Anterior Cruciate Ligament Reconstruction: Two-Tunnel Technique

Anthony D. Bratton, MD

Dharmesh Vyas, MD, PhD

Christopher D. Harner, MD

Dr. Harner or an immediate family member has received nonincome support (such as equipment or services), commercially derived honoraria, or other non-research-related funding (such as paid travel) from the Arthroscopy Association of North America, Donjoy, and Smith & Nephew and serves as a board member, owner, officer, or committee member of the American Academy of Orthopaedic Surgeons, the American Orthopaedic Association, the International Society of Arthroscopy, Knee Surgery, Orthopaedic Sports Medicine, and the Musculoskeletal Transplant Foundation. Neither of the following authors nor any immediate family member has received anything of value from or has stock or stock options held in a commercial company or institution related directly or indirectly to the subject of this chapter: Dr. Bratton and Dr. Vyas.

INTRODUCTION

The anterior cruciate ligament (ACL) has been shown to play a critical role in the maintenance of knee stability. Leaving an ACL-deficient knee untreated can result in recurrent instability, meniscal pathology, and articular cartilage damage.¹^,² Despite the fact that ACL injury has become one of the most popular topics of study in orthopaedic sports medicine, significant disagreement exists on the appropriate management of this injury.³^,⁴ Despite adherence to strict surgical principles, the inability to predict long-term articular cartilage degeneration after ACL reconstruction (ACLR) has raised questions about the choice of surgical technique, graft choices, fixation, and rehabilitation. In this chapter, we present our preference for ACLR, which is based on a single-bundle reconstruction primarily using a bone-patellar tendon-bone (BTB) autograft. The procedure takes advantage of the medial portal technique (versus transtibial) for femoral tunnel placement.⁵^,⁶ Unique to this technique is its versatility, being appropriate for all autograft and allograft types as well as fixation methods.⁵

PATIENT SELECTION

The decision to proceed with an ACLR begins with a comprehensive history and physical examination. This includes a demonstration of ACL insufficiency and an assessment of the patient’s expectations, activity level, and comorbidities. Surgical indications are founded on three major criteria: the degree of perceived instability, associated knee injuries (meniscus or multiligament), and chronicity of the ligament insufficiency.

Before surgical intervention, the patient is instructed to perform physical therapy exercises, emphasizing the achievement of full range of motion, symmetric quadriceps strength, and decreasing an effusion if present. Generally, most patients meet these criteria within 3 to 4 weeks. In the context of an associated medial collateral ligament (MCL) injury amenable to nonsurgical management, we delay surgery for up to 6 weeks to allow time for the MCL to heal. Contraindications to ACLR include (1) partial tears with minimal reported instability and no joint laxity on examination; (2) elderly, low-demand patients with minimal instability; and (3) comorbidities that make surgical intervention unsafe for the patient.

GRAFT CHOICE

Graft options are individualized for each patient and are contingent on age, activity level, the grade of injury (partial versus complete), associated injuries, and the return-to-play timeline. In most cases, autografts are recommended for patients younger than 35 years, and allografts are reserved for older patients.⁷ This is based on the notion that younger patients generally have more active lifestyles.

We prefer to use BTB in younger, active athletes, especially if they are involved in cutting sports (eg, football, soccer, basketball), and in larger patients⁸ (Figure 1). Hamstring grafts are used in patients who require single-bundle augmentation, those with contraindications to BTB, and females with donor site incisional cosmesis concerns (unless the activity level dictates otherwise). Quadriceps tendon autograft is becoming a more popular option and can be particularly useful in revision cases if another autograft has been utilized. When the quadriceps tendon is used, we prefer to harvest the graft without a bone block (soft-tissue graft only).

