Impact of Femoral Stem Design on Failure After Anterior Approach Total Hip Arthroplasty.

BACKGROUND:An increased rate of complications related to femoral component failure has been described with less invasive total hip arthroplasty (THA). This study evaluated the incidence of femoral complications associated with the direct anterior approach for THA. METHODS:Retrospective review was performed of the initial 1120 consecutive patients who underwent direct anterior THA by 2 surgeons. RESULTS:A total of 899 patients (80.3%) had a 2-year follow-up (range, 2-8 years). Complications within 90 days occurred in 20 patients (1.8%): 10 calcar fractures, 1 greater trochanter fracture, 1 canal perforation, 3 hematomas, 2 dislocations, 2 superficial, and 1 deep infection. Nine patients (1%) underwent revision: 5 for aseptic femoral loosening (0.55%), 1 for periprosthetic joint infection, 1 for dislocation, 1 for hip flexor irritation, and 1 for a damaged polyethylene liner. Of the 5 patients with aseptic femoral loosening, 3 had a short, mediolateral tapered stem, 1 cemented stem, and 1 S-ROM stem placed to bypass a canal perforation. There were no revisions for aseptic loosening in the collared, fully hydroxyapatite (HA)-coated compaction broached or triple tapered proximal fit and fill stem designs (70.6% of all stems). Revision rate for femoral loosening was significantly higher for tapered wedge over HA-coated, compaction broached stems (P < .005). CONCLUSION:Pain and function improved predictably with a 0.55% rate of femoral loosening at 2-year follow-up. Among collared, fully HA-coated and triple taper fit and fill femoral stems, there were no instances of revision for aseptic loosening vs 3 in the short stem, collarless mediolateral tapered group.