Introduction
Anterior cruciate ligament (ACL) injury causes anteroposterior and rotational instability
of the knee. Isolated intra-articular reconstructions often do not achieve satisfactory
rotational control, maintaining instability and imposing greater stress on the neoligament.
Young patients, with high athletic demands, who practice sports with rotation on the
knee and with grade 2 or 3 pivot-shift have a higher risk of re-rupture after isolated
ACL reconstruction.[1]
[2]
[3]
In order to reduce residual instability and re-rupture, lateral extra-articular reconstructions
are performed concomitantly with ACL reconstruction. Among the techniques described,
one of the most used is the modified Lemaire-type or “mini-Lemaire” lateral extra-articular
tenodesis (LET). Biomechanical studies show great versatility of the technique due
to its close to isometric stretching pattern between 0-60° when the iliotibial band
(ITB) tape is passed deep to the fibular collateral ligament (FCL). This allows its
fixation to the femur to be carried out at different degrees of flexion (0-60°).[3]
[4] Studies also demonstrate that due to the dynamic tensioning effect that the FCL
imposes on the graft, its fixation can be done at different anatomical points in the
metaphyseal region of the lateral femoral condyle, as long as it is proximal to the
femoral insertion of the FCL, providing the same rotational control characteristics.[3]
[4]
[5]
It is important to highlight that the mini-Lemaire fixation point is often close to
the femoral fixation of the ACL graft, with the confluence of the tunnels or small
bone wall between them being a concern when using an interference screw, which is
very common in our country.[6] Due to these concerns, staples or anchors are often used for this purpose, which
can cause irritation and pain due to the material protusion, requiring removal.[2] Therefore, a technique that avoids such difficulties is desirable.
The indications for performing LET as well as technical variations are constantly
evolving.[1]
[2]
[7] The objective of the present work is to describe an accessible and reproducible
technique for anterolateral extra-articular reconstruction of the mini-Lemaire type,
using the same femoral tunnel as the ACL, and fixing them together with a single interference
screw, minimizing the risk of tunnel confluence and providing adequate fixation of
the grafts with less material.
The present study did not require approval by an ethics committee because the technique
described is a modification of widely performed procedures.
Description of the Technique
Conventional patient positioning for knee arthroscopy. After intra-articular procedures,
the femoral tunnel described below is created and then the ACL tibial tunnel in the
usual way.
Lateral Incision
Make an incision of approximately 3cm on the lateral aspect of the knee, about 2cm
proximal to Gerdy's tubercle, proceeding proximally along the lateral aspect of the
distal femur, at the level of the lateral epicondyle. Variations in length and position
may be necessary depending on associated procedures and the thickness of the adipose
tissue.
Dissect the subcutaneous tissue to achieve adequate exposure of the ITB, from Gerdy's
tubercle to approximately 5cm proximal to the lateral epicondyle.
Graft Removal
Remove a strip from the posterior half of the iliotibial tract measuring approximately
1 × 8cm. Release the strip from lateral adhesions, taking care not to damage adjacent
structures such as the joint capsule, lateral collateral ligament, capsulo-osseous
layer of the IT band, while maintaining its insertion on the proximal tibia at Gerdy's
tubercle.
Perform repair of the proximal stump using absorbable Vicryl suture size 1 ([Fig. 1]).
Fig. 1 ((A) Access with dissected ITB. (B) Demarcation of the graft donor area. (C) Graft removed and repaired.
Femoral tunnel
Identify the FCL and lateral epicondyle by palpation through the gap of the previous
ITB strip incision the previous incision to remove the ITB strip. If there is difficulty,
perform varus with the knee in flexion to tension the ligament (figure “4” with lower
limb).
Pass the guide wire using the “outside-in” technique, ensuring that the wire entry
point into the lateral femoral condyle is approximately 1 cm away from the lateral
epicondyle ([Fig. 2]).
Fig. 2 Identification of the lateral epicondyle (clamp) and femoral point of the mini-Lemaire
(guide wire).
The tunnel must be made with a drill with a diameter 1mm larger than the ACL graft,
in order to allow joint passage of the ACL graft and the ITB strip into the tunnel.
Then drill the tibial tunnel in the usual way according to the size of the graft removed
for the ACL.
Deep Passage to the FCL
On the posterior and proximal margin of the FCL, make a small longitudinal incision
with a scalpel to allow the introduction of a hemostatic clamp, taking care not to
damage its fibers.
