Reconstruction of the Anterior Cruciate Ligament and the Posterolateral Corner With a Single Combined Femoral Tunnel

Abstract

Background:

Posterolateral knee injuries can occur in 16% of patients with acute ligament injuries, and up to 70% have a combined anterior cruciate ligament (ACL) tear. Studies have shown that, in different populations, the distance between the insertion of the popliteus tendon and the lateral collateral ligament (LCL) may be smaller than the 18.5 mm previously reported in the literature. When we have an associated injury of the ACL and the posterolateral corner (PLC), the confluence of tunnels in the lateral femoral condyle can be a potential problem during reconstruction surgery.

Indications:

The indication of this technique is the combined injury of the ACL and the PLC.

Technique Description:

The reconstruction is performed with 2 semitendinosus tendons and 1 gracilis tendon. The technique consists of making a tunnel in the lateral wall of the femur, from the outside-in, at the isometric point between the origin of the LCL and insertion of the popliteus tendon, and emerging in the inner wall of the lateral femoral condyle at the anatomic point of the ACL. The graft is passed from the tibia to the femur with the doubled gracilis tendon and the 2 simple semitendinosus tendons for the ACL graft. The remaining portions of the semitendinosus tendons are left for reconstruction of the PLC structures, with one of them going straight to the posterolateral tibial tunnel (reconstructing the popliteus tendon), and the other passing through the fibular head tunnel (reconstructing the LCL) and continuing from the fibular head to the posterolateral tibial tunnel (reconstructing the popliteofibular ligament).

Results:

Patients undergoing this technique achieved good functional outcomes and a failure rate similar to that reported in the literature for combined ACL and PLC reconstruction.

Discussion/Conclusion:

This technique is an excellent option for patients with the combined injury of the ACL and the PLC, avoiding the confluence of tunnels in the lateral femoral condyle. It presents good results and acceptable complication rates, compatible with the severity of this lesion.

Patient Consent Disclosure Statement:

The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication.

Graphical Abstract

This is a visual representation of the abstract.

Video Transcript

Posterolateral knee injuries can occur in 16% of patients with acute ligament injuries,^2-4 and up to 70% have a combined anterior cruciate ligament (ACL) tear. ⁴ Studies have shown that, in different populations, the distance between the insertion of the popliteus tendon and the lateral collateral ligament (LCL) may be smaller than the 18.5 mm previously reported in the literature. ⁵ When we have an associated injury of the ACL and the posterolateral corner (PLC), the confluence of tunnels in the lateral femoral condyle can be a potential problem during reconstruction surgery. ¹

The technique presented in this video proposes the associated reconstruction of the ACL and the PLC with a single combined tunnel in the lateral femoral condyle. The patient presented is a 24-year-old woman who suffered a motorcycle accident 1 year before surgery, with torsional trauma to the right knee, progressing with significant knee instability. On physical examination, she has a positive Lachman test, a positive anterior drawer test, a positive varus stress test, and a positive posterolateral drawer test.

The indication of this technique is the combined injury of the ACL and the PLC. ¹ The contraindication is the presence of limb malalignment, particularly varus, that may require combined osteotomy, and semitendinosus graft length of less than 27 cm that will probably be insufficient for the combined reconstruction. ¹

The reconstruction is performed with 2 semitendinosus tendons and 1 gracilis tendon. The technique consists of making a tunnel in the lateral wall of the femur, from the outside-in, at the isometric point between the origin of the LCL and insertion of the popliteus tendon, and emerging in the inner wall of the lateral femoral condyle at the anatomic point of the ACL. ¹ The graft is passed from the tibia to the femur with the doubled gracilis tendon and the 2 simple semitendinosus tendons for the ACL graft. ¹ The remaining portions of the semitendinosus tendons are left for reconstruction of the PLC structures, with one of them going straight to the posterolateral tibial tunnel (reconstructing the popliteus tendon), and the other passing through the fibular head tunnel (reconstructing the LCL), and continuing from the fibular head to the posterolateral tibial tunnel (reconstructing the popliteofibular ligament). ¹

The patient is placed in the supine position on a radiolucent table, with both legs prepared. The procedure starts with the hamstring tendon harvesting from the affected limb, and semitendinosus tendon harvesting from the contralateral limb. A posterolateral access is made from a point 2 cm proximal to the lateral epicondyle to 2 cm below the head of the fibula. Here we see the iliotibial tract, the biceps tendon, the head of the fibula, and that is the interval posterior to the biceps where we are going to dissect to find the peroneus nerve. The nerve is identified, dissected, protected, and isolated with the blue vessel loop.

