 2008 and March 2010 at the Nuffield Orthopaedic Centre (Oxford, UK).
Participants by arm
| Arm | Count |
|---|---|
| Cementless Oxford Unicompartmental Knee Arthroplasty Phase III Cementless Oxford Unicompartmental Knee Replacement (Biomet)
Cementless Oxford Unicompartmental Knee Arthroplasty: All patients will undergo the same surgical approach. 0.8mm diameter tantalum marker balls will be placed in the tibia and femur in all cases. Cementless components have a hydroxy-appatite coating to facilitate bone ingrowth. The cementless femoral component also has a smaller second peg, located anteriorly to the larger central peg that is also present of the cemented femoral component. | 23 |
| Cemented Oxford Unicompartmental Knee Arthroplasty Phase III Cemented Oxford Unicompartmental Knee Replacement (Biomet)
Cemented Oxford Unicompartmental Knee Arthroplasty: All patients will undergo the same surgical approach. 0.8mm diameter tantalum marker balls will be placed in the tibia and femur in all cases. All cemented components will be secured using the same cement. | 24 |
| Total | 47 |
Withdrawals & dropouts
| Period | Reason | FG000 | FG001 |
|---|---|---|---|
| Overall Study | Death | 1 | 2 |
| Overall Study | Mobile bearing dislocation | 0 | 1 |
| Overall Study | Revision of implant | 1 | 1 |
| Overall Study | Withdrawal by Subject | 5 | 5 |
Baseline characteristics
| Characteristic | Total | Cementless Oxford Unicompartmental Knee Arthroplasty | Cemented Oxford Unicompartmental Knee Arthroplasty |
|---|---|---|---|
| Age, Categorical <=18 years | 0 Participants | 0 Participants | 0 Participants |
| Age, Categorical >=65 years | 28 Participants | 15 Participants | 13 Participants |
| Age, Categorical Between 18 and 65 years | 19 Participants | 8 Participants | 11 Participants |
| Age, Continuous | 66.7 years | 67.7 years | 65.9 years |
| Race and Ethnicity Not Collected | 0 Participants | — | — |
| Region of Enrollment United Kingdom | 47 participants | 23 participants | 24 participants |
| Sex: Female, Male Female | 21 Participants | 9 Participants | 12 Participants |
| Sex: Female, Male Male | 26 Participants | 14 Participants | 12 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | 1 / 23 | 2 / 24 |
| other Total, other adverse events | 0 / 23 | 1 / 24 |
| serious Total, serious adverse events | 1 / 23 | 1 / 24 |
Outcome results
Primary
Clinical Assessment
Clinical assessment will involve documentation with the Oxford Knee Score. The score will be calculated on a scale of 0 (worst) to 48 (best).
Time frame: Patients will be assessed pre-operatively.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Cementless Oxford Unicompartmental Knee Arthroplasty | Clinical Assessment | 24 score on a scale | Standard Deviation 7 |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Clinical Assessment | 23 score on a scale | Standard Deviation 6 |
Primary
Clinical Assessment
Clinical assessment will involve documentation with the Oxford Knee Score. The score will be calculated on a scale of 0 (worst) to 48 (best).
Time frame: Patients will be assessed at 120 months post surgery.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Cementless Oxford Unicompartmental Knee Arthroplasty | Clinical Assessment | 42 score on a scale | Standard Deviation 7 |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Clinical Assessment | 39 score on a scale | Standard Deviation 10 |
Primary
Clinical Assessment
Clinical assessment will involve documentation with the Oxford Knee Score. The score will be calculated on a scale of 0 (worst) to 48 (best).
Time frame: Patients will be assessed at 60 months post surgery.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Cementless Oxford Unicompartmental Knee Arthroplasty | Clinical Assessment | 41 score on a scale | Standard Deviation 7 |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Clinical Assessment | 37 score on a scale | Standard Deviation 12 |
Primary
Clinical Assessment
Clinical assessment will involve documentation with the Oxford Knee Score. The score will be calculated on a scale of 0 (worst) to 48 (best).
Time frame: Patients will be assessed at 24 months post surgery.
| Arm | Measure | Value (MEAN) |
|---|---|---|
| Cementless Oxford Unicompartmental Knee Arthroplasty | Clinical Assessment | 42 score on a scale |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Clinical Assessment | 38 score on a scale |
Primary
Clinical Assessment
Clinical assessment will involve documentation with the Oxford Knee Score. The score will be calculated on a scale of 0 (worst) to 48 (best).
Time frame: Patients will be assessed at 12 months post surgery.
| Arm | Measure | Value (MEAN) |
|---|---|---|
| Cementless Oxford Unicompartmental Knee Arthroplasty | Clinical Assessment | 41 score on a scale |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Clinical Assessment | 40 score on a scale |
Primary
Radiographic Examination
Fluoroscopic imaging will be used to study the occurence of radiolucencies beneath the components. Anteroposterior radiographs will be analysed to assess the presence and position of radiolucencies. Radiolucencies will be graded as either 'no radiolucency present', 'partial radiolucency', or 'complete radiolucency'.
Time frame: Patients will be examined at 24 months post surgery.
