Hand and finger tendon injuries

Flexor

Background

• Hand surgeon should repair all flexor tendon lacerations
• Primary repair should occur w/in 12hr; secondary repair can occur up to 4wk after injury

Zones

1. Zone I
   1. Extends from insertion of flexor digitorum profundus to superficialis
   2. Loss of flexion at DIP joint
   3. Retrieval of proximal tendon is often difficult
2. Zone II
   1. Portion of digital canal occupied by both flexor digitorum super. and profundus tendons
   2. Close proximity of these tendons makes exact repair essential
   3. Partial lacerations are more common in this zone than complete injuries
3. Zone III
   1. Extends from distal edge of the carpal tunnel to the proximal edge of the flexor sheath
   2. Outcomes are generally favorable
4. Zone IV
   1. Involves the carpal tunnel and related structures
   2. Area must be explored carefully as many vital structures traverse this region
   3. Isolated injuries are the exception
5. Zone V
   1. Proximal to the carpal tunnel
   2. Injuries tend to be severe and often involve multiple tendons/median and ulnar nerves

Extensor

Background

• Most common site of tendon injuries b/c of superfical location on dorsum of hand

Images

• Flexor Zones

• Extensor Zones