Volar Approach to the Wrist

The uses of the volar approach to the wrist include:

1. Decompression of median nerve.
2. Flexor tendon synovectomy.
3. Carpal tunnel tumor excision.
4. Carpal tunnel nerve and tendon repair.
5. Drainage of sepsis tracking up from the mid-palmar space.
6. Open reduction and internal fixation (ORIF) of fractures and dislocations of the distal radius and carpus.
   • Especially volar lip fractures of the radius.

• Place the patient supine on an operating table
• Supinate the arm and place it on arm board with palm facing up.

• Landmark:
  1. Thenar crease.
  2. Transverse skin crease .
  3. Tendon of the palmaris longus muscle .
• Incision:
  • Make incision just ulnar to the thenar crease in hand and ulnar to palmaris longus in wrist:
    • Begin 4cm distal to flexion crease.
    • Make ulnar curve so you don’t cross perpendicular to flexion crease.
      • also helps protect palmar cutaneous branch.
    • End 3 cm proximal to flexion crease.

• • There is No true internervous plane for the volar approach to the wrist.
  • No muscles are transected:
    • Abductor pollicis brevis and palmaris brevis fibers that cross the midline can occasionally be dissected.
  • True anatomic dissection:
    • Major nerves identified, dissected out and preserved.
    • Plane of dissection between median nerve and flexor carpi radialis tendon.

• Incise skin flaps,
• Incise fat,
• Section fibers of superficial palmar fascia in line with incision,
• Retract curved flaps medially to expose insertion of palmaris longus into flexor retinaculum,
• Retract palmaris longus tendon toward ulna to expose median nerve between palmaris longus and flexor carpi radialis tendon,
• Pass a blunt object between median nerve and flexor retinaculum.
• Incise entire length of retinaculum / transverse carpal ligament on ulnar side of the nerve.

• Identify motor branch of the median nerve (anterolateral side of the median nerve as it emerges from carpal tunnel).
• If require access to volar aspect of wrist joint:
  • Mobilize median nerve and retract radially (so you don’t stretch motor branch).
  • Mobilize and retract flexor tendons.
  • Incise base of carpal tunnel longitudinally.
• The most convenient approach for access to the volar aspect of the distal radius is the distal portion of the volar approach to the radius .

• Proximal Extension:
  • The volar approach to the wrist can be extended to expose the median nerve.
  • To accomplish this:
    • extend the skin incision proximally, running it up the middle of the anterior surface of the forearm.
    • Incise the deep fascia of the forearm between the palmaris longus and flexor carpi radialis muscles.
    • Retract the flexor carpi radialis in a radial direction and the palmaris longus in an ulnar direction, exposing the muscle belly of the flexor digitorum superficialis muscle in the distal two thirds of the forearm.
    • The median nerve adheres to the deep surface of the flexor digitorum superficialis, held there by fascia.
    • Thus, if the flexor digitorum superficialis is reflected, the nerve goes with it.
• Distal Extension:
  • The volar approach to the wrist can be extended into a volar zigzag approach for any of the fingers, providing complete exposure of all the palmar structures (Volar Approach to the Flexor Tendons).

• The structures at risk during the volar approach to the wrist include:
  1. Palmar cutaneous branch of median nerve:
     • Arises 5 cm proximal to wrist joint.
     • Runs ulnar to flexor carpi radialis tendon before crossing flexor retinaculum.
     • Greatest risk if the skin incision is not angled to the ulnar side of the forearm .
  2. Motor branch of median nerve:
     • Significant anatomic variation.
     • Risk to nerve minimized if incision through retinaculum made ulnar to median nerve.
  3. Superficial palmar arch:
     • Crosses palm at level of distal end of outstretched thumb.
     • In danger if flexor retinaculum blindly cut (can go too far distally)
     • Avoid injury if retinaculum is cut under direct observation for its entire length.

• Surgical Exposures in Orthopaedics book - 4th Edition
• Campbel's Operative Orthopaedics book 12th