Detaillierte Beitrags-Information
| Beitragstitel | Coronal alignment parameters vary widely in non-osteoarthritic knees – a study performed on 3DCT |
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| Beitragscode | P047 |
| Autoren | |
| Präsentationsform | Poster |
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| Abstract |
Introduction: The postoperative coronal alignment is a key factor for a good clinical outcome in total knee arthroplasty (TKA). At the same time, the optimal alignment has been under debate in recent years. Some surgeons promote TKA alignment concepts where the alignment goal is defined according to the native alignment of the patient. Such approaches require a profound knowledge about the variability of the native alignment, which seems to be missing. Only few studies assess the variability of the native alignment and the few only used radiographs. The purpose of this study was therefore to assess the variability of the coronal alignment in native knees using 3D reconstructed CT scans. Methods: The hospital registry was searched for patients older than 16 and younger than 45 years, who received a CT according to the Imperial Knee Protocol. Patients with prosthesis, osteoarthritis, fractures or injury of the collateral ligaments were excluded. Finally, 308 non-osteoarthritic knees of 160 patients remained (102 males and 58 females, mean age ± standard deviation (SD) 30±7 years). The following angles were measured using a validated software (KneePLAN 3D, Symbios, Yverdon les Bains, Switzerland): hip-knee-ankle angle (HKA, angle formed by the lines connecting the centers of the femoral head, the knee and the talus), femoral mechanical angle (FMA, angle between the mechanical axis of the femur and the tangent to the distal femoral condyles) and tibial mechanical angle (TMA, angle between the mechanical axis of the tibia and the tangent to the tibial plateau). Since a neutrally aligned limb is the current gold standard for TKA, it was further assessed how variable FMA and TMA were in neutrally aligned limbs (HKA 180°±3). Results: The overall mean HKA±SD was 179.7°±2.9 varus. Values ranged from 172.6° varus to 187.1° valgus. The overall mean FMA±SD was 93.4°±2.0 and values ranged from 87.9° varus to 100° valgus. The overall mean TMA±SD was 87.2°±2.4 with a range from 81.3° varus to 94.6° valgus. A neutrally aligned limb was found in 76% of the population. The FMA of these limbs ranged from 88° varus to 100° valgus and the TMA from 81° varus to 92° valgus. A neutrally aligned limb with a neutrally aligned tibia and femur (90°±3) was found in 19% of the population. Conclusion: All coronal alignment parameters varied widely in a young non-osteoarthritic population. The variability of FMA and TMA remains high even when the overall alignment is limited to neutral. |