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T. LORDING, A. GETGOOD, T.P. BRANCH
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injury to the secondary stabilizers. Advances in
imaging technology and technique may allow
for accurate diagnosis of and targeted treatment
for these injuries. LaPrade reported 95%
accuracy in diagnosing injury to the
meniscotibial portion of the mid-third lateral
capsular ligament using magnetic resonance
imaging (MRI) [14], while Claes has also
identified a high rate of ALL abnormalities in
association with ACL injury [50]. In a recent
case series of 90 knees with ACL injury shown
onMRI, 41%were noted to have an abnormality
of the ALL [51]. Of those knees with an intact
ALL, 31% were observed to have a lateral
meniscus tear. In contrast, 61% of knees with
an ALL injury had a lateral meniscus tear.
Mansour retrospectively reviewed 200 MRI
scans and found a significant correlation
between ACL and ITB injury [52]. The site of
ITB injury, however, was not reported.
The ideal lateral extra-articular procedure is
also unclear. ALL reconstruction is an attractive
option, due to its anatomical nature. However,
recent biomechanical studies suggest the native
ALL is important only at deeper flexion angles,
and as such anatomical ALL reconstruction
may not control the pivot shift. This suggestion
is supported by the study of Spencer, who
found anatomical ALL reconstruction did not
restore internal rotational control in a simulated
early phase pivot shift [32]. More traditional
ITB based reconstructions, such as the Lemaire
procedure, may be superior in terms of
functional rotational control.
Tears involving the posterior root of the
lateral meniscus have been reported in up to
12% of ACL injured knees [53]. Injuries to
the meniscal roots have biomechanical
consequences similar to total meniscectomy
[54, 55], and may lead to meniscal extrusion
and progressive chondral degeneration [56-
58]. These effects may be mitigated to a degree
in the lateral compartment by the presence of
intact meniscofemoral ligaments [59-61].
Biomechanical studies of transosseous repair
techniques for lateral root tears generally show
a reduction in contact pressures to near normal
levels compared to the injured state [61-63].
Clinical studies show encouraging results.
Anderson reported the mid-term results of
eight radial root tear suture repairs and
16 posterior horn reattachments performed
through the tibial ACL tunnel [64]. 22 of
24 repairs functioned successfully, with better
subjective results in the transosseous repair
group. Ahn reported second look arthroscopic
results for eight patients treated with either
side-to-side or transosseous techniques, with
almost complete healing noted in all cases at a
mean of 18 months [65].
We recommend careful inspection of the lateral
meniscal root for injury during ACL re
construction, and repair of these lesions where
possible. Such a repair has two potential
benefits; improved rotational control, and long
term maintenance of the chondroprotective
function of the meniscus.
CONCLUSION
The anterolateral ligament, iliotibial band and
lateral meniscus all contribute to the restraint of
anterolateral rotatory instability at the knee, and
together can be considered to constitute the
“anterolateral corner” of the knee. Injury to these
secondary stabilizers contribute to the spectrum
of instability seen with ACL injury, and surgery
should aim to address these lesions where
possible. The indications and ideal technique for
anterolateral extra-articular procedures are yet to
be determined. Repair of lateral meniscal root
injuries has potential benefits for both knee
stability and chondral protection, and should be
undertaken where possible.