Impairment of growth of the distal end of the ulna was produced in
rabbits by excision of the distal epiphyseal plate. This caused a sequence
of changes in the distal radial epiphysis consisting of combined increased
chondrogenesis and decreased osteogenesis of the radial two-thirds of the
distal epiphysis, and decreased chondrogenesis and increased osteogenesis
on the ulnar side. At six to nine days postoperatively, cracks appeared
concomitant with tilting of the plate and epiphysis, in the epiphyseal
plate or at its metaphyseal junction. An incomplete radial epiphyseal
separation occurred, a step-like deformity developed in the metaphysis, and
an ulnar deviation developed.