With regards to recognising soft-tissue hand injuries the clinician needs to be aware of:
Tendon rupture
Tendon rupture may occur without overlying skin laceration.
Tendons may rupture internally due to the following:
Nerve injury
Nerve injury is an important consideration in all hand injuries.
Sensory loss following a proximal crush injury or closed fracture suggests ongoing nerve compression and may require surgical decompression.
Sensory loss in relation to a hand laceration is a sign of nerve division and requires surgical exploration.
Temporary nerve malfunction may occur in a closed injury due to mechanical trauma (neuropraxia). Serial examinations by the same observer may be useful in distinguishing neuropraxia from progressive compression neuropathy in the hand.
Two-point discrimination is the most reliable test for sensory examination of the hand [2-3]. A paper clip is usually adequate to perform this test. It can be performed as either a static or a dynamic examination. The patient should be asked to close or avert their eyes to remove any visual compensation.
The static two-point discrimination test is performed using progressively narrowing prongs from a starting point of 8 mm.
In the moving examination the prongs are moved progressively proximally to distally – across the finger being examined.
Two-point discrimination of greater than 6 mm static or 4 mm moving is abnormal [2-3].
Normal skin is slightly moist. The absence of sweating in the skin of the hand or fingers is a sign of nerve injury due to loss of sympathetic innervation. The body of a pen glides smoothly across such dry skin but not across slightly moist normal skin (pen test) [4].
Open hand injuries
In open hand injuries when the deep fascia or palmar aponeurosis are breached, clinical examination alone is unreliable, as it cannot exclude the presence of non-radio-opaque foreign bodies, or partial injuries of tendons or nerves. (Fig 3)
Adjuncts like radiographs and examination under anaesthesia may be helpful. In these circumstances, evaluation of the hand may include formal surgical exploration with tourniquet control to exclude or treat the underlying injury, wound closure, followed by early rehabilitation. Such injuries are best managed under the care of a specialist hand surgeon.