Purpose: It has been assumed that anterior cruciate ligament (ACL) and meniscus tears in children have increased in recent years. This increase has been attributed to more participation in sports, better clinician awareness and recognition of the signs and symptoms of ACL and meniscal tears, and the expanded role of MRI in the diagnosis of intra-articular knee pathology. To our knowledge, no study has specifically shown there to be an increased incidence of ACL and meniscus tears in children recent years. The purpose of this study is to determine if the number of ACL and meniscal tears treated at our institution has increased over the past 12 years.
Methods: Using ICD-9 and CPT codes, a retrospective review of billing records was performed for all patients under 18 years old with tibial spine fractures and ACL and meniscal tears treated at a large academic children's hospital from 1/1/1999 to 1/1/2011. Tibial spine fractures were included to account for increased referral to our institution. Cases were sorted by year. Multivariate linear regression was employed to compare the trends over time using tibial spine fractures as a control in the case of ACL reconstructions and overall meniscal surgeries.
Results: A total of 155 tibial spine fractures (range 4-24 per year), 914 ACL tears (range 9-143 per year), and 996 meniscus tears (range 20-166 per year) were identified. Tibial spine fractures, ACL tears, and meniscus tears all significantly increased over time (see Figure 1). On average, tibial spine fractures increased by 1.07 per year, ACL tears increased by 11.35 per year, and meniscus tears increased by 13.95 per year. The increase in ACL tears (p<0.001) and the increase in meniscal surgeries (p<0.001) were both significantly greater than the increase in tibial spine fractures seen during this time period.
Conclusion: The numbers of tibial spine fractures, ACL tears, and meniscus tears have all increased over the last 12 years. The increases in ACL and meniscus tears have increased to a much larger extent than tibial spine fractures. The etiology of this increase is unknown but possible causes include increased diagnosis, earlier referral, more aggressive treatment, and increased incidence. Because the increase in tibial spine fractures would likely account for other causes encompassed by increased referral patterns, our analysis suggests that more ACL and meniscus tears are being diagnosed in this age group and may suggest that the true incidence is actually increasing.
Figure 1. Number of ACL tears, meniscus tears, and tibial spine fractures per year.