New Anatomic Anterolateral Ligament Reconstruction Used in a Complex Revision ACL Reconstruction

Abstract

Background:

Anterior cruciate ligament reconstructions (ACLRs) are performed to restore knee biomechanics, increase knee stability, and slow the progression of osteoarthritis. After ACLRs, many patients still have residual anterolateral instability which is a risk factor for ACL graft failure. An anterolateral ligament reconstruction (ALLR) attempts to restore the native function of the anterolateral complex to augment the ACL. Performing an ALLR with an ACLR has been reported to reduce symptoms of instability and improve clinical outcomes.

Indications:

While no definitive indication for an ALLR has been set, current considerations include high posterior tibial slope >12°, revision ACLR, high-grade pivot shift, skeletally immature patients, hyperlaxity, and patients in high-level sports.

Technique Description:

The preoperative assessment includes a thorough physical examination with special attention paid to rotational laxity assessed via the pivot-shift examination. Imaging should include standard radiographic series (anteroposterior, posteroanterior flexion, lateral, and sunrise views), long-leg mechanical axis views to assess coronal plane alignment and standing lateral ACL stress radiographs to assess sagittal alignment and objective instability. The iliotibial band ALLR graft is harvested first. An 8-cm long by 1-cm wide strip of the inferior iliotibial band is harvested in a standard fashion, leaving the distal aspect attached to Gerdy’s tubercle. An anchor is placed centered upon the native ALL distal tibial insertion. The native ALL femoral origin is identified at 4.7 mm posterior and proximal to the fibular collateral ligament, and a second suture anchor is placed at this point. Final fixation is performed after the final fixation of the ACLR graft.

Results:

A study by Pioger et al reported that patients with ACLR and ALLR had significantly less reoperation rate than patients with isolated ACLR, 8.9% versus 20.5% respectively. Lee et al found that a revision ACLR in combination with an ALLR was effective in reducing rotational laxity, which was assessed by the pivot-shift test.

Discussion:

We describe a technique for a new anatomic ALLR using the iliotibial band that attempts to restore the native ALL anatomy. This surgical technique effectively restores rotational laxity and improves knee stability.

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

This is a video presentation demonstrating a new anatomic anterolateral ligament reconstruction (ALLR) used in a complex revision anterior cruciate ligament reconstruction (ACLR).

Shown here are the disclosures for the senior author.

There have been significant recent advances in the understanding of native ACL anatomy and biomechanics. This understanding has allowed notable improvements in surgical techniques and patient outcomes. ² However, in certain patient populations, ACLR failure rates can still be quite high. Due to this, there has been a push to address specific risk factors to improve ACLR outcomes. ⁹ One such technique is a soft tissue ALL augmentation in the form of an ALLR. ⁶ There are several risk factors which have been discussed as an indication for an anterolateral knee complex augmentation including increased posterior tibial slope greater than 12°, revision ACLR, skeletally immature or adolescent individuals, high-level athletes, high-grade pivot shift, meniscal deficiency, and hypermobility/recurvatum.^5,9 Biomechanical studies have reported that ALLR increases knee stability ³ and several techniques described report good clinical outcomes and a reduced ACLR failure rate when a concomitant ALLR is performed.^4,5,7

The patient presented is a 42-year-old female who has chronic right knee pain. She had an acute right knee injury in 1998 jumping off of a stage and had a subsequent ACLR in 2000. Recently, she has been dealing with pain, swelling, and difficulty walking. She reports that a lateral unloader brace has helped to relieve symptoms.

On physical examination, the patient has a range of motion from 6-cm heel height to 140° of flexion. She also has a grade 2+ Lachman, grade 2 pivot shift, and grade 1 anterior drawer. The examination is suggestive of a failed ACLR.

Anteroposterior radiographs of the left knee are unremarkable with no obvious osseous pathology. Posterior tibial slope was measured at 14.6° on the mechanical axis. A long-leg mechanical axis radiograph demonstrates moderate valgus alignment on the right side.

Magnetic resonance imaging findings demonstrate a ramp tear of the posterior horn of the medial meniscus, the lateral compartment with grade 3 to 4 chondromalacia with signs of a deficient lateral meniscus due to a previous meniscectomy, a previously unrepaired lateral meniscus root tear, and a nonfunctional and attenuated ACL graft.

In summary, the patient has a right knee failed ACLR, with a concomitant tear of the posterior horn of the medial meniscus. Further, the patient has lateral meniscus deficiency, grade 3 to 4 chondromalacia of the lateral compartment, significant knee hyperextension, and valgus alignment. Given her diagnosis and significant risk factors, the decision was made to proceed with a quadriceps tendon autograft revision ACLR, a medial meniscus repair, a lateral meniscus partial meniscectomy, and a distal femoral opening wedge osteotomy. In addition, due to the patient requiring a revision ACLR, increased recurvatum, a high-grade pivot-shift examination, and an increased posterior tibial slope, the patient will undergo an ALLR using our novel technique.

The examination under anesthesia was consistent with previous clinical findings. The patient had a range of motion of 6 cm of heel height to 140° of flexion. Her Lachman and pivot shifts were both a 3+, which were more severe than in clinic. She had no significant varus or valgus gapping.

Prior to the harvest of the graft for the ALLR, the quadriceps tendon autograft for the ACLR was harvested first. A full thickness quadriceps tendon autograft that was 8 cm long and 9 mm wide was harvested with a 10 × 15 mm bone plug off the patella.

