Pearls for combined ACL, anterolateral ligament reconstruction with single femoral tunnel
ACL reconstruction is one of the most common orthopedic procedures. Although this procedure has a high success rate, certain patient groups may have a higher risk for reconstruction failure.
Lateral extra-articular procedures, such as modified Lemaire tenodesis and anterolateral ligament (ALL) reconstruction, have emerged in the past 10 years as options for ACL reconstruction augmentation, aiming to improve outcomes and reduce the risk of failure. The main indications include a grade 2 or 3 pivot shift, generalized ligament hyperlaxity or knee hyperextension, young patients intending to return to pivoting sports, chronic ACL lesions and revision surgery. However, nowadays, any patient at an increased risk for failure can be a candidate for this augmentation procedure.
Source: Camilo P. Helito, MD, PhD, Prof.
Several techniques have been described for the reconstruction of the ACL and the ALL. The combined reconstruction with a single femoral tunnel using hamstrings tendon graft is a simple and reproducible technique with no significant increase in surgical time and excellent clinical outcomes reported. This article aims to provide a step-by-step description and some useful pearls and tips for performing this technique.
Surgical approach
The patient is placed in a supine position on the surgical table. A pneumatic tourniquet is set proximally on the injured limb and inflated after placing sterile drapes.
Graft harvesting: Harvesting of the semitendinosus and gracilis tendons is performed as usual. A longitudinal skin incision of approximately 3 cm is made over the insertion of the hamstrings on the anteromedial surface of the tibia. The fascia of the sartorius muscle is opened, the semitendinosus and gracilis tendons are identified and its extremities are repaired with a 1-0 Vicryl suture. After disinserting the tendons of the tibia, the semitendinosus and gracilis tendons are harvested with the aid of a tendon stripper (Figure 1).
Surgical tip: To perform the combined reconstruction, the semitendinosus tendon must be at least 24 cm in length for making an 8-cm three-strand graft and the gracilis tendon must be at least 16 cm in length (considering 8 cm for the ACL graft, 6 cm for the ALL graft and a minimum of 2 cm inside the tibial tunnel for the interference screw fixation). Tendons are almost always of sufficient length.
Graft preparation: Semitendinosus and gracilis tendons are cleaned of muscle residue and the extremities are prepared with a continuous suture.
The graft is prepared with a three-strand semitendinosus tendon and a single-strand gracilis tendon, resulting in a quadruple ACL graft. The remaining portion of the gracilis is used for the ALL reconstruction. The ACL graft diameter is usually 8 mm to 9 mm (Figures 2 and 3).
Surgical tip: The suture at the extremity of the gracilis tendon used for the ALL must be longer and prepared with a high-resistance suture, going up to approximately 5 cm to 6 cm from the tip of the graft. In this way, the portion of the ALL graft that will remain inside the tibial tunnel will be covered with the suture, facilitating the passage of the interference screw and avoiding tearing of the graft.
Arthroscopy
Arthroscopy starts with standard anterolateral and anteromedial portals. At this point, the joint cavity is inspected and any associated meniscal or chondral lesions are properly treated. After that, the lateral wall of the intercondylar notch is prepared.
Combined femoral tunnel preparation: A skin incision is made slightly posterior and proximal to the lateral epicondyle of the femur (Figure 4), and the iliotibial tract is longitudinally opened. The anatomical point of the ALL on the lateral femoral condyle is located posterior and proximal to the lateral epicondyle.
The outside-in guide is placed close to the anteromedial bundle footprint of the native ACL on the inner wall of the lateral femoral condyle and, externally, on the previously marked point of the ALL. A guidewire is passed through the outside-in guide and its position is checked. If the position is suitable, the tunnel is drilled with the previously measured diameter of the quadruple ACL graft.
Surgical tip: During the positioning of the outside-in guide at the point of the ALL on the femur, care must be taken not to posteriorize the guide too much and compromise the posterior wall of the tunnel. Also, care must be taken to not harm the lateral collateral ligament femoral attachment.
