Dorsolateral approach to the wrist

The dorsolateral approach to the wrist provides excellent and safe exposure of the scaphoid bone. This approach places the superficial branch of the radial nerve at risk and can also compromise the dorsal blood supply to the scaphoid.

Indications for the Dorsolateral Approach

The dorsolateral approach to the wrist is used for several key procedures, including:

1. Bone grafting for scaphoid nonunion.
2. Excision of the proximal fragment of a ununited scaphoid.
3. Excision of the radial styloid process, often combined with one of the procedures listed above.
4. Open reduction and internal fixation (ORIF) of scaphoid fractures. For this indication, this approach is frequently combined with a volar approach to the scaphoid.

Patient Positioning

• Place the patient supine on the operating table with the arm extended on an arm board.
• Pronate the forearm to expose the dorsoradial side of the wrist, then apply a blood-absorbing dressing and a tourniquet.

Landmarks and Incision

Landmarks

• Radial styloid process
• Anatomical snuffbox
• First metacarpal bone

Incision

• Make a gently curved, S-shaped incision centered over the anatomical snuffbox.
• The incision should extend from the base of the first metacarpal bone to a point approximately 3 cm proximal to the snuffbox.

Internervous Plane

There is no true internervous plane for the dorsolateral approach to the wrist. The dissection plane lies between the tendons of the extensor pollicis longus (EPL) and extensor pollicis brevis (EPB) muscles, both of which are innervated by the posterior interosseous nerve.

• Because both muscles receive their nerve supply far proximal to this dissection, using this plane will not result in denervation.

Superficial Dissection

• Identify the tendons of the extensor pollicis longus (dorsal) and extensor pollicis brevis (ventral).
• Open the fascia between the two tendons, taking care not to cut the sensory branch of the superficial radial nerve, which lies superficial to the EPL tendon.
• Separate the tendons by retracting the EPL dorsally and toward the ulna, and the EPB ventrally.
• Identify the radial artery as it crosses the lower edge of the wound, lying on the bone.
• Locate the tendon of the extensor carpi radialis longus as it lies on the dorsum of the wrist.
• Mobilize this tendon and retract it dorsally and ulnarward together with the EPL tendon to expose the dorsoradial aspect of the wrist.

Deep Dissection

• Incise the wrist capsule longitudinally.
• Retract the capsule dorsally and volarly to expose the articulation between the distal end of the radius and the proximal end of the scaphoid.
• The radial artery will retract radially and volarly with the joint capsule.
• Bring the wrist into ulnar deviation and continue to elevate the capsule off the scaphoid to fully expose the joint.
• Preserve as many soft tissue attachments to the bone as possible. Modern guide systems have significantly reduced the need for radial dissection during ORIF of scaphoid fractures.

Approach Extension

There is no extensile option for the dorsolateral approach to the wrist.

Dangers

Structures at risk during the dorsolateral approach to the wrist include:

• The superficial radial nerve:
  • It lies directly over the extensor pollicis longus tendon.
  • It is very easy to cut when mobilizing the tendon.
  • Cutting the nerve can lead to a painful neuroma.

References

• Book "Surgical Exposures in Orthopaedics" – 4th Edition
• Campbell's Operative Orthopaedics, 12th Edition