Anterior Cruciate Ligament Reconstruction: Single-Bundle Transtibial Technique

Kelechi R. Okoroha, MD

Bernard R. Bach Jr, MD

Dr. Bach 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 Arthrex, Smith & Nephew, Conmed Linvatec, and Össur. Neither Dr. Okoroha 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.

This chapter is adapted from Strauss EJ, Yanke AB, Bach BR: Anterior cruciate ligament reconstruction: Single-bundle transtibial technique, in Flatow E, Colvin AC, eds: Atlas of Essential Orthopaedic Procedures. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2013, pp 95-101.

INTRODUCTION

Injuries to the anterior cruciate ligament (ACL) are common, typically occurring in association with participation in athletic activities. For active patients, surgical reconstruction of the ACL following injury is recommended in an effort to restore stability and normal knee kinematics that will lead to an improvement in function and a return to an active lifestyle. Various reconstruction techniques and graft options are available for ACL reconstruction, including autograft (bone-patellar tendon-bone [BPTB], quadriceps tendon, and hamstring) and allograft (BPTB, hamstring, anterior and posterior tibialis tendons, and Achilles tendon) tissue.¹^,² For the past 25 years in my practice, patellar tendon autograft reconstruction has been my most commonly used technique secondary to its acceptable biomechanical strength, accessibility and ease of graft harvest, bone-to-bone healing, rigid initial interference screw fixation, and its track record of clinical success.¹^,²^,³^,⁴^,⁵^,⁶^,⁷ This chapter describes the surgical technique for endoscopic ACL reconstruction with BPTB autograft using a single-bundle transtibial approach. This endoscopic technique can be used with patellar tendon autograft tissue, enabling the creation of a femoral tunnel that theoretically replicates a portion of both the posterolateral and anteromedial bundles, thereby potentially eliminating both the abnormal Lachman test results and, more importantly, the pivot-shift phenomenon, with the primary downside being potentially higher graft site morbidity.

PATIENT SELECTION

Indications

The ideal patient for ACL reconstruction using a BPTB autograft is young (<40 years) with an active, athletic lifestyle. Other considerations include the specific type of sports involvement, the hours of sports involvement weekly, KT-1000 arthrometer (MEDmetric)-instrumented side-to-side differences, concomitant meniscal pathology, the failure of nonsurgical care, and the ability to participate in a structured postoperative physical therapy program. In our practice, approximately 15% of patients are older than 40 years, and for these patients, different graft sources are generally recommended, preferably patellar tendon allograft. Surgical intervention is delayed until the patient’s postinjury effusion has fully resolved, full knee range of motion has been regained, quadriceps control is achieved, and personal and professional issues are “under control” so that the patient is physically and psychologically prepared for surgery. In our practice, if patients have normal or nearly normal motion recovery before surgery, the incidence of revision surgery for symptomatic scar tissue/arthrofibrosis has averaged 1% to 2% since 1986.¹⁷ Ideally, the patient should have no evidence of patellar tendon disease, should have no patellar malalignment or antecedent patellofemoral symptoms, and should not be employed or a member of a profession or religion that requires repetitive or prolonged kneeling secondary to the potential incidence of postoperative anterior knee pain or kneeling pain following graft harvest.

Contraindications

BPTB autograft reconstruction is contraindicated in patients with open physes and those with symptomatic preoperative patellar tendon disease. In adolescents, we use a variety of factors—onset of menses in females, skeletal bone age as determined by a PA radiograph of the hand, parent height, and Tanner characteristics—to guide the recommendation for ACL surgery and graft choice. Relative contraindications include radiographic evidence of degenerative joint disease, a sedentary or inactive lifestyle, and an unwillingness or inability to comply with the required rigorous postoperative rehabilitation protocol.

PREOPERATIVE IMAGING

During the initial evaluation of patients with ACL injuries, radiographs are obtained to assess the quality of the joint space, the bony alignment, and the notch architecture. The
four-view series includes a weight-bearing AP view in full extension, a weight-bearing PA 45° flexion view, a non-weight-bearing 45° flexion lateral view, and a Merchant view of the patellofemoral joint. Plain radiographs may identify a Segond fracture consistent with a lateral capsular avulsion (<1%), a tibial spine fracture, a “lateral notch” sign, or loose bodies present within the joint.

Although the KT-1000 arthrometer does not measure rotational translations and for this reason some authors question its value, we have used the KT-1000 arthrometer in our practice since 1986. It gives valuable information both preoperatively and postoperatively. Anterior translations greater than 10 mm or side-to-side differences exceeding 3 mm are highly suggestive of an ACL injury.

