Carpal Tunnel Release

1. Tourniquet and exsanguinator
2. Local or GA
3. Position arm on table supine
4. Incision well to the ulnar side of the thenar crease;
- extends from distal wrist crease to point in line with distal level of outstretched thumb
- can extend past the wrist creases (helpful in obese patients)
- this site keeps off the branches of palmar cutaneous branch of the median nerve.
- may see large branches off ulnar nerve; can protect.
- at this point the median nerve is well protected medially under flexor retinaculum and will be out of way of healing fascia wound.
5. Spread apart subcutaneous fat with scalpel or scissors to expose the  flexor retinaculum (aka transverse carpal ligament)
- use only bipolar diathermy (nerve)
- will go through 2 layers of fascia: palmar aponeurosis before the flexor retinaculum / transverse carpal ligament.
6. Define distal end point of release; V between thenar and hypothenar muscles (which arise from the flexor retinaculum)
- a little soft yellow fat at this location is a helpful landmark
- avoid the palmar arch (ulnar a meets superficial palmar branch of radial); 1-2cm beyond end of flexor retinaculum
7. Now open flexor retinaculum with a scalpel
- will see a different greyish colour as the carpal tunnel is entered
- gentle extend sharp incision (no plunging) distally to distal landmark
8. Insert a nerve protector to protect components as contents opened.
9. Swap sides and extend incision further with careful scissor action to proximal extent; pulling flexor retinaculum distally.
- about level of wrist; will know when its done as abrupt fall-off of fascia.
- if in doubt extend incision across release; want it safe and complete
10. Close with vertical mattress sutures and apply marcain