43. Fractures of the carpal, metacarpal bones and phalanges

Scaphoid fractures

Definition

• Scaphoid fractures are the most common carpal fractures and tend to occur in younger, active individuals.
• They account for 2% to 7% of all fractures and 60% to 70% of carpal bone fractures

Etiology

• Fall onto an outstretched hand
• Axial loading of the wrist in forced hyperextension and radial deviation can cause the fracture as the scaphoid impacts on the dorsal rim of the radius.
• Contact sports
• Road traffic accidents
• Tumours (uncommon)
• Infections (uncommon)

Symptoms

• Pain and swelling at the base of the thumb
• Pain is often centered on the radial side of the wrist and is worse with movement
• Restricted range of motion of wrist
• Tenderness
• Inability to perform daily activities
• Bruising
• Weakness

Physical exam

• Examination of the wrist should follow the “look, feel, move” pattern
• It is important to palpate over the distal radius and ulna and metacarpals to assess for any associated injury
• Classically, there is tenderness in the anatomic snuffbox dorsally
• There may also be tenderness over the scaphoid tubercle on the volar aspect
• Scaphoid compression test- involves placing the examining index finger and thumb over each pole of the scaphoid and compressing.
• This maneuver is likely to elicit pain in the presence of a fracture

Lab tests/Diagnosis

• PA and lateral X-rays
• CT
• MRI

Treatment

• Non operative- immobilization in a hand plaster splint for 10 days
• Surgical- cannulated screws and Herbert’s screw are used
• Complications
• Avascular necrosis
• Non-union
• Delayed union
• Scapholunate dissociation