the
patient almost loses the use of it; in some cases this would appear to
be due to the median nerve having been injured at the same time.

[Illustration: FIG. 90.--Drop-wrist following Fracture of Shaft of
Humerus.]

If the lesion is high up, as it is, for example, in crutch paralysis,
the triceps and anconeus may also suffer.

_Treatment._--The slighter forms of injury by compression recover under
massage, douching, and electricity. If there is drop-wrist, the hand and
forearm are placed on a palmar splint, with the hand dorsiflexed to
nearly a right angle, and this position is maintained until voluntary
dorsiflexion at the wrist returns to the normal. Recovery is sometimes
delayed for several months.

In the more severe injuries associated with fracture of the humerus and
attended with the reaction of degeneration, it is necessary to cut down
upon the nerve and free it from the pressure of a fragment of bone or
from callus or adhesions. If the nerve is torn across, the ends must be
sutured, and if this is impossible owing to loss of tissue, the gap may
be bridged by a graft taken from the superficial branch of the radial
nerve, or the ends may be implanted into the median.

Finally, in cases in which the paralysis is permanent and incurable, the
disability may be relieved by operation. A fascial graft can be employed
to act as a ligament permanently extending the wrist; it is attached to
the third and fourth metacarpal bones distally and to the radius or ulna
proximally. The flexor carpi radialis can then be joined up with the
extensor digitorum communis by passing its tendon through an aperture in
the interosseous membrane, or better still, through the pronator
quadratus, as there is less likelihood of the formation of adhesions
when the tendon passes through muscle than through interosseous
membrane. The palmaris longus is anastomosed with the abductor pollicis
longus (extensor ossis metacarpi pollicis), thus securing a fair amount
of abduction of the thumb. The flexor carpi ulnaris may also be
anastomosed with the common extensor of the fingers. The extensors of
the wrist may be shortened, so as to place the hand in the position of
dorsal flexion, and thus improve the attitude and grasp of the hand.

_The superficial branch of the radial_ (radial nerve) _and the deep
branch_ (posterior interosseous), apart from suffering in lesions of the
radial, are liable to be contused or torn is dislocation of the head