Assessment
A careful history and
examination is as important for the wrist and hand as anywhere else.
History
•
General — Is the patient left or right handed? Occupation, hobbies and
ambitions? How do the symptoms interfere with these?
•
Pain — What is the site of the pain, what makes it better or worse, how
long has it been present, does it fluctuate?
•
Function — Is the grip weak? Are there problems with fine motor tasks,
such as doing up buttons, or coarse tasks, such as opening a jar? Are there
clicks or clunks?
•
Sensation — Loss of sensation? Tingling? Which part of the hand?
•
Injury — The exact nature of the injury: a cut (sharp, blunt, dirty?),
a crush, a fall (how far?), a bite, a punch, an avulsion?
•
General health — Diabetes? Smoking? Steroids? Cardiac or respiratory problems which may influence the choice of anaesthetic?
Examination
•
In the injured patient, are there Airway, Breathing or Circulation
problems which should take priority?
•
Skin — Are there cuts or bruises? Is there skin loss, and if so are
tendons or bone exposed? Are there previous surgical or traumatic scars? Are
there signs of infection?
• Bones — Is there deformity or tenderness? The precise of
tenderness can be diagnostic, for example a tender lunate with Kienbock’s
disease or a tender anatomical snuffbox with a scaphoid fracture.
• Joints — Is there deformity or tenderness? Ligament
stability should be tested by stabilising the proximal bone and gently
stressing the distal. The active and passive range of movement in each
joint should be established. A similar restriction in both active and passive
movement may be caused by pain or joint stiffness. A discrepancy may be due to
tendon rupture, tendon adhesions or a nerve palsy.
• Tendons — Passive tenodesis is a useful screening
test: the hand is relaxed and the wrist is moved into flexion and then extension
by the examiner. As the wrist extends, the fingers should curl into a neat
cascade, and as the wrist is flexed the fingers should open. The function of
each individual tendon is established. Flexor digitorum pro fundus is
tested in each finger by supporting the proximal interphalangeal joint and
middle phalanx then asking the patient to flex the distal interphalangeal joint.
Flexor digitorum superficialis is tested with the examiner holding the
other three fingers straight and asking the patient to flex the proximal
interphalangeal joint of the remaining finger. Extensor digitorum communis is
tested by asking the patient to fully extend the metacarpophalangeal joints (interphalangeal
joint extension is a function of the intrinsic muscles).
• Nerves — The nerves supplying the hand can be quickly
checked. If there is a cut in the palm or finger, the digital nerves should be
tested by checking sensation on each side of the finger tip. Two-point
discrimination is useful in partial nerve lesions or recovering nerves; two
prongs of a paper clip are spread and the patient asked to say whether one or
two points can be felt. Normal discrimination in the finger tips is about 6 mm. Tinel’s
percussion sign — tapping on a nerve and causing ‘tingling’— is
present at the site of nerve compression, a neuroma or at the advancing tip of a
recovering nerve. In the unconscious patient or young child, the plastic pen
test is helpful. If the nerve is normal then the side of a pen brushed
gently across the skin will stick because of the intact supply to sweat glands;
if the nerve is divided, the pen will brush off smoothly.
Examining the nerves of the hand
Nerve
Altered sensation
Weakness, wasting
Anterior
Nil
Flexor pollicis longus, flexor
interosseous
digitorum profundus (FDP)
to index
Posterior
Nil
Extensors of wrist and
interosseous
metacarpophalangeal joint
Median
Thenar eminence, palmar
Flexor carpi radialis,
side of thumb, index,
pronator teres, long finger
middle and radial half of
flexors (except FOP to ring
ring finger
and little), abductor pollicis
brevis, opponens pollicis
Ulnar Ulnar
side of hand, palmar
Flexorcarpi ulnaris, FOP to
side of little finger and
ring and little finger,
ulnar half of ring finger
adductor pollicis,
interossei, hypothenar
eminence, Froment’s sign
Superficial Anatomical
snuffbox
Nil
radial
• Circulation — A white or blue fingertip suggests circulation
problems. If the finger nail is compressed and then released, the circulation
should return in less than 2 seconds. If not, this suggests either systemic
hypotension or loss of the local blood supply. With the Allen test, one
can tell whether both radial and ulnar arteries are intact. Both are compressed
by the examiner’s fingers, the patient squeezes his or her hand to express the
blood and then relaxes. The hand will be white. The examiner then releases one
artery; if the hand does not ‘pink up’, that artery is occluded or divided.
The test is repeated for the other side.
Investigation
• Plain radiographs — The standard views are a posteroanterior
and true lateral. Oblique views are helpful particularly for intra-articular
fractures and scaphoid fractures. Special views, for example stress views
for ulnar collateral ligament injuries of the thumb or a clenched fist view
for carpal instability, are sometimes needed.
• Magnetic resonance imaging (MRI) — This can detect, for
example, Kienböck’s disease before it is apparent on plain radiographs and
gives some indication of the vascularity of a scaphoid fracture.
• Isotope bone scanning — In difficult cases this helps by
disclosing
the inflammation that accompanies undisclosed fractures or bone lesions such as
osteoid osteoma.
• Wrist arthroscopy — This can diagnose tears of the triangular
fibrocartilage complex (TFCC), carpal instability and arthritis. Some TFCC tears
are treatable arthroscopically.
• Electrophysiology — For a clinically obvious carpal
tunnel syndrome these may not be required; for less clear neurological
symptoms these tests detect if and where there is nerve compression.