Dorsal Approach to the Wrist

The dorsal approach to the wrist provides excellent exposure of all the extensor tendons that pass over the dorsal surface of the wrist. It also allows access to the dorsal aspect of the wrist itself, the dorsal aspect of the carpus, and the dorsal surface of the proximal ends of the middle metacarpals.

The dorsal approach to the wrist uses include the following:

1. Synovectomy and repair of extensor tendons.
2. Wrist fusion.
3. Posterior interosseous nerve (PIN) neurectomy.
4. Excision of lower end of the radius.
5. Proximal row carpectomy.
6. Proximal pole scaphoid fractures.
7. Open reduction and internal fixation of the distal radius fractures (displaced intra-articular dorsal lip fractures).
8. Open reduction and internal fixation of the carpal fractures and dislocations.

Position of the Patient

• Place the patient supine on the operating table.
• Pronate the forearm and put the arm on an arm board.

Landmarks and Incision

• Landmarks:
  1. The radial styloid.
  2. The ulnar styloid.
• Incision:
  • Make an 8-cm longitudinal incision on the dorsal aspect of the wrist, crossing the wrist joint midway between the radial and ulnar styloids.
  • The incision begins 3 cm proximal to the wrist joint and ends about 5 cm distal to it. It can be lengthened if necessary.

Because the skin on the dorsum of the wrist is pliable and redundant, the incision does not cause a contracture of the wrist joint, even though it crosses a major skin crease at right angles.

Internervous plane

• There is no true internervous plane for the dorsal approach to the wrist, because both the extensor carpi radialis longus muscle and the extensor carpi radialis brevis muscle are supplied by the radial nerve.
• Dissection is carried out between the third and fourth extensor compartments of the wrist.

Superficial dissection

Incise the subcutaneous fat in line with the skin incision to expose the extensor retinaculum that covers the tendons in the six compartments on the dorsal aspect of the wrist.

Deep dissection

• Incise extensor retinaculum over the extensor digitorum communis and extensor indicis proprius (fourth compartment).
• Mobilize tendons radially and ulnarly to expose the underlying radius and joint capsule.
• Incise the joint capsule longitudinally on the dorsal radius and carpus.
• Continue dissection below the capsule (dorsal radiocarpal ligament) toward the radial and ulnar sides of the radius to expose the entire distal radius and carpal bones.

Approach Extension

• Proximal Extension:
  • The dorsal approach to the wrist cannot be extended proximally to expose the rest of the radius, because it does not make use of an internervous plane.
  • It can be extended to expose the distal half of the dorsal aspect of the radius, however, by retracting the abductor pollicis longus and extensor pollicis brevis muscles, which cross the operative field obliquely.
• Distal Extension:
  • To expose the entire dorsal surface of the metacarpals, extend the incision distally and retract the extensor tendons (This type of extension is rarely used in practice).

Dangers

The structures at risk during dorsal approach to the wrist include:

• Radial nerve (superficial radial nerve):
  • The superficial radial nerve emerges from beneath brachioradialis tendon just above the wrist joint before traveling to dorsum of the hand.
• Dorsal cutaneous branches:
  • It is supplied by both radial and ulnar nerves.
  • Lies in subcutaneous fat.
  • Its Injury may lead to painful neuromas.
• Radial artery:
  • The Radial artery crosses wrist joint laterally.
  • It can be avoided by maintaining dissection below the periosteum.
• Interosseous ligaments:
  • Interosseous ligaments injuries can destabilize carpus.
  • It can be avoid by raising flaps.
• Scaphoid devascularization:
  • It can be avoid by not detaching capsular attachment on dorsal ridge of scaphoid.

References

• Surgical Exposures in Orthopaedics book – 4th Edition
• Campbel’s Operative Orthopaedics book 12th