MRI is used as an adjunct to the patient’s history and physical examination to support the diagnosis of an ACL tear. However, our experience suggests that it is extremely unusual to require MRI to establish the diagnosis of an ACL injury. It is critical to emphasize that the physical history and physical examination, along with a KT-1000 arthrometer measurement, establishes the diagnosis of ACL injury in over 98% of our patients. Nevertheless, MRI has been demonstrated to be both sensitive and specific for ACL injuries in addition to providing information about the status of other intra-articular structures, such as the menisci, posterior cruciate ligament, medial collateral ligament, lateral collateral ligament, and chondral surfaces. Bone bruises associated with ACL injury are often readily identifiable on MRI, typically presenting in the mid portion of the lateral femoral condyle and in the posterior aspect of the lateral tibial plateau. A careful review of the preoperative MRI can alert the treating orthopaedic surgeon to concomitant injuries that may need to be addressed during the ACL reconstruction.

VIDEO 16.1 Anterior Cruciate Ligament Reconstruction: Single-Bundle Transtibial Technique. Eric J. Strauss, MD; Adam Yanke, MD; Bernard R. Bach, Jr, MD (19 min)

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Video 16.1

PROCEDURE

Room Setup/Patient Positioning

Following the induction of anesthesia, the patient is positioned supine on the operating room table. The waist of the operating table is reflexed to reduce the amount of lumbar extension and, subsequent to the examination under anesthesia, the opposite leg is placed in a gynecological leg holder to protect the femoral and peroneal nerves. The surgical knee is carefully examined under anesthesia, evaluating the amount of translation present with the anterior and posterior drawer tests and the Lachman test, knee stability with applied varus and valgus stress, and whether a pivot-shift phenomenon is present. The status of the posterolateral corner is assessed for asymmetric external rotation at both 30° and 90° of knee flexion, with comparison made to the contralateral side. If a pivot-shift is noted during the examination under anesthesia, the BPTB graft harvest can proceed before diagnostic arthroscopy.

FIGURE 1 Photograph shows positioning of a left lower extremity for anterior cruciate ligament reconstruction. With the foot of the operating room table flexed completely, the surgical knee is capable of at least 110° of flexion.

A tourniquet is then placed on the thigh, and the surgical lower extremity is placed in an arthroscopic leg holder. Although some surgeons routinely use a tourniquet, we rarely inflate it during the procedure. The foot of the operating room table is flexed completely, allowing the surgical knee to flex to at least 110° (Figure 1). The leg is then prepped and draped, and a preoperative dose of a first-generation cephalosporin is administered.

Special Instruments/Equipment/Implants

The single-bundle transtibial BPTB autograft ACL reconstruction is performed using a standard arthroscopy setup and instruments, including arthroscopic scissors and a basket. For the graft harvest, a No. 10 scalpel, forceps with teeth, two Senn retractors, an Army-Navy retractor, a metal ruler, 3/8- and 1/4-in curved osteotomes, a mallet, and Metzenbaum scissors are required. The bone plugs are created using an oscillating saw with a 10-mm-wide blade (No. 238 blade). For graft preparation, a rongeur, 10- and 11-mm sizing tubes, a Kirschner-wire (K-wire) driver with 0.062-in smooth K-wires, and two No. 5 sutures are needed. A tibial aiming device (we prefer the elbow aimer to the tip aimer) for the tibial tunnel and a 7-mm offset aimer are required for drilling the femoral tunnel, using 11-mm and 10-mm acorn reamers,
respectively. A chamfer reamer and a hand rasp are used to aid in tibial tunnel preparation. A large shaver, a 1/4-in (7-mm) curved osteotome, and a large spherical burr, or bone cutting shaver are needed for clearing and preparing the intercondylar notch. A satellite pusher is used to aid in graft passage, and for graft fixation, a 14-in hyperflex nitinol wire and 7 × 25-mm metal interference screw are used for the femoral tunnel, and a 9 × 20-mm screw is used for the tibial tunnel.

FIGURE 2 Photograph shows the incision for autologous bone-patellar tendon-bone anterior cruciate ligament reconstruction. The incision extends from the distal aspect of the patella to 2 cm distal to the tibial tubercle just medial to the midline.

