A new mini-navigation tool allows accurate component placement during anterior total hip arthroplasty

Abstract

IntroductionComputer-assisted navigation systems have been explored in total hip arthroplasty (THA) to improve component positioning. While these systems traditionally rely on anterior pelvic plane registration, variances in soft tissue thickness overlying anatomical landmarks can lead to registration error, and the supine coronal plane has instead been proposed. The purpose of this study was to evaluate the accuracy of a novel navigation tool, using registration of the anterior pelvic plane or supine coronal plane during simulated anterior THA.MethodsMeasurements regarding the acetabular component position, and changes in leg length and offset were recorded. Benchtop phantoms and target measurement values commonly seen in surgery were used for analysis. Measurements for anteversion and inclination, and changes in leg length and offset were recorded by the navigation tool and compared with the known target value of the simulation. Pearson’s r assessed the relationship between the measurements of the device and the known target values.ResultsThe device accurately measured cup position and leg length measurements to within 1° and 1 mm of the known target values, respectively. Across all simulations, there was a strong, positive relationship between values obtained by the device and the known target values (r=0.99).ConclusionThe preliminary findings of this study suggest that the novel navigation tool tested is a potentially viable tool to improve the accuracy of component placement during THA using the anterior approach.

Accuracy of Acetabular Component Positioning Using Computer-assisted Navigation in Direct Anterior Total Hip Arthroplasty

“…The anterior application of the navigation tool has been previously described [20]. In brief, the system consists of a camera, probe, and tracker within the sterile field, and a workstation monitor located outside of the sterile field.…”

Advanced, Imageless Navigation in Contemporary THA: Optimising Acetabular Component Placement

“…Whilst a relatively recent addition to the arthroplasty surgeon's armamentarium in many parts of the world, the use of intra-operative computer-assisted hip navigation provides another means for aiding cup insertion [75,92]. In its two most basic forms, such systems use either pre-operative 'imaging informed' or 'imageless' [73,93] approaches. As with accepted total knee arthroplasty (TKA) applications, both portable (i.e.…”

“…'mini-nav' [94,95]) and 'full navigation' systems are available for use during hip surgery. Whilst large volume data are still pending, early applications of navigated THA suggest consistent improvements in achieving the desired insertion orientation [93,94,96] with significantly less (p < 0.001) deviations from target [92,97]. Most commercially-available navigation systems reference the APP which provides the frame-of-reference orientation for later angular measurement [51,73] although the paper by Vigdorchik and colleagues suggests that the perpendicular hip-shoulder-axis may actually be the more accurate and consistent registration plane [98].…”

Surgical Approach and Reaming Depth Influence the Direction and Magnitude of Acetabular Center of Rotation Changes During Total Hip Arthroplasty

“…1). Detailed explanations of the navigation device for lateral, posterior, and direct anterior approaches have been previously described [20,21]. The navigation tool measures kinematic HCOR, where the native HCOR is recorded by placing the tracker on the femoral platform, located on the operative greater trochanter, and articulating the leg to capture a wide range of angular motion with the camera.…”

“…A subgroup analysis of the cohort was conducted to evaluate HCOR displacement stratified by the surgical approach. Specifically, device data obtained from surgeries performed via the direct anterior approach were compared with data from surgeries performed via the posterior and lateral surgical approaches [20,21]. The latter were grouped together in the final analysis, as the vast majority of cases were performed via the posterior approach, so much so that a subgroup analysis comparing posterior and lateral approach results would not be statistically meaningful.…”