scholarly journals Kinematic Analysis of Total Knee Arthroplasty using Verasense: Genesis-II prosthesis versus Anthem prosthesis

2020 ◽  
Vol 8 (5_suppl5) ◽  
pp. 2325967120S0010
Author(s):  
Ik-sun Choi ◽  
Seung-Min Na ◽  
Jong-Keun Seon ◽  
Eun-Kyoo Song
Keyword(s):  
Femoral Component ◽  
External Rotation ◽  
Lateral Compartment ◽  
Medial Compartment ◽  
Femoral Rotation ◽  
Significant Difference ◽  
Total Knee ◽  
Genesis Ii ◽  
Femoral Rollback ◽  
Roll Back

Purpose The purpose of this study was to elucidate kinematic change according to the implant’s specific femoral rotation by using orthosensor (Verasense) implant with three degrees external rotation of femoral rotation rebuilt (Genesis-II) and traditional TKA implant without rebuilt of the femoral rotation (Anthem). Methods Twenty-eight patients (34 knees) underwent TKA using Anthem (Smith &Nephew, Memphis, TN, USA) and 16 patients (22 knees) underwent TKA using Genesis-II (Smith & Nephew, Memphis, TN, USA). Patients were followed up for at least 1 year. Mean age of patients was 71.1 years (range, 60 to 80 years) at the time of surgery. After implantation of femur and tibial components, we applied Verasense, the orthosensor system, to evaluate femoral rollback of the new artificial joint. Femoral rollback was analyzed using digitized screenshot function of Verasense. Results Overall femoral tracking proportion regardless of implants was significantly higher on the medial compartment compared to that on the lateral compartment (13.3 ±8.4% vs. 6.3 ± 5.0%, p < 0.001). Regarding femoral tracking according to each compartment, Genesis-II and Anthem showed 12.1 ± 8.2% and 14.2 ± 8.6% ( p = 0.371) on the medial compartment and 8.0 ± 5.8% and 5.2 ± 4.2% ( p = 0.059) on the lateral compartment, respectively. Conclusion Our study showed reverse femoral roll-back movement with higher tracking distance on the lateral compartment during TKA. Genesis-II TKA system with femoral component 3-degree rebuilt showed less roll-back difference between medial and lateral compartments compared to traditional TKA system. Fortunately, both TKA systems had excellent short-term clinical outcomes without having significant difference between the two. With longer follow-up and larger cohort, the advantage and effectiveness of femoral component rotation can be elucidated in the future.

scholarly journals Kinematic Analysis of Total Knee Arthroplasty(TKA) using Orthosensor system: Externally rotated femoral prosthesis versus Traditional design prosthesis

10.29007/95p5 ◽  
2020 ◽  
Author(s):  
Seung-Min Na ◽  
Gun-Woo Kim ◽  
Nam-Hun Lee ◽  
Young-Woo Chung ◽  
Jongkeun Seon ◽  
...  
Keyword(s):  
Femoral Component ◽  
External Rotation ◽  
Lateral Compartment ◽  
Medial Compartment ◽  
Femoral Rotation ◽  
Femoral Prosthesis ◽  
Significant Difference ◽  
Total Knee ◽  
Femoral Rollback ◽  
Roll Back

Purpose The purpose of this study was to elucidate kinematic change according to the implant’s specific femoral rotation by using orthosensor implant with three degrees external rotation of femoral rotation rebuilt and traditional TKA implant without rebuilt of the femoral rotation .Methods Twenty-eight patients (34 knees) underwent TKA using traditional TKA implant and 16 patients (22 knees) underwent TKA using implant with three degrees external rotation of femoral rotation. Patients were followed up for at least 1 year. Mean age of patients was 71.1 years (range, 60 to 80 years) at the time of surgery. After implantation of femur and tibial components, we applied the orthosensor system, to evaluate femoral rollback of the new artificial joint. Femoral rollback was analyzed using digitized screenshot function of orthosensor system.Results Overall femoral tracking proportion regardless of implants was significantly higher on the medial compartment compared to that on the lateral compartment (13.3 ± 8.4% vs. 6.3 ± 5.0%, p &lt; 0.001). Regarding femoral tracking according to each compartment, externally rotated femoral prosthesis and traditional prosthesis showed 12.1 ± 8.2% and 14.2 ± 8.6% (p = 0.371) on the medial compartment and 8.0 ± 5.8% and 5.2 ± 4.2% (p = 0.059) on the lateral compartment, respectively.Conclusion Our study showed reverse femoral roll-back movement with higher tracking distance on the lateral compartment during TKA. externally rotated femoral prosthesis TKA system with femoral component 3-degree rebuilt showed less roll-back difference between medial and lateral compartments compared to traditional TKA system. Fortunately, both TKA systems had excellent short-term clinical outcomes without having significant difference between the two. With longer follow-up and larger cohort, the advantage and effectiveness of femoral component rotation can be elucidated in the future.

