How do sex, age, and osteoarthritis affect cartilage thickness at the thumb carpometacarpal joint? Insights from subject-specific cartilage modeling

Abstract

Studying the morphology of the thumb carpometacarpal (CMC) joint cartilage in both health and disease is warranted by the high incidence of CMC osteoarthritis (OA), especially in women; however, quantifying CMC cartilage variation in vivo remains challenging with current modalities.We used a subject-specific cartilage model that is based on joint space volume computations from sequential CT scans to find that cartilage thickness does not differ with sex and age, but that it does with early signs of OA. These findings advance the general understanding of CMC joint mechanics and OA pathogenesis by verifying that metabolic or genetic differences, under the influence of mechanical loading, rather than mechanical factors alone, are implicated in the pathoetiology of CMC OA. This model may be used to study cartilage degradation in vivo, may be incorporated into subject-specific mechanical simulations, and may have clinical applications for OA staging if combined with dynamic volume CT.