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The apparently greater risk of anterior cruciate ligament damage among female
athletes has sometimes been attributed to the wider pelvis and larger Q-angle
of women, but some of the following research also suggests that another
factor also needs to be examined, namely the width of the intercondylar notch
on the femur. The narrowing of the posterior arch of the intercondylar notch
observed in ACL patients may predispose female or male knees to ACL tear.
Several of the other articles below question the simplistic interpretation of
such measurements.
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Intercondylar notch width and the risk for anterior cruciate ligament
rupture. A case-control study in 46 female handball players.
Lund-Hanssen H, Gannon J, Engebretsen L, Holen KJ, Anda S, Vatten L.
Acta Orthop Scand 1994 Oct;65(5):529-32
We measured the intercondylar notch of the femur in female handball players
from radiographs of 20 players with previous unilateral anterior cruciate
ligament injury, and 26 controls without injury. The groups were comparable
regarding age, height, weight and level of performance. Intercondylar fossa
radiographs were obtained in a posteroanterior axial position.
The anterior opening of the intercondylar notch was narrower in the healthy
knee of the injured group compared to the controls. There was an increased
risk of anterior cruciate ligament injury associated with decreasing notch
opening: female handball players with 17 mm or less anterior notch width were
6 times more susceptible to anterior cruciate ligament injury compared to
players with wider notch width.
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Femoral intercondylar notch stenosis and correlation to anterior cruciate
ligament injuries. A prospective study
LaPrade RF, Burnett QM 2nd
Am J Sports Med 1994 Mar-Apr;22(2):198-202; discussion 203
To evaluate the possible relationship between femoral intercondylar notch
stenosis and anterior cruciate ligament injuries in pivoting and cutting
sports, a 2-year prospective study was performed on intercollegiate athletes
at a Division I university. Daily practice times and athlete participation in
practices and games were recorded for each sport during the 2-year period.
Bilateral intercondylar notch view radiographs were taken of all athletes
enrolled in the study. The notch width index, a ratio that measures the width
of the anterior outlet of the intercondylar notch divided by the total
condylar width at the level of the popliteal groove, was measured for each
knee. A total of 213 athletes, representing 415 anterior cruciate
ligament-intact knees, were enrolled in the study. There were 7 anterior
cruciate ligament tears.
Statistical analysis demonstrated a correlation between femoral intercondylar
notch stenosis and anterior cruciate ligament injuries. No statistical
difference was found between the sex of the athlete and notch width indices
or rate of anterior cruciate ligament tears. Athletes with intercondylar
notch stenosis appear to be at increased risk for noncontact anterior
cruciate ligament injuries.
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The intercondylar notch in acute tears of the anterior cruciate ligament: a
computer graphics study
Houseworth SW, Mauro VJ, Mellon BA, Kieffer DA
Am J Sports Med 1987 May-Jun;15(3):221-4
Although the intercondylar notch becomes narrowed with a failed repair of the
ACL or with chronic instability of the knee, narrowed intercondylar notches
have frequently been observed during arthrotomy for an acute ACL tear in
previously uninjured knees. In order to determine whether the structure of
the intercondylar notch predisposes a knee to anterior cruciate tears, a
computer graphics study was designed. Notch view roentgenograms of 50
patients with an acute ACL injury and 50 "normal" patients without history of
significant knee injury were compared. An interactive graphics design station
was used to obtain the area of the anterior opening (ANT) and posterior arch
(POST) of the intercondylar notch. A "total" (TOTAL) area was obtained by
tracing the distal 7.5 cm of the femur.
Only the ratios of areas obtained from each roentgenogram were used for
comparison because of varying femur sizes among patients and possible
slightly varying techniques of taking the notch view roentgenogram itself.
The following ratios were developed: ANT/POST, POST/TOTAL, and
(POST-ANT)/TOTAL. The difference between the means of the ratio POST/TOTAL
for knees with acute ACL tears and those for normal knees was statistically
significant.
This study suggests that a narrowed posterior arch of the intercondylar notch
may predispose a knee to ACL tear.
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Analysis of the intercondylar notch by computed tomography
Anderson AF, Lipscomb AB, Liudahl KJ, Addlestone RB
Am J Sports Med 1987 Nov-Dec;15(6):547-52
The purposes of this study were to document the dimensions and configuration
of the intercondylar notch in the normal knee; to compare normal knee
intercondylar notches to those of knees with unilateral and bilateral ACL
tears to determine if there is a relationship between intercondylar notch
stenosis and ACL tears; and to determine if generalized ligamentous laxity is
associated with intercondylar notch stenosis and ACL tears. Three groups were
compared: Group I, bilateral ACL tears; Group II, unilateral tears; and Group
III, normal knees. Notch dimensions were computer-generated from CT scans.
