Cookies on this website
We use cookies to ensure that we give you the best experience on our website. If you click 'Continue' we'll assume that you are happy to receive all cookies and you won't see this message again. Click 'Find out more' for information on how to change your cookie settings.

Anteromedial gonarthrosis (AMG) displays a well recognised pattern of cartilage damage on the medial tibial plateau. Anteriorly there is a full thickness cartilage defect, with transition to a partial thickness defect, becoming full thickness cartilage in the posterior third of the tibial plateau. The retained posterior cartilage is macroscopically normal. This study characterises the histological changes of AMG and examines the usefulness of two histological assessment tools. Sixteen unicompartmental resection specimens of patients with primary AMG were assessed. Samples were stained with Haematoxylin and Eosin and Safranin-O stains and scored using the modified Mankin grade, and the OOCHAS assessment tool. Each specimen was assessed at five regions along the antero-posterior axis starting from the exposed bone to the region of macroscopically normal cartilage. From anterior to posterior the staining showed a consistent increase in structural integrity and cellularity of the cartilage, matched by a qualitative increase in GAG content. Mean modified Mankin and OOCHAS scores showed a progressive decrease in grade (p < 0.001). The OOCHAS grade had a good correlation with the modified Mankin grade (ρ = 0.886) and there was good intra- and inter-observer variability with both assessment tools. We conclude that there is progressive decrease in histological score from anterior to posterior in AMG and that the macroscopically normal cartilage seen posteriorly is histologically normal. Both the modified Mankin and OOOCHAS assessment tools are useful in histological grading but we found the OOCHAS easier and quicker to use. We propose that AMG represents a spatial model of progressive cartilage damage.

Original publication

DOI

10.1016/j.knee.2010.04.010

Type

Journal article

Journal

Knee

Publication Date

06/2011

Volume

18

Pages

172 - 176

Keywords

Aged, Aged, 80 and over, Cartilage, Articular, Disease Progression, Female, Humans, Knee Joint, Male, Middle Aged, Observer Variation, Osteoarthritis, Knee, Phenotype, Reproducibility of Results, Severity of Illness Index