ACL tibial tunnel preparation: The tibial ACL tunnel is performed as usual, aiming for intra-articular positioning in the native ACL footprint, in line with the anterior horn of the lateral meniscus and between the tibial spines.
ALL tibial tunnel preparation: A 2-cm incision is made at the midpoint between Gerdy’s tubercle and the head of the fibula on the anterolateral region of the tibial plateau (Figure 4). After skin and subcutaneous dissection, the anatomical point of ALLs insertion is located, approximately 5 mm to 10 mm distal to the joint line, at the midpoint between Gerdy’s tubercle and the head of the fibula. A guidewire is inserted free-handed at this point, toward the anteromedial face of the tibia, approximately a digital pulp distal to the entry of the tibial tunnel of the ACL, avoiding confluence of the tunnels. The position is checked and a 5 mm to 6 mm tunnel is drilled.
Graft passage and fixation
The graft is passed from the tibia to the femur with the ACL graft properly positioned in the tunnels and the ALL graft exiting through the tunnel in the outer wall of the lateral femoral condyle (Figure 5).
Surgical tip: The quadruple ACL graft must be entirely inside the femoral tunnel, otherwise the graft can irritate the iliotibial band.
Once the graft is properly positioned, femoral fixation is performed using an interference screw with the same diameter as the tunnel. The graft is pretensioned and fixed in the tibial tunnel with an interference screw 1 mm larger than the tunnel, with the knee at approximately 20° of flexion and posteriorization force applied to the tibia.
Surgical tip: A protruded femoral screw can irritate the iliotibial band and be a cause of constant lateral pain. Care must be taken when passing the interference screw to not leave it prominent.
With the ACL fixed, the remaining portion of the gracilis is passed deep to the iliotibial tract toward the anterolateral incision in the tibia (Figure 6) and pulled into the ALL tibial tunnel (Figure 7).
When the ALL graft reaches the exit of the tibial tunnel on the anteromedial region of the tibia, the passage of the interference screw can be performed both from lateral to medial and from medial to lateral. If the graft does not extend to the exit of the tunnel, the fixation must be performed from lateral to medial. For ALL fixation, the knee must be positioned in full extension and neutral rotation.
Postoperative management
The rehabilitation protocol for patients undergoing combined ACL and ALL reconstruction is the same as for isolated ACL reconstruction. Partial weight-bearing is allowed with crutches and progressed as tolerated. Full weight-bearing usually occurs around week 4. No immobilization or movement restriction device is used. Range of motion is free and encouraged from the first postoperative day, associated with quadriceps activation exercises to reach full extension as early as possible.
In patients with associated meniscal sutures or osteotomies, there may be load and range of motion restrictions, according to each case. The return to sports and full activity usually occurs after 9 months postoperatively.
- References:
- Firth AD, et al. Am J Sports Med. 2022;doi:10.1177/03635465211061150.
- Helito CP, et al. Arthroscopy. 2019;doi:10.1016/j.arthro.2019.03.059.
- Helito CP, et al. Arthroscopy. 2023;doi:10.1016/j.arthro.2019.03.059.
- Helito CP, et al. Video Journal of Sports Medicine. 2021;doi:10.1177/26350254211004597.
- Mall NA, et al. Am J Sports Med. 2014;doi:10.1177/0363546514542796.
- Saithna A, et al. J Knee Surg. 2021;doi:10.1055/s-0040-1701220.
- Sonnery-Cottet B, et al. J Orthop Traumatol. 2017;doi:10.1007/s10195-017-0449-8.
- For more information:
- Andre G. M. da Silva, MD, and Camilo P. Helito, MD, PhD, Prof., can be reached at the Hospital das Clínicas at the University of São Paulo in São Paulo. da Silva’s email: andre.giardino1@gmail.com. Helito’s email: camilo_helito@yahoo.com.br.
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