In Arthroscopy : the journal of arthroscopic & related surgery : official publication of the Arthroscopy Association of North America and the International Arthroscopy Association
PURPOSE : To perform patellofemoral joint (PFJ) geometric measurements in knee MRIs and determine their relationships with chondral lesions in a multi-center cohort using deep learning.
METHODS : Sagittal tibial tubercle trochlear groove (sTTTG) distance, tibial tubercle trochlear groove (TTTG) distance, trochlear sulcus angle, trochlear depth, Caton-Deschamps index (CDI), and flexion angle were measured using deep learning-generated segmentations on a subset of the OsteoArthritis Initiative with radiologist-graded PFJ cartilage gradings (N=2461). Kruskal-Wallis H-tests compared differences in PFJ morphology between subjects without and with PFJ osteoarthritis (OA). PFJ morphology was correlated with secondary outcomes of mean patellar cartilage thickness and mean patellar cartilage T2 relaxation time using linear regression models controlling for age, sex, and BMI.
RESULTS : A total of 1626 knees did not have PFJ OA, while 835 knees possessed PFJ OA. Knees without PFJ OA had an increased (anterior) sTTTG (11.1±12.8 mm) compared to subjects with PFJ OA (8.4±12.7 mm) (p<0.001), indicating a more posterior tibial tubercle for subjects with PFJ OA (mean±standard deviation). Knees without PFJ OA had a decreased sulcus angle (127.4±7.1 degrees v. 128.0±8.4 degrees, p=0.01) and increased trochlear depth (9.1±1.7 mm v. 9.0±2.0 mm, p=0.03) compared to subjects with PFJ OA. Decreased patellar cartilage thickness was associated with decreased trochlear depth (β=0.12, p=0.002) and increased CDI (β=-0.07, p<0.001). Increased patellar cartilage T2 relaxation time correlated with decreased sTTTG (β=-0.08, p=0.01), decreased sulcus angle (β=-0.12, p=0.04), and decreased CDI (β=-0.12, p<0.001).
CONCLUSIONS : PFJ OA, patellar cartilage thickness, and patellar cartilage T2 relaxation time were demonstrated to be associated with the underlying geometries within the PFJ. This large, longitudinal study highlights that decreased sTTTG (i.e. a more posterior tibial tubercle) is significantly associated with PFJ degenerative cartilage change.
Namiri Nikan K, Càliva Francesco, Martinez Alejandro Morales, Pedoia Valentina, Lansdown Drew A
2022-Dec-26
