Automated Impaction Improves Femoral Component Canal Fit in Total Hip Arthroplasty: A Matched Study

Automated impaction in total hip arthroplasty (THA) is a new technology in femoral canal preparation. Recent studies have shown that it improves component alignment and fit and reduces operative time. The purpose of our study is to further investigate this technology's impact on femoral component canal fit, fracture risk, and operative time.

We conducted a retrospective, matched analysis of 274 patients who underwent THA via automated impaction (N = 137) or manual impaction (N = 137). Postoperative radiographs were assessed to measure canal fill (CF) at the level of the neck cut, the lesser trochanter (LT), and 10 mm above (LT+10) and 60 mm below (LT-60) the LT. The average CF across these measurement points was calculated. The incidence of intraoperative fracture and average CF percentage were compared between the two cohorts.

The average CF percentage was significantly higher in the automated cohort (79.6 ± 5.6) than in the manual cohort (76.3 ± 5.6) (P < .001) as well as at each individually measured level. Operative time was significantly less in the automated cohort (93.9 ± 12.5) vs manual (100.6 ± 21.7 mins) (P = .006). There was no difference in the risk of intraoperative fracture (automated = 1/137 [0.7%] vs manual = 2/137 [1.5%], P = 1.00).

Our study results suggest that automated femoral canal impaction improved CF and reduced operative time without introducing additional risk of intraoperative fracture in THA. Of note, these results cannot determine whether automated impaction has clinical benefit with respect to pain, function, or survivorship of the femoral component.