The role of anterolateral complex surgery and slope-reducing osteotomies in revision ACL reconstructions: a narrative review

Abstract

Background and objective: Anterior cruciate ligament reconstruction (ACLR) failures occur for various reasons including residual laxity, untreated concomitant injuries, poor graft quality, and high tibial slope. Various additional procedures can help to decrease revision ACLR failures including anterolateral complex (ALC) procedures and slope-reducing osteotomies for patients with high tibial slopes. This narrative review aims to review the literature on the roles of ALC augmentation procedures and slope-reducing osteotomies in the setting of patients undergoing revision ACLRs.

Methods: A narrative review of relevant literature was performed in July 2024. Studies about anterolateral complex reconstructions and slope-reducing osteotomies in revision ACLRs were included.

Key content and findings: The literature reported that lateral extra-articular tenodesis (LET) and anterolateral ligament reconstructions (ALLR) can be used in revision ACLR cases to significantly reduce clinical knee laxity and the risk of repeated graft failure. There is not currently a strong opinion on which ALC procedure is superior. There are reported slight differences in lateral knee pain and knee stiffness, but both similarly significantly improve clinical and functional outcomes. In revision ACLR cases that also have a high posterior tibial slope (PTS), a slope-reducing tibial osteotomy is warranted. An anterior closing wedge proximal tibial osteotomy (ACW-PTO) significantly reduces anterior tibial translation and graft failure. There is concern about the changes to patellar height, but the literature has found that such changes are either slight or absent by 6 months postoperatively.

Conclusions: The risk of ACLR failure is increased by risk factors like high tibial slope, preoperative knee laxity, and prior ACLR rupture. Anterolateral complex procedures and slope-reducing osteotomies may be used to address these specific concerns and reduce the risk of graft rupture. For revision ACLR cases with lower PTS, augmentation with a LET or an ALLR to reduce the risk of graft failure and improve rotational stability may be warranted. In the setting of a revision ACLR in patients with a high PTS of ≥12°, a concomitant ACW-PTO and ALC procedure should be considered to decrease the risk of an ACLR graft failure.

Keywords: Anterolateral complex; anterolateral ligament reconstruction (ALLR); lateral extra-articular tenodesis (LET); revision anterior cruciate ligament reconstruction (revision ACLR); slope-reducing osteotomy.

Figure 1

Lateral knee radiograph indicating the lateral posterior tibial slope angle (yellow arrow point to yellow line). The lateral PTS can be calculated by finding the angle between a line connecting the highest points of the lateral tibial plateaus and the anatomic axis of the tibia. The anatomic axis of the tibia can be found by drawing a line connecting the midpoints of the width of the bone at points 5 cm to the tibial plateau and 5 cm proximal to the tibial plafond. The PTS is calculated by subtracting that angle from 90°. The PTS in this image is 16.3°. PTS, posterior tibial slope.

Figure 2

Depiction of the modified Lemaire LET technique. An 8 cm long by 1 cm wide band of distal ITB is left attached distally to Gerdy’s tubercle and is passed deep to the FCL. The LET is fixated proximally and posterior to the femoral attachment of the FCL at 30° of knee flexion. Reproduced with permission from Geeslin et al. (23). LET, lateral extra-articular tenodesis; ITB, iliotibial band; ALL, anterolateral ligament; FCL, fibular collateral ligament; PFL, popliteofibular ligament.

Figure 3

Depiction of anterior (left) and lateral (right) views of a concomitant ALLR and ACLR. The ACLR is performed with a bone-patellar tendon-bone autograft, and the ALLR with a semitendinosus allograft. The ALLR graft is fixated with an interference screw distally to a point 1 cm distal to the joint line, midway between the fibular head and Gerdy’s tubercle, and proximally 4.7 mm posterior and proximal to the femoral attachment of the fibular collateral ligament. The graft is fixated with the knee at 20° of flexion in neutral rotation. Reproduced with permission from Nitri et al. (19). ALL, anterolateral ligament; ALLR, anterolateral ligament reconstruction; ACLR, anterior cruciate ligament reconstruction; FCL, fibular collateral ligament.

Figure 4

Fluoroscopic image of the 4 guide pins used to mark the location of the ACW-PTO. The two distal guide pins are placed first on either side of the patellar tendon, just proximal to the patella attachment on the tibia. These should be perpendicular to the tibial shaft. The two proximal guide pins should be angled to meet the first two pins at the posterior cortex. The distance between the entry of the proximal and distal pins should equal the desired correction size, roughly 1 mm per 1° of desired correction. Using these pins as guides, the bone wedge can be resected. ACW-PTO, anterior closing wedge proximal tibial osteotomy.

Figure 5

Depiction of a 15° posterior tibial slope (A) corrected to 5° (B) using an anterior closing-wedge proximal tibial osteotomy closed with two proximal tibial staples. The measurements labeled “A” and “B” represent the distance from the lowest point of the patellar articular surface to the tibial articular surface, and the length of the patellar articular surface, respectively. The ratio of A to B is the Caton-Deschamps Index, a measure of patellar height. Reproduced with permission from Tollefson et al. (9).