Aims The aim of this study was to identify patient- and surgery-related risk factors for sustaining an early periprosthetic fracture following primary total hip arthroplasty (THA) performed using a double-tapered cementless femoral component (Bi-Metric femoral stem; Biomet Inc., Warsaw, Indiana).
Patients and Methods A total of 1598 consecutive hips, in 1441 patients receiving primary THA between January 2010 and June 2015, were retrospectively identified. Level of pre-operative osteoarthritis, femoral Dorr type and cortical index were recorded. Varus/valgus placement of the stem and canal fill ratio were recorded post-operatively. Periprosthetic fractures were identified and classified according to the Vancouver classification. Regression analysis was performed to identify risk factors for early periprosthetic fracture.
Results The mean follow-up was 713 days (1 to 2058). A total of 48 periprosthetic fractures (3.0%) were identified during the follow-up and median time until fracture was 16 days, (interquartile range 10 to 31.5). Patients with femoral Dorr type C had a 5.2 times increased risk of post-operative periprosthetic fracture compared with type B, while female patients had a near significant two times increased risk over time for post-operative fracture.
Conclusion Dorr type C is an independent risk factor for early periprosthetic fracture, following THA using a double tapered cementless stem such as the Bi-Metric. Surgeons should take bone morphology into consideration when planning for primary THA and consider using cemented femoral components in female patients with poor bone quality.
Cite this article: Bone Joint J 2017;99-B:451–7.
K. Gromov: Study design, Data collection, Data analysis, Writing of paper, Paper review.
A. Bersang: Data collection, Data analysis, Paper review.
C. Skovgaard: Data collection, Paper review.
T. Kallermose: Data analysis, Paper review.
H. Husted: Study design, Paper review.
A. Troelson: Study design, Paper review.
The authors declare that this study was partially funded by a grant from Zimmer Biomet.
The author or one or more of the authors have received or will receive benefits for personal or professional use from a commercial party related directly or indirectly to the subject of this article. In addition, benefits have been or will be directed to a research fund, foundation, educational institution, or other nonprofit organisation with which one or more of the authors are associated.
This article was primary edited by G. Scott.
- Received April 21, 2016.
- Accepted December 15, 2016.
- ©2017 The British Editorial Society of Bone & Joint Surgery