Is a hollow centralizer necessary when using a polished, tapered, cemented femoral stem? : A randomized, controlled RSA study of 60 hips with 10 years of follow-up
(2017) In Acta Orthopaedica 88(4). p.377-382- Abstract
Background and purpose — A tapered, polished and collarless stem is normally equipped with a hollow centralizer to prevent the stem from becoming end-bearing in the cement as the stem subsides. In a randomized clinical trial, we evaluated such a stem (MS-30), which was initially introduced with a solid centralizer but was later recommended to be fitted with a hollow centralizer. We hypothesized that while the stem would sink more, it would become rotationally stable and have less retroversion with a hollow centralizer than with a solid centralizer. Patients and methods — We randomized 60 patients with primary hip arthritis to receive either a hollow centralizer or a solid centralizer with the stem. The effect was evaluated over a... (More)
Background and purpose — A tapered, polished and collarless stem is normally equipped with a hollow centralizer to prevent the stem from becoming end-bearing in the cement as the stem subsides. In a randomized clinical trial, we evaluated such a stem (MS-30), which was initially introduced with a solid centralizer but was later recommended to be fitted with a hollow centralizer. We hypothesized that while the stem would sink more, it would become rotationally stable and have less retroversion with a hollow centralizer than with a solid centralizer. Patients and methods — We randomized 60 patients with primary hip arthritis to receive either a hollow centralizer or a solid centralizer with the stem. The effect was evaluated over a 10-year follow-up period with repeated RSA examinations, conventional radiographs, and clinical follow-ups using the WOMAC and SF-12 questionnaires. Results — At 10-year follow-up, the group with hollow centralizers had subsided more than the group with solid centralizers (1.99 mm (hollow) as opposed to 0.57 mm (solid); p < 0.001). However, rotation was similar at 10-year follow-up (mean retroversion 1.34° (hollow) and 1.30° (solid)). Both groups showed excellent 10-year results, with similar clinical outcome, and none of the stems were radiographically loose or had been revised. Interpretation — As expected, there was more subsidence in the group with hollow centralizers, and with similar magnitude to that reported in earlier RSA studies on conceptually similar prostheses. Interestingly, there was no difference in the rotational behavior of the prostheses. This stem type appears to have a design that, regardless of the type of centralizer and the possibility of subsidence, withstands the rotational forces it is subjected to very well. This study does not support the need for a hollow centralizer for these types of stems.
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- author
- Weber, Erik LU ; Olsson, Christer ; Kesteris, Uldis LU and Flivik, Gunnar LU
- organization
- publishing date
- 2017-07-04
- type
- Contribution to journal
- publication status
- published
- subject
- in
- Acta Orthopaedica
- volume
- 88
- issue
- 4
- pages
- 6 pages
- publisher
- Taylor & Francis
- external identifiers
-
- scopus:85017598586
- pmid:28418269
- wos:000404588400003
- ISSN
- 1745-3674
- DOI
- 10.1080/17453674.2017.1315553
- language
- English
- LU publication?
- yes
- id
- dce27900-b5fa-4daf-8ee6-83445efc73e9
- date added to LUP
- 2017-07-26 08:16:53
- date last changed
- 2025-01-07 17:45:43
@article{dce27900-b5fa-4daf-8ee6-83445efc73e9,
abstract = {{<p>Background and purpose — A tapered, polished and collarless stem is normally equipped with a hollow centralizer to prevent the stem from becoming end-bearing in the cement as the stem subsides. In a randomized clinical trial, we evaluated such a stem (MS-30), which was initially introduced with a solid centralizer but was later recommended to be fitted with a hollow centralizer. We hypothesized that while the stem would sink more, it would become rotationally stable and have less retroversion with a hollow centralizer than with a solid centralizer. Patients and methods — We randomized 60 patients with primary hip arthritis to receive either a hollow centralizer or a solid centralizer with the stem. The effect was evaluated over a 10-year follow-up period with repeated RSA examinations, conventional radiographs, and clinical follow-ups using the WOMAC and SF-12 questionnaires. Results — At 10-year follow-up, the group with hollow centralizers had subsided more than the group with solid centralizers (1.99 mm (hollow) as opposed to 0.57 mm (solid); p < 0.001). However, rotation was similar at 10-year follow-up (mean retroversion 1.34° (hollow) and 1.30° (solid)). Both groups showed excellent 10-year results, with similar clinical outcome, and none of the stems were radiographically loose or had been revised. Interpretation — As expected, there was more subsidence in the group with hollow centralizers, and with similar magnitude to that reported in earlier RSA studies on conceptually similar prostheses. Interestingly, there was no difference in the rotational behavior of the prostheses. This stem type appears to have a design that, regardless of the type of centralizer and the possibility of subsidence, withstands the rotational forces it is subjected to very well. This study does not support the need for a hollow centralizer for these types of stems.</p>}},
author = {{Weber, Erik and Olsson, Christer and Kesteris, Uldis and Flivik, Gunnar}},
issn = {{1745-3674}},
language = {{eng}},
month = {{07}},
number = {{4}},
pages = {{377--382}},
publisher = {{Taylor & Francis}},
series = {{Acta Orthopaedica}},
title = {{Is a hollow centralizer necessary when using a polished, tapered, cemented femoral stem? : A randomized, controlled RSA study of 60 hips with 10 years of follow-up}},
url = {{http://dx.doi.org/10.1080/17453674.2017.1315553}},
doi = {{10.1080/17453674.2017.1315553}},
volume = {{88}},
year = {{2017}},
}