In the December 19, 2018 issue of The Journal, Toth et al. histologically examined 59 biopsy samples from the central condyles of 26 pediatric cadavers to look for areas of epiphyseal cartilage necrosis. Hypothesizing that such evaluation would reveal some lesions similar to those found in animals, the authors did indeed identify 6 samples with 1 or more areas of necrotic cartilage, which were either incorporated into subchondral bone or associated with focal failure of endochondral ossification. Those characteristics are consistent with a similar disease process called osteochondrosis manifesta seen in pigs and horses. While the clinical significance of these findings remains to be determined, the authors suggest that they may help explain an epiphyseal etiology of JOCD, and the data suggest that these microscopic changes (some of which are rendered in this article as whole-slide images) are probably present in young people 5 to 10 years prior to the clinical manifestations of JOCD.
These findings lend credence to the theory that the underlying etiology of JOCD primarily involves the epiphyseal growth plate rather than subchondral bone. Furthermore, the similarities between these cadaveric specimens and osteochondrosis manifesta lesions in porcine and equine femoral condyles may help us develop improved models to better diagnose, prevent, and treat this pathology.
Chad A. Krueger, MD
JBJS Deputy Editor for Social Media