POSTER ABSTRACTS - ISAKOS

Introduction: Several studies recently
demonstrated that in ACL reconstruction the less
perpendicular the angle of the graft in the coronal
plane to the joint line resulted in reduced loss of
flexion and anterior laxity. It was also reported
that when a tibial tunnel was drilled at the angle
of 60 degrees, 70 degrees, and 80 degrees in the
coronal plane and the femoral tunnel was drilled
using the transtibial technique in cadaveric knees,
placing the femoral tunnel at 60 degrees in the
coronal plane lowered graft tension in flexion.
Therefore, the importance of graft positioning in
the coronal plane is emphasized. However, the
angle of normal human ACL in the coronal plane
is unknown.
Purpose: The aim of this study is to measure the
angle of human ACL in the coronal plane in
cadaveric knees.
Method: 50 cadavers from the anatomical course
for medical students at the medical school were
inspected. The cadavers were perfusion-fixed in
embalming fluid containing formaldehyde. The
measurements of height and weight of the donors
were recorded at the anatomy department. We
dissected 100 knees of 50 cadavers in order to
select the bilateral knee in best condition from
each, and then dissected that knee joint. Knees
that displayed macroscopically degenerative
changes or evidence of trauma, such as
osteoarthritis, meniscal tears or ligament injury,
were excluded. Finally, 36 knee specimens were
examined, 20 male and 16 female, with a mean
age of 82 years. Frontal views of the knee joints
were photographed. The angle of the medial edge
and lateral edge of ACL in the coronal plane were
measured as the angle subtended by the medial
and lateral edge of ACL and a line drawn parallel
to the articular surface of the proximal tibiae in
the photographed frontal view of the dissected
knee joints. The width of the articular surface of
the proximal tibia between the medial to lateral
was also measured.
Results: The angle of the medial edge of ACL was
60?7.6? (mean?SD), the lateral edge of ACL was
68?8.4?, and the medial to lateral width of the
articular surface of the proximal tibia was 88?7.2
mm. The angle of the medial edge of ACL
significantly correlated with that of the lateral
edge, but the angle of either edge did not
correlate with the width of the proximal tibia. The
angle of either edge of ACL had no correlation
with height or weight. The width of the proximal
tibia significantly correlated with height and
weight. The angle of the lateral edge of ACL was
smaller in males than females. The width of the
tibia was shorter in females than males.
Conclusion: A clinical study of ACL reconstruction
using the transtibial technique recommended
drilling the tibial tunnel at an angle of 65 degrees
to 70 degrees in the coronal plane. Our results
suggest drilling the tibial tunnel at an angle of 60
to 68 degrees in the coronal plane to reconstruct
anatomically. Furthermore, more care should be
taken when drilling at these angles in male
patients than in female.
E-poster #305
The Effect of the Oral Contraceptive Pill on
Ligamentous Laxity
Paul A. Martineau, Montreal, Quebec, CANADA
Fawzi Al-Jassir, Montreal, Quebec, CANADA
Eric Lenczner, Montreal, Quebec, CANADA
Mark L Burman, Montreal, Quebec, CANADA
Presenter
McGill University, Montreal, Quebec, CANADA
Purpose: Our goal was to explore the
relationship between oral contraceptive pill (OCP)
use and ligamentous laxity in female athletes.
Conclusion: The use of the OCP by female
athletes yielded statistically significant decreases
in knee laxity when compared to female athlete
nonusers especially when comparing laxity of
athletes under the influence of the exogenous
OCP hormones at the time of laxity testing.
Significance: Women participating in sports
are 4-8 times more likely to sustain a serious knee
injury than men. Sex steroids are known to affect
ligamentous tissue composition.
Summary of Results: Non-dominant knee KT-
1000 measurements at 67N and 89N for the 42
OCP users and the 36 nonusers were: mean
translation at 67N, 3.00 mm vs. 3.86 mm (p 0.011);
at 89N, 3.98mm vs. 4.83mm respectively (p 0.018).
Results of the 29 OCP users not menstruating at
the time of the measurements vs. nonusers were:
at 67N, 2.95 mm vs. 3.86 mm (p 0.008); at 89N,
3.88mm vs. 4.83mm respectively (p 0.011).
Methods: 127 female athletes underwent
KT-1000 measurements of anterior translation of
the tibia. A screening questionnaire was
administered to exclude athletes with history
suggestive of previous knee injuries or hormonal
imbalance.
Discussion: OCP use yielded statistically
significant decreases in anterior translation of the
tibia as compared to nonusers. The OCP may have