Emergency Medicine

300 Orthopaedic Emergencies

INJURIES TO THE WRIST AND HAND

Flexor tendon injuries in the hand

DIAGNOSIS

1 These injuries occur from direct laceration or blunt injury.

2 Assess for a f lexor tendon injury:

(i) Flexor digitorum profundus causes flexion at the distal

interphalangeal joint.

(ii) Flexor digitorum superficialis causes flexion of the finger at the

proximal interphalangeal joint, while the neighbouring fingers

are held extended.

(iii) Suspect a partial tendon division from pain or reduced function

against resistance.

MANAGEMENT

1 Refer every suspected f lexor tendon injury directly to the orthopaedic team.

2 Give tetanus prophylaxis for a penetrating wound.

Extensor tendon injuries in the hand

DIAGNOSIS

1 Injury can occur by:

(i) Direct laceration.

(ii) Avulsion of the middle slip of the extensor tendon that inserts

onto the middle phalanx.

(iii) Avulsion of the distal slip of the extensor tendon that inserts onto

the distal phalanx.

2 Assess for an extensor tendon injury:

(i) Avulsion of the distal insertion causes a ‘mallet-finger’ deformity.

The patient is unable to extend the distal interphalangeal joint

with the middle phalanx held.

(ii) Avulsion of the middle slip that inserts onto the middle phalanx

may be missed

(a) initially, the proximal interphalangeal joint can be extended

by the two lateral bands, but as they displace into a volar

direction, they then begin to act as flexors

(b) finally, the proximal interphalangeal joint becomes flexed

and the distal interphalangeal joint hyperextended, resulting

in the boutonnière deformity.

3 Request an X-ray to show an associated f lake fracture of avulsed bone.

MANAGEMENT

1 Refer a lacerated tendon or middle slip avulsion immediately to the ortho-

paedic team.