Preparation of the tunnels starts at the head of the fibula. A guidewire is passed at the widest diameter of the head, in the anterolateral to posteromedial direction. The tibial tunnel for the posterolateral structures starts at the Gerdy's tubercle with direction to the posterior region of the tibia, immediately above and medial to the tip of the head of the fibula. Then, the position of the guidewires is checked by fluoroscopy. If the positions are suitable, the tunnels are drilled with the smaller interference screw diameter, usually 6 or 7 mm.

The LCL and the popliteus tendon are dissected and the isometric point between their insertions is identified. ¹ This point can be checked in the absolute lateral view of the distal femur, where the line that passes across the anterior border of the posterior cortex of the femur crosses the Blumensaat line. ¹ Here is being pointed the LCL, passing behind the iliotibial tract, and here is the popliteus tendon. The guidewire should be located just anterior to the crossing point between the LCL and the popliteus tendon. ¹

After that, arthroscopy is initiated with anterolateral and anteromedial portals. At this moment, treatment of any meniscal and chondral lesions is carried out, and the lateral wall of the intercondylar notch is prepared.

The standard outside-in femoral guide for the ACL is positioned at the anatomic point of the ACL footprint inside the knee, and, outside, at the previously marked point for the posterolateral structures on the lateral femoral condyle. ¹ With the guide correctly placed, a guidewire is inserted from the outside-in. The guidewire position is arthroscopically checked before drilling. Then, the combined femoral tunnel is drilled in the previously measured diameter of the ACL graft. The femoral tunnel is checked for its position and integrity of the posterior wall. The tibial tunnel for the ACL is made in the extension of the anterior horn of the lateral meniscus and between the tibial spines. An Ethibond 5 (Ethicon Inc.) is inserted into the joint through the femoral tunnel and pulled into the tibial tunnel with a grasper. The Ethibond is used to guide the passage of the graft from the tibia to the femur. The graft is positioned in the femoral tunnel, with the remaining 2 portions of the semitendinosus grafts exiting the outer wall of the lateral femoral condyle. ¹ The graft is fixed in the femoral tunnel with an interference screw that enters the lateral cortex of the femur.

The remaining grafts of the semitendinosus are passed behind the iliotibial band. One of them is passed through the fibular tunnel to reconstruct the LCL, and then both semitendinosus tendons are pulled into the posterolateral tibial tunnel, reconstructing the popliteus tendon and popliteofibular ligament. ¹ The LCL is fixed with an interference screw in the fibular tunnel, with valgus force being applied. ¹ Then, the grafts are fixed in the tibial tunnel, from anterior to posterior, with the knee flexed at 60°, ² with internal rotation and valgus force. ¹ Then, after pretensioning the graft, tibial fixation of the ACL is performed with an interference screw, with the knee at 30° of flexion and posterior drawer applied. ¹ After that, the wounds are sutured by layers and that is the final physical examination, with satisfactory joint stability.

These are the postoperative radiographs showing the combined reconstruction with a single tunnel in the lateral femoral condyle.

The peroneal nerve injury is a potential complication. ² To avoid that, peroneal nerve must be identified and protected during the procedure. The fibular tunnel must be in the center of the head of the fibula, at the widest diameter, to avoid fibular head fracture. ¹ Protruded femur screw can irritate iliotibial band, which can be a cause of constant lateral pain. To avoid that, we must be careful when passing the femoral screw not to leave it prominent. ¹

After surgery, free range of motion of the knee is allowed. For the first 6 weeks, patients can walk with partial weightbearing with crutches and a knee brace. From the seventh week, the knee immobilizer is discontinued, and weightbearing is progressed as tolerated. The return to full activity happens between 9 and 12 months after surgery.

In our series, we have the reported outcomes of 18 patients who underwent surgery at our institution between 2009 and 2015, with a minimum follow-up of 2 years, and a mean follow-up time of 59.7 months. ³ As complications, we had 1 patient with loss of flexion and 1 patient with failure of the reconstruction. ³ The mean IKDC (International Knee Documentation Committee) subjective score was 83.7 ± 14.6. ³ The mean Lysholm score was 87.1 ± 12.8. ³

These were the references for this video. Thank you.