Population: Plain radiographs were only available for 21 of the 22 Cementless Oxford Unicompartmental Knee Arthroplasties at the 60 month timepoint, which explains the discrepency between the number of patients analyzed and the number of patients reported in the patient flow.
| Arm | Measure | Group | Category | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|---|---|
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiographic Examination | Tibial Component | No Radiolucency | 15 Participants |
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiographic Examination | Femoral Component | Complate Radiolucency | 0 Participants |
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiographic Examination | Femoral Component | No Radiolucency | 21 Participants |
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiographic Examination | Tibial Component | Complate Radiolucency | 0 Participants |
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiographic Examination | Tibial Component | Partial Radiolucency | 6 Participants |
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiographic Examination | Femoral Component | Partial Radiolucency | 0 Participants |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiographic Examination | Femoral Component | Complate Radiolucency | 0 Participants |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiographic Examination | Tibial Component | Complate Radiolucency | 5 Participants |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiographic Examination | Tibial Component | No Radiolucency | 8 Participants |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiographic Examination | Femoral Component | Partial Radiolucency | 0 Participants |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiographic Examination | Femoral Component | No Radiolucency | 21 Participants |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiographic Examination | Tibial Component | Partial Radiolucency | 8 Participants |
Primary
Radiographic Examination
Fluoroscopic imaging will be used to study the occurence of radiolucencies beneath the components. Anteroposterior radiographs will be analysed to assess the presence and position of radiolucencies. Radiolucencies will be graded as either 'no radiolucency present', 'partial radiolucency', or 'complete radiolucency'.
Time frame: Patients will be examined at 120 months post surgery.
Population: Plain radiographs were only available for 15 of the 16 Cementless Oxford Unicompartmental Knee Arthroplasties and 14 of the 15 Cemented Oxford Unicompartmental Knee Arthroplastiesat the 60 month timepoint, which explains the discrepency between the number of patients analyzed and the number of patients reported in the patient flow.
| Arm | Measure | Group | Category | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|---|---|
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiographic Examination | Tibial Component | Partial Radiolucency | 1 Participants |
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiographic Examination | Tibial Component | Complete Radiolucency | 0 Participants |
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiographic Examination | Tibial Component | No Radiolucency | 14 Participants |
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiographic Examination | Femoral Component | Partial Radiolucency | 0 Participants |
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiographic Examination | Femoral Component | Complete Radiolucency | 0 Participants |
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiographic Examination | Femoral Component | No Radiolucency | 15 Participants |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiographic Examination | Femoral Component | Complete Radiolucency | 0 Participants |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiographic Examination | Tibial Component | Partial Radiolucency | 6 Participants |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiographic Examination | Femoral Component | Partial Radiolucency | 0 Participants |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiographic Examination | Tibial Component | Complete Radiolucency | 0 Participants |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiographic Examination | Femoral Component | No Radiolucency | 14 Participants |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiographic Examination | Tibial Component | No Radiolucency | 8 Participants |
Primary
Radiographic Examination
Fluoroscopic imaging will be used to study the occurence of radiolucencies beneath the components. Anteroposterior radiographs will be analysed to assess the presence and position of radiolucencies. Radiolucencies will be graded as either 'no radiolucency present', 'partial radiolucency', or 'complete radiolucency'.
Time frame: Patients will be examined at 60 months post surgery.
Population: Plain radiographs were only available for 18 of the 20 Cemented Oxford Unicompartmental Knee Arthroplasties at the 60 month timepoint, which explains the discrepency between the number of patients analyzed and the number of patients reported in the patient flow.
| Arm | Measure | Group | Category | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|---|---|
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiographic Examination | Tibial Component | Partial Radiolucency | 1 Participants |
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiographic Examination | Tibial Component | Complete Radiolucency | 0 Participants |
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiographic Examination | Tibial Component | No Radiolucency | 18 Participants |
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiographic Examination | Femoral Component | Partial Radiolucency | 0 Participants |
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiographic Examination | Femoral Component | Complete Radiolucency | 0 Participants |
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiographic Examination | Femoral Component | No Radiolucency | 19 Participants |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiographic Examination | Femoral Component | Complete Radiolucency | 0 Participants |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiographic Examination | Tibial Component | Partial Radiolucency | 6 Participants |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiographic Examination | Femoral Component | Partial Radiolucency | 0 Participants |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiographic Examination | Tibial Component | Complete Radiolucency | 1 Participants |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiographic Examination | Femoral Component | No Radiolucency | 18 Participants |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiographic Examination | Tibial Component | No Radiolucency | 11 Participants |
Primary
Radiographic Examination
Fluoroscopic imaging will be used to study the occurence of radiolucencies beneath the components. Anteroposterior radiographs will be analysed to assess the presence and position of radiolucencies. Radiolucencies will be graded as either 'no radiolucency present', 'partial radiolucency', or 'complete radiolucency'.