Next, the lateral approach was performed and the osteotomy and ALLR would be completed through this incision. For the ALLR autograft, dissection was carried down using a large Cobb elevator to expose the iliotibial (IT) band. First, the length of the IT band autograft was measured at 8 cm from the center of Gerdy’s tubercle. The graft was then marked along the length to obtain a 1-cm-wide graft originating from the inferior aspect of the IT band. Both the proximal and distal ends of the graft are left attached to help facilitate the detachment of underlying tissues. Once the graft is free of adhesions, it is amputated proximally. The graft should flare at Gerdy’s tubercle to aid in positioning the graft.

This slide is included to help visualize the attachment sites for the ALLR on the femur and tibia. The anatomic ALL attachment to the femur is located 4.7 mm posterior and proximal to the fibular collateral ligament (FCL). The anatomic ALL attachment on the tibia is located midway between the center of Gerdy’s tubercle and the anterior margin of the fibular head and 9.7 mm distal to the joint line. The ALL runs superior to the FCL and popliteus tendon. The advantages of this technique compared with previously described techniques include reproducing the native ALL anatomy, not requiring the graft to run under the FCL, no closure of the IT band is required, and this technique uses an autograft.

The proximal landmark of the origin of the ALL was located, which is approximately 5 mm posterior and proximal to the FCL origin and was marked for later placement of a Q-Fix anchor for the ALLR graft fixation. Next, the location where the ALL attaches to the tibia, midway between the fibular head and Gerdy’s tubercle, and 1 cm distal to the joint line, was located. A spinal needle is placed at the joint line to aid in measuring. This location is marked, and a Q-Fix anchor is placed by first placing the guide at the location, drilling a pilot hole, and releasing the Q-Fix anchor into the pilot hole. Next, to perform the osteotomy, the IT band was split, and the vastus lateral musculature was elevated to expose the osteotomy site.

The medial and lateral portals were now made for arthroscopy.

She had a moderate amount of scarring of her suprapatellar pouch and retropatellar fat pad, which was cleared out.

Her medial compartment showed mild surface chondromalacia, grade 1, and a very large ramp tear.

Her ACL graft was nonfunctional. The ACL remnant was now debrided.

The ACL revision reconstruction was performed as previously described. ¹

Her lateral compartment demonstrated some areas of grade 4 chondromalacia posteriorly. There was also only about 3 mm of rim posteriorly and the lateral meniscus root was not attached. It was not fixable due to limited remaining lateral meniscus volume.

A rasp was then used to rasp around the ramp tear. It had significant tearing posteriorly. Four all-inside FAST-FIX FLEX anchors were placed to perform the medial meniscus ramp tear repair.

The ACL graft was then fixated, and the osteotomy was completed. The osteotomy correction was completed using a 5-mm Puddu plate that was secured with four 4.5-mm cortical screws and two 6.5-mm cancellous screws.

After the rest of the surgery is complete and the ACL revision reconstruction graft is confirmed to be taut, the anatomic ALLR graft can be fixated into its final position. The graft was first fixed at the distal location with the previously placed Q-fix anchor using a modified Mason-Allen stitch technique. During this process, the proximal end of the graft should be held over the previously marked fixation location on the femur to ensure the graft is in the proper orientation when secured distally. A second Q-fix anchor is now placed on the femur in the previously marked location. This is performed in the same manner as the Q-Fix anchor that was fixated in the tibia. The graft can now be secured at the proximal attachment using the same modified Mason-Allen stitch technique. The graft should be fixated with the knee at 20° of flexion and neutral rotation to ensure proper tensioning. The second suture can be used to tighten the graft if necessary. The graft should be checked to ensure it tightens with internal rotation and loosens with increasing knee flexion.

The deep and superficial tissues were closed with sutures. The IT band does not need to be closed due to harvesting the graft at the inferior aspect of the IT band.

She will be nonweightbearing on her right lower extremity for 8 weeks. We will limit her flexion to 90° for the first 2 weeks, and then she may increase her range of motion as tolerated. Radiographs will be taken at day 1 postoperatively and 8 weeks postoperatively. If there is evidence of healing at 8 weeks, partial protected weightbearing can begin advancing a quarter body weight per week. At 3 months, if the radiographs show further evidence of healing, the patient can wean off her crutches.

This technique is not without potential complications. First, a benefit of this described new ALLR technique is the ability to harvest a shorter IT band graft relative to traditional technique, 8 versus 10 cm. However, harvesting a graft too short can lead to inadequate graft length. To avoid this complication, the graft should be at least 8 cm and measured from the center of Gerdy’s tubercle. In addition, dissection of the graft should continue all the way to Gerdy’s tubercle. Finally, when placing sutures in the graft, the assistant should hold the proximal extent of the graft taut to ensure fixation distally does not lead to inadequate length proximally.

Suture pull through or failure at the suture anchor is another potential complication. Placing the sutures in a modified Mason-Allen configuration with 2 tails on the proximal aspect of the IT band graft and 2 distally allows for even tensioning of the graft and minimizes the risk of suture pull out.

The last complication worth noting is potential iatrogenic intra-articular penetration of the suture anchor. Placing a spinal needle at the lateral joint line helps to localize the appropriate anatomic location of the insertion of the native ALL, and further aiming the drill and subsequent anchor slightly distally upon placement helps to further minimize risk of iatrogenic intra-articular placement.

A clinical study by Pioger et al ⁸ reported on 1009 matched pairs of patients who underwent either isolated ACLR or ACLR with ALLR. The patients who underwent isolated ACLR were 3-fold more likely to experience graft failure than patients with ACLR and ALLR. In addition, the patients with ACLR and ALLR had a significantly lower reoperation rate than patients with isolated ACLR, 8.9% versus 20.5% respectively.

Anteroposterior and lateral radiographs were obtained in clinic on postoperative day 1. There is no evidence of acute fractures or soft tissue abnormalities appreciated. Hardware is intact and nondisplaced.