POSTER ABSTRACTS - ISAKOS

ACL -reconstructed knees during stimulation
tended to be less than that before stimulation,
although the difference was not statistically
significant.
Conclusion: These data suggest that the ACLhamstring
reflex arc in ACL-reconstructed knees
may be not fully restored.
E-poster w/ Standard #427
The Variability in Accuracy of the Rolimeter in
Assessing Anterior Cruciate Ligament Laxity as
Tested by Users of Different Experience.
Gareth Stables, Lymm, UNITED KINGDOM,
Presenter
James Arbuthnot, Warrington, Cheshire UNITED
KINGDOM
Julian Hatcher, Salford, Manchester UNITED
KINGDOM
Michael J McNicholas, Warrington, Cheshire
UNITED KINGDOM
North Cheshire NHS Trust, Warrington, UNITED
KINGDOM
Instrumented arthrometry is a widely used
technique for the quantification of cruciate
ligament laxity. It is used both before and after
surgery. The Rolimeter knee tester (Aircast,
Europe) is a tool that is used in such scenarios. It
has several advantages over its cousins; it is more
compact, lighter, less expensive and amenable to
sterilization techniques, allowing it to be used
intra-operatively. The other leading arthrometers
have however had over 15 years of clinical use and
their reliability has been thoroughly assessed.
Balsach et al 2 and Ganko et al have already
demonstrated that the Rolimeter knee tester has
no significant difference in sensitivity for the
diagnosis of an ACL deficient knee when
compared to the KT-1000 arthrometer
(MEDMetric, San Diego, CA). Muellner et al found
no significant difference in the intra-tester and
inter-tester results obtained on Rolimeter
assessment of the knees of un-injured healthy
subjects.
Our study assesses the inter-tester and intratester
variability when the Rolimeter is applied to
patients with unilateral ACL-deficient knees. It
also examines whether the level of experience of
the examiner influences the results in this group
of patients.
Materials and Methods:
Six examiners each examined thirty-three subjects
on two occasions. One examiner was medically
qualified but had never performed a Lachman or
anterior drawer test. Two examiners were qualified
physiotherapists who routinely examined knees,
but had never used a Rolimeter. One medically
qualified examiner was considered to be of
intermediate experience, having used the
Rolimeter regularly for six months. Two examiners
were regarded as expert Rolimeter users, having
used the device regularly for several years (one
was medically qualified and the other was a
qualified physiotherapist).
For each examination a Rolimeter reading was
taken three times with the knee at 30 degrees of
flexion and three times at 90 degrees of flexion for
both knees. The interval between examinations
was at least thirty minutes. All the readings were
acquired on the same day. The examiners were
blinded to whether the subject was known to be
ACL deficient or not.
The results of the examinations were entered onto
a database (SPSS Chicago, Illinois). Repeated
measures analysis of variance was used to test for
the effects of the following factors, difference
between examiners, reproduction of results
between examinations for each examiner.
Results:
Repeated measures analysis of variance, intra
class coefficients (ICC), pearson corrrelation
coefficient (PCC) and a single tailed t-test were
used to test for the following effects,
reproducibility of readings (intra-tester reliability)
,differences in the readings taken by the different
examiners (inter-tester reliability) and wether the
rolimeter could diagnose ACL laxity > 3mm (
diagnostic reliability) regardless of users
experience level.There was statistically significant
good inter-tester reliability with ICC > 0.9 for all
measurements. PCC with r2 values > 0.6 showed
good intra-tester reliability.Measurements were
significantly higher in the ACL - deficient group
compared to the normal knees (p3mm in
the ACLD group (p