Related Experiment Video
Updated: Mar 23, 2026
Cone Beam Intraoperative Computed Tomography-based Image Guidance for Minimally Invasive Transforaminal Interbody Fusion
Published on: August 6, 2019
Radiographic outcomes in the coronal plane with iASSIST™ versus optical navigation for total knee arthroplasty: A
A Desseaux1, P Graf2, F Dubrana1
1Université de Bretagne occidentale, faculté de médecine, 22, avenue Camille-Desmoulins, 29200 Brest, France; CHRU de Brest, service de chirurgie orthopédique et traumatologique, boulevard Tanguy-Prigent, 29200 Brest, France.
The iASSIST™ navigation system for total knee arthroplasty (TKA) is as accurate as the Navitrack™ system. Both systems achieve excellent mechanical axis restoration and component positioning without significant differences in operative time or adverse events.
Area of Science:
- Orthopedic Surgery
- Medical Device Technology
- Biomechanical Engineering
Background:
- Total knee arthroplasty (TKA) outcomes depend on accurate component placement and mechanical axis restoration.
- Conventional optical navigation systems (e.g., Navitrack™) are established tools for improving TKA accuracy.
- Emerging inertial navigation systems, such as iASSIST™, offer potential advantages in TKA surgery.
Purpose of the Study:
- To prospectively compare the accuracy of the iASSIST™ inertial navigation system against the Navitrack™ optical navigation system in TKA.
- To evaluate key accuracy metrics including mechanical axis restoration, component positioning, operative time, and adverse events.
Main Methods:
- A prospective study involving 40 patients undergoing primary TKA, with 20 patients in the iASSIST™ group and 20 in the Navitrack™ group.
- Postoperative coronal radiographs were analyzed at six months to assess hip-knee-ankle angle (HKA), mechanical lateral distal femoral angle (mLDFA), and mechanical medial proximal tibial angle (mMPTA).
- Comparison of HKA restoration rates, component positioning adequacy, operative time, and navigation-related adverse events between the two systems.
Main Results:
- No significant differences were found in the rates of HKA restoration (P=0.3), femoral component positioning (P=0.12), or tibial component positioning (P=0.12).
- The iASSIST™ system demonstrated significantly better HKA (P=0.02) and mMPTA (P=0.01) values and angular deviations compared to Navitrack™.
- Operative time (P=0.06) and navigation-related adverse events (P=0.18) showed no significant differences between the groups.
Conclusions:
- The iASSIST™ navigation system achieves accuracy comparable to the Navitrack™ optical system for TKA.
- iASSIST™ effectively provides neutral mechanical axis and optimal component positioning in the coronal plane in 95% of cases.
- The findings support iASSIST™ as a viable and accurate navigation tool for total knee arthroplasty.
