We investigated whether a novel, real-time fluoroscopy based navigation system optimized component positioning and leg length in fluoroscopically aided Direct Anterior Approach Total Hip Arthroplasty (DAA-THA). We retrospectively reviewed 75 fluoroscopically assisted DAA-THA performed by a single surgeon: 37 procedures used the software intraoperatively to overlay anteversion, inclination, and leg length information over the existing fluoroscopic radiograph with the aim of enhancing component positioning. The control group consisted of 38 procedures from the single surgeon's patient pool who had undergone non-navigated fluoroscopic assisted DAA-THA one month prior to the system's trial. We used the software to compute each data point on an immediate post operative AP radiograph to replicate the intra operative measurement process. Our results demonstrate that the navigation group measurements were significantly closer to the target numbers with less variation. The mean values were significantly closer to target values anteversion (control: 14°, navigated: 19.1°), inclination (control: 37.7°, navigated: 40.8°) and leg length discrepancy (control: 4.7mm, navigated: 0.1mm). The mean difference from target value were also statistically significant: for anteversion (control: −6.0°, navigated: −0.9°), inclination (control: −2.3°, navigated: 0.8°) and leg length discrepancy (control: 2.7°, navigated: −1.9°). In addition, surgical time was shorter in the navigation group (75.7 vs. 74 minutes; p=0.001). The p values were all statistically significant (anteversion 0.0001, inclination 0.0019, LLD < 0.001 and surgical time 0.001). The real-time feedback and calculations provided by the navigation software provided a reproducible precision for component positioning and leg length measurement during DAA-THA.

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Background

Venous thromboembolism (VTE) is a common, costly, and morbid complication following TJA. Consequently, the current standard of care recommends that all TJA candidates receive some form of thromboprophylaxis postoperatively. Chemoprophylaxis, however, is not without its own risks and has been associated with greater risk of perioperative complications such as major bleeding, infection, stroke, and increased wound drainage. Mechanical compression devices serve as an alternative to chemoprophylaxis. Compression devices are thought to function by decreasing venous stasis and activating fibrinolysis. Intermittent pneumatic compression devices (IPCD) function by providing pressure at a constant cycle; whereas continuous enhanced circulation therapy (CECT) devices such as ActiveCare portable system (Medical Compression Systems, Or Akiva, Israel) function in a synchronized manner with the patient's own respiratory cycles. While both of these systems are widely utilized, there is scarce data comparing their effectiveness as thromboprophylatic agents following TJA. The purpose of this meta-analysis is to comparatively evaluate the efficacy of ActiveCare to IPCDs in the prevention of thromboembolic events following TJA.