|
About the atlas
In
contrast to the knee, hip and hands, there are no standardised atlases
for grading the severity of osteoarthritis (OA) in the foot. The small
number of previous studies that have assessed foot OA have applied the
Kellgren and Lawrence scale to a limited number of foot joints. While
these studies have provided useful information about foot OA, concerns
have previously been raised about the Kellgren and Lawrence scale due to
its over-reliance on the presence of osteophytes to classify a joint as
osteoarthritic, and inconsistencies in the interpretation of the grading
descriptors.
In
response to these limitations,
A/Prof
Hylton Menz,
Dr Shannon Munteanu,
Dr
Karl Landorf,
Gerard Zammit
and
Prof Flavia Cicuttini recently developed the La Trobe radiographic
atlas of foot OA, which can be used to grade the severity of OA in
commonly-affected joints of the foot. The aim of the project was to
develop a useful tool to assist in the standardization of foot OA
assessment for epidemiologic studies and clinical trials.
Which joints are included in the atlas?
The
atlas includes
five foot joints:
-
first metatarsophalangeal joint
-
first cuneo-metatarsal joint
-
second metatarsal-intermediate
cuneiform joint
-
navicular-first cuneiform joint
-
talo-navicular joint
These joints were selected as they are the joints most commonly affected
by foot OA, and are the joints that can be most easily viewed with
standard radiographic foot projections.
Which radiographic projections are
required?
The
original version of the atlas requires weightbearing dorso-plantar (DP)
and lateral projections. However, research is currently being conducted
to determine the relative accuracy of grading OA using the DP view only.
How is the atlas scored?
For
each joint, the presence of osteophytes is graded as absent (score = 0),
small (score = 1), moderate (score = 2) or severe (score = 3), and
presence of joint space narrowing is graded as none (score = 0),
definite (score = 1), severe (score = 2), or joint fusion at at least
one point (score = 3).
With
the exception of the TNJ, both DP and lateral views used to assess
osteophytes and joint space narrowing. For the grading of TNJ
osteophytes, only the lateral view is used, as osteophytes cannot be
clearly visualized from the dorso-plantar radiograph.
How is foot OA defined with the
atlas?
Case definitions of foot OA will vary
depending on the research question. However, we have proposed the
following definition of foot OA:
for
each joint, radiographic OA can be considered to be present if:
Can an 'overall' score be
calculated?
A summary score (ie:
observations from all joints and views combined) can be used to provide
an 'overall' indicator of the degree of foot OA. However, this score
requires further validation and factor analysis to determine the
relative contributions of OA in each joint.
Has the atlas been published?
A description of the
development of the atlas and reliability testing has been published in
the journal Osteoarthritis and Cartilage. To access this
publication,
click here. Please note that the copyright to this paper is held by
Elsevier Science. However, Elsevier has provided permission to reproduce
the atlas images on this website free of charge.
How reliable is the atlas?
Observations using
the atlas demonstrate moderate to excellent reliability within examiners
(percentage agreement from 86 to 99% and weighted kappas from 0.45 to
0.95), and, with the exception of joint space narrowing of the 2nd MCJ
from the lateral view, fair to excellent reliability between examiners
(percentage agreement from 86 to 97% and weighted kappas from 0.32 to
0.87). Intra-class correlation coefficients for the overall foot OA
score (representing the sum of observations for all joints from left and
right feet) ranged between 0.83 and 0.89 for intra-examiner comparisons,
and 0.72 to 0.74 for inter-examiner comparisons. For further info,
please refer to the journal publication.
Who can use the atlas?
Elsevier has provided
permission to reproduce the atlas images on this website free of charge,
so the authors are happy for the atlas to be freely downloaded and
distributed. However, we would appreciate if you could let us know that
you are using the atlas by sending us an
email.
How to obtain the atlas
You
can download the full atlas file as a PDF by clicking on the image
below. We are also developing a DVD of the atlas (with greater
resolution images) which will be available soon.
|
 |
La Trobe radiographic atlas of
foot osteoarthritis (22 page PDF, 19.7Mb) |
For further info
If
you require any further information, please contact
A/Prof Hylton Menz.
|
