Muscle atrophy and metal-on-metal hip implants

Berber, Reshid, Khoo, Michael, Cook, Erica, Guppy, Andrew, Hua, Jia, Miles, Jonathan, Carrington, Richard, Skinner, John and Hart, Alister (2015) Muscle atrophy and metal-on-metal hip implants. Acta Orthopaedica, 86 (3). pp. 351-357. ISSN 1745-3674

[img]
Preview
PDF - Published version (with publisher's formatting)
Available under License Creative Commons Attribution-NonCommercial.

Download (1MB) | Preview

Abstract

Background and purpose — Muscle atrophy is seen in patients with metal-on-metal (MOM) hip implants, probably because of inflammatory destruction of the musculo-tendon junction. However, like pseudotumors, it is unclear when atrophy occurs and whether it progresses with time. Our objective was to determine whether muscle atrophy associated with MOM hip implants progresses with time.

Patients and methods — We retrospectively reviewed 74 hips in 56 patients (32 of them women) using serial MRI. Median age was 59 (23–83) years. The median time post-implantation was 83 (35–142) months, and the median interval between scans was 11 months. Hip muscles were scored using the Pfirrmann system. The mean scores for muscle atrophy were compared between the first and second MRI scans. Blood cobalt and chromium concentrations were determined.

Results — The median blood cobalt was 6.84 (0.24–90) ppb and median chromium level was 4.42 (0.20–45) ppb. The median Oxford hip score was 34 (5–48). The change in the gluteus minimus mean atrophy score between first and second MRI was 0.12 (p = 0.002). Mean change in the gluteus medius posterior portion (unaffected by surgical approach) was 0.08 (p = 0.01) and mean change in the inferior portion was 0.10 (p = 0.05). Mean pseudotumor grade increased by 0.18 (p = 0.02).

Interpretation — Worsening muscle atrophy and worsening pseudotumor grade occur over a 1-year period in a substantial proportion of patients with MOM hip implants. Serial MRI helps to identify those patients who are at risk of developing worsening soft-tissue pathology. These patients should be considered for revision surgery before irreversible muscle destruction occurs.

Item Type: Article
Additional Information: Published online: 14 Jan 2015
Research Areas: A. > School of Science and Technology > Natural Sciences > Biophysics and Bioengineering group
Item ID: 16420
Notes on copyright: Open Access - This article is distributed under the terms of the Creative Commons Attribution Noncommercial License which permits any noncommercial use, distribution, and reproduction in any medium, provided the source is credited.
Useful Links:
Depositing User: Jia Hua
Date Deposited: 28 May 2015 13:23
Last Modified: 04 Apr 2019 05:25
URI: https://eprints.mdx.ac.uk/id/eprint/16420

Actions (login required)

Edit Item Edit Item

Full text downloads (NB count will be zero if no full text documents are attached to the record)

Downloads per month over the past year