Dorsal approach to the wrist

Introduction

The dorsal approach to the wrist provides excellent visualization of all extensor tendons crossing the dorsal surface of the wrist. It also offers access to the dorsal side of the wrist joint itself, the dorsal carpus, and the dorsal surface of the proximal ends of the middle metacarpals.

Indications

The dorsal approach to the wrist can be used for several procedures, including:

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

Patient Positioning

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

Landmarks and Incision

Landmarks

1. Radial styloid process
2. Ulnar styloid process

Incision

• Make an 8 cm longitudinal incision on the dorsum of the wrist, crossing the wrist midway between the radial and ulnar styloids.
• The incision begins 3 cm proximal to the wrist and ends approximately 5 cm distal to it. It can be extended if necessary.

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

Internervous Plane

• There is no true internervous plane for the dorsal approach to the wrist, as both the extensor carpi radialis longus and extensor carpi radialis brevis muscles are supplied by the radial nerve.
• Dissection is performed 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, which covers the tendons in the six compartments on the dorsum of the wrist.

Deep Dissection

• Incise the extensor retinaculum over the extensor digitorum communis and extensor indicis proprius (fourth compartment).
• Mobilize the tendons radially and ulnarly to expose the underlying radius and joint capsule.
• Incise the joint capsule longitudinally along the dorsal radius and carpus.
• Continue the dissection beneath 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 utilize an internervous plane.
• However, it can be extended to expose the distal half of the dorsal aspect of the radius 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

Structures at risk during a dorsal approach to the wrist include:

• Radial nerve (superficial radial nerve):
  • The superficial radial nerve emerges from beneath the brachioradialis tendon just proximal to the wrist and then courses to the dorsum of the hand.
• Dorsal cutaneous branches:
  • Supplied by both the radial and ulnar nerves.
  • Located within the subcutaneous fat.
  • Injury can lead to painful neuromas.
• Radial artery:
  • The radial artery runs laterally across the wrist.
  • This can be avoided by performing dissection beneath the periosteum.
• Interosseous ligaments:
  • Injury to the interosseous ligaments can destabilize the carpus.
  • This can be avoided by raising flaps.
• Devascularization of the scaphoid:
  • This can be avoided by not disrupting the capsular attachment to the dorsal scaphoid ridge.

References

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