We observed the healing process under rigid external fixation after Salter-Harris type-1 or type-2 physeal separation at the proximal tibia in immature rabbits.

Metaphyseal vessels grew across the gap with little delay; the site of separation then came to lie in the metaphysis and was bridged by endochondral ossification. Union was achieved within two days in all rabbits.

Progression of endochondral ossification repaired the separated physis, thus showing ‘primary healing of physeal separation’. This depends on accurate reduction and stable fixation to allow the survival of vessels across the gap.

A new method of replacement for the paralysed anterior deltoid is described. The latissimus dorsi with its neurovascular pedicle is freed and rotated, and then placed over the anterior part of the paralysed muscle. The lever arm of the transposed muscle is as long as that of the deltoid, and the muscle volume is enough to restore the natural contour of the shoulder. We report operations on 10 patients with shoulder palsy, eight caused by brachial plexus injury and two by resection of a neurilemmoma of the plexus. In six cases, active flexion to over 90 degrees was achieved. At least one of the rotator cuff muscles or the long head of biceps should have some active function if good results are to be obtained.