Injuries
Vascular
injuries
Vessel
division
A partial injury of an artery will not contract and seal itself so
it continues to bleed. Bleeding should be controlled with pressure — it is
dangerous to use a tourniquet (which can be forgotten) or to clip the vessel
blindly (which spoils the chance for repair and can damage the nearby nerve).
Compartment
syndrome
Following crush injuries and fractures of the forearm or
hand, or prolonged ischaemia from vessel damage, tourniquet or tight
dressings, a compartment syndrome can develop. The pressure within the fascial
compartments (superficial flexor, deep flexor, extensor, interossei, thenar and
hypothenar) rises and occludes the microcirculation which supplies the muscles
and nerves. The symptoms are pain, tingling, cold; the signs
Fractures
Scaphoid
This bone is fractured by a fall on the outstretched hand. The fracture
is easily overlooked — it causes little deformity or pain and does not always
show clearly on plain radiographs. However, it is notorious for two reasons
— it may not unite (particularly in the relatively avascular proximal
pole) or it may present later with intercarpal collapse and
osteoarthritis. If there is doubt about the diagnosis, the wrist is best
immobilised and radiographs repeated 2 weeks later. If there is still doubt,
isotope bone scanning or MRI scanning will confirm the diagnosis. Plaster
immobilisation is needed for at least 8 weeks; delayed union (e.g. if not healed
by about 3 months) may merit bone graft and internal fixation (Fig.
30.6). Some unstable displaced fractures probably need early internal fixation.
Distal
radius
This is commonly injured. There are broadly three groups of fracture.
• Children. Usually a
Salter Harris type 2 physeal injury, with the distal ulna sometimes fractured as
well. Manipulation and plaster fixation for a few weeks is usually adequate.
Percutaneous Kirschner wires are sometimes needed for unstable injuries.
• Young adults. Usually
a high-energy injury, with several intra-articular fragments. Perfect anatomical
reduction is most likely to give the best result; this may need a selection of
techniques, including bone graft, percutaneous wires, internal fixation and
distraction with an external fixator.
• Older adults. Typically
through osteoporotic bone in a postmenopausal female after a fairly minor fall.
This is the classic Colles’ fracture. The distal fragment is tilted dorsally
and radially; the radius is shortened because of impaction. Reduction is
easily achieved by manipulation under regional anaesthesia or haematoma block,
but slippage is common and percutaneous wires may be chosen for some.
Metacarpals
and phalanges
• Fifth metacarpal neck: usually caused by a punch (hence ‘Boxer’s
fracture’). Up to 600 of flexion at the fracture site
• Metacarpal shaft fractures: most
metacarpal fractures are stable and undis placed, and need a resting
splint for 1—2 weeks followed by careful mobilisation. If spiral, the
finger rotates (no longer points to the scaphoid tubercle along with the other
fingers when flexed into the palm); if angulated the prominent metacarpal
head can be uncomfortable when gripping. Therefore some metacarpal fractures
need manipulation and fixation with plates or percutaneous Kirschner wires.
• Phalangeal fractures: whatever the fracture and its management,
the fingers must be moved within a few days of injury to avoid stiffness. Most
phalangeal fractures are undisplaced or can be manipulated under local
anaesthetic into a stable, anatomical position. The hand is splinted and
elevated for a few days then the fractured finger is strapped to a neighbouring
finger and mobilised. If the fracture is displaced and unstable, or if
the joint surface is disrupted, accurate reduction and fixation is
needed. Rigid fixation with miniplates and screws allows early mobilisation
which prevents stiffness, but unfortunately the soft-tissue dissection required
paradoxically can cause stiffness. Therefore, percutaneous wires are generally
preferred unless open surgery is needed for reduction.
Ligaments
Carpal
instability
No tendons attach to the scaphoid, lunate or triquetral. These bones are
called the ‘intercalated segment’, and their position and stability are
controlled by the stout ligaments interconnecting them. Damage to these
ligaments, usually after a fall on the outstretched hand, causes the bones to
rotate abnormally in relation to each other (Fig. 30.7). If the scapholunate
ligament is ruptured, the lunate tilts dorsally and the scaphoid flexes forward;
on the posteroanterior radiograph the flexed scaphoid looks like a ‘ring’
and the scapholunate gap opens up. Early repair and temporary stabilisation with
wires should be considered.
