er side of the foot.

_Arthrodesis._--This operation, first performed by Albert in 1877,
consists in removing the cartilage covering the articular surfaces of
bones with the object of producing a firm ankylosis. The procedure is
most successful in the ankle and mid-tarsal joints, and as a result of
it there is obtained a secure and firm base of support in walking.
Before performing arthrodesis, the surgeon must decide whether the
patient will be better off with a stiff joint or with a weak and
movable ankle supported by apparatus. This is often a matter of social
position; in the poor, an ankylosed joint is more useful and less
expensive. An arthrodesis should seldom be performed at the ankle
until the child has passed his eighth year, or at the knee until he
has reached his twentieth year. There is plenty to be done during the
period of waiting, and if this is done well, it is possible that the
operation may not be required. The existing deformities, for example,
will have to be corrected, areas of skin removed to relieve
functionless muscles of strain, the body weight appropriately
deflected, and the child must be taught to walk with the aid of a
support, swinging his limb about, and using it effectively in a
correct position. Such exercise is a powerful agent in promoting
physiological and functional development.

_Nerve anastomosis_, which seeks to provide a new channel for the
transmission of motor impulses to the paralysed muscles, has as yet a
restricted field of application--for example, the tibial and peroneal
nerves may be anastomosed when the muscles supplied by one of them are
paralysed. Stoffel of Heidelberg lays stress on regard being paid to
the anatomical arrangement of the nerve bundles within the nerve-trunk
so that motor fibres may be joined to motor ones and not to sensory.
It is necessary also to cut across some of the fibres of the healthy
nerve in order that they may grow into the nerve which is degenerated.

In extreme cases in which the limb is hopelessly paralysed and
useless, it may be _amputated_ to admit of an artificial limb being
worn; it must be borne in mind, however, that such limbs furnish poor
stumps, usually quite unable to bear pressure.

#Cerebral Palsies of Childhood--Spastic Paralysis.#--These may be due
to arrest of development of the brain, to injuries of the head at
birth, to meningeal haemorrhage, or to other lesions of the brain, with
secondary degenerative changes in th