2015 ISAKOS Biennial Congress ePoster #1259
Narrow Femoral Intercondylar Notch Width: A Risk Factor For Uni- And Bilateral ACL Tears in Children and Adolescents
Joseph Yellin, BA, Philadelphia, PA UNITED STATES
Christine Goodbody, BA, Philadelphia, PA UNITED STATES
Wajdi Kanj, MD, Philadelphia, PA UNITED STATES
Nicholas Beck, MD, Philadelphia, PA UNITED STATES
Adam Nasreddine, MA, Philadelphia, PA UNITED STATES
David Ramski, MD, Philadelphia, PA UNITED STATES
Mininder Kocher, MD, MPH, Boston, MA UNITED STATES
Theodore Ganley, MD, Philadelphia, PA UNITED STATES
The Children's Hospital of Philadelphia and Boston Children's Hospital, Philadelphia, Boston, PA, MA, USA
FDA Status Not Applicable
Summary: We compared mean notch width index (NWI), age, and gender between pediatric patients with bilateral anterior cruciate ligament (ACL) tears, a unilateral ACL tear, and controls and demonstrated that only decreased NWI is associated with unilateral and bilateral ACL tears in pediatric patients.
The purpose of this study was to compare mean notch width index (NWI), age, and gender between pediatric patients with bilateral anterior cruciate ligament (ACL) tears, a unilateral ACL tear, and controls.
This is a retrospective cohort study of patient records from two surgeons at two large pediatric trauma centers from 1999-2010 with either bilateral ACL tears, a unilateral ACL tear, or no ACL tear. The control group consisted of patients who obtained an MRI while treated for knee pain who were not found to have any ligamentous pathology. Demographic information was collected for each subject. NWI was measured on the coronal MRI slice in which the ACL and PCL cross one another at the midsubstance of the ACL, and calculated as a ratio of the femoral intercondylar notch width to bicondylar width. Two measurements were made at least 24 hours apart by one observer. NWI, age, gender, and intra-rater reliability were analyzed using Student’s t-test (NWI and age), Fisher exact test, and correlation coefficient, respectively.
Analysis included a consecutive series of 26 bilateral (39 total available MRIs), 22 unilateral (all MRIs available), and 23 control patients (all MRIs available) for a total of 84 knees. When bilateral and unilateral patients were combined, they had a significantly lower NWI compared to patients without an ACL tear (p<0.01). However, there was no significant difference between the NWI of the bilateral and unilateral groups (p=0.54). There was no significant difference in age between any of the three groups (mean age bilateral group: 15.0 years, unilateral group: 14.5 years, control group: 14.5 years). While there was a larger percentage of females in the bilateral group (bilateral group: 64.7% female, unilateral group: 54.5% female, control group: 56.5% female), this difference was not statistically significant. Intra-rater reliability was strongly positive (r=0.96).
Similar to findings in adult populations, we have demonstrated that decreased NWI is associated with both unilateral and bilateral ACL tears in pediatric patients.