discover and isolate the ends of the
tendon; if the interval is too wide to admit of their being approximated
by sutures, means must be taken to lengthen the tendon, or one from some
other part may be inserted in the gap. A new sheath may be provided for
the tendon by resecting a portion of the great saphenous vein.

_Injuries of the tendons of the fingers_ are comparatively common. One
of the best known is the partial or complete rupture of the aponeurosis
of the extensor tendon close to its insertion into the terminal
phalanx--_drop-_ or _mallet-finger_. This may result from comparatively
slight violence, such as striking the tip of the extended finger against
an object, or the violence may be more severe, as in attempting to catch
a cricket ball or in falling. The terminal phalanx is flexed towards the
palm and the patient is unable to extend it. The treatment consists in
putting up the finger with the middle joint strongly flexed. In
neglected cases, a perfect functional result can only be obtained by
operation; under a local anaesthetic, the ruptured tendon is exposed and
is sutured to the base of the phalanx, which may be drilled for the
passage of the sutures.

_Subcutaneous rupture_ of one or other _of the digital tendons_ in the
hand or at the wrist can be remedied only by operation. When some time
has elapsed since the accident, the proximal end may be so retracted
that it cannot be brought down into contact with the distal end, in
which case a slip may be taken from an adjacent tendon; in the case of
one of the extensors of the thumb, the extensor carpi radialis longus
may be detached from its insertion and stitched to the distal end of the
tendon of the thumb.

Subcutaneous _rupture of the tendon of the extensor pollicis longus_ at
the wrist takes place just after its emergence from beneath the annular
ligament; the actual rupture may occur painlessly, more frequently a
sharp pain is felt over the back of the wrist. The prominence of the
tendon, which normally forms the ulnar border of the snuff-box,
disappears. This lesion is chiefly met with in drummer-boys and is the
cause of drummer's palsy. The only chance of restoring function is in
uniting the ruptured tendon by open operation.

[Illustration: FIG. 108.--Avulsion of Tendon with Terminal Phalanx of
Thumb.

(Surgical Museum, University of Edinburgh.)]

_Avulsion of Tendons._--This is a rare injury, in which the tendons of a
finger or toe are torn