Looking at the Wrong Thing: Misguided Metrics in Evaluating Success

For years, the emphasis on focal cartilage lesions has been primarily on restoring the cartilage cap. However, evolving knowledge suggests that the subchondral plate might be a bigger part of the overall picture. 

Density of subchondral plate

In a study by Oshibashi et al. (2024), researchers used Hounsfield units (HUs) to analyze the superior tali removed during the total ankle replacement. They conducted a comparative analysis of these units alongside histologic findings to determine if the condition of the subchondral plate correlated with histologic observations in ankle osteoarthritis (OA). 

Predicting the success of interventions

As OA progresses, cartilage defects increase. In conjunction with cartilage degeneration, the subchondral bone plate thickens, and the HU values rise. The next step may be to base the success of cartilage interventions on the thickness of the subchondral plate. This also adds another nail in the coffin of microfracture techniques, since they further damage the subchondral plate.