High Incidence of Migration with Poor Initial Fixation of the Accolade® Stem

Abstract

Background Numerous cementless femoral stem design variations are in clinical use. Because initial implant instability and micromotion are associated with aseptic loosening of the femoral component, migration analysis provides an early assessment of implant survivorship. Questions/purposes We determined the (1) migration pattern of the Accolade 1 cementless femoral stem; (2) clinical factors predisposing to stem migration; (3) selfreported patient outcomes; and (4) our current rate of aseptic stem loosening. Methods We retrospectively analyzed 81 femoral stems for aseptic migration using Ein-Bild-Roentgen-Analysefemoral component analysis. Postoperatively, patients completed the WOMAC and SF-12 questionnaires. We assessed radiographic factors potentially associated with subsidence: indices of bone shape and quality, canal fill of the implant, and radiographic signs of loosening. Minimum followup was 24 months (mean, 29 months; range, 24-48 months). Results The average subsidence at 24 months was 1.3 mm (range, 0-1.5 mm). In the first 2 years, 36% of stems subsided more than 1.5 mm. Large stem size was associated with subsidence. Radiolucent lines ([ 1.5 mm in three zones) were present in 10% of stems and associated with lower questionnaire scores. The 5-year survivorship for aseptic loosening of the 367 stems was 97% with revision as end point and 95% for radiographic failure.

Early Migration Predicts Aseptic Loosening of Cementless Femoral Stems: A Long-term Study

“…Specifically, the hips analyzed were not different from those not analyzed in key areas such as age, sex, duration of followup, and cumulative incidence of stem loosening. In addition, when compared with other migration analysis studies using EBRA-FCA [9,19,38], our dropout rate was lower. We also recognize a possible bias because the acetabular components used in this cohort showed a high rate of aseptic loosening [7,8], as patients with cup loosening might reduce their activity which could influence wear and aseptic loosening of the stem; surgery for cup loosening also might have an influence on stem revision rate.…”

“…Roentgen stereophotogrammetric analysis (RSA) generally is accepted as the gold standard in migration measurement, especially regarding accuracy and three-dimensional (3-D) migration measurement. Another validated and frequently used technique for measurement of distal stem migration is Einzel-Bild-Röntgen-Analysefemoral component analysis (EBRA-FCA), which also allows accurate measurement of femoral stem subsidence [4] without the need for implanting tantalum markers [5,38] and can be performed retrospectively using standard radiographs. The EBRA method is a software-based method using digitized radiographs and differs from other non-RSA measurement systems as it contains an algorithm (termed the comparability limit) that excludes radiographs from a patient's measurement series that have more than a preset level of positioning or rotational error and reduces variability secondary to patient positioning [4].…”

Catastrophic Femoral Neck Failure after THA with the Accolade® I Stem in Three Patients

“…White et al [18] reported on factors predictive of catastrophic failure of THAs, which included implant loosening, distal potting of the femoral stem with cantilever bending, varus positioning, excessive body weight, metallurgic defects, and medial calcar bone resorption. Failure of the femoral component at the neck has been attributed to mechanical (including fatigue) and material properties of the implant, corrosion, and increased neck lengths [3,8,11,16].…”

The correlation between clinical radiological outcome and contact state of implant and femur using three-dimensional templating software in cementless total hip arthroplasty

“…Several studies have reported good mid-and long-term results for cementless THA using a tapered wedge stem [2][3][4]. However, some reports reported that tapered proximally porous wedge stem raised failure of osteointegration and the progressive stem subsidence due to distal fixation of tapered wedge stem and the mismatch between implant and femur [5,23,24]. Therefore, these reports indicated that achieving the good adaptability of contact state between implant and femur is very important factor in using tapered wedge stem.…”

“…Several studies have reported good mid-and long-term results for cementless THA using a tapered wedge stem [2][3][4]. But if ideal initial fixation of the femoral component is not achieved with the tapered wedge stem, stem subsidence in the early postoperative period, severe stress shielding, and aseptic loosening may result, thereby requiring revision THA [5].…”