Biomechanical Comparison of Kinematic and Mechanical Knee Alignment Techniques in a Computer Simulation Medial Pivot Total Knee Arthroplasty Model

2021 ◽  
Author(s):  
Young Dong Song ◽  
Shinichiro Nakamura ◽  
Shinichi Kuriyama ◽  
Kohei Nishitani ◽  
Hiromu Ito ◽  
...  
Keyword(s):  
Femoral Component ◽  
Knee Flexion ◽  
External Rotation ◽  
Knee Kinematics ◽  
Lateral Compartment ◽  
Contact Stresses ◽  
Contact Forces ◽  
Medial Compartment ◽  
Tibial Insert ◽  
Medial Pivot

AbstractSeveral concepts may be used to restore normal knee kinematics after total knee arthroplasty. One is a kinematically aligned (KA) technique, which restores the native joint line and limb alignment, and the other is the use of a medial pivot knee (MPK) design, with a ball and socket joint in the medial compartment. This study aimed to compare motions, contact forces, and contact stress between mechanically aligned (MA) and KA (medial tilt 3° [KA3] and 5° [KA5]) models in MPK. An MPK design was virtually implanted with MA, KA3, and KA5 in a validated musculoskeletal computer model of a healthy knee, and the simulation of motion and contact forces was implemented. Anteroposterior (AP) positions, mediolateral positions, external rotation angles of the femoral component relative to the tibial insert, and tibiofemoral contact forces were evaluated at different knee flexion angles. Contact stresses on the tibial insert were calculated using finite element analysis. The AP position at the medial compartment was consistent for all models. From 0° to 120°, the femoral component in KA models showed larger posterior movement at the lateral compartment (0.3, 6.8, and 17.7 mm in MA, KA3, and KA5 models, respectively) and larger external rotation (4.2°, 12.0°, and 16.8° in the MA, KA3, and KA5 models, respectively) relative to the tibial component. Concerning the mediolateral position of the femoral component, the KA5 model was positioned more medially. The contact forces at the lateral compartment of all models were larger than those at the medial compartment at >60° of knee flexion. The peak contact stresses on the tibiofemoral joint at 90° and 120° of knee flexion were higher in the KA models. However, the peak contact stresses of the KA models at every flexion angle were <20 MPa. The KA technique in MPK can successfully achieve near-normal knee kinematics; however, there may be a concern for higher contact stresses on the tibial insert.

Incidence of Femoral Component Malrotation Using Posterior Condylar Referencing in Total Knee Arthroplasty

2019 ◽  
Vol 33 (10) ◽  
pp. 971-977
Author(s):  
Diana K. Lee ◽  
Matthew J. Grosso ◽  
David P. Trofa ◽  
Julian J. Sonnenfeld ◽  
H. John Cooper ◽  
...  
Keyword(s):  
Total Knee Arthroplasty ◽  
Femoral Component ◽  
Knee Arthroplasty ◽  
External Rotation ◽  
Prognostic Impact ◽  
Posterior Condylar Axis ◽  
Femoral Component Rotation ◽  
Component Rotation ◽  
Posterior Condylar ◽  
Total Knee