Time frame: Patients will be examined at 12 months post surgery.
| Arm | Measure | Group | Category | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|---|---|
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiographic Examination | Tibial Component | No Radiolucency | 14 Participants |
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiographic Examination | Tibial Component | Complete Radiolucency | 1 Participants |
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiographic Examination | Femoral Component | Partial Radiolucency | 0 Participants |
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiographic Examination | Femoral Component | Complete Radiolucency | 0 Participants |
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiographic Examination | Femoral Component | No Radiolucency | 22 Participants |
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiographic Examination | Tibial Component | Partial Radiolucency | 7 Participants |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiographic Examination | Femoral Component | No Radiolucency | 21 Participants |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiographic Examination | Tibial Component | Complete Radiolucency | 2 Participants |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiographic Examination | Femoral Component | Partial Radiolucency | 0 Participants |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiographic Examination | Tibial Component | No Radiolucency | 8 Participants |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiographic Examination | Femoral Component | Complete Radiolucency | 0 Participants |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiographic Examination | Tibial Component | Partial Radiolucency | 11 Participants |
Primary
Radiostereometric Analysis Examination - Maximum Total Point Motion
Patients will have weight-bearing stereoradiographs. These stereoradiographs will be analysed using model-based radiostereometric analysis which will allow the migration of the components relative to the bone to be determined. Maximum Total Point Motion (MTPM - defined as the length of the translation vector of the point of the component model that has migrated the most) will be measured in millimetres.
Time frame: Patients will be assessed at 6 months post surgery.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Maximum Total Point Motion | Femoral MTPM | 0.86 millimetres | Standard Deviation 0.43 |
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Maximum Total Point Motion | Tibial MTPM | 0.79 millimetres | Standard Deviation 0.42 |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Maximum Total Point Motion | Femoral MTPM | 0.80 millimetres | Standard Deviation 0.44 |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Maximum Total Point Motion | Tibial MTPM | 0.64 millimetres | Standard Deviation 0.45 |
Primary
Radiostereometric Analysis Examination - Maximum Total Point Motion
Patients will have weight-bearing stereoradiographs. These stereoradiographs will be analysed using model-based radiostereometric analysis which will allow the migration of the components relative to the bone to be determined. Maximum Total Point Motion (MTPM - defined as the length of the translation vector of the point of the component model that has migrated the most) will be measured in millimetres.
Time frame: Patients will be examined at 3 months post surgery.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Maximum Total Point Motion | Femoral MTPM | 0.93 millimetres | Standard Deviation 0.67 |
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Maximum Total Point Motion | Tibial MTPM | 0.84 millimetres | Standard Deviation 0.45 |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Maximum Total Point Motion | Femoral MTPM | 0.80 millimetres | Standard Deviation 0.36 |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Maximum Total Point Motion | Tibial MTPM | 0.61 millimetres | Standard Deviation 0.4 |
Primary
Radiostereometric Analysis Examination - Maximum Total Point Motion
Patients will have weight-bearing stereoradiographs. These stereoradiographs will be analysed using model-based radiostereometric analysis which will allow the migration of the components relative to the bone to be determined. Maximum Total Point Motion (MTPM - defined as the length of the translation vector of the point of the component model that has migrated the most) will be measured in millimetres.
Time frame: Patients will be examined at 12 months post surgery.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Maximum Total Point Motion | Femoral MTPM | 0.76 millimetres | Standard Deviation 0.35 |
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Maximum Total Point Motion | Tibial MTPM | 0.78 millimetres | Standard Deviation 0.37 |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Maximum Total Point Motion | Femoral MTPM | 0.80 millimetres | Standard Deviation 0.53 |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Maximum Total Point Motion | Tibial MTPM | 0.65 millimetres | Standard Deviation 0.45 |
Primary
Radiostereometric Analysis Examination - Maximum Total Point Motion
Patients will have weight-bearing stereoradiographs. These stereoradiographs will be analysed using model-based radiostereometric analysis which will allow the migration of the components relative to the bone to be determined. Maximum Total Point Motion (MTPM - defined as the length of the translation vector of the point of the component model that has migrated the most) will be measured in millimetres.
Time frame: Patients will be examined at 24 months post surgery.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Maximum Total Point Motion | Femoral MTPM | 0.87 millimetres | Standard Deviation 0.42 |
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Maximum Total Point Motion | Tibial MTPM | 0.84 millimetres | Standard Deviation 0.39 |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Maximum Total Point Motion | Femoral MTPM | 0.94 millimetres | Standard Deviation 0.87 |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Maximum Total Point Motion | Tibial MTPM | 0.64 millimetres | Standard Deviation 0.51 |
Primary
Radiostereometric Analysis Examination - Maximum Total Point Motion
Patients will have weight-bearing stereoradiographs. These stereoradiographs will be analysed using model-based radiostereometric analysis which will allow the migration of the components relative to the bone to be determined. Maximum Total Point Motion (MTPM - defined as the length of the translation vector of the point of the component model that has migrated the most) will be measured in millimetres.
Time frame: Patients will be examined at 60 months post surgery.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Maximum Total Point Motion | Femoral MTPM | 0.87 millimetres | Standard Deviation 0.4 |
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Maximum Total Point Motion | Tibial MTPM | 0.79 millimetres | Standard Deviation 0.3 |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Maximum Total Point Motion | Femoral MTPM | 0.95 millimetres | Standard Deviation 0.88 |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Maximum Total Point Motion | Tibial MTPM | 0.80 millimetres | Standard Deviation 0.68 |
Primary
Radiostereometric Analysis Examination - Maximum Total Point Motion
Patients will have weight-bearing stereoradiographs. These stereoradiographs will be analysed using model-based radiostereometric analysis which will allow the migration of the components relative to the bone to be determined. Maximum Total Point Motion (MTPM - defined as the length of the translation vector of the point of the component model that has migrated the most) will be measured in millimetres.
