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Quantification of intra-articular fibrosis in patients with stiff knee arthroplasties using metal-reduction MRI

Lookup NU author(s): Professor Derek Mann, Dr Lee Borthwick, Professor David Deehan, Dr Nicholas Kalson



This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License (CC BY-NC-ND).


© 2020 Author(s) et al.Aims: Stiffness is a common complication after total knee arthroplasty (TKA). Pathogenesis is not understood, treatment options are limited, and diagnosis is challenging. The aim of this study was to investigate if MRI can be used to visualize intra-articular scarring in patients with stiff, painful knee arthroplasties. Methods: Well-functioning primary TKAs (n = 11), failed non-fibrotic TKAs (n = 5), and patients with a clinical diagnosis of fibrosis1 (n = 8) underwent an MRI scan with advanced metal suppression (Slice Encoding for Metal Artefact Correction, SEMAC) with gadolinium contrast. Fibrotic tissue (low intensity on T1 and T2, low-moderate post-contrast enhancement) was quantified (presence and tissue thickness) in six compartments: supra/infrapatella, medial/ lateral gutters, and posterior medial/lateral. Results: Fibrotic tissue was identified in all patients studied. However, tissue was significantly thicker in fibrotic patients (4.4 mm ± 0.2 mm) versus non-fibrotic (2.5 mm ± 0.4 mm) and normal TKAs (1.9 mm ± 0.2 mm, p = < 0.05). Significant (> 4 mm thick) tissue was seen in 26/48 (54%) of compartments examined in the fibrotic group, compared with 17/30 (57%) non-fibrotic, and 10/66 (15%) normal TKAs. Although revision surgery did improve range of movement (ROM) in all fibrotic patients, clinically significant restriction remained post-surgery. Conclusion: Stiff TKAs contain intra-articular fibrotic tissue that is identifiable by MRI. Studies should evaluate whether MRI is useful for surgical planning of debridement, and as a non-invasive measurement tool following interventions for stiffness caused by fibrosis. Revision for stiffness can improve ROM, but outcomes are sub-optimal and new treatments are required.

Publication metadata

Author(s): Attard V, Li CY, Self A, Mann DA, Borthwick LA, O'Connor P, Deehan DJ, Kalson NS

Publication type: Article

Publication status: Published

Journal: Bone and Joint Journal

Year: 2020

Volume: 102

Issue: 10

Pages: 1331-1340

Print publication date: 03/10/2020

Online publication date: 03/10/2020

Acceptance date: 02/04/2016

Date deposited: 12/01/2021

ISSN (print): 2049-4394

ISSN (electronic): 2049-4408

Publisher: British Editorial Society of Bone and Joint Surgery


DOI: 10.1302/0301-620X.102B10.BJJ-2020-0841.R1

PubMed id: 32993344


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Funder referenceFunder name
MR/R023026/1Medical Research Council (MRC)
Wellcome Trust (204787/Z/16/Z)