Low-dose CT-based implant motion analysis is a precise tool for early migration measurements of hip cups: a clinical study of 24 patients

Authors

  • Cyrus Brodén Department of Surgery and Cancer, Imperial College London, London, UK; Department of Clinical Sciences, Danderyd Hospital, Karolinska Institutet, Stockholm, Sweden
  • Olof Sandberg Sectra, Linköping, Sweden
  • Olof Sköldenberg Department of Clinical Sciences, Danderyd Hospital, Karolinska Institutet, Stockholm, Sweden
  • Hampus Stigbrand Department of Orthopedic Surgery, Länssjukhuset, Gävle, Sweden; Center for Research and Development, Uppsala University/County Council of Gävleborg, Sweden
  • Mari Hänni Department of Surgical Sciences, Section of Radiology, Uppsala University Hospital, Uppsala, Sweden
  • Joshua W Giles Department of Mechanical Engineering, University of Victoria, Victoria, BC, Canada
  • Roger Emery Department of Orthopaedic Surgery, St Mary’s Hospital, London, UK
  • Stergios Lazarinis Department of Orthopedics, Institute of Surgical Sciences, Uppsala University Hospital, Uppsala, Sweden
  • Andreas Nyström Department of Orthopedics, Institute of Surgical Sciences, Uppsala University Hospital, Uppsala, Sweden
  • Henrik Olivecrona Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden

DOI:

https://doi.org/10.1080/17453674.2020.1725345

Abstract

Background and purpose — Early implant migration is known to be a predictive factor of clinical loosening in total hip arthroplasty (THA). Radiostereometric analysis (RSA) is the gold standard used to measure early migration in patients. However, RSA requires costly, specialized imaging equipment and the image process is complex. We determined the precision of an alternative, commercially available, CT method in 3 ongoing clinical THA studies, comprising 3 different cups.

Materials and methods — 24 CT double examinations of 24 hip cups were selected consecutively from 3 ongoing prospective studies: 2 primary THA (1 cemented and 1 uncemented) and 1 THA (cemented) revision study. Precision of the CT-based implant motion analysis (CTMA) system was calculated separately for each study, using both the surface anatomy of the pelvis and metal beads placed in the pelvis.

Results — For the CTMA analysis using the surface anatomy of the pelvis, the precision ranged between 0.07 and 0.31 mm in translation and 0.20° and 0.39° for rotation, respectively. For the CTMA analysis using beads the precision ranged between 0.08 and 0.20 mm in translation and between 0.20° and 0.43° for rotations. The radiation dose ranged between 0.2 and 2.3 mSv.

Interpretation — CTMA achieved a clinically relevant and consistent precision between the 3 different hip cups studied. The use of different hip cup types, different CT scanners, or registration method (beads or surface anatomy) had no discernible effect on precision. Therefore, CTMA without the use of bone markers could potentially be an alternative to RSA to measure early migration.

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Published

2020-02-14

How to Cite

Brodén, C., Sandberg, O., Sköldenberg, O., Stigbrand, H., Hänni, M., Giles, J. W., Emery, R., Lazarinis, S., Nyström, A., & Olivecrona, H. (2020). Low-dose CT-based implant motion analysis is a precise tool for early migration measurements of hip cups: a clinical study of 24 patients. Acta Orthopaedica, 91(3), 260–265. https://doi.org/10.1080/17453674.2020.1725345