thesis
Tendon transfers to restore opposition of the thumb
- Publication date
- 8 May 1970
- Publisher
- In man and some of the apes, the thumb has the function of a contrafinger.
This function is made possible by a great freedom of movement
of the first metacarpal and a highly developed and differentiated
thumb musculature. The grasp function of the hand is dependent on
the oppositional capacity and adductive power of the thumb, and is
severely limited by a paralysis or dysfunction of the intrinsic thumb
muscles. Whereas loss of the function of the adductor pollicis can be
partially compensated for by the adductive action of the extensor
pollicis longus, in paralysis or dysfunction of the radial thenar
muscles compensation can only be provided by surgery.
Since 1918, many methods of tendon transfer have been described
for the restoration of thumb opposition, all of which bring about an
improvement of the grasp function, albeit to different degrees. These
methods vary in the selection of the motor, the direction of pull of
the tendon, the use of a fulcrum, and the mode of insertion. The
highly effective method of Bunnell (1938) is often used as the standard
procedure. With this method, the flexor superficialis tendon of the
ring finger is looped around the tendon of the flexor carpi ulnaris
and passed subcutaneously across the thenar eminence, after which
it is fixed on the thumb at the level of the metacarpo-phalangeal joint.
In the reconstruction of the thumb opposition, however, a standard
procedure often cannot be applied, because the muscle-tendon unit
usually used for this purpose has been damaged or because the
transfer route is blocked by scar tissue.