Time frame: Patients will be examined at 120 months post surgery.
Population: 1 Cemented Oxford Unicompartmental Knee Arthroplasty could not be analysed due poor quality stereoradiographs with obstruction of bone markers being obstructed. Consequently, although 15 Cemented Oxford Unicompartmental Knee Arthroplasties were followed-up at 120 months, only 14 could be analysed.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Maximum Total Point Motion | Femoral MTPM | 0.98 millimetres | Standard Deviation 0.41 |
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Maximum Total Point Motion | Tibial MTPM | 0.82 millimetres | Standard Deviation 0.32 |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Maximum Total Point Motion | Femoral MTPM | 0.84 millimetres | Standard Deviation 0.41 |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Maximum Total Point Motion | Tibial MTPM | 0.95 millimetres | Standard Deviation 1.33 |
Primary
Radiostereometric Analysis Examination - Rotations
Patients will have weight-bearing stereoradiographs. These stereoradiographs will be analysed using model-based radiostereometric analysis which will allow the migration of the components relative to the bone to be determined. Three-dimensional rotations will be measured in degrees.The component position at the post-operative timepoint was used as the baseline for measurement of migration. Migration can be interpreted as: * For the Femoral Component\* X Rotation: Positive (+ve) = Increased Flexion; Negative (-ve) = Decreased Flexion Y Rotation: Positive (+ve) = Internal Rotation; Negative (-ve) = External Rotation Z Rotation: Positive (+ve) = Valgus; Negative (-ve) = Varus * For the Tibial Component\* X Rotation: Positive (+ve) = Reduced Slope; Negative (-ve) = Increased Slope Y Rotation: Positive (+ve) = Internal Rotation; Negative (-ve) = External Rotation Z Rotation: Positive (+ve) = Valgus; Negative (-ve) = Varus
Time frame: Patients will be examined at 24 months post surgery.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Rotations | Femoral Z Migration | 0.00 Degrees | Standard Deviation 1.28 |
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Rotations | Tibial X Migration | -0.40 Degrees | Standard Deviation 0.76 |
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Rotations | Tibial Y Migration | 0.24 Degrees | Standard Deviation 0.61 |
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Rotations | Femoral X Migration | 0.20 Degrees | Standard Deviation 0.54 |
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Rotations | Femoral Y Migration | 0.23 Degrees | Standard Deviation 0.52 |
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Rotations | Tibial Z Migration | -0.01 Degrees | Standard Deviation 0.6 |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Rotations | Tibial Z Migration | -0.31 Degrees | Standard Deviation 0.68 |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Rotations | Femoral Z Migration | -0.06 Degrees | Standard Deviation 0.75 |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Rotations | Femoral Y Migration | 0.32 Degrees | Standard Deviation 0.52 |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Rotations | Tibial X Migration | -0.17 Degrees | Standard Deviation 0.69 |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Rotations | Femoral X Migration | 0.23 Degrees | Standard Deviation 0.68 |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Rotations | Tibial Y Migration | 0.03 Degrees | Standard Deviation 0.44 |
Primary
Radiostereometric Analysis Examination - Rotations
Patients will have weight-bearing stereoradiographs. These stereoradiographs will be analysed using model-based radiostereometric analysis which will allow the migration of the components relative to the bone to be determined. Three-dimensional rotations will be measured in degrees.The component position at the post-operative timepoint was used as the baseline for measurement of migration. Migration can be interpreted as: * For the Femoral Component\* X Rotation: Positive (+ve) = Increased Flexion; Negative (-ve) = Decreased Flexion Y Rotation: Positive (+ve) = Internal Rotation; Negative (-ve) = External Rotation Z Rotation: Positive (+ve) = Valgus; Negative (-ve) = Varus * For the Tibial Component\* X Rotation: Positive (+ve) = Reduced Slope; Negative (-ve) = Increased Slope Y Rotation: Positive (+ve) = Internal Rotation; Negative (-ve) = External Rotation Z Rotation: Positive (+ve) = Valgus; Negative (-ve) = Varus
Time frame: Patients will be examined at 60 months post surgery.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Rotations | Femoral X Rotation | 0.35 Degrees | Standard Deviation 0.44 |
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Rotations | Femoral Y Rotation | 0.29 Degrees | Standard Deviation 0.79 |
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Rotations | Femoral Z Rotation | -0.17 Degrees | Standard Deviation 1.14 |
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Rotations | Tibial X Rotation | -0.28 Degrees | Standard Deviation 0.8 |
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Rotations | Tibial Y Rotation | 0.28 Degrees | Standard Deviation 0.47 |
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Rotations | Tibial Z Rotation | -0.13 Degrees | Standard Deviation 0.68 |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Rotations | Femoral X Rotation | 0.16 Degrees | Standard Deviation 0.54 |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Rotations | Tibial Y Rotation | 0.07 Degrees | Standard Deviation 0.4 |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Rotations | Femoral Y Rotation | -0.34 Degrees | Standard Deviation 2.07 |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Rotations | Tibial X Rotation | -0.34 Degrees | Standard Deviation 1.19 |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Rotations | Femoral Z Rotation | 0.25 Degrees | Standard Deviation 0.88 |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Rotations | Tibial Z Rotation | -0.45 Degrees | Standard Deviation 0.8 |
Primary
Radiostereometric Analysis Examination - Rotations
Patients will have weight-bearing stereoradiographs. These stereoradiographs will be analysed using model-based radiostereometric analysis which will allow the migration of the components relative to the bone to be determined. Three-dimensional rotations will be measured in degrees.The component position at the post-operative timepoint was used as the baseline for measurement of migration. Migration can be interpreted as: * For the Femoral Component\* X Rotation: Positive (+ve) = Increased Flexion; Negative (-ve) = Decreased Flexion Y Rotation: Positive (+ve) = Internal Rotation; Negative (-ve) = External Rotation Z Rotation: Positive (+ve) = Valgus; Negative (-ve) = Varus * For the Tibial Component\* X Rotation: Positive (+ve) = Reduced Slope; Negative (-ve) = Increased Slope Y Rotation: Positive (+ve) = Internal Rotation; Negative (-ve) = External Rotation Z Rotation: Positive (+ve) = Valgus; Negative (-ve) = Varus
Time frame: Patients will be examined at 120 months post surgery.