All patients were examined for ligamentous laxity. Statistically significant
differences were found between normal and ACL-injured knees in regard to
opening notch angle, ratio of notch width at two-thirds of the notch length
to condylar width, and ratio of maximum notch width to condylar width,
suggesting a significant association between anterior outlet stenosis and
unilateral and bilateral ACL tears. The shapes of the notches were determined
from tracings of the distal CT scan.
Shapes ranged from inverted U to cresting wave. Narrow notches tended to be
waveshaped, but more study is needed in this area. Notch-plasty is
recommended for those with documented stenosis. The ratio of maximum notch
width at two-thirds of the notch height to maximum condyle width should not
be much less than 0.2, and the opening notch angle should be at least 50
degrees.
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***This article questions the contention that a narrow intercondylar notch
may contains a smaller anterior cruciate ligament, which may explain why
people with narrow notches have a higher incidence of anterior cruciate
ligament injuries.
Intercondylar notch width and its relation to the configuration and
cross-sectional area of the anterior cruciate ligament. A cadaveric knee
study.
Muneta T, Takakuda K, Yamamoto H.
Am J Sports Med 1997 Jan-Feb;25(1):69-72
If a narrow intercondylar notch contains a smaller anterior cruciate
ligament, that may explain why people with narrow notches have a higher
incidence of anterior cruciate ligament injuries. To investigate the
significance of notch width measurement, we used 16 embalmed cadaveric knees.
A positive mold of the entire anterior cruciate ligament, including its
femoral and tibial insertions, was created with silicone rubber and plaster
commonly used for dental molding. We had two hypotheses to test from this
study. One was that the dimensions of the anterior cruciate ligament can be
predicted by the notch width. The other was that the size of a person's
anterior cruciate ligament can be predicted by a caliper measurement of the
intercondylar notch.
The width, sagittal length, and cross-sectional area of the midsubstance and
the femoral and tibial insertions of the anterior cruciate ligament were
measured. The notch width index, the ratio of notch width to width of the
femoral condyle, showed a positive correlation only to the ratio of width to
sagittal length of the tibial insertion. None of the parameters showed any
differences between the knees with a notch width index less than or equal to
0.2 and those with a notch width index greater than 0.2. The knees with small
notch width indexes did not have thinner anterior cruciate ligaments in them.
These findings may not be applicable to knees obtained from other races,
i.e., not Japanese.
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Correlation of the intercondylar notch width of the femur to the width of the
anterior and posterior cruciate ligaments.
Davis TJ, Shelbourne KD, Klootwyk TE.
Knee Surg Sports Traumatol Arthrosc 1999;7(4):209-14
The purpose of this study was to determine if a correlation exists between
the intercondylar notch width (NW) of the femur and the width of the anterior
cruciate ligament (ACL) and posterior cruciate ligament (PCL). A study group
of 124 consecutive patients (mean age 36.6 +/- 15.2 years; 67 men, 57 women)
underwent a magnetic resonance imaging evaluation for knee pain but did not
have an ACL or PCL tear or arthrosis. A T2 weighted coronal cut was
identified and was located at the middle of the tibial spine, which
represented the plane where the ACL and PCL cross each other when the knee is
in 10 degrees of flexion. The NW and the width of the ACL and PCL were
measured at the level of the middle of the popliteal hiatus on a
physician-independent console that allowed for digital measurements in
millimeters.
Our results showed a statistically significant correlation between NW and ACL
width and between NW and PCL width. The mean ACL width was 6.4 ± 1.4 mm
(range 3-10 mm). The mean PCL width was 10.2 ± 2.0 mm (range 6-17 mm). The
mean ACL width was 5.7 ± 1.1 mm for women and 7.1 ± 1.2 mm for men. The
mean PCL width was 9.5 ± 1.7 mm for women and 10.9 ± 2.0 for men. Our
results indicate that NW correlates with ACL and PCL width. In addition, ACL
and PCL widths are narrower in women than men.
