PURPOSE: Accurate cup placement is challenging in total hip arthroplasty (THA) for dysplastic hip osteoarthritis (DHOA) because of the complex morphology of the acetabulum. Studies have reported good accuracy for total hip arthroplasty (THA) using computed tomography-based navigation (CTN)
however, in recent years, portable navigation (PN) has become more widely applied because of its low cost and ease of use. This study aimed to compare the accuracy of portable navigation with that of CT-based navigation. METHODS: A total of 114 patients underwent THA for DHOA via the standard posterior approach in the lateral decubitus position using the CTN (CTN-THA group) or PN (PN-THA group) system. After propensity score matching, 32 patients were included in each group. The accuracy of cup inclination, anteversion, cup placement position, and operative time were compared between the groups. RESULTS: There was no difference in accuracy error between the CTN-THA (inclination 2.8 ± 2.0° and anteversion 3.4 ± 2.1°) and PN-THA groups (inclination 2.5 ± 1.8° and anteversion 2.6 ± 2.2°). The CTN-THA group (inclination 2.2 ± 2.0° and anteversion 2.1 ± 1.6°) achieved better navigation error compared to the PN-THA group (inclination 2.6 ± 2.2° and anteversion 3.8 ± 3.3°). The error of cup placement position in the anteroposterior direction was significantly larger in the PN-THA group (4.27 ± 3.02 mm) than in the CTN-THA group (2.13 ± 2.17 mm). The operative time was significantly longer in the CTN-THA group (115 ± 41 min) than in the PN-THA group (87 ± 19 min). CONCLUSIONS: CTN-THA exhibited better accuracy than PN-THA for both cup placement angles and positions. CTN-THA tended to increase the operative time compared to PN-THA.