The Effects of Tibiofemoral Conformity on the Kinematic Freedom of Revision Total Knee Arthroplasty Systems

Motivation Revision Total Knee Arthroplasty (rTKA) is commonly used to revise a primary procedure or to address severe deformities in a complex primary procedure. In both situations, residual knee instability could pose challenges in achieving satisfactory soft-tissue balance. These concerns can be addressed by increasing tibiofemoral conformity in the revision knee systems. However, highly conforming designs may restrict the tibiofemoral kinematic freedom at the joint. Therefore, the revision knee system must provide sufficient joint stability without constraining the desired kinematic freedom. The objective of this work was to describe the tibiofemoral kinematics and passive laxity envelope of three contemporary revision knee systems in a controlled setting and relate those differences to design characteristics. Methods Twelve cadaveric knees (age: 69.5±18.5 years, BMI 25.3±4.3) were implanted with a DePuy Synthes ATTUNE® Revision, Zimmer Biomet NexGen® LCCK, or a Zimmer Biomet Vanguard® 360 revision knee system by a trained orthopedic surgeon. Each knee had two assessments, a dynamically simulated weight-bearing gait and squat activities and a passive laxity envelope. Profiles with increasing internal-external (IE) torques were applied to each knee during the physiological simulation. Results The change in varus-valgus (VV) motion with an increased IE torque was minimal for all three systems. However, an increased IE torque showed an increase in IE rotational motion for the ATTUNE® Revision knee compared to the NexGen® LCCK and Vanguard® 360 Revision knee systems. Discussion The VV and IE rotations observed in both squat and gait kinematics as well as passive laxity envelope were similar for each system; though, there was a slight increase in IE rotational freedom seen in the ATTUNE® Revision implants. The additional IE motion allowed by the ATTUNE® Revision implants could promote soft tissue contribution while maintaining VV stability.

Grantor dc:publisher

University of Kansas

Year dc:date.issued

2019

Author dc:creator

• Howard, Kaitlyn Callahan

Advisor dc:contributor.advisor

• Maletsky, Lorin P

• Biomechanics
• Bioengineering
• Biomedical engineering
• knee laxity
• passive laxity envelope
• revision knee system
• Revision Total Knee Arthroplasty
• tibiofemoral conformity
• tibiofemoral kinematics

Statement dc:rights

• Copyright held by the author.

Language dc:language.iso

en

Dc Identifier Other

http://dissertations.umi.com/ku:16818

OAI identifier oai:identifier

oai:kuscholarworks.ku.edu:1808/36653