Population: 1 Cemented Oxford Unicompartmental Knee Arthroplasty could not be analysed due poor quality stereoradiographs with obstruction of bone markers being obstructed. Consequently, although 15 Cemented Oxford Unicompartmental Knee Arthroplasties were followed-up at 120 months, only 14 could be analysed.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Rotations | Femoral Y Rotation | 0.19 Degrees | Standard Deviation 0.79 |
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Rotations | Femoral X Rotation | -0.02 Degrees | Standard Deviation 0.5 |
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Rotations | Tibial Y Rotation | 0.18 Degrees | Standard Deviation 0.48 |
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Rotations | Femoral Z Rotation | 0.53 Degrees | Standard Deviation 0.9 |
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Rotations | Tibial Z Rotation | -0.50 Degrees | Standard Deviation 0.64 |
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Rotations | Tibial X Rotation | -0.43 Degrees | Standard Deviation 0.74 |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Rotations | Tibial Z Rotation | -0.79 Degrees | Standard Deviation 1.14 |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Rotations | Femoral X Rotation | 0.27 Degrees | Standard Deviation 0.55 |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Rotations | Femoral Y Rotation | 0.38 Degrees | Standard Deviation 0.81 |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Rotations | Femoral Z Rotation | 0.38 Degrees | Standard Deviation 1.16 |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Rotations | Tibial X Rotation | -0.66 Degrees | Standard Deviation 2.59 |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Rotations | Tibial Y Rotation | 0.15 Degrees | Standard Deviation 0.36 |
Primary
Radiostereometric Analysis Examination - Rotations
Patients will have weight-bearing stereoradiographs. These stereoradiographs will be analysed using model-based radiostereometric analysis which will allow the migration of the components relative to the bone to be determined. Three-dimensional rotations will be measured in degrees.The component position at the post-operative timepoint was used as the baseline for measurement of migration. Migration can be interpreted as: * For the Femoral Component\* X Rotation: Positive (+ve) = Increased Flexion; Negative (-ve) = Decreased Flexion Y Rotation: Positive (+ve) = Internal Rotation; Negative (-ve) = External Rotation Z Rotation: Positive (+ve) = Valgus; Negative (-ve) = Varus * For the Tibial Component\* X Rotation: Positive (+ve) = Reduced Slope; Negative (-ve) = Increased Slope Y Rotation: Positive (+ve) = Internal Rotation; Negative (-ve) = External Rotation Z Rotation: Positive (+ve) = Valgus; Negative (-ve) = Varus
Time frame: Patients will be examined at 12 months post surgery.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Rotations | Tibial Z Rotation | 0.10 Degrees | Standard Deviation 0.63 |
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Rotations | Femoral X Rotation | 0.22 Degrees | Standard Deviation 0.57 |
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Rotations | Femoral Y Rotation | 0.24 Degrees | Standard Deviation 0.52 |
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Rotations | Tibial X Rotation | -0.38 Degrees | Standard Deviation 0.73 |
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Rotations | Femoral Z Rotation | -0.26 Degrees | Standard Deviation 0.93 |
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Rotations | Tibial Y Rotation | 0.16 Degrees | Standard Deviation 0.54 |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Rotations | Tibial Z Rotation | -0.29 Degrees | Standard Deviation 0.67 |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Rotations | Femoral Z Rotation | 0.25 Degrees | Standard Deviation 0.8 |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Rotations | Tibial X Rotation | -0.10 Degrees | Standard Deviation 0.7 |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Rotations | Femoral Y Rotation | -0.05 Degrees | Standard Deviation 0.63 |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Rotations | Tibial Y Rotation | -0.02 Degrees | Standard Deviation 0.45 |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Rotations | Femoral X Rotation | 0.16 Degrees | Standard Deviation 0.65 |
Primary
Radiostereometric Analysis Examination - Rotations
Patients will have weight-bearing stereoradiographs. These stereoradiographs will be analysed using model-based radiostereometric analysis which will allow the migration of the components relative to the bone to be determined. Three-dimensional rotations will be measured in degrees.The component position at the post-operative timepoint was used as the baseline for measurement of migration. Migration can be interpreted as: * For the Femoral Component\* X Rotation: Positive (+ve) = Increased Flexion; Negative (-ve) = Decreased Flexion Y Rotation: Positive (+ve) = Internal Rotation; Negative (-ve) = External Rotation Z Rotation: Positive (+ve) = Valgus; Negative (-ve) = Varus * For the Tibial Component\* X Rotation: Positive (+ve) = Reduced Slope; Negative (-ve) = Increased Slope Y Rotation: Positive (+ve) = Internal Rotation; Negative (-ve) = External Rotation Z Rotation: Positive (+ve) = Valgus; Negative (-ve) = Varus
Time frame: Patients will be examined at 6 months post surgery.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Rotations | Femoral X Rotation | 0.04 Degrees | Standard Deviation 0.56 |
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Rotations | Femoral Z Rotation | -0.11 Degrees | Standard Deviation 0.9 |
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Rotations | Tibial X Rotation | -0.46 Degrees | Standard Deviation 0.78 |
