Distribution of cartilage thickness on the head of the human first metatarsal bone

Articular hyaline cartilage takes on the contours of the subchondral bone o n which it lies, but its thickness varies between joints, within a single j oint and within a single articular surface. Previous studies have correlate d articular cartilage thickness distribution with the degree of stress and weight bearing on joint surfaces, but few studies have considered the thick ness of the calcified cartilage in relation to these parameters. Here we re port a correlation between the cartilage thickness distribution and weight bearing distribution on the head of the Ist metatarsal bone, a component of one of the major weight bearing joints in the lower extremity during the g ait cycle. The greatest total and uncalcified articular cartilage thickness was found on the central and lateral distal aspects of the metatarsal head , a region that receives maximal ground reactive force during the propulsiv e phase of the normal gait cycle. Although the thickness of the calcified c artilage was correlated with the thickness of the uncalcified cartilage, it varied to a lesser extent across the articular surface than did that of th e uncalcified cartilage.