“Over-the-Top” Anterior Cruciate Ligament Reconstruction Associated With a Lateral Extra-Articular Tenodesis in Children

Anterior cruciate ligament (ACL) tears are one of the most frequent injuries in growing children, and they are often associated with other injuries such as meniscal and chondral injuries. In the past, treatment of ACL tears in growing patients relied on activity modification and bracing. However, surgical treatment has prevailed over conservative treatment in recent years. A surgical technique is presented for ACL reconstruction using an “over-the-top” technique associated with a lateral extra-articular tenodesis procedure in children. An extra-articular lateral tenodesis is done first. The gracilis and semitendinous tendons are then extracted using a tenotome without releasing their distal desinsertions. The tibial guide is then centered over the ACL tibial footprint under arthroscopic vision and an image intensifier, proximal to the physis. Then, a Kocher-type forceps is used to pass a suture “over the top” from the posterolateral window to the tibial tunnel. The double-bundle graft and iliotibial tract graft are fixed within the tunnel in full extension and neutral rotation with an interference screw.

T he number of knee injuries in growing children has increased considerably in recent year due to the higher levels of sports activities and professionalization of sports. 1 Anterior cruciate ligament (ACL) tears are one of the most frequent injuries in this age group, and they are often associated with other injuries such as meniscal and chondral injuries. 2 In the past, treatment of ACL tears in growing patients relied on activity modification and bracing. 3 However, surgical treatment has prevailed over conservative treatment in recent years 4,5 since there is a higher risk of chondral and meniscal injuries in patients with ACL deficiency who are treated conservatively. 6 Regarding the surgical treatment of these injuries, we must bear in mind that these patients are growing. Therefore, the physis should be spared to avoid potential growth deformities. Accordingly, many surgical techniques and treatment algorithms have been described to manage ACL injuries, based on age, sex, and the state of the growth plate. "Over-the-top" techniques with autologous hamstring tendon grafting have been used for the treatment of ACL injuries. 7,8 These techniques have few complications involving the growth and angulation of the operated knee, restore joint stability and the biomechanics of the knee, and have a similar reoperation rate and clinical outcomes compared to epiphyseal techniques. 7,9,10 On the other hand, due to their excellent results, lateral reinforcements by associating an extra-articular lateral tenodesis (LET) to ACL reconstruction the "over-the-top" technique is becoming progressively more popular in growing patients with an immature skeleton. 7,11 The anterolateral reinforcement associated with reconstruction of the ACL provides greater resistance to internal rotation and anterior tibial translation. It reduces the rate of graft failure, even in patients with a higher risk of failure, such as young patients. [12][13][14][15] The objective of this study is to report our physissparing ACL reconstruction technique using an "over-the-top" technique associated with a lateral extra-articular tenodesis procedure.

Patient Positioning
The patient is subjected to general anesthesia and placed in the supine position. A tourniquet is placed on the proximal thigh, and an L-shaped support is placed on the distal end of the table to keep the knee in about 90o of flexion. Two additional supports are placed laterally (Fig 1, Video 1).

Extra-Articular Lateral Tenodesis
A 3-to 4-cm lateral incision is performed over the lateral epicondyle (Fig 2). A 1-cm thick band is detached from the iliotibial band and extended from Gerdy's tubercle proximally to gain the maximum possible length (Fig 3). The free end of the graft is sutured with a No. 2 high-resistance FiberWire (Arthrex) suture and passed under the lateral collateral ligament (Figs 4 and 5, Video 1).

Arthroscopic Exploration
Standard anterolateral and anteromedial portals are made to perform a full exploration of the knee. Then any meniscal injuries are identified and repaired using Truespan (Depuy-Synthes) implants. The ACL tear is confirmed and a debridement of any remnant tissues is performed using a No. 4 arthroscopy shaver (Depuy-Synthes). Then the exit point of the tibial tunnel is marked with an electrocautery device (Depuy-Synthes) (Video 1).

Graft Harvesting and Preparation
An oblique incision is made on the medial aspect of the tibia, above and in the same direction as the hamstring tendons (Fig 6). The gracilis and semitendinous tendons are then extracted using a tenotome without releasing their distal insertions. Next, the tendons are cleaned from any remaining muscle fibers, and their ends are sutured with a No. 2 high-resistance thread (Fig 7). Finally, the diameter of the doublebundle autograft is measured before drilling the tibial tunnel (Video 1).

Tibial Tunnel Preparation
The tibial guide is then centered over the ACL tibial footprint under arthroscopic vision and an image intensifier (Fig 8). A guide-pin is inserted proximal to the tibial physis and drilled in an outside-in direction (Fig 9). The angulation of the tibial guide varies depending on the position of the physis (Fig 10). The diameter of the tunnel is determined by the size of the double-bundle graft (Video 1).
Step "Over the Top" and Graft Passage Next, a small window is made through the posterolateral capsule of the knee (Fig 11). A Kocher-type forceps is then used to pass a suture "over the top" from the posterolateral window to the anteromedial portal ( Fig 12). Finally, the suture is retrieved through the tibial tunnel and used to pass the graft to the posterolateral window (Figs 13-17, Video 1).

