Juvenile osteochondritis dissecans (JOCD) is a pediatric orthopedic disorder that involves the articular–epiphyseal cartilage complex and underlying bone. Clinical disease is often characterized by the presence of radiographically apparent osteochondral flaps and fragments. The existence of early JOCD lesions (osteochondrosis latens [OCL] and osteochondrosis manifesta [OCM]) that precede the development of osteochondral flaps and fragments is also well recognized. However, identification of naturally occurring OCL lesions (confined to cartilage) using noninvasive imaging techniques has not yet been accomplished. We hypothesized that 10.5 T magnetic resonance imaging (MRI) can identify naturally occurring OCL lesions at predilection sites in intact joints of juvenile pigs. Unilateral elbows and knees (stifles) were harvested from three pigs aged 4, 8, and 12 weeks, and scanned in a 10.5 T MRI to obtain morphological 3D DESS images, and quantitative T2 and T1ρ relaxation time maps. Areas with increased T2 and T1ρ relaxation times in the articular–epiphyseal cartilage complex were identified in 1/3 distal femora and 3/3 distal humeri and were considered suspicious for OCL or OCM lesions. Histological assessment confirmed the presence of OCL or OCM lesions at each of these sites and failed to identify additional lesions. Histological findings included necrotic vascular profiles associated with areas of chondronecrosis either confined to the epiphyseal cartilage (OCL, 4- and 8-week-old specimens) or resulting in a delay in endochondral ossification (OCM, 12-week-old specimen). Future studies with clinical MR systems (≤7 T) are needed to determine whether these MRI methods are suitable for the in vivo diagnosis of early JOCD lesions in humans.
Bibliographical noteFunding Information:
We thank Paula Overn from the University of Minnesota Masonic Cancer Center Comparative Pathology Shared Resource Laboratory for assistance with the preparation of the histological sections. We also thank Drs. Essa Yacoub and Jan Zimmermann from the University of Minnesota Center for Magnetic Resonance Research for allowing us to use the 10.5 T head coil hardware and Dr. Casey Johnson from the University of Minnesota Department of Veterinary Clinical Sciences for providing the T1ρ sequence. Funding for this study was provided by grants from several institutes at the NIH, including the National Institute for Arthritis and Musculoskeletal and Skin Diseases (R01AR070020, T32 AR050938), National Institute of Biomedical Imaging and Bioengineering (P41 EB027061) and Office of the Director (T32 OD010993, K01 OD021293). The study sponsors had no role in the study design, collection, analysis and interpretation of data, the writing of the manuscript, or the decision to submit the manuscript for publication. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.
© 2022 The Authors. Journal of Orthopaedic Research® published by Wiley Periodicals LLC on behalf of Orthopaedic Research Society.
- diagnostic methods
Center for Magnetic Resonance Research (CMRR) tags
PubMed: MeSH publication types
- Journal Article
- Research Support, N.I.H., Extramural