2021 ISAKOS Biennial Congress ePoster
Comparable kinematic behaviour between an ultracongruent and a posterior stabilized total knee arthroplasty design during in vivo sit-to-stand
Stefano Zaffagnini, MD, Prof., Bologna ITALY
Tommaso Roberti di Sarsina, MD, Bologna ITALY
Domenico Alesi, MD, Bologna ITALY
Stefano Di Paolo, Eng, Bologna ITALY
Raffaele Zinno, MSc, Bologna ITALY
Nicola Pizza, MD, Bologna ITALY
Giulio Maria Marcheggiani Muccioli, MD, PhD, Associate Professor, Bologna ITALY
Laura Bragonzoni, Prof., Bologna ITALY
IRCCS Istituto Ortopedico Rizzoli, Bologna, ITALY
FDA Status Cleared
Summary
The TKA designs evaluated in the present study by dynamic RSA showed comparable in-vivo kinematics in terms of medial pivot pattern, but differences in terms of absolute AP translation.
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Abstract
Purpose
To compare the in-vivo under weight-bearing kinematic behavior of a posterior-stabilized (PS) and of an ultra-congruent (UC) total knee arthroplasty (TKA) during a sit-to-stand motor task.
The hypothesis was that UC and PS designs would present a comparable kinematics.
Methods
A cohort of 16 randomly selected patients (8 PS Persona Zimmer, 8 UC Persona Zimmer; mean age 70.0 ± 7.3 years old) was evaluated through dynamic radiostereometric analysis (RSA) at a minimum of 9 months after TKA, during the execution of a sit-to-stand motor task. The anteroposterior (AP) translation of the femoral component and the AP translation of the Low Point (tibio-femoral contact point) of medial and lateral femoral compartments were compared through Student’s t test (p < 0.05).
Results
A significantly greater anterior translation of the femoral component was found for the PS group compared to the UC group, mainly to almost complete extension (p=0.017). Both groups showed a significantly greater anterior translation of the Low Point of the lateral compartment with respect to the medial one (PS: p=0.0117, UC: p= 0.0181). This was consistent with a medial-pivot pattern. Furthermore, a comparison of the anterior translation of the medial compartment between the PS group and the UC group was statistically significant and showed a greater excursion in the PS group (p= 0.001). The same pattern was observed for the lateral compartment (p=0.0065).
Conclusions
The TKA designs evaluated in the present study by dynamic RSA showed comparable in-vivo kinematics in terms of medial pivot pattern, but differences in terms of absolute AP translation.