Emil Toft Petersen1,2,3, Søren Rytter4,5,6, Daan Koppens7,6, Jesper Dalsgaard7, Torben Bæk Hansen7,4, Michael Skipper Andersen8, Maiken Stilling4,5,6. 1. University Clinic for Hand, Hip and Knee Surgery, Holstebro Central Hospital, Holstebro, Denmark. emiltp@clin.au.dk. 2. Department of Clinical Medicine, Aarhus University, Aarhus N, Denmark. emiltp@clin.au.dk. 3. AutoRSA Research Group, Orthopaedic Research Unit, Aarhus University Hospital, Aarhus N, Denmark. emiltp@clin.au.dk. 4. Department of Clinical Medicine, Aarhus University, Aarhus N, Denmark. 5. AutoRSA Research Group, Orthopaedic Research Unit, Aarhus University Hospital, Aarhus N, Denmark. 6. Department of Orthopaedic Surgery, Aarhus University Hospital, Aarhus N, Denmark. 7. University Clinic for Hand, Hip and Knee Surgery, Holstebro Central Hospital, Holstebro, Denmark. 8. Department of Materials and Production, Aalborg University, Aalborg, Denmark.
Abstract
PURPOSE: New total knee arthroplasty implant designs attempt to normalize kinematics patterns that may improve functional performance and patient satisfaction. It was hypothesized that a more medial congruent (MC) anatomic bearing design (1) influences the tibiofemoral kinematics and (2) enhances articular congruency compared to a standard symmetrical cruciate retaining (CR) bearing design. METHODS: In this double-blinded randomized study, 66 patients with knee osteoarthritis were randomly included in two groups: MC (n = 31) and CR (n = 33). Clinical characteristics such as knee ligament lesions and knee osteoarthritis scores were graded on preoperative magnetic resonance imaging and radiography. At the 1-year follow-up, dynamic radiostereometric analysis was used to assess tibiofemoral joint kinematics and articulation congruency. Patient-reported outcome measures, Oxford Knee Score, the Forgotten Joint Score, and the Knee Osteoarthritis Outcome Score, were assessed preoperatively and at the 1-year follow-up. RESULTS: Compared to the CR bearing, the MC bearing displayed an offset with approximately 3 mm greater anterior tibial drawer (p < 0.001) during the entire motion, and up to approximately 3.5 degrees more tibial external rotation (p = 0.004) from mid-swing to the end of the gait cycle at the 1-year follow-up. Furthermore, the congruency area in the joint articulation was larger during approximately 80% of the gait cycle for the MC bearing compared to the CR. The patient-reported outcome measures improved (p < 0.001), but there were no differences between groups. In addition, there were no differences in clinical characteristics and there were no knee revisions or recognized deep infections during follow-up. CONCLUSION: The study demonstrates that the MC-bearing design changes tibiofemoral kinematics and increases the area of congruency towards more native knee kinematics than the CR bearing. In perspective this may contribute to a more stabilized knee motion, restoring the patient's confidence in knee function during daily activities.
PURPOSE: New total knee arthroplasty implant designs attempt to normalize kinematics patterns that may improve functional performance and patient satisfaction. It was hypothesized that a more medial congruent (MC) anatomic bearing design (1) influences the tibiofemoral kinematics and (2) enhances articular congruency compared to a standard symmetrical cruciate retaining (CR) bearing design. METHODS: In this double-blinded randomized study, 66 patients with knee osteoarthritis were randomly included in two groups: MC (n = 31) and CR (n = 33). Clinical characteristics such as knee ligament lesions and knee osteoarthritis scores were graded on preoperative magnetic resonance imaging and radiography. At the 1-year follow-up, dynamic radiostereometric analysis was used to assess tibiofemoral joint kinematics and articulation congruency. Patient-reported outcome measures, Oxford Knee Score, the Forgotten Joint Score, and the Knee Osteoarthritis Outcome Score, were assessed preoperatively and at the 1-year follow-up. RESULTS: Compared to the CR bearing, the MC bearing displayed an offset with approximately 3 mm greater anterior tibial drawer (p < 0.001) during the entire motion, and up to approximately 3.5 degrees more tibial external rotation (p = 0.004) from mid-swing to the end of the gait cycle at the 1-year follow-up. Furthermore, the congruency area in the joint articulation was larger during approximately 80% of the gait cycle for the MC bearing compared to the CR. The patient-reported outcome measures improved (p < 0.001), but there were no differences between groups. In addition, there were no differences in clinical characteristics and there were no knee revisions or recognized deep infections during follow-up. CONCLUSION: The study demonstrates that the MC-bearing design changes tibiofemoral kinematics and increases the area of congruency towards more native knee kinematics than the CR bearing. In perspective this may contribute to a more stabilized knee motion, restoring the patient's confidence in knee function during daily activities.
Authors: Hans A Gray; Shanyuanye Guan; Lucas T Thomeer; Anthony G Schache; Richard de Steiger; Marcus G Pandy Journal: J Orthop Res Date: 2019-02-27 Impact factor: 3.494
Authors: Stefano Ghirardelli; Jessica L Asay; Erika A Leonardi; Tommaso Amoroso; Thomas P Andriacchi; Pier Francesco Indelli Journal: J Funct Morphol Kinesiol Date: 2021-03-15