Background: Treatment choices for skeletally immature patients sustaining anterior cruciate ligament (ACL) injuries have been controversial. The main dilemma is whether surgical treatment should be provided before patients reach skeletal maturity or whether nonoperative treatment should be provided until the physis has closed. Surgical reconstruction risks physeal damage, while delaying surgery may increase menisci and cartilage damage.
Purpose: To identify patients at the onset of ACL injury and follow them longitudinally to surgery or final follow-up to describe differences between nonoperative and operative patients and to analyze the effect of delayed reconstruction.
Study design: Cohort study; Level of evidence, 3.
Methods: A retrospective review of patients enrolled at a large integrated health care system (IHS) between January 1, 2005, and December 31, 2008, was performed. The study sample included all females ≤12 years old and males ≤14 years old who were evaluated with an ACL injury. The incidence of ACL injuries in each age group was calculated using the number of covered lives by the IHS system per age category as the denominator. Each patient was longitudinally followed using an electronic health record that captures all patient encounters. Every encounter was reviewed for symptoms associated with the index knee, and encounters were considered significant if new-onset pain or swelling was reported. Patients were instructed to restrict their activities while awaiting skeletal maturity to undergo reconstruction by not participating in activities that included any cutting or pivoting movements that would risk injury to the knee. Cartilage and meniscal injuries were recorded for patients who underwent reconstruction.
Results: A total of 71 patients were identified during the study period (66 males, 4 females). At the completion of this study, 47 (66.2%) patients had undergone ACL reconstruction, and 24 (33.8%) were being treated nonoperatively. While there were no significant associations between time to surgery and meniscal or cartilage injury, there was a positive association between the number of significant encounters and the likelihood of a combined cartilage and meniscal injury (P = .01).
Conclusion: This is the first study to measure the incidence of ACL injuries in a skeletally immature population. For patients undergoing ACL reconstruction, an increased number of significant encounters was statistically significantly associated with combined meniscal and cartilage injuries, while increased time from injury to surgery was not significantly associated with additional injuries. In addition, one-third of the patients continued nonoperative treatment without symptoms that warranted surgical interventions during the follow-up period.
Keywords: anterior cruciate ligaments; articular cartilage; epidemiology; knee meniscus; pediatric sports medicine.