GROWTH OF THE RADIUS IN SHEEP - AN EXPERIMENTAL-MODEL FOR MONITORING ACTIVITY OF THE GROWTH PLATES

This study documents growth of the radius at weekly intervals in 10 ma le lambs from 6 to 18 weeks of age. The lambs were randomised in 2 gro ups. In the first group, 2.0 mm diameter pins were inserted above and below the distal radial growth plate. Animals of the second group serv ed as a control. Body weight, weight distribution, length of the radiu s, growth rate of each radial physis and distal growth plate area were assessed. No differences were observed between the two groups showing that pin insertion did not modify growth. Mean body weight ranged fro m 8.9 kg at 6 weeks of age to 37.7 kg at 18 weeks of age. The mean wei ght exerted on the forelimbs during this follow-up was 58.3 % of the t otal weight. Mean radial length ranged from 11.8 cm at 6 weeks of age to 16.1 cm at 18 weeks of age. Growth repartition during this period w as 68.3 % for the distal physis and 31.7 % for the proximal physis. Th e mean distal radial growth plate area ranged from 8.2 cm(2) at 6 week s of age to 13.3 cm(2) at 18 weeks of age. The body weight, radial len gth and distal growth plate area between 8 and 14 weeks of age could b e assimilated as straight lines. The data obtained in this study will allow more accurate quantitation of skeletal growth in further experim ental investigations.