Quantitative Variable Assessment of Patellar Instability: An MRI-Based Study
Michael V Friedman1, Travis J Hillen1, Sunil Misra1
1Washington University School of Medicine, Mallinckrodt Institute of Radiology, 510 S Kingshighway Blvd, St. Louis, MO 63110.
AJR. American Journal of Roentgenology
|September 9, 2020
Summary
Quantitative MRI parameters reliably assess anatomic predispositions for patellar instability. Trochlear dysplasia and tibial tubercle-to-trochlear groove distance are key indicators, aiding personalized orthopedic treatment strategies.
Area of Science:
- Orthopedic imaging
- Radiology
- Biomedical engineering
Background:
- Patellar instability is a complex condition with multifactorial causes.
- Quantitative MRI parameters are increasingly used to assess anatomical predispositions.
- Reproducibility of these measurements is crucial for clinical application.
Purpose of the Study:
- To evaluate the reproducibility of three quantitative MRI parameters for patellar instability.
- To determine if these parameters individually or collectively predict patellar instability.
- To assess their role in identifying anatomical predisposition.
Main Methods:
- Retrospective analysis of MRI scans from 100 patellar dislocation patients and 100 controls.
- Measurement of tibial tubercle-to-posterior cruciate ligament (TT-PCL) distance, tibial tubercle-to-trochlear groove (TT-TG) distance, and TG depth (trochlear dysplasia).
- Intraobserver and interobserver reliability assessed using intraclass correlation coefficients (ICC).
Main Results:
- All three MRI parameters demonstrated high intraobserver (ICC ≥ 0.88) and interobserver (ICC ≥ 0.82) reliability.
- Parameters were significantly more prevalent in the patellar instability group.
- Trochlear dysplasia showed the strongest association, especially with abnormal TT-TG distance.
Conclusions:
- Quantitative MRI parameters for patellar instability are highly reproducible.
- These parameters identify unique and overlapping anatomical predispositions.
- Combined assessment of TT-PCL, TT-TG, and trochlear dysplasia aids in personalized patient management and surgical planning.
