F- CLINICAL ASPECTS OF SPINAL CORD INJURIES
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deficit in hand and fingers, and at the same time will allow the medical attendant to assess
properly the chances as well as the risks of tendon transfers.
There is general agreement that in all operative procedures the mobility of the wrist
joints is of the greatest importance.
In analysing the various levels of complete spinal cord lesions the following have to be
considered:
C5/6
lesions.
At this level all muscles of the forearms and hands including brachioradialis
and pronator teres are paralysed, or the brachioradialis is only very weak. The only
muscles of good or moderate power are the deltoid and biceps. To restore extension of
the wrist, which is so important for some daily activities in this type of tetraplegia,
cock-up splints, as devised by Nickel and his co-workers, can be used beneficially. Alter
natively, a fusion of the wrist joints in moderate extension can be contemplated, and in
one of our cases has proved of benefit.
Lesions below C6.
In these cases, the function of the brachioradialis and pronator teres
is preserved to varying degrees, while the extensors of the wrist, in particular the extensor
carpi radialis brevis, are either weak or paralysed. In such a case, the brachioradialis, if
of strong power (at least 4), can be connected with the tendons of the extensor carpi
radialis brevis and thus the radial deviation as a result of the over action of the extensor
carpi radialis longus can be corrected, and full extension of the wrist restored. By full
extension of the wrist, passive flexion of the fingers on the metacarpophalangeal and inter-
phalangeal joints results, and this enables the patient by exercises to acquire some degree
of grasping power.
Opposition of the thumb may be obtained by fixing the proximal end of the opponens
to the distal part of the ulnar, thereby, the extension of the wrist will pull the thumb into
some degree of opposition. However, a number of workers in this field prefer the perma
nent stabilization of the thumb in opposition through a metacarpal bone block between
the first and second metacarpals. The first metacarpal is brought into abduction and
flexion as well as medial rotation, and this position is fixed by the bone graft which is
taken from the iliac crest.
Lesions at and below Cj.
In these cases the flexor carpi-radialis is active. Lamb (1972)
potentiated the natural tenodesing effect of the long flexors, when the wrist is dorsiflexed
by transferring the extensor carpi-radialis longus through a large window cut in the
interosseus membrane above the pronator quadratus to the flexor digitorum profundus.
The branchioradialis was transferred to the flexor pollicis longus. The extensor carpi-
radialis brevis was left to dorsiflex the wrist. Lamb carried out this operation in 13 patients
of whom 11 were improved. However, no details were given of the type of improvement
in these cases, particularly Cy where the flexor carpi-radialis is working (Group 4 of
Lipscomb). This muscle was used by Lamb as the motor for the abduction-opposition
of the thumb muscle by using a free tendon graft from the palmaris muscle.
In lesions at C8,
the interossei and lumbricales are still paralysed and so are the abductor
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