A model was developed in the dog to allow both the metaphysis and epiphysis of the distal ulnar growth plate to be microsurgically revascularised from the pedicle of the anterior interosseous vessels. With both circulations revascularised, grafts retained their structural integrity and growth continued at rates only slightly less than normal (mean 85%). If either or both circulations were not revascularised, growth rates were lower and were associated with skeletal collapse in the ischaemic bone segment.

We investigated the feasibility in the dog of using transfers of the distal ulna into the radius either as growth plate replacements or as accessory growth plates in the diaphysis. Preliminary work determined the most satisfactory method of skeletal fixation. The experimental study showed that transfers used as growth plate replacements grew at almost normal rates, uniting with the recipient bone in a mean of 7.1 weeks. Transfers into the diaphysis initially nearly doubled the growth rate of the radius, although in the long-term results were unsatisfactory, because of fracture of the graft after a mean period of 8.2 weeks.

Distraction fractures of the upper lumbar spine are most often associated with the wearing of seat-belts. Twenty patients with this spinal fracture were reviewed and half of them had intra-abdominal injuries. Eight patients required an exploratory laparotomy. Three distinct patterns of distraction fractures have been identified. Open reduction, local spinal fusion and Harrington instrumentation are recommended for unstable fractures and for those with neurological involvement. Four cases of non-union are included ln the series. Legislation for the compulsory wearing of seat-belts should encompass improvements in design and stricter criteria for installation.