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Rotations | Tibial Y Rotation | 0.12 Degrees | Standard Deviation 0.58 |
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Rotations | Tibial Z Rotation | 0.33 Degrees | Standard Deviation 0.71 |
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Rotations | Femoral Y Rotation | 0.48 Degrees | Standard Deviation 0.79 |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Rotations | Tibial Z Rotation | 0.15 Degrees | Standard Deviation 0.98 |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Rotations | Femoral Y Rotation | 0.05 Degrees | Standard Deviation 0.62 |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Rotations | Tibial Y Rotation | 0.07 Degrees | Standard Deviation 0.36 |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Rotations | Femoral Z Rotation | 0.19 Degrees | Standard Deviation 0.76 |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Rotations | Femoral X Rotation | 0.27 Degrees | Standard Deviation 0.81 |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Rotations | Tibial X Rotation | -0.25 Degrees | Standard Deviation 0.65 |
Primary
Radiostereometric Analysis Examination - Rotations
Patients will have weight-bearing stereoradiographs. These stereoradiographs will be analysed using model-based radiostereometric analysis which will allow the migration of the components relative to the bone to be determined. Three-dimensional rotations will be measured in degrees.The component position at the post-operative timepoint was used as the baseline for measurement of migration. Migration can be interpreted as: \*For the Femoral Component\* X Rotation: Positive (+ve) = Increased Flexion; Negative (-ve) = Decreased Flexion Y Rotation: Positive (+ve) = Internal Rotation; Negative (-ve) = External Rotation Z Rotation: Positive (+ve) = Valgus; Negative (-ve) = Varus \*For the Tibial Component\* X Rotation: Positive (+ve) = Reduced Slope; Negative (-ve) = Increased Slope Y Rotation: Positive (+ve) = Internal Rotation; Negative (-ve) = External Rotation Z Rotation: Positive (+ve) = Valgus; Negative (-ve) = Varus
Time frame: Patients will be examined at 3 months post surgery.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Rotations | Femoral X Rotation | 0.22 Degrees | Standard Deviation 0.95 |
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Rotations | Femoral Y Rotation | 0.26 Degrees | Standard Deviation 0.55 |
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Rotations | Femoral Z Rotation | -0.16 Degrees | Standard Deviation 0.89 |
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Rotations | Tibial X Rotation | -0.48 Degrees | Standard Deviation 0.88 |
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Rotations | Tibial Y Rotation | 0.05 Degrees | Standard Deviation 0.63 |
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Rotations | Tibial Z Rotation | 0.36 Degrees | Standard Deviation 0.7 |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Rotations | Tibial Y Rotation | -0.08 Degrees | Standard Deviation 0.46 |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Rotations | Femoral X Rotation | 0.19 Degrees | Standard Deviation 0.47 |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Rotations | Tibial X Rotation | -0.09 Degrees | Standard Deviation 0.5 |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Rotations | Femoral Y Rotation | 0.10 Degrees | Standard Deviation 0.74 |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Rotations | Tibial Z Rotation | -0.10 Degrees | Standard Deviation 0.68 |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Rotations | Femoral Z Rotation | -0.10 Degrees | Standard Deviation 0.95 |
Primary
Radiostereometric Analysis Examination - Translations
Patients will have weight-bearing stereoradiographs. These stereoradiographs will be analysed using model-based radiostereometric analysis which will allow the migration of the components relative to the bone to be determined. Three-dimensional translations will be measured in millimetres. The component position at the post-operative timepoint was used as the baseline for measurement of migration. Migration can be interpreted as: * X translation: Positive (+ve) = Medial; Negative (-ve) = Lateral * Y translation: Positive (+ve) = Superior; Negative (-ve) = Inferior * Z translation: Positive (+ve) = Anterior; Negative (-ve) = Posterior
Time frame: Patients will be examined 12 months post surgery.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Translations | Femoral X Translation | -0.18 millimetres | Standard Deviation 0.28 |
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Translations | Femoral Y Translation | -0.12 millimetres | Standard Deviation 0.24 |
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Translations | Tibial X Translation | -0.04 millimetres | Standard Deviation 0.21 |
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Translations | Tibial Z Translation | -0.01 millimetres | Standard Deviation 0.15 |
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Translations | Femoral Z Translation | 0.26 millimetres | Standard Deviation 0.31 |
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Translations | Tibial Y Translation | -0.28 millimetres | Standard Deviation 0.19 |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Translations | Tibial Y Translation | -0.09 millimetres | Standard Deviation 0.19 |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Translations | Femoral X Translation | 0.05 millimetres | Standard Deviation 0.28 |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Translations | Femoral Y Translation | -0.12 millimetres | Standard Deviation 0.25 |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Translations | Femoral Z Translation | 0.24 millimetres | Standard Deviation 0.32 |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Translations | Tibial Z Translation | 0.00 millimetres | Standard Deviation 0.26 |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Translations | Tibial X Translation | 0.01 millimetres | Standard Deviation 0.24 |
