Total hip arthroplasty (THA) is a very successful procedure. Revision THA is becoming increasingly common. Recent developments to improve outcomes include the development of large trabecular metal (TM) acetabular cups and augments. There is a paucity of data on the benefit of these new techniques.
A single-centre retrospective review consisting of a radiological review of post-op revision THA anteroposterior pelvis. Data collection was performed using the Irish National Orthopaedic Register (INOR) and from a previous project. We used a technique developed by Fessy et al in 1999 to measure the centre of rotation (COR) of the hip. We then compared our study to that of a study measuring the COR of healthy native hips.
127 revision THA analysed. Native COR calculated by Fessy et al showed a mean horizontal (x) axis 33.6 mm (standard deviation [SD] 5.74) and a vertical (y) axis 16.4 mm (SD 4.67). Non-TM revisions showed a mean x axis of 29 mm (SD 3.9) and y axis 17.9 (SD 5.9). TM Augments had a mean x axis 29.2 mm (SD 7.9) and y axis of 21.5 (SD 8.4). TM Cups alone had a mean x axis 27 mm (SD 6.9) and y axis 22 mm (SD 10.18).
COR of TM implants showed considerable deviation from the norm. Non-TM implants showed a COR within acceptable physiological range. TM components consistently failed to restore a natural COR in our cohort. The implications of this remain uncertain but must be considered in any decision to use TM.
Post author correction
Article Type: ORIGINAL RESEARCH ARTICLE
Article Subject: Hip replacement
AuthorsCarl O’Brien, Cillian J. Keogh, Ailish Hannigan, Stephen Brennan, Cian Kennedy, Rehan Gul, James A. Harty
- • Accepted on 11/02/2017
- • Available online on 01/07/2017
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- O’Brien, Carl [PubMed] [Google Scholar] 1
- Keogh, Cillian J. [PubMed] [Google Scholar] 1, * Corresponding Author (cillianjkeogh@RCSI.ie)
- Hannigan, Ailish [PubMed] [Google Scholar] 2
- Brennan, Stephen [PubMed] [Google Scholar] 1
- Kennedy, Cian [PubMed] [Google Scholar] 1
- Gul, Rehan [PubMed] [Google Scholar] 1
- Harty, James A. [PubMed] [Google Scholar] 1
Department of Orthopaedics, Cork University Hospital, Cork - Republic of Ireland
Department of Statistics, Graduate Entry Medical School, University of Limerick, Cork - Republic of Ireland