AANA master lecture recommends surgery for ACL tears in prepubescent children
A 12-year-old basketball player has a badly torn anterior cruciate ligament (ACL). A top player in her middle-school league, she is being courted by several private high schools and could win a scholarship if she continues to drive her team to victory. A magnetic resonance image (MRI) shows open physes and she has not reached menarche. Although she is tall for her age at 5'6'', she is shorter than her 6'1'' mother and her 6'8'' father.
What do you recommend? Do you perform surgery and risk causing iatrogenic bone-growth disturbances? Or do you take a more conservative approach and brace the knee, prescribe physical therapy, and sideline her, probably eliminating her opportunity to get a scholarship and further her basketball career?
Because the physes of prepubescent athletes are still open, nonsurgical treatment—braces and removal from athletic activities—is often recommended. In his master lecture on “Pediatric ACL Injuries and Surgery,” presented during the 2007 annual meeting of the Arthroscopy Association of North America, Marc J. Friedman, MD, challenged that view and outlined why surgery is actually the better alternative for these very young patients.
“Orthopaedic surgeons think they have to wait until the growth is complete,” he says. “But the literature includes numerous articles that show nonsurgical treatment of young children with ACL tears doesn’t work.”
Bracing usually fails in children ages 10 to 12 years old, he believes, “because they won’t wear the braces and taking them out of sports doesn’t work because they’re children and they’re going to play with their friends.” At least one study suggests that not repairing ACL injuries can actually cause further problems, concluding that “…nonoperative management of complete tears generally has a poor prognosis, with recurrent instability leading to further meniscal and chondral injury.”
“Many of my patients are 13- and 14-year-old female basketball players with ACL tears. They have been told by their doctor that they can’t have surgery for at least a year or two until their growth is complete. So essentially they lose their whole high school basketball career. They really don’t—and shouldn’t—have to wait,” said Dr. Friedman. “If a doctor is not comfortable doing this surgery, he or she should refer the patient to the appropriate specialist.”
Determining skeletal maturity
Dr. Friedman uses the criteria described by Tanner and Whitehouse to determine the child’s biologic age and divides his patients into two broad categories—Tanner 1/2 and Tanner 3/4. He defines the Tanner 1/2 patient as the immature child with “wide open epiphyses—who is 2'' or 3'' shorter than the parents and has a lot of growth left.” He advises using a surgical technique that doesn’t violate the epiphysis and strongly cautions, “If you are going to stabilize a very immature person, don’t drill anything across the physis. Use either the Anderson or Kocher technique.” He adds that he tries to make the tibia tunnel as small and centrally located as possible; so it is a little more vertical than it would normally be for an adult.
The Kocher technique for prepubescent, skeletally immature children uses a “physeal-sparing, combined intra-articular and extra-articular reconstruction, with use of an autog-enous iliotibial band graft.” In a study of 44 children with a mean skeletal age of 10.1 years, conducted over 5 years, the technique was found to have an “excellent functional outcome with a low revision rate and no growth disturbance.” The procedure successfully avoids the physis by putting the graft in the “over-the-top” position on the femur and under the intermeniscal ligament on the tibia.
The arthroscopic surgical technique developed by Allen F. Anderson, MD, for prepubescent patients, is a transepiphyseal replacement of the ACL with a quadruple hamstring tendon graft. Instead of using the “over-the-top” technique, Dr. Anderson measures the diameter of the graft, drills a femoral hole to that size and, with guide wires placed in the epiphysis medial to the tibial tubercle, pulls the tendons with the use of sutures, through the tibia and out the lateral femoral condyle. The graft is then secured by tying sutures over a tibial screw and post.
The Tanner 3/4 classification, in which an adolescent is in early to late pubescence, is the “middle ground” for Dr. Friedman. The Tanner 3 classification denotes a time of accelerated growth—when secondary sexual characteristics are further delineated. The growth rate begins to slow during Tanner 4, with the physeal plates starting to close. He defines the patient in the Tanner 5 classification as an adult with almost no growth left. He assesses maturation in several ways.
“The tendency is to look at the X-ray and not to think about other important variables such as shoe size in the male or menarche in the female,” he says. In addition to using radiographic material, he considers several other variables when evaluating the growth of a patient.
“A girl who has been menstruating for 18 months has achieved 90 percent of her growth. A boy whose shoe size has not changed for a year has reached 90 percent of his growth,” he says. He also considers the height of the parents. “For example, if the child is 5'4'' and the dad is 6'10'' and the mother is 6'1'', you can probably assume that their child is still growing.”
When he is performing surgery on a patient who meets the criteria of Tanner 3/4, he takes one of two surgical approaches. “You can drill across the tibial physis. Or you can go over the top of the femur,” he says. “But since the femoral physis is near the over-the-top position in a child, it is very important not to rasp over the top as you would with an adult.”
Not for every surgeon
Dr. Friedman admits that not every orthopaedic surgeon will be comfortable operating on young children with ACL tears. He encourages his colleagues to evaluate each case and refer those patients to surgeons who focus on sports medicine or pediatric orthopaedics and have training and experience in these procedures.
“It’s really not fair to make young athletes wait for the surgery when we have the knowledge and the procedures to get them back in the game and protect them from sustaining meniscal and/or chondral damage,” he says.
For more information on the Kocher technique, refer to Kocher MS, Garg S, Micheli LJ: Physeal sparing reconstruction of the anterior cruciate ligament in skeletally immature prepubescent children and adolescents. J Bone Joint Surg Am 2005;87:2371-2379. Information on the Anderson technique is available in Anderson AF: Transepiphyseal replacement of the anterior cruciate ligament in skeletally immature patients: A preliminary report. J Bone Joint Surg Am 2003;85:1255-1263.
Annie Hayashi is the senior science writer for AAOS Now. She can be reached at firstname.lastname@example.org.