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Abnormal lateral notch in knees with anterior cruciate ligament injury
Nakauchi M, Kurosawa H, Kawakami A
J Orthop Sci 2000;5(2):92-5
We reviewed plain radiograms of anterior cruciate ligament injuries to
determine the frequency of an abnormal lateral notch found in the lateral
femoral condyle, and we investigated a possible mechanism for its occurrence
by determining the relationship with associated injuries. We analyzed data
for 216 patients who underwent ACL reconstruction between 1993 and 1996,
whose radiographic images of the contralateral knee were available. The
numbers of male and female patients were 122 and 94, respectively, and their
ages ranged from 14 to 47 years (average, 25 years).
The abnormal notch visualized by lateral radiograph was found in 66 of 216
knees (30. 6%) and was classified into three types. The type of abnormal
notch seen most frequently (73%) was located at the same site as the notch on
the contralateral side, but appeared deeper than normal.
Knees with abnormal notches showed lateral meniscal injuries more frequently
than those without such notches. The abnormal notch was assumed to have
formed at the time of injuries, after impingement of the lateral femoral
condyle on the lateral tibial condyle. Cartilage damage at the abnormal notch
should be carefully observed in the future.
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Symmetry of the femoral notch width index
Teitz CC, Lind BK, Sacks BM
Am J Sports Med 1997 Sep-Oct;25(5):687-90
A small femoral notch width index has been reported as a predictive factor
for anterior cruciate ligament injury and implicated in the higher incidence
of anterior cruciate ligament injuries in female athletes. Notch-plasty has
been recommended for the unaffected knees of patients who have torn one
anterior cruciate ligament and whose notch width index falls one standard
deviation below "normal". However, the symmetry of the notch width index has
not been specifically studied. We compared the notch width index in both
knees of 40 male and 40 female patients. Half of the patients in each group
had anterior cruciate ligament injuries, all from a noncontact mechanism. We
found that the notch width indexes of the right and left knees of the same
patient are essentially symmetrical, regardless of sex or anterior cruciate
ligament status.
Although the female patients tended to have smaller notch width indexes than
the male patients, the difference was not statistically significant.
Moreover, the ranges of notch width indexes in male and female patients
overlapped considerably. Finally, there was no difference in notch width
index between patients with and without anterior cruciate ligament tears.
These findings suggest that the notch width index alone is not the critical
etiologic factor in the patient with a unilateral anterior cruciate ligament
tear. Furthermore, the increased incidence of anterior cruciate ligament
tears in female patients compared with male patients in the same sports
cannot be attributed to notch width index alone.
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Quantitative analysis of human cruciate ligament insertions
Harner CD, Baek GH, Vogrin TM, Carlin GJ, Kashiwaguchi S, Woo SL
Arthroscopy 1999 Oct;15(7):741-9
The objective of this study was to provide quantitative data on the insertion
sites of the cruciate ligaments. In the first part of the study, we
determined the shapes and sizes of the insertions of the anterior and
posterior cruciate ligaments (ACL and PCL), and further compared these data
with the midsubstance cross-sectional areas of the ligaments. The
cross-sectional area of the ACL and PCL midsubstance of 5 human knees was
measured using a laser micrometer system. The insertion sites of each
ligament were then digitized and the 2-dimensional insertion site areas were
determined.
Relative to the ligament midsubstance, the PCL tibial and femoral insertions
were approximately 3 times larger, whereas those of the ACL were over 3.5
times larger. In the second part of the study, the ACLs and PCLs of 10 knees
were each divided into their 2 components and the areas of each insertion
were determined. Each component was approximately 50% of the total ligament
insertion area and no significant difference between the 2 could be shown.
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The natural history of the intercondylar notch after notchplasty
Mann TA, Black KP, Zanotti DJ, Barr M, Teater T
Am J Sports Med 1999 Mar-Apr;27(2):181-8
Ten patients who underwent anterior cruciate ligament reconstruction by one
surgeon using autologous patellar tendon grafts were evaluated. A
standardized technique of performing a notchplasty was done to remove at
least 5 mm of bone at the anterior outlet of the intercondylar notch.
Computed tomography scans were done preoperatively, within 1 week
postoperatively, and after 1 year of follow-up.
There were no statistically significant differences in the measured
dimensions of the intercondylar notch between 1 week and 1 year
postoperatively. While previous investigations have evaluated the
relationship between intercondylar notch dimensions and risk of anterior
cruciate ligament injury, we believe this is the first statistical study that
addresses the natural history of the intercondylar notch in humans after bone
resection. We believe that the data reported here may enhance our
understanding and treatment of patients who have undergone previously failed
anterior cruciate ligament reconstructions.
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Dr Mel C Siff
Denver, USA
http://groups.yahoo.com/group/Supertraining/
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