Insert the hemostatic clamp deep to the FCL through the incision made. It is possible
to palpate the clamp immediately anterior to the FCL, where a new incision should
be made to expose its tip. The clamp should always stay close to the ligament, being
careful not to inadvertently damage the popliteal tendon or penetrate the intra-articular
space.
After creating the tunnel deep to the FCL, pass the graft from anterior to posterior
through it ([Fig. 3]).
Fig. 3 ((A) Passage of the deep hemostat to the LCL. (B) Passage of the deep graft to the LCL.
Introduction of ACL and LET Grafts Through the Femoral Tunnel
After passing the LET graft deep into the LCL, use grasper forceps to pass the graft
repair (Vicryl) through the femoral tunnel in order to visualize it in the intra-articular
space. After, use the grasper again to expose the repair through the anteromedial
portal. Then pull it so that the graft enters the tunnel.
Pass an Ethibond 5 thread through the femoral and tibial tunnels, where the ACL graft
will be located, in the usual way.
During the introduction of the ACL graft, slight traction must be maintained on the
ITB strip repair through its end in the anteromedial portal in order to prevent its
extrusion through the external orifice of the femoral tunnel. Using the Ethibond 5
thread, introduce the ACL graft in a retrograde manner, first into the tibial tunnel
and then into the femoral tunnel ([Fig. 4]).
Fig. 4 (A) Passage of the LET in the femoral tunnel. (B) Passage of the flexor graft in the femoral tunnel. (C) Schematic drawing demonstrating position of grafts and tunnels.
Femoral Fixation of Grafts
The grafts are fixed to the femur with the knee in full extension.
Keep the knee in neutral varus/valgus and internal/external rotation.
Maintaining gentle traction on the LET and ACL graft, fixation is performed with an
interference screw ([Fig. 5]).
Fig. 5 (A) Panoramic photo with both grafts passed, position of fixation of the graft on the
femur. (B) Photo of the intra-articular removal of Vicryl used to repair the TEL. It is possible
to identify the ACL graft below the clamp to the left of the lateral wall of the intercondyle.
(C) Post-operative X-ray of the described technique.
Be careful not to over-tension the LET graft, in order to avoid increased pressure
in the lateral compartment postoperatively. Do not leave a segment of the ACL protruding
from the lateral femoral condyle, which could cause friction and subsequent pain.
ACL Tibial Fixation
Fix the graft to the tibia in the usual way with an interference screw, maintaining
distal traction on the graft, knee at 20-30°, neutral varus/valgus and internal/external
rotation.
Remove a spare segment of the ACL graft from the tibia if necessary.
Removal of Intra-articular Segment of LET
Remove the LET repair wire and, if necessary, a spare segment of the graft through
arthroscopy with basket forceps ([Fig. 5]).
Iliotibial Band Closure
Suture the gap in the iliotibial tract corresponding to the donor area with interrupted
stitches with Vicryl 1.
Final Considerations
Studies indicate that any point proximal to the lateral epicondyle in the distal femoral
metaphysis is suitable for mini-Lemaire reconstruction. A distance of 1cm is adopted,
considering that ACL grafts should have a minimum diameter of 8mm, which can be larger.
Thus, after drilling the ACL tunnel, a safe distance is preserved between the tunnel
and the origin of the FCL. This distance can be increased if necessary.
Exposing the repair thread of the iliotibial tract through the anteromedial portal
facilitates the retrograde passage of the ACL graft. After both are passed, the repair
thread can be switched between portals as needed.
The decision is made to fix the mini-Lemaire graft on the femur with the knee in extension
to ensure proper joint reduction and positioning of the graft in the distal femoral
tunnel. This prevents joint malreduction, graft laxity, or over-tensioning, ensuring
the maintenance of full knee extension.
It is not uncommon for the quadrupled hamstring graft (authors' preference) to have
a greater length than the ACL tunnels. Retrograde introduction allows excess removal
in the tibia without risking injury to the graft and facilitates tensioning. If anterograde
introduction leads to excess graft in the femur, its removal may cause inadvertent
injury to the graft or generate friction and pain if prominent.
If the described steps are followed, the occurrence of an intra-articular excess segment
of the iliotibial tract at the end of the procedure is uncommon, requiring only the
removal of the absorbable suture used at the femoral tunnel level in the intercondylar
area. If there is an intra-articular segment of the ITB, it can be easily removed
in the same way, taking care not to damage the ACL graft.
Postoperative rehabilitation is independent of ITB tenodesis and can be carried out
in the usual manner for ACL reconstruction.
