Dimensional accuracy of TKA cut surfaces with an active robotic system

Area of Science:

• Orthopedic Surgery
• Robotics in Medicine
• Biomedical Engineering

Background:

• Robotic-assisted surgery is increasingly used in total knee arthroplasty (TKA).
• Ensuring the dimensional accuracy of bone cuts is critical for successful TKA outcomes.
• Current methods for assessing bone cut accuracy in robotic TKA require novel approaches.

Purpose of the Study:

• To evaluate the dimensional accuracy of femoral and tibial bone cuts made by a robotic system during TKA.
• To introduce and validate a novel methodology for measuring bone cut precision.

Main Methods:

• Robotic TKA performed on four cadaveric knees by a single surgeon.
• CT scans for pre-operative planning and nominal cut surface generation.
• Laser scanning of post-TKA bone cut surfaces and femoral components.
• Analysis of flatness, angular errors, and bone-to-implant gap.

Main Results:

• Average bone cut flatness was 0.16 ± 0.06 mm with low variability.
• Average angular errors for femoral cuts were 0.47 ± 0.39°, comparable to implant errors.
• Bone-to-implant gap was within ±1 mm for 97.9% of the surface on average.

Conclusions:

• The active robotic system demonstrated high dimensional accuracy for both femoral and tibial bone cuts in TKA.
• The novel measurement methodology proved effective in quantifying bone cut precision.
• Further comparative studies with other robotic systems and manual techniques are warranted.