Primary
Radiostereometric Analysis Examination - Translations
Patients will have weight-bearing stereoradiographs. These stereoradiographs will be analysed using model-based radiostereometric analysis which will allow the migration of the components relative to the bone to be determined. Three-dimensional translations will be measured in millimetres. The component position at the post-operative timepoint was used as the baseline for measurement of migration. Migration can be interpreted as: * X translation: Positive (+ve) = Medial; Negative (-ve) = Lateral * Y translation: Positive (+ve) = Superior; Negative (-ve) = Inferior * Z translation: Positive (+ve) = Anterior; Negative (-ve) = Posterior
Time frame: Patients will be examined 3 months post surgery.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Translations | Femoral X Migration | -0.01 millimetres | Standard Deviation 0.36 |
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Translations | Femoral Y Migration | -0.10 millimetres | Standard Deviation 0.34 |
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Translations | Tibial X Migration | -0.09 millimetres | Standard Deviation 0.22 |
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Translations | Femoral Z Migration | 0.26 millimetres | Standard Deviation 0.48 |
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Translations | Tibial Y Migration | -0.23 millimetres | Standard Deviation 0.18 |
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Translations | Tibial Z Migration | -0.03 millimetres | Standard Deviation 0.2 |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Translations | Femoral Y Migration | -0.17 millimetres | Standard Deviation 0.25 |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Translations | Femoral X Migration | 0.05 millimetres | Standard Deviation 0.4 |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Translations | Tibial Y Migration | -0.10 millimetres | Standard Deviation 0.17 |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Translations | Femoral Z Migration | 0.14 millimetres | Standard Deviation 0.33 |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Translations | Tibial X Migration | 0.08 millimetres | Standard Deviation 0.28 |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Translations | Tibial Z Migration | -0.02 millimetres | Standard Deviation 0.26 |
Primary
Radiostereometric Analysis Examination - Translations
Patients will have weight-bearing stereoradiographs. These stereoradiographs will be analysed using model-based radiostereometric analysis which will allow the migration of the components relative to the bone to be determined. Three-dimensional translations will be measured in millimetres. The component position at the post-operative timepoint was used as the baseline for measurement of migration. Migration can be interpreted as: * X translation: Positive (+ve) = Medial; Negative (-ve) = Lateral * Y translation: Positive (+ve) = Superior; Negative (-ve) = Inferior * Z translation: Positive (+ve) = Anterior; Negative (-ve) = Posterior
Time frame: Patients will be examined 120 months post surgery.
Population: 1 Cemented Oxford Unicompartmental Knee Arthroplasty could not be analysed due poor quality stereoradiographs with obstruction of bone markers being obstructed. Consequently, although 15 Cemented Oxford Unicompartmental Knee Arthroplasties were followed-up at 120 months, only 14 could be analysed.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Translations | Tibial Y Translation | -0.29 millimetres | Standard Deviation 0.2 |
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Translations | Femoral Z Translation | 0.20 millimetres | Standard Deviation 0.36 |
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Translations | Tibial Z Translation | -0.01 millimetres | Standard Deviation 0.21 |
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Translations | Femoral Y Translation | -0.14 millimetres | Standard Deviation 0.27 |
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Translations | Femoral X Translation | -0.12 millimetres | Standard Deviation 0.5 |
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Translations | Tibial X Translation | 0.00 millimetres | Standard Deviation 0.26 |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Translations | Tibial X Translation | 0.00 millimetres | Standard Deviation 0.16 |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Translations | Femoral Y Translation | -0.16 millimetres | Standard Deviation 0.21 |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Translations | Femoral Z Translation | 0.14 millimetres | Standard Deviation 0.28 |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Translations | Tibial Y Translation | -0.15 millimetres | Standard Deviation 0.42 |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Translations | Tibial Z Translation | 0.02 millimetres | Standard Deviation 0.23 |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Translations | Femoral X Translation | 0.24 millimetres | Standard Deviation 0.31 |
Primary
Radiostereometric Analysis Examination - Translations
Patients will have weight-bearing stereoradiographs. These stereoradiographs will be analysed using model-based radiostereometric analysis which will allow the migration of the components relative to the bone to be determined. Three-dimensional translations will be measured in millimetres.