Femoral Tunnel Preparation and Graft Fixation
Next, the joint diameters of both the hamstring graft and the iliotibial tract graft are measured (Figs 18  and 19).
Finally, a femoral tunnel is drilled proximally and posteriorly to the distal femoral physis under image the intensifier from lateral to medial (Fig 20). The doublebundle graft and iliotibial band graft are fixed within the tunnel in full extension and neutral rotation with an interference screw (Fig 21, Video 1).

Discussion
ACL injuries in the pediatric age group are progressively becoming more frequent due to the increase in the intensity and demand of physical activities in children. 6 Numerous techniques and algorithms have been described for the treatment of these injuries, to avoid damage to the growth plate and to obtain higher return to play rates. 7,16,17 For example, the LET seems to reduce ACL rerupture rate recurrence of these injuries. 18,19 In our technique, we present a combination of an "over-the-top" ACL reconstruction and a lateral extraarticular tenodesis. All techniques for ACL reconstruction ("over the top," transtibial, and all-epiphyseal)  achieve a significant improvement in anterior-posterior and rotational stability. 8,20 However, none of them recovers the stability levels of an intact ACL independently. 20 Accordingly, the combination of both techniques ("over the top" and LET) could improve the biomechanical stability. Moreover, this technique combines the advantages of a physeal-sparing ACL reconstruction for patients with an immature skeleton and that of an extra-articular lateral tenodesis without the need to make 2 femoral tunnels. In addition, it eliminates the risk of femoral tunnel confluence, 21,22 which is a real risk in pediatric patients with relatively smaller knee joints (Table 1). Similar techniques have been described in the literature. Marcacci et al. 23 combined an ACL reconstruction using an "over-the-top" technique with an extraarticular lateral reinforcement. In contrast to our technique, Marcacci et al. 23 used the remaining hamstring graft and fixed it with a staple at the anterolateral ligament's origin in the tibia. Accordingly, this technique does not need any femoral tunnels, but it is dependent on the length on the tendinous remnant.
In our technique, the iliotibial band was used to perform the lateral tenodesis. Therefore, we did not rely on the total hamstring graft length. Moreover, by using an interference screw fixation, we avoided any potential discomfort caused by the staples.
Grassi et al. 24 and Zaffagnini et al. 8 reported good clinical results and low rerupture rates using this technique with 10 and 20 years of follow-up, respectively. Moreover, the authors did not report an increase in lateral compartment osteoarthritis.
The main difference between our technique and the modified Lemaire-type extra-articular lateral tenodesis lies in the femoral fixation point. The femoral location of this tenodesis has been analyzed in various anatomic and biomechanical studies. Accordingly, it has been described to be proximal and posterior to the epicondyle. 25 In our case, the position of the physis should be taken into consideration when fixing the tenodesis, placing it as proximal as necessary so as not to invade it.
As Kittl et al. 26 demonstrated, the most important thing in performing this technique is passing the tenodesis under the lateral collateral ligament, acting as a pulley. The fixation must be proximal to the lateral epicondyle, regardless of the exact point once the plasty has passed under the lateral collateral ligament.
Both the Lemaire technique and ACL reconstruction can be fixed in full extension, therefore making this technique suitable for simultaneous fixation. However, a drawback of our technique could be the thickness of the ACL graft, which usually does not measure more than 6 mm in diameter. Some authors have described that the tunnel localization is a more relevant factor in  e446 ACL reconstruction failure than the diameter of the ACL graft. 27 Furthermore, in previous studies, Di Sarsina et al. 7 and Grassi et al. 28 reported excellent results in skeletally immature patients subjected to an ACL reconstruction using the technique by Marcacci et al. 23 with graft diameters similar to the ones found in our study.
The preservation of the tibial insertion of the gracilis and semitendinous tendons maintains their vascularization and innervation, therefore improving their integration compared with free grafts. 29,30

Conclusions
The "over-the-top" technique for ACL reconstruction with an extra-articular lateral tenodesis is a safe technique that may increase the rotational stability of the operated knee, avoiding the confluence of tunnels and the risk of rupture of the plasty. Perform full femoral tunnel to avoid problems of tension of the plasty. Minimizes the risk of confluence of femoral tunnels Plasty thickness less than 8 mm Fix the graft in 0 of extension and neutral rotation. Maintains the vascularization and innervation of the gracilis and semitendinosus tendons Use the tibial angulation necessary to avoid damaging the tibial growth plate.
The decreased diameter of the tibial tunnel increases the safety margin for keeping the tunnel within the tibial epiphysis and avoids the risk of fracture. No plasty length issues LET, extra-articular lateral tenodesis.
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