Volar Approach to the Wrist
The uses of the volar approach to the wrist include:
- Decompression of median nerve.
- Flexor tendon synovectomy.
- Carpal tunnel tumor excision.
- Carpal tunnel nerve and tendon repair.
- Drainage of sepsis tracking up from the mid-palmar space.
- 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:
- Thenar crease.
- Transverse skin crease .
- 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.
- Make incision just ulnar to the thenar crease in hand and ulnar to palmaris longus in wrist:
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- 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:
- 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 .
- Motor branch of median nerve:
- Significant anatomic variation.
- Risk to nerve minimized if incision through retinaculum made ulnar to median nerve.
- 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.
- Palmar cutaneous branch of median nerve:
- Surgical Exposures in Orthopaedics book - 4th Edition
- Campbel's Operative Orthopaedics book 12th