Quantitative evaluation in vivo of the degree of differentiation of hindlimb cartilage in a rat clubfoot model.

The Limb Morphogenetic Differentiation Scoring system introduced by Neubert and Barrach in 1977 has been used in drug testing as a measure of the degree of cartilage growth inhibition especially for forelimb in vitro. There is no scoring system to quantify the degree of hindlimb bud cartilage differentiation in vivo. A total of 60 female Sprague-Dawley rats weighing 220-250 g were assigned at random to six control groups and six experimental groups on day 0 of pregnancy.