Accuracy of Computer-Assisted Navigation in Total Ankle Arthroplasty Surgery Using Computed Tomography: A Short Report

Computer-assisted navigation (CAN) offers dynamic intraoperative guidance in total ankle arthroplasty (TAA). Although laboratory data suggest superior precision, in vivo evidence is lacking. This study used weightbearing computed tomography (WBCT) to evaluate CAN accuracy of postoperative TAA implant position relative to the plan. We hypothesized that absolute discrepancies would be <3 mm or <3°.

Thirteen consecutive patients (November 2024-November 2025) underwent TAA using CAN. Preoperative computed tomography-based 3D models were used for templating. Postoperative WBCT scans were used to measure final implant seating, and computerized measurements were used to identify implant placement discrepancy. We analyzed absolute discrepancies between planned vs final postoperative positions.

Tibial absolute discrepancies were within desired limits for varus/valgus (1.65° ± 1.43°), slope (1.87° ± 1.34°), and cut height (0.68 ± 0.62 mm) but not for axial rotation (3.97 ± 2.64). For the talus, varus/valgus (2.93° ± 1.86°) and cut height (0.66 ± 0.71 mm) absolute discrepancies were within desired limits. The increased talar slope deviation (3.90 ± 2.89) in the final position may be due to non-navigated implant impaction.

Although discrepancies persisted in tibial rotational alignment and talar positioning, the low variability across measurements suggests that CAN may support accurate implant positioning. These short-term positioning accuracy findings support the utility of CAN as a potential tool for enhancing implant positioning reproducibility in TAA.

Level IV, case series.