Relationship between articular cartilage damage and bone density in the first metatarsal.

It is well known that bone changes occur in relationship to the articular cartilage damage seen in osteoarthritis. Numerous studies have shown a relationship between bone density and articular cartilage damage in knee and hip joints, but it is controversial as to whether or not an increased subchondral bone density results in greater cartilage damage. We studied 49 pairs of cadaveric first metatarsals in an attempt to correlate the level of cartilage damage seen on the distal articular surface with areal and volumetric density and other parameters such as bone geometry. A positive correlation was detected between articular cartilage damage and bone density by peripheral quantitative computed tomography in five of eight frontal slices in the head of the left metatarsal in the male sample only. The more extensive subchondral cysts found in the right male metatarsal may have contributed to the lack of correlation between the two variables on the right side. In addition, females displayed significantly greater osteophytosis than males at a given grade of cartilage damage, thus, possibly leading to a painful, apropulsive gait and a disuse osteopenia which would neutralize any subchondral bone density increase associated with cartilage damage. Microscopic investigations are, therefore, warranted to detect bone changes on a more discreet level, particularly within the subchondral plate.