The relationship between articular cartilage degeneration and bone changes of the first metatarsophalangeal joint.

Plain-film radiography is commonly used in the assessment of joints affected by osteoarthritis. It has been shown that the condition of articular cartilage in the knee, when grossly assessed, does not always correlate well to the radiographic evaluation of the joint. The aim of this study was to determine whether a relationship existed between the radiographic appearance of the subchondral bone and the morphological condition of the articular cartilage surfaces of the first metatarsophalangeal joint. Forty-nine pairs of cadaveric metatarsals and their respective proximal phalanges were studied in order to determine the correlation between articular cartilage degeneration and radiographic grade using a modified Kellgren-Lawrence scale. The relationship between cartilage degeneration and age, gender, osteophytes, metatarsal length, and measured angles (proximal articular set angle, distal articular set angle, intermetatarsal angle) was also investigated. It was found that there was a significant correlation between radiographic grade and cartilage degeneration on both the metatarsal head and the base of the proximal phalange (r2 = .2038 and .1733, respectively). However, while useful in the clinical setting, bony changes of the first metatarsophalangeal joint, as seen radiographically, fail to provide a full representation of the level of cartilage degeneration on the articular surfaces of this joint.