Surgical Technique

Graft Harvest

Before making the surgical incision, anatomic landmarks, including the distal aspect of the patella, the tibial tubercle, and the borders of the patellar tendon, are marked using a surgical marking pen. The BPTB autograft is harvested through an 8-cm incision extending from the distal patellar pole to the tibial tubercle region, paralleling the medial edge of the patellar tendon (Figure 2). This incision allows for both graft harvest and tibial tunnel drilling through the same approach. The incision is taken down to the transverse fibers of the patellar tendon paratenon. At this level, medial and lateral skin flaps are created. A No. 15 scalpel is then used to make a midline, longitudinal incision in the paratenon, which is extended both proximally and distally with Metzenbaum scissors. The Metzenbaum scissors are then used to elevate the paratenon from the patellar tendon both medially and laterally, fully exposing the patellar tendon. The tendon width is measured and recorded in the surgical report.

The ideal BPTB autograft is 10 mm wide with 10 × 25-mm bone plugs. The center of the inferior pole of the patella and the center of the distal patellar tendon at the tibial tubercle are marked with a surgical marking pen, and a curved 3/8-in osteotome (which is roughly 10 mm in width) is used as a cutting guide for the central third of the patellar tendon. With the Army-Navy retractor placed proximally, parallel longitudinal incisions are made using a No. 10 scalpel, starting on the patella and continuing into the patellar tendon. Once the midpoint of the patellar tendon is reached, the Army-Navy retractor is switched to the inferior aspect of the wound to protect the skin as the incision is extended distally 2.5 cm past the tendo-osseous junction on the tibial tubercle (Figure 3). This process is repeated on the other side, creating a 10-mm-wide graft.

FIGURE 3 Photograph shows a central-third bone-patellar tendon-bone autograft harvest using a No. 10 scalpel blade starting on the patella and continuing into the patellar tendon.

Bone cuts are then made using an oscillating saw with a 10-mm (No. 238) blade, starting on the tibial side. Cuts on the right side of the graft are made with the saw in the surgeon’s right hand and those on the left with the saw in the surgeon’s left hand (Figure 4). With the saw supported by the surgeon’s thumb and the tendon graft-bone interval identified with the index finger, the oscillating saw is used to first score the cortex, starting at the tendo-osseous junction, followed by angling of the saw to create a tibial plug with an equilateral triangle profile. The transverse bone cut is then made with the saw angled 45°, using the corner of the blade on each side of the graft to avoid the creation of stress risers. The patellar bone plug is then cut in a similar fashion, angling the saw during the longitudinal cuts to create a plug that is trapezoidal in shape. The saw blade should not penetrate deeper than 6 to 7 mm, to avoid injury to the patellar articular surface. The transverse bone cut is similarly made with the saw angled 45°. The tibial bone plug is then carefully freed from its osseous bed using 3/8- and 1/4-in osteotomes, without levering. A lap sponge is then placed around the freed tibial plug to apply traction on the graft as Metzenbaum
scissors are used to remove any remaining connections to the underlying fat pad. The patellar bone plug is then similarly freed from its osseous bed (Figure 5), and the harvested graft is wrapped in a moist sponge and walked to the back table by the operating surgeon.

FIGURE 4 Intraoperative photographs show bone cuts made using an oscillating saw with a 10-mm (No. 238) blade. Cuts on the right side are made with the saw in the surgeon’s right hand (A) and those on the left are made with the saw in the surgeon’s left hand (B).

Graft Preparation

The first assistant prepares the BPTB autograft, fashioning the graft’s bone plugs to 10 × 25-mm dimensions. The first step is the measurement and documentation of the overall graft length, the length of its tendinous portion, and the length of each bone plug (Figure 6, A). Fine-tuning of the bone plugs is performed using a rongeur to allow for passage through the 10-mm sizing tube (Figure 6, B). Excess bone removed during the preparation process should be saved for later bone grafting of the harvest sites. Once appropriately sized, two drill holes are made in the tibial bone plug using a smooth 0.062-in K-wire, parallel to its cortex (Figure 6, C). A No. 5 suture is then placed through each hole. Because we prefer to use a push-in technique for graft passage, no drill holes are created in the femoral bone plug. A surgical marking pen is then used to mark the tendo-osseous junction on the femoral side of the graft to aid in assessing the full seating of the graft in the femoral tunnel, and the distal cortical edge of the tibial plug is marked to assist in graft orientation. The prepared BPTB graft is then wrapped in a moist sponge and safely set aside in a kidney basin. It is critical that all operating room staff know where the graft has been placed so it is not inadvertently passed off the field.

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