Second-Generation Electronic Ligament Balancing for Knee Arthroplasty: A Cadaver Study

Area of Science:

• Orthopedic Surgery
• Biomedical Engineering
• Biomechanics

Background:

• Knee instability is a significant complication following total knee arthroplasty (TKA).
• Ligament laxity and component alignment are key factors influencing TKA outcomes.
• Current knee balancing relies heavily on surgeon's subjective assessment.

Purpose of the Study:

• To evaluate the accuracy of an electronic ligament-balancing device in quantifying knee balance corrections after soft-tissue releases.
• To measure the change in knee laxity following medial release during TKA procedures.

Main Methods:

• A second-generation electronic ligament-balancing device was compared against two mechanical instruments.
• The study involved 12 cadaver knees undergoing total knee arthroplasty (TKA).
• Measurements were taken sequentially: pre-TKA, post-trial component, post-medial release, and post-PCL resection.

Main Results:

• The electronic device demonstrated superior accuracy over mechanical instruments in measuring distracted gap and force.
• Medial release increased the medial gap in flexion and induced greater passive knee valgus laxity.
• Posterior cruciate ligament (PCL) release enlarged the tibiofemoral gap, particularly the lateral aspect.

Conclusions:

• The electronic balancing device proved significantly more accurate than mechanical methods.
• This device can accurately record knee balance across the full range of flexion.
• Improved accuracy in soft-tissue balancing holds potential for enhanced TKA patient outcomes.