AbstractProper femoral component rotation in total knee arthroplasty (TKA) is important, given the prognostic impact of a poorly positioned component. The purpose of this observational study was to determine the incidence of femoral component malrotation using posterior condylar axis (PCA) referencing. A total of 100 knees in 92 patients with varus gonarthritis of the knee undergoing primary TKA using a standard medial parapatellar approach were evaluated intraoperatively. After distal femoral resection, the standard femoral sizing guide referencing the posterior condylar axis was used to set femoral component rotation. This was then compared with both the transepicondylar (TEA) and trochlear anteroposterior axes (TRAx). Disparites were recorded and corrected in line with the epicondylar axis. Rotational adjustment for addition of further external rotation was made in 13 (13.0%) cases. In seven cases, the medial pin sites were raised between 1 and 3 mm, and in six cases, the lateral pin site was lowered between 1 and 3 mm (based on risk of notching the femoral cortex). It is critical to not rely exclusively on the PCA to confirm rotational positioning of the femoral component as predicted by posterior condylar referencing guides. Intraoperative adjustment and confirmation using the TEA and TRAx occurred in 13% of primary TKA cases, which might have, otherwise, had a significant effect on the clinical outcome.

scholarly journals Correlation Between Asymmetric Resection of Posterior Femoral Condyles and Femoral Component Rotation in Total Knee Arthroplasty

2014 ◽  
Vol 2 (11_suppl3) ◽  
pp. 2325967114S0014
Author(s):  
Harun Reşit Güngör ◽  
Nusret Ök ◽  
Kadir Ağladıoğlu ◽  
Semih Akkaya ◽  
Esat Kıter
Keyword(s):  
Total Knee Arthroplasty ◽  
Femoral Component ◽  
Knee Arthroplasty ◽  
Trochlear Groove ◽  
Femoral Component Rotation ◽  
Component Rotation ◽  
Significant Difference ◽  
Total Knee ◽  
The Mean ◽  
The Asymmetry

Objectives: Pertaining to peculiar designs of current knee prostheses, more bone is removed from posteromedial femoral condyle than posterolateral condyle to obtain desired femoral component rotation. The aim of our study was to evaluate whether there is a correlation between the asymmetry of the cuts and the femoral component rotation in total knee arthroplasty. Methods: We built a model to simulate anterior chamfer cut (ACC) performed during total knee arthroplasty for measuring posterior condylar offset (PCO). Right knee axial MRI slices of a total 290 consecutive patients (142 male, 138 female, and mean age 31.39 ± 6.6) were examined. A parallel line to surgical transepiphyseal axis was drawn, and placed at the deepest part of trochlear groove. Posteromedial and posterolateral condylar offsets were measured by drawing perpendicular lines to ACC beginning from the intersection points of both anteromedial and anterolateral cortices to posterior joint line (PJL), respectively. Differences between posteromedial and posterolateral PCO were calculated, and femoral rotation angles (FRA) relative to PJL were measured. Results: The mean surgical FRA was 4.76 ± 1.16 degrees and the mean PCO differencesss- was 4.35 ± 1.04 mm for the whole group and there was no statistically significant difference between genders. There was a strong correlation between surgical FRA and PCO difference (p<0.0001, r=0.803). Linear regression analyses revealed that 0.8 mm of difference between the anteroposterior dimensions of medial and lateral PCO corresponds to 1 degree of surgical FRA (p<0.0001, R2=0.645). Conclusion: Correlation between the asymmetry of posterior chamfer cuts and achieved femoral component rotation can verify the accuracy of desired rotation, intraoperatively. However, further clinical investigations should be planned to test the results of our morphometric study.

scholarly journals The comparison of femoral component rotation in the total knee arthroplasty

2017 ◽  
Vol 17 (3) ◽  
pp. 24-31
Author(s):  
M Chmurny ◽  
S Krivanek ◽  
M Melisik ◽  
M Rovnak ◽  
L. Necas
Keyword(s):  
Total Knee Arthroplasty ◽  
Femoral Component ◽  
Knee Arthroplasty ◽  
Significance Level ◽  
Femoral Component Rotation ◽  
Gap Technique ◽  
Component Rotation ◽  
Significant Difference ◽  
Total Knee ◽  
Balanced Gap Technique

