Pediatric patella MRI update

Published Feb 11, 2026 in the American Journal of Sports Medicine, the multicenter case‑control study by Green et al. evaluated pediatric patellofemoral instability with an MRI‑based Dejour modification. (read.qxmd.com) The cohort included 144 knees from 127 patients with objective PFI matched 1:1 to 144 controls, and four blinded raters measured seven MRI parameters including cartilaginous sulcus angle and lateral patellofemoral angle (LPFA). (read.qxmd.com) Applying adult Dejour v3.0 cutoffs produced AUCs of 0.79–0.87 in the pediatric sample, so the authors used regression‑tree recursive partitioning to derive pediatrics‑specific thresholds and identified five cutoff combinations. (read.qxmd.com) A single cartilaginous sulcus angle ≥151° yielded sensitivity 93% (95% CI 87.6%–96.6%), specificity 87% (95% CI 80.2%–91.9%), AUC 0.94; the paired rule (LPFA <0.45° when sulcus angle <151°) reached sensitivity 98% (95% CI 94.0%–99.6%), specificity 85% (95% CI 78.6%–90.7%), AUC 0.97, with the RF AUC noninferior (P =.33). (read.qxmd.com) The study’s focus on objective MRI metrics builds on prior work adapting the Dejour scheme for MRI that showed substantially higher inter‑ and intra‑reader reliability in 171 knee MRIs (median age 34.3 years), supporting a broader shift toward quantitative MRI classification. (link.springer.com) Because contemporary surgical decision‑making for recurrent PFI explicitly uses anatomic risk factors—trochlear dysplasia, patella alta and TT–TG distance—published management reviews recommend defining those factors preoperatively, making pediatric‑specific MRI thresholds directly actionable for triage and operative planning. (eor.bioscientifica.com)