Comparison of the Femoral Prothesis-rotation in Conventional X-ray, in Axial CT Slices and 3D-reconstructed CT

Study Overview
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Brief Summary
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Femoral component rotation in total knee arthroplasty (TKA) has been considered an important factor for outcome. However, measurement of femoral component rotation is difficult to perform. Femoral TKA component rotation can be assessed on special radiographs (Kanekasu technique), axial CT slices and 3D reconstructed CT images. It was the hypothesis that measurements on radiographs are comparable to measurement on CT images. Measurements of femoral TKA rotation will be measured three times by three different observers and inter- and intraobserver reliability is calculated. The absolute values of each measurement method is noted in degrees.

Detailed Description
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Femoral component rotation in total knee arthroplasty (TKA) has been considered an important factor for outcome. However, measurement of femoral component rotation is difficult to perform. Femoral TKA component rotation can be assessed on special radiographs (Kanekasu technique), axial CT slices and 3D reconstructed CT images. It was the hypothesis that measurements on radiographs are comparable to measurement on CT images. In agreement with our standard diagnostic algorithm for patients with pain and problems after TKA CT images as well as Kanekasu radiographs are performed. If the Kanekasu radiograph is comparable reliable, it could be possible to use this radiograph instead. Measurements of femoral TKA rotation will be measured three times by three different observers and inter- and intraobserver reliability is calculated. The absolute values of each measurement method is noted in degrees. The measurements are performed with two weeks interval and the different observers are blinded to their previous and the measurements of the others. The absolute difference of femoral TKA rotation is calculated between and inter the groups investigated. Intra class correlation coefficients are calculated for inter- and intraobserver reliability.

Official Title
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Comparative Study pf the Femoral Prothesis-rotation in Conventional X-Ray, in Axial CT Slices and 3D-reconstructed CT

Conditions
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Osteoarthritis

Intervention / Treatment
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* Other: Kanekasu radiographs


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Total Knee prosthesis (primary) >55 years Exclusion Criteria: pregnancy lactating women

Ages Eligible for Study
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Minimum Age: 55 Years
Maximum Age: 95 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Diagnostic
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Other: Kanekasu radiographs<br>No drugs or devices are used in this study. Commonly available radiological techniques such as radiographs and CT are used. All patients undergo a CT of the knee and a special radiograph (Kanekasu technique). | Other: Kanekasu radiographs<br>* No interventions are performed here. All patients undergo CT and special radiographs of the knee to assess femoral TKA rotation.<br>* Other names: kanekasu-technic;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Femoral TKA component rotation in degrees | Femoral TKA component rotation in degrees is assessed on radiographs (Kanekasu), axial CT and 3D reconstructed CT images. All three measurement by each three observers are compared to each other. | one year | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Inter- and intraobserver reliability of TKA femoral component rotation | Inter- and intraobserver reliability of TKA femoral component rotation are calculated by intra class correlation coefficients (ICC) and compared between all three measurement methods. | one year | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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total knee arthroplasty, total knee prothesis, X-Ray, Kanekasu radiographs, femoral component rotation, effects