Use of an Automated Surgical Impactor Reduces Femoral Broaching Time in Direct Anterior Approach Total Hip Arthroplasty: Results From a Randomized, Multicenter Study.

Background: Impaction in total hip arthroplasty has typically been conducted using a mallet. A surgical automated impactor has been developed with the goal of reducing surgeon variability, fatigue, and injury. There is also potential to reduce the variability of each impaction step in which automated impaction is used, through reproducible and consistent application of force. Methods: Patients were randomized into either the mallet control group, or the automated impaction study group (1:1 randomization). The primary endpoint analysis was conducted to demonstrate that femoral broaching time (in minutes) with an automated impactor is noninferior to femoral broaching time with manual instruments (mallet) under a noninferiority (NI) margin of 1.25 minutes, with a subsequent test of superiority. A total of 218 patients were randomized and treated (109 in each group). Results: Mean femoral broaching time was 5.8 minutes in the automated impaction study group (automated), and 8.1 minutes in the mallet control group (mallet), a 28.4% reduction ( Conclusions: In this randomized multicenter study, an automated impactor was shown to reduce femoral broaching time in primary total hip arthroplasty, with no increase in fractures, but no decrease in operating room time was noted.