2025 ISAKOS Biennial Congress ePoster
There is a Difference in Preoperative Through-the-Knee Femorotibial Rotation in Pediatric Patients with Anterior Cruciate Ligament Rupture Versus Patients with Patellofemoral Instability
Danielle E. Chipman, BS, Buffalo, NY UNITED STATES
Nicolas Pascual-Leone, MD, New York, New York UNITED STATES
Preston W Gross, BS, New York, New York UNITED STATES
Emilie Lijesen, BS, New York, New York UNITED STATES
Shae K Simpson, BS, New York, New York UNITED STATES
Roger F Widmann, MD
Peter D. Fabricant, MD, MPH, New York, NY UNITED STATES
Daniel W. Green, MD, MS, New York, NY UNITED STATES
Hospital for Special Surgery, New York, New York, UNITED STATES
FDA Status Not Applicable
Summary
Pediatric patients with anterior cruciate ligament (ACL) rupture and patellofemoral instability (PFI) exhibit differences in femorotibial rotation, suggesting an association between femorotibial rotation and knee pathology.
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Abstract
Background
Various risk factors for anterior cruciate ligament (ACL) rupture and patellofemoral instability (PFI) have been identified, including sex, joint laxity, tibial slope, variations in the intercondylar notch, patella alta, trochlear dysplasia, tibial tubercle to trochlear groove (TT-TG) distance, and posterior cruciate ligament (PCL) morphology. The primary aim of this study was to evaluate differences in standing femorotibial rotation measurements between pediatric patients with ACL rupture and PFI.
Methods
Patients aged 8 to 21 years who sustained an ACL rupture or PFI-related injury between January 2015 and August 2022 were identified at a single institution. Only participants with a preoperative lower limb x-ray using the EOS system (EOS imaging, France) were included. Participants with a history of previous knee surgery in either knee, more than one diagnosis of either ACL rupture or PFI, and/or no preoperative biplane hip-to-ankle EOS radiograph were excluded. Participants were compared to a cohort of scoliosis patients with a Cobb angle of less than 20° who had biplane EOS radiographs (Controls). All preoperative radiographs were sent for EOS 3D reconstructions and femorotibial rotation data was acquired. Positive femorotibial rotation output measurements refer to external rotation while negative measurements refer to internal rotation. Demographics for all patients were gathered. A Kruskal-Wallis test was run to compare femorotibial rotation between the three groups (ACL, PFI, Controls) and pairwise comparisons were also analyzed.
Results
Of the identified patients, 197 met final inclusion criteria (60 ACL, 92 PFI, 45 Controls). The mean age at time of imaging was 14.4±2.2 years (ACL: 14.3±1.8 years; PFI: 14.3±2.4 years; Controls: 14.9±2.4 years) and 50.8% were female (ACL: 43.3% female; PFI: 58.7% female; Controls: 44.4% female). The median femorotibial rotation was 4.8° (ACL: -2.1°; PFI: 10.2°; Controls: 4.4°). Femorotibial rotation was noted to be significantly different between cohorts (P ≤ 0.001), and the pairwise comparison between each group was also significant (ACL-Control: P ≤ 0.001, ACL-PFI: P ≤ 0.001, Control-PFI: P ≤ 0.001).
Conclusions
Femorotibial rotation differed significantly between patients with ACL rupture, PFI, and a comparison cohort, suggesting that femorotibial rotation may be associated with differences in knee pathology in pediatric patients. The majority of ACL patients had internal femorotibial rotation, while the majority of PFI patients had external femorotibial rotation.