The Reliability of Sensor-Assisted Soft Tissue Measurements in Primary Total Knee Arthroplasty

Area of Science:

• Orthopedic Surgery
• Biomedical Engineering
• Surgical Technology

Background:

• Improving soft tissue balance is crucial for successful total knee arthroplasties (TKAs).
• A novel wireless device has been developed to measure femorotibial pressures during TKAs.
• Evaluating the reliability of this new device is essential for its clinical adoption.

Purpose of the Study:

• To assess the reliability of a wireless sensor for measuring femorotibial contact pressures in total knee arthroplasty.
• To determine the consistency of pressure measurements under different visual feedback conditions (blinded vs. observed).

Main Methods:

• Contact pressures were measured three times using a wireless sensor after 33 TKAs were balanced conventionally.
• Measurements were taken twice with the examiner blinded to the results and once with visual feedback.
• Femorotibial pressures were recorded in medial and lateral compartments at 10°, 45°, and 90° flexion, with additional calculations for combined and differential pressures.

Main Results:

• The intraclass correlation coefficient (ICC) between blind measurements showed poor reliability in 17%, moderate in 33%, and good in 50% of cases.
• The ICC between blind and observed measurements indicated poor reliability in 17%, moderate in 50%, and good in 33% of cases.
• Measurements at 10° of knee flexion demonstrated particularly lower reliability.

Conclusions:

• The wireless sensor demonstrates moderate to good reliability in 83% of measurements for assessing femorotibial pressures.
• The device shows potential utility in improving soft tissue balancing during total knee arthroplasty procedures.
• Further investigation may be needed to optimize measurement protocols, especially at lower flexion angles.