0071643192.pdf

ORTHOPEDICS

MECHANISM

FOOSH

DIAGNOSIS

Suspect diagnosis if there is tenderness over middorsum of the wrist, worse

with axial compression of the middle finger. X-rays are often negative in acute

injury.

TREATMENT

Thumb spica, referral

COMPLICATIONS

Kienbock’s disease(avascular necrosis of the lunate)

SCAPHOLUNATEDISSOCIATION

The most common carpal ligamentous wrist injury, typically resulting from

an acute tear of the scapholunate ligament

MECHANISM

FOOSH is most common, though may result from chronic overuse

DIAGNOSIS

■ Signet ring sign on AP radiograph: Loss of ligamentous support results in

rotary subluxation and palmar tilt of the scaphoid, causing the circular

cortex to appear as a ring.

■ Terry Thomas sign(widening of the scapholunate joint space) on AP X-ray

(see Figure 4.4): Terry Thomas was a comedian with a large space between

his two front teeth. The space between the scaphoid and lunate is normally

the same as between the other carpal bones (< 2 mm).

TREATMENT

Radial gutter splint and orthopedic consultation

COMPLICATIONS

May be associated with lunate and perilunate dislocations

LUNATEDISLOCATION

MECHANISM

FOOSH (of significant force, eg, fall from height) with wrist hyperextension

and disruption of carpal ligaments

DIAGNOSIS

X-ray findings include the spilled teacup sign(lateral view) and piece-of-pie

sign(AP view)(lunate normally has a quadrangular shape on AP X-ray but

when dislocated, it looks triangular; see Figure 4.5).

FIGURE 4.4. Scaphol-

unate dissociation.