Time frame: Patients will be examined 60 months post surgery.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Translations | Femoral X Translation | -0.02 millimetres | Standard Deviation 0.46 |
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Translations | Femoral Y Translation | -0.07 millimetres | Standard Deviation 0.29 |
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Translations | Femoral Z Translation | 0.14 millimetres | Standard Deviation 0.31 |
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Translations | Tibial X Translation | -0.03 millimetres | Standard Deviation 0.21 |
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Translations | Tibial Y Translation | -0.28 millimetres | Standard Deviation 0.19 |
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Translations | Tibial Z Translation | 0.00 millimetres | Standard Deviation 0.11 |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Translations | Tibial Y Translation | -0.14 millimetres | Standard Deviation 0.29 |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Translations | Femoral X Translation | 0.10 millimetres | Standard Deviation 0.35 |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Translations | Tibial X Translation | 0.03 millimetres | Standard Deviation 0.22 |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Translations | Femoral Y Translation | -0.16 millimetres | Standard Deviation 0.19 |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Translations | Tibial Z Translation | 0.01 millimetres | Standard Deviation 0.31 |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Translations | Femoral Z Translation | 0.20 millimetres | Standard Deviation 0.3 |
Primary
Radiostereometric Analysis Examination - Translations
Patients will have weight-bearing stereoradiographs. These stereoradiographs will be analysed using model-based radiostereometric analysis which will allow the migration of the components relative to the bone to be determined. Three-dimensional translations will be measured in millimetres. The component position at the post-operative timepoint was used as the baseline for measurement of migration. Migration can be interpreted as: * X translation: Positive (+ve) = Medial; Negative (-ve) = Lateral * Y translation: Positive (+ve) = Superior; Negative (-ve) = Inferior * Z translation: Positive (+ve) = Anterior; Negative (-ve) = Posterior
Time frame: Patients will be examined 24 months post surgery.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Translations | Femoral X Translation | -0.05 millimetres | Standard Deviation 0.53 |
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Translations | Tibial Y Translation | -0.34 millimetres | Standard Deviation 0.23 |
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Translations | Tibial Z Translation | -0.02 millimetres | Standard Deviation 0.16 |
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Translations | Femoral Y Translation | -0.04 millimetres | Standard Deviation 0.27 |
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Translations | Femoral Z Translation | 0.21 millimetres | Standard Deviation 0.23 |
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Translations | Tibial X Translation | 0.01 millimetres | Standard Deviation 0.19 |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Translations | Tibial Z Translation | 0.03 millimetres | Standard Deviation 0.22 |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Translations | Femoral X Translation | 0.03 millimetres | Standard Deviation 0.34 |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Translations | Tibial X Translation | 0.06 millimetres | Standard Deviation 0.26 |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Translations | Femoral Z Translation | 0.22 millimetres | Standard Deviation 0.42 |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Translations | Tibial Y Translation | -0.13 millimetres | Standard Deviation 0.23 |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Translations | Femoral Y Translation | -0.05 millimetres | Standard Deviation 0.32 |
Primary
Radiostereometric Analysis Examination - Translations
Patients will have weight-bearing stereoradiographs. These stereoradiographs will be analysed using model-based radiostereometric analysis which will allow the migration of the components relative to the bone to be determined. Three-dimensional translations will be measured in millimetres. The component position at the post-operative timepoint was used as the baseline for measurement of migration. Migration can be interpreted as: * X translation: Positive (+ve) = Medial; Negative (-ve) = Lateral * Y translation: Positive (+ve) = Superior; Negative (-ve) = Inferior * Z translation: Positive (+ve) = Anterior; Negative (-ve) = Posterior
Time frame: Patients will be examined 6 months post surgery.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Translations | Tibial Z Migration | -0.03 millimetres | Standard Deviation 0.13 |
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Translations | Femoral X Migration | -0.12 millimetres | Standard Deviation 0.31 |
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Translations | Femoral Y Migration | -0.02 millimetres | Standard Deviation 0.39 |
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Translations | Femoral Z Migration | 0.24 millimetres | Standard Deviation 0.39 |
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Translations | Tibial X Migration | 0.06 millimetres | Standard Deviation 0.19 |
| Cementless Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Translations | Tibial Y Migration | -0.28 millimetres | Standard Deviation 0.17 |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Translations | Tibial X Migration | 0.06 millimetres | Standard Deviation 0.19 |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Translations | Tibial Z Migration | -0.05 millimetres | Standard Deviation 0.3 |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Translations | Femoral Z Migration | 0.16 millimetres | Standard Deviation 0.29 |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Translations | Femoral X Migration | 0.05 millimetres | Standard Deviation 0.28 |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Translations | Tibial Y Migration | 0.06 millimetres | Standard Deviation 0.18 |
| Cemented Oxford Unicompartmental Knee Arthroplasty | Radiostereometric Analysis Examination - Translations | Femoral Y Migration | -0.02 millimetres | Standard Deviation 0.39 |