A TKA Insert with A Lateral Flat Articular Surface Maximizes External and Internal Tibial Orientations without Anterior Lift-Off Relative to Low- and Ultracongruent Surfaces
Background: In total knee arthroplasty (TKA), inserts can have different levels of medial and lateral congruency determined by the acuteness of the upslopes of the anterior and posterior articular surfaces. The present study evaluated an insert with different levels of lateral congruency and a media...
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| Format: | Article |
| Language: | English |
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MDPI AG
2022-08-01
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| Series: | Journal of Personalized Medicine |
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| Online Access: | https://www.mdpi.com/2075-4426/12/8/1274 |
| _version_ | 1797432049778294784 |
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| author | Alexander J. Nedopil Stephen M. Howell Maury L. Hull |
| author_facet | Alexander J. Nedopil Stephen M. Howell Maury L. Hull |
| author_sort | Alexander J. Nedopil |
| collection | DOAJ |
| description | Background: In total knee arthroplasty (TKA), inserts can have different levels of medial and lateral congruency determined by the acuteness of the upslopes of the anterior and posterior articular surfaces. The present study evaluated an insert with different levels of lateral congruency and a medial ball-in-socket congruency to test the hypothesis that a lateral flat (F) insert maximizes external tibial orientation at extension and internal orientation at 90° flexion and lowers the incidence of anterior lift-off relative to low-congruent (LC) and ultracongruent (UC) lateral inserts. Methods: Two surgeons treated 23 patients with unrestricted caliper-verified kinematic alignment (KA) and posterior cruciate ligament (PCL) retention. They randomly trialed inserts with a medial radial dial that functioned as a built-in goniometer by measuring the tibial orientation relative to a sagittal line on the femoral trial component. Anterior lift-off of the insert from the baseplate indicated PCL tightness. Results: The F insert’s mean of 9° of external tibial orientation was higher than that of the LC (5°, <i>p</i> < 0.0001) and UC inserts (2°, <i>p</i> < 0.0001). The −13° of internal tibial orientation at 90° flexion was higher than that of the LC (−9°, <i>p</i> < 0.0001) and UC inserts (−7°, <i>p</i> < 0.0001). The 0% incidence of anterior lift-off was less than that of the LC (26%) and UC inserts (57%) (<i>p</i> < 0.0001). Conclusions: Surgeons and implant manufacturers should know that adding congruency to the lateral articular surface limits external tibial orientation in extension and internal tibial orientation at 90° flexion and overtightens the PCL. These rotational limitations and flexion space tightness can adversely affect patellofemoral tracking and knee flexion. |
| first_indexed | 2024-03-09T09:54:40Z |
| format | Article |
| id | doaj.art-bf90e67044a849b08790fa6721073251 |
| institution | Directory Open Access Journal |
| issn | 2075-4426 |
| language | English |
| last_indexed | 2024-03-09T09:54:40Z |
| publishDate | 2022-08-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Journal of Personalized Medicine |
| spelling | doaj.art-bf90e67044a849b08790fa67210732512023-12-01T23:52:50ZengMDPI AGJournal of Personalized Medicine2075-44262022-08-01128127410.3390/jpm12081274A TKA Insert with A Lateral Flat Articular Surface Maximizes External and Internal Tibial Orientations without Anterior Lift-Off Relative to Low- and Ultracongruent SurfacesAlexander J. Nedopil0Stephen M. Howell1Maury L. Hull2Orthopädische Klinik König-Ludwig-Haus, Lehrstuhl für Orthopädie der Universität Würzburg, 97074 Wurzburg, GermanyDepartment of Biomedical Engineering, University of California, Davis, CA 95616, USADepartment of Biomedical Engineering, University of California, Davis, CA 95616, USABackground: In total knee arthroplasty (TKA), inserts can have different levels of medial and lateral congruency determined by the acuteness of the upslopes of the anterior and posterior articular surfaces. The present study evaluated an insert with different levels of lateral congruency and a medial ball-in-socket congruency to test the hypothesis that a lateral flat (F) insert maximizes external tibial orientation at extension and internal orientation at 90° flexion and lowers the incidence of anterior lift-off relative to low-congruent (LC) and ultracongruent (UC) lateral inserts. Methods: Two surgeons treated 23 patients with unrestricted caliper-verified kinematic alignment (KA) and posterior cruciate ligament (PCL) retention. They randomly trialed inserts with a medial radial dial that functioned as a built-in goniometer by measuring the tibial orientation relative to a sagittal line on the femoral trial component. Anterior lift-off of the insert from the baseplate indicated PCL tightness. Results: The F insert’s mean of 9° of external tibial orientation was higher than that of the LC (5°, <i>p</i> < 0.0001) and UC inserts (2°, <i>p</i> < 0.0001). The −13° of internal tibial orientation at 90° flexion was higher than that of the LC (−9°, <i>p</i> < 0.0001) and UC inserts (−7°, <i>p</i> < 0.0001). The 0% incidence of anterior lift-off was less than that of the LC (26%) and UC inserts (57%) (<i>p</i> < 0.0001). Conclusions: Surgeons and implant manufacturers should know that adding congruency to the lateral articular surface limits external tibial orientation in extension and internal tibial orientation at 90° flexion and overtightens the PCL. These rotational limitations and flexion space tightness can adversely affect patellofemoral tracking and knee flexion.https://www.mdpi.com/2075-4426/12/8/1274total knee arthroplastykinematic alignmentimplant designPCL retentioncongruency congruency |
| spellingShingle | Alexander J. Nedopil Stephen M. Howell Maury L. Hull A TKA Insert with A Lateral Flat Articular Surface Maximizes External and Internal Tibial Orientations without Anterior Lift-Off Relative to Low- and Ultracongruent Surfaces Journal of Personalized Medicine total knee arthroplasty kinematic alignment implant design PCL retention congruency congruency |
| title | A TKA Insert with A Lateral Flat Articular Surface Maximizes External and Internal Tibial Orientations without Anterior Lift-Off Relative to Low- and Ultracongruent Surfaces |
| title_full | A TKA Insert with A Lateral Flat Articular Surface Maximizes External and Internal Tibial Orientations without Anterior Lift-Off Relative to Low- and Ultracongruent Surfaces |
| title_fullStr | A TKA Insert with A Lateral Flat Articular Surface Maximizes External and Internal Tibial Orientations without Anterior Lift-Off Relative to Low- and Ultracongruent Surfaces |
| title_full_unstemmed | A TKA Insert with A Lateral Flat Articular Surface Maximizes External and Internal Tibial Orientations without Anterior Lift-Off Relative to Low- and Ultracongruent Surfaces |
| title_short | A TKA Insert with A Lateral Flat Articular Surface Maximizes External and Internal Tibial Orientations without Anterior Lift-Off Relative to Low- and Ultracongruent Surfaces |
| title_sort | tka insert with a lateral flat articular surface maximizes external and internal tibial orientations without anterior lift off relative to low and ultracongruent surfaces |
| topic | total knee arthroplasty kinematic alignment implant design PCL retention congruency congruency |
| url | https://www.mdpi.com/2075-4426/12/8/1274 |
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