Effects of the Medial Plateau Bearing Insert Conformity on Mid-Flexion Paradoxical Motion in a Posterior-Stabilized Total Knee Arthroplasty Design
| Autor: | Milad Khasian, M LaCour, B Meccia, Richard D. Komistek |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
musculoskeletal diseases
Knee Joint media_common.quotation_subject Total knee arthroplasty Kinematics Prosthesis Design Conformity Condyle law.invention Contact force 03 medical and health sciences 0302 clinical medicine law Medicine Humans Orthopedics and Sports Medicine Range of Motion Articular Arthroplasty Replacement Knee media_common Orthodontics 030222 orthopedics Bearing (mechanical) business.industry musculoskeletal system Sagittal plane Biomechanical Phenomena medicine.anatomical_structure business Knee Prosthesis |
| Zdroj: | The Journal of arthroplasty. 36(7) |
| ISSN: | 1532-8406 |
| Popis: | Background One of the most common kinematic abnormalities reported for posterior-stabilized (PS) total knee arthroplasty (TKA) design is paradoxical anterior sliding during early and mid-flexion. PS TKAs have been designed such that the cam-post mechanism does not engage until later in flexion, making these implants vulnerable to anterior sliding during early and mid-flexion. The objective of this study is to investigate the biomechanical effect of increasing bearing conformity on a PS TKA. Methods Using a validated computational model of the knee joint, the sagittal conformity of the medial plateau of a PS TKA design was altered. Three scenarios were created and evaluated for mechanics: (1) baseline conformity, (2) increased conformity, and (3) decreased conformity. Results From full extension to approximately 70° of knee flexion, the medial condyle demonstrated minimal anterior sliding for the increased medial conformity design but revealed anterior sliding of 2 and 4 mm for the baseline and decreased conformity designs, respectively. After cam-post engagement, the medial condyle consistently rolled back for all 3 designs. The lateral condyle experienced consistent rollback throughout the entire flexion range for all 3 designs. However, femorotibial contact force was higher for the increased conformity design, peaking at 3.13 times body weight (×BW) compared to 3.0 × BW contact force for other 2 designs. Conclusion Increasing medial conformity of the bearing insert appears to reduce mid-flexion sliding for PS TKA designs, although this comes at the expense of increased femorotibial forces. This could be due to kinematic conflicts that may be introduced with highly constraining designs. |
| Databáze: | OpenAIRE |
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