Does accelerometer-based portable navigation provide more accurate and precise cup orientation without prosthetic...

Area of Science:

• Orthopedic Surgery
• Medical Technology
• Biomechanical Engineering

Background:

• Hip replacement surgery aims for optimal cup orientation to maximize range of motion and minimize impingement.
• Conventional mechanical guides have limitations in achieving precise cup positioning.
• Advancements in surgical navigation aim to improve accuracy and patient outcomes.

Purpose of the Study:

• To compare the accuracy and precision of accelerometer-based navigation versus conventional mechanical guides for cup orientation in total hip arthroplasty.
• To evaluate the impact of cup orientation on potential hip range of motion (RoM) and prosthetic impingement using CT-based simulation.

Main Methods:

• A prospective randomized controlled study involving 60 hips allocated to either accelerometer-based navigation or conventional guidance.
• Standard posterolateral approach and combined anteversion technique were employed.
• Computed tomography (CT) was used to measure cup inclination, cup anteversion, and stem anteversion; CT-based simulation assessed impingement-free RoM.

Main Results:

• No significant differences in absolute cup inclination and anteversion error were found between the navigation and conventional groups.
• Accelerometer-based navigation demonstrated significantly less variation in anteversion error (p = .0049), indicating greater precision.
• The navigation cohort showed a trend towards greater potential extension and external rotation (ER), though differences in achieving daily activity RoM and avoiding impingement were not significant.

Conclusions:

• Accelerometer-based navigation offers enhanced precision for cup anteversion in hip replacement compared to conventional guides.
• While accuracy was comparable, the navigation system may facilitate improved hip joint mechanics.
• Both methods achieved satisfactory functional outcomes regarding impingement-free range of motion for daily activities.