Emergency Medicine

294 Orthopaedic Emergencies

INJURIES TO THE WRIST AND HAND

4 Give the patient a high-arm sling and refer to the next fracture clinic.

5 The scaphoid has a critical role in the proximal carpal row and is important

in maintaining radiocarpal stability.

(i) Orthopaedic review is essential to reduce complications and

potential loss of function, as well as to exclude a possible missed

injury such as scapholunate dissociation, radial styloid fracture,

or even a Bennett’s fracture of the base of the thumb metacarpal.

(ii) Delayed complications of scaphoid fracture include avascular

necrosis, non-union and osteoarthritis, which result in pain and

loss of wrist function.

Dislocations of the carpus

DIAGNOSIS

1 Dislocations of the carpus are uncommon, and are caused by a fall on the

outstretched hand. Two important types are seen:

(i) Dislocation of the lunate: the distal carpal bones and hand

maintain their normal alignment with the radius, but the lunate

is squeezed out anteriorly, like a pip.

(ii) Perilunate dislocation of the carpus: the lunate maintains its

alignment with the radius, but the distal carpal bones and the

hand are driven dorsally

(a) a displaced fracture through the scaphoid is often present.

2 Test for median nerve compression in dislocation of the lunate, causing loss

of sensation in the radial three-and-a-half digits and weakness of abductor

pollicis.

3 Request X-rays t hat a re ea sy to m isi nter pret a s ‘nor ma l ’ i n lu nate d isloc at ion,

but look particularly for:

(i) The normal curved joint space between the distal radius and the

scaphoid and lunate is disrupted on the anteroposterior view, so

the lunate looks triangular instead of quadrilateral.

(ii) The dislocated lunate lies anteriorly on the lateral view, in the

shape of the letter ‘C’.

MANAGEMENT

1 Refer all cases immediately to the orthopaedic team, particularly if median

nerve compression is found.

Fractures of the other carpal bones

DIAGNOSIS

1 These fractures are rare, and include fractures of the capitate, triquetral,

hook of hamate and pisiform bones.