ACL Reconstruction in Adolescent and Preadolescent Patients

By Theodore J. Ganley, MD
http://www.orthosupersite.com/view.asp?rID=44983

ORTHOPEDICS 2009; 32:833


In this issue of Orthopedics, Dr Theodore Ganley discusses the pros and cons of delaying anterior cruciate ligament reconstruction in skeletally immature patients.
What are the major concerns regarding performing anterior cruciate ligament (ACL) reconstruction in skeletally immature patients?

Early ACL reconstruction primarily risks damaging the growing physis and inducing a growth disturbance.

Describe the surgical approach in prepubescent patients vs that in adolescent patients?

Theodore J. Ganley
Surgical options include transphyseal, epiphyseal, and extra-articular procedures. For prepubescent and younger adolescent patients, I perform an all-epiphyseal ACL reconstruction. Epiphyseal tunnels are placed by way of a tibial docking technique and a femoral outside-in technique (Figure). This procedure avoids the physis and allows for customized tunnel placement proximally and distally. For older adolescent patients with a closing physis, I perform a transphyseal ACL reconstruction with hamstring autograft and fixation adjacent to but not at the level of the growth plates.

What are the benefits of delaying ACL reconstruction?

In the all-epiphyseal ACL reconstruction technique, epiphyseal tunnels are placed by way of a tibial docking and femoral outside-in technique.
Patients are frequently given a brief period of several weeks or, at times, over a month to regain motion preoperatively. Surgery can also be delayed for prolonged periods of time. If there is a delay until skeletal maturity, the risk of growth plate disturbance can be removed altogether.

What are the risks of delaying ACL reconstruction?

Delaying ACL reconstruction risks ongoing intra-articular damage due to knee instability. I conducted a study with my colleague, Todd Lawrence, MD, PhD, to quantify these risks and to identify independent risk factors for patients 14 years and younger.1 Using logistic regression models we found that time to reconstruction was significantly associated with medial meniscus tears and chondral injuries in the group with delay greater than 12 weeks. For medial meniscus tears, time to reconstruction and a history of instability were identified as independent risk factors. The odds ratio for delaying treatment was 4 and 11 for instability. Treatment delay was also associated with an increase in tear severity including irreparable tears.

When is nonoperative management indicated?

Nonoperative management is indicated when a patient’s physical, mental, or social situation precludes them from surgical treatment or from participating in rehabilitation. Nonoperative treatment is also indicated if families prefer activity restriction over reconstruction.

Does potential growth disturbance caused by ACL reconstruction outweigh complications that stem from nonoperative management?

Because a delay in treatment was associated with a several-fold increase in medial meniscus tears and severe lateral compartment cartilage injuries, the risks of delaying surgery outweigh the risks to the growth plates, especially given current techniques. To further minimize risk, I currently use computer navigation to guide tunnel placement in preadolescents. Image guidance is not a prerequisite for all-epiphyseal procedures; however, I currently use it as an extra precautionary measure to accommodate for the undulating nature of the physes. This is especially useful in younger patients with potentially as much as 12 to 18 inches of growth remaining.

How big of a role does chronological, skeletal, and physiological age play in determining the management of ACL injuries in adolescents?

Chronological age and skeletal age can be markedly different in the same patient. We base decision making on the status of the growth plates at the time of surgery.

Explain why management in preadolescents is more problematic than in any other adolescent group.

From a physiologic and anatomic standpoint, prepubescent patients frequently have an extensive amount of growth remaining, a considerably smaller knee, and physes that are undulating in the coronal and sagittal planes. Compliance with postoperative rehabilitation is more challenging, and it is therefore useful to have an initial team of therapists and nurses who are comfortable treating these younger patients. A postoperative protocol that accommodates for these potential differences in compliance is also helpful. I require preadolescent patients to undergo formal testing to monitor strength progression. These patients are also required to refrain from a return to sports for at least 3 months longer than older adolescents.

Reference

Lawrence JTR, Ganley T. Degeneration of the knee joint in skeletally immature patients with a diagnosis of an anterior cruciate ligament tear: is there harm in delay of treatment. Paper presented at: Annual Meeting of the American Orthopaedic Society for Sports Medicine; July 8-12, 2009; Keystone, CO.
Author
Dr Ganley is Sports Medicine Director, The Children’s Hospital of Philadelphia and Associate Professor of Orthopedic Surgery, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania.
Dr Ganley has no relevant financial relationships to disclose.