The effectiveness of sequential medial soft tissue release on coronal alignment in total knee arthroplasty: using a...

Area of Science:

• Orthopaedic Surgery
• Biomechanical Analysis
• Surgical Navigation Technology

Background:

• Effective soft tissue management is critical for successful total knee arthroplasty (TKA).
• Understanding the precise biomechanical effects of sequential soft tissue release is essential for optimizing limb alignment and joint stability.
• Previous studies often lack precise, real-time measurement of these effects during surgery.

Purpose of the Study:

• To analyze the relationship between sequential medial soft tissue release and changes in the anteroposterior limb axis and tibiofemoral gaps during TKA.
• To quantify the impact of specific release maneuvers (e.g., medial collateral ligament release, posterior cruciate ligament sacrifice) on knee kinematics.
• To leverage computer-assisted surgery for objective, navigation-controlled assessment of soft tissue manipulation.

Main Methods:

• Utilized a CT-free navigation system (Ci navigation system) for intraoperative measurements.
• Sequentially performed medial soft tissue releases in a controlled manner.
• Measured changes in the anteroposterior limb axis and tibiofemoral gaps at different stages of release and knee flexion (extension and 90 degrees).

Main Results:

• Each release step significantly affected the leg axis (P < .001).
• The most substantial changes in leg axis occurred with a 6-cm release in extension and medial collateral ligament release at 90 degrees flexion.
• Medial gap differences were significant for most release steps, with the greatest increase observed after posterior cruciate ligament sacrifice in both extension and 90 degrees flexion.

Conclusions:

• Computer-assisted surgery provides a valuable tool for precisely evaluating the biomechanical consequences of soft tissue release in TKA.
• Sequential release of medial soft tissues significantly alters limb alignment and tibiofemoral kinematics.
• This navigation-controlled study offers critical insights into optimizing soft tissue management strategies for total knee arthroplasty.