Midterm Clinical Results After All-Epiphyseal Double-Bundle Reconstruction of the Anterior Cruciate Ligament in Children With Open Physes

摘要

The incidence of injuries to the anterior cruciate ligament (ACL) in skeletally immature patients is increasing. ~( 1 , 10 ) The primary goal of managing ACL injury is to restore knee stability to minimize the risk of the secondary damage of menisci and joint cartilage. To avoid the risk of growth disturbance from iatrogenic physeal damage, ACL reconstruction (ACLR) was traditionally delayed until the child was close to the end of the prepubertal growth spurt; however, studies have suggested that the incidences of meniscal damage and cartilage destruction were higher when ACLR was delayed. ~( 8 , 12 ) Therefore, surgical intervention has been advocated early to improve functional outcomes even in these skeletally immature patients. ~( 21 ) Restoring knee stability after ACL injury without growth disturbances is crucial, and various surgical techniques have been described. The 2 main surgical techniques are transphyseal- and physeal-sparing techniques. Physeal-sparing techniques have several variations, depending on the graft passage routes: extra-articular “over-the-top” graft placement, partial physeal-sparing, and complete physeal-sparing (or all-epiphyseal) reconstruction. Each technique has advantages and disadvantages. According to cadaveric studies, ~( 13 , 16 , 25 , 27 ) a more anatomic reconstruction might be necessary to improve the knee stability after ACL injury, ~( 26 ) especially with regard to rotational stability. Although the clinical benefits of double-bundle ACLR are still unclear, the double-bundle technique has gained popularity for adult ACL injury because of an improved ability to replicate the morphology of the intact ACL. Therefore, we have performed all-epiphyseal double-bundle ACLR on patients with wide open physes, in which all bone tunnels were created with the physeal-sparing technique in an attempt to achieve anatomic reconstruction without physeal injury. According to recent reviews, ~( 6 , 11 ) the risk of growth abnormalities is not necessarily eliminated in physeal-sparing procedures. In addition to the surgical technique, bone growth during a growth spurt is expected to have some effects on the ACL graft and, consequently, on knee stability. However, the literature contains few descriptions of these effects. The aim of this study was to evaluate the midterm results of all-epiphyseal double-bundle ACLR on skeletally immature patients and to assess the alignment and morphometric changes in the bone around the knee after the surgery. Methods Patients Since 2012, we have performed all-epiphyseal double-bundle ACLR in 3 children (2 boys and 1 girl). At the time of the operation, 1 boy was 12 years old, the other was 14 years old, and the girl was 13 years old. All patients were evaluated clinically and with magnetic resonance imaging (MRI), and a high-intensity wide band of physes was confirmed on MRI. The mean time from injury to surgery was 3 months (range, 2-5 months). Arthroscopy revealed no concomitant meniscal lesions. The mean length of follow-up was 52.7 months (range, 42-60 months). All methods of data collection received the approval of an institutional review board. Surgical Technique Both femoral and tibial bone tunnels were created within the distal femoral and the proximal tibial epiphyses; with fluoroscopic imaging, we ensured that the tunnels did not affect the epiphyseal line ( Figure 1 ). Femoral tunnels for the anteromedial bundle (AMB) and posterolateral bundle (PLB) were created with the outside-in technique, and their positioning on the intercondylar wall of the lateral femoral condyle was determined by reference to the lateral intercondylar ridge. Tibial tunnels were created with remnants of ACL fiber for anatomic placement. A doubled autologous semitendinosus tendon and a gracilis tendon were prepared as the grafts for the AMB and PLB, respectively. The mean diameters of the AMB and PLB grafts were 6 and 5 mm, respectively. Each graft was fixed by an Endobutton CL (Smith & Nephew) on the femoral side and by double-stapling over the surface of the metaphysis away from the proximal physis on the tibial side. The staples were removed 1 year after ACLR. Figure 1. Diagrams of the surgical technique and the 4 drill hole placement. AMB, bone tunnels for anteromedial bundle; PLB, bone tunnels for posterolateral bundle. Rehabilitation Program Patients began partial weightbearing with crutches 1 week after surgery, and full weightbearing was allowed at 4 weeks after surgery. The operated limb was initially placed at 30° of flexion in an immobilizing brace, and gentle range of motion exercise was allowed 1 week after surgery. Maximum knee flexion was restricted to 120° until the third week postoperatively. When proper muscle conditioning was achieved, running was permitted at 3 months after surgery. Clinical Evaluation Clinical examination comprised the assessment of knee stability and range of motion. Postoperative knee stability was evaluated with the Lachma