PREOPERATIVE IMAGING

Radiography

Diagnostic imaging begins with plain radiographs. These include 45° flexion weight-bearing PA views of both knees, a lateral view, and Merchant patella views. These radiographs are used to identify associated fractures (avulsion, plateau, or subchondral impaction), gauge the amount of joint-space narrowing in the three compartments, and assess patellar height (lateral view), tilt, and subluxation (Merchant view). Determination of patella alta versus patella baja is critical for medial portal ACLR because it influences the correct position
of the portals. Furthermore, radiographs are a prerequisite in pediatric patients to assess the status of the epiphyseal plate. In these patients, hand and wrist radiographs are often obtained to assist in the determination of skeletal age.⁹

FIGURE 1 Photographs depict autograft options. A, Bone-patellar tendon-bone: femoral side with EndoButton CL BTB (Smith & Nephew Endoscopy) and tibial side with Ethibond (Ethicon) lead sutures. The first blue mark is at the bone-tendon junction, and the second mark indicates the amount of graft needed in the femoral tunnel for the EndoButton to engage the lateral femoral cortex. B, Quadrupled hamstring: semitendinosus and gracilis. C, Quadriceps with patellar bone block.

Magnetic Resonance Imaging

Based on the patient’s history and physical examination, if an ACL tear is suspected, then a noncontrast magnetic resonance scan of the knee is obtained in most cases. Discontinuity of the ACL in the coronal and sagittal planes on either the T1 or T2 image sequences is a reliable indication of an ACL tear. Importantly, MRI helps the clinician identify associated injuries of the knee, such as meniscal tears, chondral damage including bone bruises, and associated ligament injuries. This is especially important in the patient with an acute knee injury when the physical examination for associated injuries can be limited by pain and swelling.

PROCEDURE

Room Setup/Patient Positioning

On the day of surgery, laterality is marked and consent is reviewed with the patient in the preoperative holding area. Femoral and sciatic nerve blocks are not routinely utilized as postoperative analgesia can be achieved with other multimodal approaches. Adductor canal nerve blocks or local anesthetic may be used if necessary to aid in postoperative pain control. Our personal experience, in a soon to be published article, is that femoral nerve blocks have an increased risk for residual quadriceps weakness and loss of extension when compared with adductor canal nerve blocks. The procedure is performed under either monitored or general anesthesia as determined by the anesthesiologist. The patient is placed supine on the operating room table, and prophylactic antibiotics are administered. The lower extremity is positioned in neutral rotation with the use of a soft gel bump under the ipsilateral hip. A 10-lb sandbag is taped to the table to support the knee at 90° of flexion (Figure 2). A lateral post is placed at the level of the midthigh to support the lower extremity. We do not use a tourniquet or thigh/leg holder. An alternative to the above setup is to use a pneumatic leg holder (Spider, Smith & Nephew), which is especially useful when additional hands are necessary but not available (Figure 3, A and B). The nonsurgical side is well padded to prevent pressure points and nerve palsies.

Special Instruments/Equipment/Implants

The procedure calls for the following equipment:

30° arthroscope
30° Steadman awl
ACL drill guide with 3/32-inch Kirschner wire (K-wire) guide pin

EndoButton CL BTB (Smith & Nephew)

FIGURE 2 Photograph shows surgical setup for anterior cruciate ligament reconstruction. The patient is positioned supine with a bump under the ipsilateral hip. A sandbag (black arrow) and a lateral post (white arrow) are used to keep the leg at 90° of flexion for most of the case.

3.2-mm EndoButton cannulated drill
Cannulated compaction reamer (7-12 mm, 0.5-mm increments)
Tunnel dilators (round, 0.5-mm increments)
Beath pin
4.5-mm cortical screw with washer
0.25% bupivacaine hydrochloride with 1:200,000 epinephrine (subcutaneous injection for local anesthesia and hemostasis)

FIGURE 3 Alternatively, a pneumatic leg holder (Spider, Smith & Nephew) can be used for patient positioning. This allows for controlled positioning of the knee in various degrees of flexion throughout the case. Photographs (A) and (B) demonstrate the setup.

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