EMQs in Clinical Medicine.pdf - Peshawar Medical College

132 Orthopaedics and rheumatology
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The anatomical snuffbox (ASB) is a triangular depression best seen when
the thumb is extended. It is bounded anteriorly by the tendons abductor
pollicis longus and extensor pollicis brevis, and posteriorly by the tendon
of the extensor pollicis longus. The scaphoid and trapezium lie at the base
of the ASB. The radial styloid process and the base of the first metacarpal
can be felt proximally and distally to the floor respectively. The radial
artery and a superficial branch of the radial nerve cross the ASB.
Pain and swelling at the ASB after injury to the arm/hand suggest fracture
of the scaphoid.
If there is high clinical suspicion of fractured scaphoid, but no positive
radiological findings, a plaster cast may be applied and a radiograph
repeated 2 weeks later (the fracture may become more clear on the radiograph
later).
A 68-year-old woman presents with fracture at distal radial head
with dorsal displacement of distal fragment after a fall.
A displaced Colles’ fracture is sometimes described as exhibiting a
‘dinner-fork’ deformity. This injury is more common in older women
where osteoporosis has increased the susceptibility to fracture. A Smith’s
fracture is a form of ‘reverse’ Colles’ fracture where the radial fragment is
angled forwards. These fractures are rare and often unstable, requiring
internal fixation.
A 7-year-old boy presents with a swollen painful elbow after a fall.
He is unable to move the arm because of the pain.
This injury is more common in children after a fall on the outstretched
hand. It is imperative to look for any signs of damage to the brachial
artery. The elbow should be kept extended to avoid arterial damage.
Displaced fractures are surgical emergencies and treated by reduction
under general anaesthesia.
A 19-year-old rugby player falls on a backward stretched hand and
presents with loss of shoulder contour and absent sensation on a
patch below the shoulder.
The loss of sensation results from damage to the axillary nerve. On a
radiograph the humeral head lies anterior and inferior to the glenoid. The
shoulder can be reduced with the Kocher’s manoeuvre. The elbow is
flexed to 90° and traction applied. The arm is slowly externally rotated
to about 90°, brought across the chest and then finally internally rotated.
A 40-year-old woman presents after a fall on an outstretched hand
with wrist drop.
The radial nerve is susceptible to injury with fracture of the humeral
shaft as it winds around the humerus in the spiral groove.