Thumb
ulnar collateral ligament
The ulnar collateral ligament of the thumb metacarpophalangeal joint
is crucial for stable pinch. It can be torn when the thumb is wrenched radially
(~skier’s thumb’). A relatively stable sprain is splinted for about 3 weeks;
an unstable ligament should be repaired; often the adductor pollicis tendon is
trapped between the torn ligament and its insertion. The thumb ulnar
collateral ligament can also be stretched with chronic overuse
(‘gamekeeper’s thumb’).
Triangular
fibrocartilage complex
This important structure attaches the base of the ulnar styloid to the
ulnar side of the distal radius. It is continuous with the dorsal and palmar
capsule of the ulnar side of the wrist. The TFCC stabilises the distal
radioulnar joint. It can be torn, leading to instability of the distal
radioulnar joint and ulnar sided wrist pain. The diagnosis is confirmed by
arthrography or arthroscopy, and some tears can be repaired.
Dislocations
Peri lunate
A fall on the outstretched hand can cause the lunate to dislocate from
the surrounding carpus, or for the carpus to dislocate around the lunate. The
scaphoid may also be fractured. Median nerve compression may result. The injury
is easily missed on radiographs. Prompt reduction should be supplemented by
ligament repair and temporary Kirschner wires.
Metacarpophalangeal
joints
These can be simple, which reduce easily, or complex, which
usually need open reduction through a dorsal approach because the palmar plate
(the thickened palmar capsule) is wedged in the joint.
Bennett’s
fracture-dislocation
This unstable intra-articular fracture of the thumb carpometacarpal
joint is difficult to treat with plaster; closed reduction and percutaneous wire
fixation for 5 weeks is more reliable.
Interphalangeal
joints
These are usually easy to reduce and are stable. However, an associated
fracture of the condyles, tendon avulsion, palmar plate avulsion or collateral
ligament tear may need specific treatment.
Tendons
Mallet
finger
Forced flexion of the distal interphalangeal joint can rupture the
insertion of the long extensor tendon. There may be a bone fragment. Closed
reduction and splintage in full extension for 8 weeks is preferable to surgery
which has a high complication rate.
Flexor
tendons
Flexor tendon injuries have a poor reputation. Surgery is particularly
demanding in Bunnell’s ‘no man’s land’ — otherwise known as zone II
— between the metacarpophalangeal joint and distal interphalangeal joint where
both flexor digitorum superficialis and flexor digitorum profundus run in an
intricate, tight fibrous sheath (Fig. 30.8). The best outcome is probably with
primary repair by an experienced surgeon using special sutures under
magnification (Fig. 30.9). Rehabilitation must be meticulous to avoid either stiffness
or rupture. Various splints and mobilisation protocols have been
recommended.
Extensor
tendons
Extensor tendon injuries generally have a better outcome than flexor
tendon injuries. They usually recover well with careful primary suture and
splintage for about 4 weeks. There are two sites where special care must be
taken.
• Cuts over the proximal interphalangeal joint, if
untreated, can lead to a ‘boutonniere’ (buttonhole) deformity because the
central slip no longer extends the proximal joint whilst the remaining extensor
mechanism hyperextends the distal joint and flexes the .proximal joint. Early
repair and splintage is therefore important.
• Cuts over the metacarpophalangeal joint, especially
following
a punch, usually enter the joint and must be thoroughly cleaned.
Fingertip
injuries
The choice of treatment depends on the type of injury, as well as the
patient’s occupation, hobbies and cosmetic demands. Many fingertip injuries
will heal when left alone beneath a semi permeable dressing. If more than
1 cm2 of skin is lost, a skin graft will speed up the overall
time to healing. If the pulp is lost and bone exposed then many techniques are
available
Replantation
With microsurgical techniques, it is sometimes both possible and
advisable to replant amputated parts (Fig. 30.11).
Replantation
Indications:
• Thumb
• Single digits in children
• Single digits at distal interphalangeal joint level
• Multiple digits
• Hand, wrist, forearm
• Single digits in adults
• Crushed, mangled or avulsed parts
• Poor general condition of patient
• Long warm ischaemic time