Kinematic Comparison between Medially Congruent and Posterior-Stabilized Third-Generation TKA Designs

Abstract

Background: This study compares knee kinematics in two groups of patients who have undergone primary total knee arthroplasty (TKA) using two different modern designs: medially congruent (MC) and posterior-stabilized (PS). The aim of the study is to demonstrate only minimal differences between the groups. Methods: Ten TKA patients (4 PS, 6 MC) with successful clinical outcomes were evaluated through 3D knee kinematics analysis performed using a multicamera optoelectronic system and a force platform. Extracted kinematic data included knee flexion angle at heel-strike (KFH), peak midstance knee flexion angle (MSKFA), maximum and minimum knee adduction angle (KAA), and knee rotational angle at heel-strike. Data were compared with a group of healthy controls. Results: There were no differences in preferred walking speed between MC and PS groups, but we found consistent differences in knee function. At heel-strike, the knee tended to be more flexed in the PS group compared to the MC group; the MSKFA tended to be higher in the PS group compared to the MC group. There was a significant fluctuation in KAA during the swing phase in the PS group compared to the MC group, PS patients showed a higher peak knee flexion moment compared to MC patients, and the PS group had significantly less peak internal rotation moments than the MC group. Conclusions: Modern, third-generation TKA designs failed to reproduce normal knee kinematics. MC knees tended to reproduce a more natural kinematic pattern at heel-strike and during axial rotation, while PS knees showed better kinematics during mid-flexion.

Association of a Wider Medial Gap (Medial Laxity) in Flexion with Self-Reported Knee Instability After Medial-Pivot Total Knee Arthroplasty

“…Patients who experienced knee instability showed significantly worse clinical results than those who did not experience knee instability. The medial compartment in medial-pivot TKA has a ball-and-socket shape and is the key to stability 7,8 . The results of this study suggest that if the medial postoperative flexion joint gap increases, knee stability may not be present on the medial side.…”

“…Nonetheless, the medial-pivot TKA might have an advantage in subjective symptoms. Medial-pivot TKA is designed to reproduce the native knee kinematics by providing high medial conformity and ample lateral space, and medial compartment stability is key to knee stability and good postoperative clinical results [6][7][8] . Therefore, in cases in which patients experience subjective knee instability postoperatively, medial-pivot TKA may have a negative effect on PROMs because of its design.…”

Intraoperative Load Sensing in Total Knee Arthroplasty Leads to a Functional but Not Clinical Difference: A Comparative, Gait Analysis Evaluation

“…Dennis et al showed a reduction in the articular motion and sagittal joint moment following TKA, independently from the level of intra-articular constraint [ 14 ]. Limitation of joint mobility up to a real stiffness represents a well-known strategy adopted by patients with advanced knee OA [ 38 ].…”

“…Gait Analysis showed to be an accurate and non-invasive tool to study in vivo joints kinetic and kinematic during the range of motion (ROM) [ 12 , 13 , 14 ]. In the TKA world, it has been used to evaluate the in vivo kinematic of the knee during the Load-Response (LR), Mid-Stance (MS) and Swing phases of gait.…”

Designing a Multiaxial Extensometric Force Platform: A Manufacturing Experience

“…Table 1 presents some of the initiatives that include the development of force platform projects in the literature. The studies on postural analysis are focused only on the use of force platforms [18][19][20][21][22][23][24][25][26][27] and are much more numerous, differently from the projects and research that show greater emphasis on the development of these platforms. The works analyzed in [5,6,[9][10][11][12][15][16][17] present descriptions that are very superficial and difficult to reproduce, in addition to all making use of load cells for commercial use, significantly increasing the cost of prototypes.…”