Averaging rotational landmarks during total knee arthroplasty reduces component malrotation caused by femoral asymmetry
Abstract Background Femoral component malrotation is a common cause of patient dissatisfaction after total knee arthroplasty. The sulcus line (SL) is more accurate than Whiteside’s line as it corrects for variation in the coronal orientation of the groove. The hypothesis is that averaging the SL and...
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| Format: | Article |
| Language: | English |
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BMC
2017-05-01
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| Series: | Journal of Orthopaedic Surgery and Research |
| Subjects: | |
| Online Access: | http://link.springer.com/article/10.1186/s13018-017-0575-2 |
| _version_ | 1818039156539916288 |
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| author | Tat Woon Chao Liam Geraghty Pandelis Dimitriou Simon Talbot |
| author_facet | Tat Woon Chao Liam Geraghty Pandelis Dimitriou Simon Talbot |
| author_sort | Tat Woon Chao |
| collection | DOAJ |
| description | Abstract Background Femoral component malrotation is a common cause of patient dissatisfaction after total knee arthroplasty. The sulcus line (SL) is more accurate than Whiteside’s line as it corrects for variation in the coronal orientation of the groove. The hypothesis is that averaging the SL and posterior condylar axis (PCA) will reduce femoral malrotation. Methods The component was inserted at a position between the SL and PCA in 91 patients. An intraoperative photograph was taken showing the landmarks. These were compared to the component position achieved relative to the surgical epicondylar axis (SEA) on a postoperative CT scan. The component position was compared to the position achieved using the individual landmarks. Results Relative to the SEA, the final component position was 0.6° (SD 1.4°, range −3.8° to +4.0°), the coronally corrected SL position was −0.7° (SD 2.3°, −5.5° to +4.6°), the PCA position was 0.9° (SD 1.9°, −6.1° to +5.0°). Averaging the landmarks significantly decreased the variance of the component position compared to using the SL and PCA individually. The number of outliers (>3° from SEA) was also significantly less (p < 0.05) for the average position (2/84) when each was compared to the SL (16/84) and PCA (14/84) individually. In 21/84 (25%) of cases, there was more than 4° of divergence between the SL and PCA. Conclusions Averaging the SL and the PCA decreases femoral component malrotation. Femora are frequently asymmetrical in the axial plane. Referencing posterior condyles alone to set rotation is likely to cause high rates of patellofemoral malalignment. |
| first_indexed | 2024-12-10T07:54:09Z |
| format | Article |
| id | doaj.art-c133f131206d49f9b5526c4c356406a7 |
| institution | Directory Open Access Journal |
| issn | 1749-799X |
| language | English |
| last_indexed | 2024-12-10T07:54:09Z |
| publishDate | 2017-05-01 |
| publisher | BMC |
| record_format | Article |
| series | Journal of Orthopaedic Surgery and Research |
| spelling | doaj.art-c133f131206d49f9b5526c4c356406a72022-12-22T01:56:57ZengBMCJournal of Orthopaedic Surgery and Research1749-799X2017-05-011211910.1186/s13018-017-0575-2Averaging rotational landmarks during total knee arthroplasty reduces component malrotation caused by femoral asymmetryTat Woon Chao0Liam Geraghty1Pandelis Dimitriou2Simon Talbot3Department of Orthopaedics, Western HealthDepartment of Orthopaedics, Western HealthDepartment of Orthopaedics, Western HealthDepartment of Orthopaedics, Western HealthAbstract Background Femoral component malrotation is a common cause of patient dissatisfaction after total knee arthroplasty. The sulcus line (SL) is more accurate than Whiteside’s line as it corrects for variation in the coronal orientation of the groove. The hypothesis is that averaging the SL and posterior condylar axis (PCA) will reduce femoral malrotation. Methods The component was inserted at a position between the SL and PCA in 91 patients. An intraoperative photograph was taken showing the landmarks. These were compared to the component position achieved relative to the surgical epicondylar axis (SEA) on a postoperative CT scan. The component position was compared to the position achieved using the individual landmarks. Results Relative to the SEA, the final component position was 0.6° (SD 1.4°, range −3.8° to +4.0°), the coronally corrected SL position was −0.7° (SD 2.3°, −5.5° to +4.6°), the PCA position was 0.9° (SD 1.9°, −6.1° to +5.0°). Averaging the landmarks significantly decreased the variance of the component position compared to using the SL and PCA individually. The number of outliers (>3° from SEA) was also significantly less (p < 0.05) for the average position (2/84) when each was compared to the SL (16/84) and PCA (14/84) individually. In 21/84 (25%) of cases, there was more than 4° of divergence between the SL and PCA. Conclusions Averaging the SL and the PCA decreases femoral component malrotation. Femora are frequently asymmetrical in the axial plane. Referencing posterior condyles alone to set rotation is likely to cause high rates of patellofemoral malalignment.http://link.springer.com/article/10.1186/s13018-017-0575-2KneeArthroplastyMalrotationProsthesisFemoral rotationWhiteside’s line |
| spellingShingle | Tat Woon Chao Liam Geraghty Pandelis Dimitriou Simon Talbot Averaging rotational landmarks during total knee arthroplasty reduces component malrotation caused by femoral asymmetry Journal of Orthopaedic Surgery and Research Knee Arthroplasty Malrotation Prosthesis Femoral rotation Whiteside’s line |
| title | Averaging rotational landmarks during total knee arthroplasty reduces component malrotation caused by femoral asymmetry |
| title_full | Averaging rotational landmarks during total knee arthroplasty reduces component malrotation caused by femoral asymmetry |
| title_fullStr | Averaging rotational landmarks during total knee arthroplasty reduces component malrotation caused by femoral asymmetry |
| title_full_unstemmed | Averaging rotational landmarks during total knee arthroplasty reduces component malrotation caused by femoral asymmetry |
| title_short | Averaging rotational landmarks during total knee arthroplasty reduces component malrotation caused by femoral asymmetry |
| title_sort | averaging rotational landmarks during total knee arthroplasty reduces component malrotation caused by femoral asymmetry |
| topic | Knee Arthroplasty Malrotation Prosthesis Femoral rotation Whiteside’s line |
| url | http://link.springer.com/article/10.1186/s13018-017-0575-2 |
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