Abstract Introduction Background: Optimal femoral component rotation in total knee arthroplasty (TKA) is crucial to establish a balanced knee reconstruction. Unbalanced knees can lead to instability, patellofemoral problems, persistent pain, stiffness, and generally poorer outcomes including early failure. There are several methods to achieve the femoral component rotation such as balanced gap technique, measured resection technique, and bone landmarks such as transepicondylar line (TEA) and Whiteside line. The purpose of this study was to compare the balan ced gap technique with the TEA technique. Materials and Methods: This randomised prospective study compares the femoral component rotation obtained with the use of balanced gap technique and the TEA, as well as compares the differences due to preoperative knee desaxations. The study includes 50 knees, 19 with neutral alignment, 22 with varus, and 9 with valgus desaxation. The femoral component rotation was measured postoperatively on photodocumentation taken after determining the TEA and balanced gap technique line peroperatively. These lines were compared to the posterior femoral condyles obtaining the degree of rotation. In case of transepicondylar line it is condylar twist angle (CTA) and in case of ligament balancer rotation axis it is ligament balancer angle (LBA). Results: The statistically significant differences in femoral component rotation using the techniques mentioned above as well as differences in individual knee desaxations were observed. The average LBA was 3.42 degrees and average CTA 3.58 in neutral knees group, but in the varus knees the average CTA value was 2.27 degrees and LBA value was 1.05 degrees. The average CTA value in patients with valgus desaxation is 4.78 degrees and LBA value is 5.22 degrees. According to Tukey Post Hoc test a statistically significant difference in LBA value is between neutral and varus knees with a significance level of p = 0.000022 and the most significant difference between varus and valgus knees with a significance level of p = 0.000011. Conclusion: The statistically significant differences in femoral component rotation using the techniques mentioned above as well as differences in individual knee desaxations were observed.

External rotation of the femoral component decreases patellofemoral contact stress in total knee arthroplasty

2014 ◽  
Vol 23 (11) ◽  
pp. 3266-3272 ◽  
Author(s):  
Takashi Terashima ◽  
Tomohiro Onodera ◽  
Naohiro Sawaguchi ◽  
Yasuhiko Kasahara ◽  
Tokifumi Majima
Keyword(s):  
Total Knee Arthroplasty ◽  
Femoral Component ◽  
Contact Stress ◽  
Knee Arthroplasty ◽  
External Rotation ◽  
Total Knee

scholarly journals Impact of surgeon’s hand and ocular dominance on right and left total knee arthroplasty alignment

2017 ◽  
Vol 86 (1) ◽  
pp. 5-7
Author(s):  
Shizar Goosheh ◽  
Jacalyn Thoren ◽  
Douglas Naudie ◽  
Mathew Teeter ◽  
James Howard ◽  
...  
Keyword(s):  
Total Knee Arthroplasty ◽  
Knee Arthroplasty ◽  
Ocular Dominance ◽  
Left Knee ◽  
Surgical Performance ◽  
Pain Scores ◽  
Significant Difference ◽  
Total Knee ◽  
Genesis Ii ◽  
Postoperative Knee

Postoperative alignment is an important modifiable confounder that contributes to the longevity of total knee arthroplasty (TKA). Studies have shown that surgeon’s handedness can affect surgical performance; however, no studies have assessed the effect of surgeon’s hand or ocular dominance on TKA alignment. The purpose of this study was to evaluate the effect of surgeon’s hand and ocular dominance on coronal plane alignment in TKA. We retrospectively evaluated 138 patients who underwent sequential bilateral TKA by the same surgeon, using the Genesis II PS knee (Smith & Nephew, Memphis, TN). We assessed postoperative alignment by measuring and comparing anatomical tibiofemoral angle (TFA) bilaterally on standard postoperative knee radiographs, as well as Knee Society function and pain scores to determine any functional differences. Lastly, we evaluated whether a crossed hand-ocular dominant surgeon had greater accuracy when performing a TKA on the side opposite their hand dominance compared to uncrossed hand-ocular dominant surgeons. All surgeons were right-hand dominant and there was a significantly larger anatomical TFA on left TKAs (mean [SD], 4.6° [2.8°]) compared to right TKAs (3.8° [2.5°]) (P = 0.003). There was no significant difference between right and left Knee Society function (P = 0.09) and pain scores (P = 0.86). When comparing left TKAs, surgeons with uncrossed hand-ocular dominance (4.5°) performed with equal accuracy compared to surgeons with crossed hand-ocular dominance (4.8°) (2-tailed test = 0.597), indicating no effect of ocular dominance. In summary, hand but not ocular dominance was shown to have significant postoperative alignment effects on TKA.

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