Histological and radiographic determination of the age of physeal closure of the distal femur, proximal tibia, and proximal fibula of the New Zealand white rabbit.

A longitudinal study was performed in a series of 124 New Zealand White rabbits to determine the radiographic versus the histologic age of closure of the growth plates of the distal femur, proximal tibia, and proximal fibula. Periodic assessment was made by standard radiographs and histological studies. Histologically, growth plates in the distal femur closed at 19-24 weeks; growth plates in the proximal tibia, at 25-32 weeks; and growth plates in the proximal fibula, at 26-32 weeks. Radiographically, evidence of closure of growth plates in the distal femur occurred at 20-23 weeks; in the proximal tibia, at 22-27 weeks; and in the proximal fibula, at 23-31 weeks. A discrepancy in age between radiographic and histologic closure of the growth plate occurred in 3.6% of the femora, 10.9% of the tibias, and 16% of the fibulas.