study on the postnatal development of the articular cartilage of the knee joint of the albino rat

The postnatal development of the articular cartilage of the femur was studied. A total number of 35 albino rats [Wister strain] was used in this study. The animals were divided into seven groups: Newborn, seven days, ten days, fourteen days, twenty-one days, one month and three months. The study revealed that the immature articular cartilage appeared at the age of twenty-one days in the form of three zones; superficial, intermediate and deep. The mature articular cartilage appeared at the age of three months and consisted of four zones; superficial, intermediate, radial and calcified. The tide mark separated the superficial three zones from the fourth one