Accuracy of computer navigation in total knee arthroplasty: A prospective computed tomography-based study

Area of Science:

• Orthopedic Surgery
• Medical Technology
• Biomechanical Engineering

Background:

• Computer navigation is increasingly advocated for total knee arthroplasty (TKA).
• Independent verification of the accuracy of new navigation systems is lacking.
• The Exactech Guided Personalised Surgery (GPS) system is one such technology requiring validation.

Purpose of the Study:

• To validate the in vivo accuracy of the Exactech GPS computer navigation system for TKA.
• To compare intraoperative 3D alignment measurements with postoperative CT-based assessments.

Main Methods:

• Prospective recruitment of consecutive patients undergoing TKA with the GPS system.
• Recording intraoperative 3D alignment parameters using the GPS navigation system.
• Comparing GPS measurements with alignment determined by the Perth CT Protocol postoperatively.

Main Results:

• A mean difference of 1.55° ± 0.22° was observed between intraoperative and postoperative alignment measures.
• Specific differences for femoral prosthesis alignment ranged from 1.38° ± 0.33° (rotation) to 2.07° ± 0.55° (flexion).
• Tibial prosthesis alignment differences were 2.03° ± 0.53° (coronal) and 1.14° ± 0.39° (slope), with whole limb coronal alignment at 2.34° ± 0.83°.

Conclusions:

• The Exactech GPS Navigation system demonstrates high accuracy in TKA.
• There is strong concordance between intraoperative and postoperative alignment and prosthesis positioning.
• The system's accuracy is validated, supporting its continued clinical use and encouraging validation of other systems.