Review Question - QID 219972

The patient has a relatively rare femoral-sided anterior cruciate ligament (ACL) avulsion and is approaching skeletal maturity (recent onset of menses and Tanner stage IV development), making an arthroscopic ACL repair with transphyseal fixation the most appropriate treatment option for her at this time (Answer 4).

For pediatric patients with ACL injuries, non-surgical treatment leads to ongoing activity-related symptoms and failure to return to healthy fitness and pre-injury level of sports activity. Furthermore, unaddressed knee instability has been associated with additional meniscal and chondral injury, especially in young athletes. In general, skeletally immature pre-adolescent patients are treated via iliotibial band reconstruction, while pre-adolescents with adequate epiphyseal bone stock that allows for epiphyseal tunnel placement can be treated via physeal-sparing ACL reconstruction. Conversely, patients approaching, or who have reached skeletal maturity, are good candidates for transphyseal, adult-type ACL reconstruction, or as in the case of this patient, transphyseal fixation for ACL repair of a proximal femoral avulsion.

DeFrancesco et al. review the challenges in the management of anterior cruciate ligament ruptures in skeletally immature patients. The authors note that although drilling 5% of the physis is associated with minimal risk of growth disturbance, the risk of growth disturbance generally increases with the proportion of the physis that is violated during surgery, with central physeal drilling being associated with a lower risk of growth arrest compared with peripheral drilling, and vertical tunnels minimizing physeal volume injured. They conclude that, although a variety of techniques are available for ACL reconstruction, orthopedic surgeons must select the technique appropriate for each patient based on the demands of their skeletal age, a process that can be guided by the algorithm they devise, which is reproduced in Illustration A.

Frank et al. review the diagnosis and management of ACL injuries in skeletally immature athletes. The authors note that the management of ACL injuries in skeletally immature patients includes physeal-sparing, partial trans-physeal, and complete trans-physeal ACL reconstruction. The partial trans-physeal technique involves a hybrid of physeal-sparing reconstruction and traditional trans-physeal procedures performed in adults, traditionally using either hamstring or bone-patellar tendon-bone grafts, with either the distal femoral or the proximal tibial physis left undisturbed, using smaller (6 to 8 mm) and more vertical bone tunnels to limit to <5% the overall cross-sectional area of physis that is interrupted. They conclude that In pre-pubescent patients (boys ≤12 years and girls ≤11 years), physeal-sparing combined intra- and extra-articular reconstruction using autogenous iliotibial band is recommended, while in adolescent patients with growth remaining (boys 13 to 16 and girls 12 to 14 years) all-epiphyseal or trans-physeal reconstruction using autogenous quadrupled hamstring tendons with smaller, more vertical tunnels and metaphyseal fixation are recommended compared to the more anatomic adult-type ACL reconstruction with autogenous quadrupled hamstring or bone-patellar tendon graft and interference screw or aperture fixation that is used in older adolescent patients with closing physes (males >16 years and females >14 years).

Figure A is an AP radiograph of the knee showing a femoral-sided avulsion of the ACL, denoted by an arrow in illustration B. Figure is a PD fat-saturated sagittal MRI sequence showing loss of the normal taut ACL fibers and evidence of the attached, avulsed bony femoral condyle fragment (Illustration B). Illustration A is a reproduction of the ACL treatment algorithm from the DeFrancesco article above. Illustration B is a reproduction of the XR and MRI from Figures A and B with arrows highlighting the avulsed bony fragment. Illustration C demonstrates post-operative AP and sagittal XRs demonstrating transphyseal femoral tunnels with cortical button fixation of the ACL avulsion injury.

Incorrect Answers:
Answers 1 and 2: Non-operative treatment is not appropriate for this active young patient with an ACL avulsion injury.
Answer 3: Adult-type ACL reconstruction is appropriate for a patient approaching skeletal maturity with evidence of a complete ACL rupture; however, this patient has an ACL avulsion that can be treated with an arthroscopic repair using transphyseal fixation.
Answer 5: In this patient who is approaching skeletal maturity (Tanner stage IV), physeal-sparing reconstruction is not indicated.