Operative steps
- Infiltrate the area with 5mls of 1% lidocaine with adrenaline.
- Incision
- The midpoint of the incision should be at the intersection of Kaplan cardinal line and radial border of 4th ring finger.
- The Kaplan cardinal line is a line drawn between the apex of the 1st web space to the pisiform.
- The incision should extend to the transverse palmar crease distally
- Don’t extend the proximal extent beyond the volar wrist crease.
- The midpoint of the incision should be at the intersection of Kaplan cardinal line and radial border of 4th ring finger.
- Dissection into the carpal tunnel
- Deepen the incision through the longitudinal fibers of the Palmar aponeurosis to expose the transverse fibers of the flexor retinaculum.
- Use a West retractor
- Incise the flexor retinaculum to expose the median nerve
- Pass a McDonald dissector below the flexor retinaculum while the remaining transverse fibers are divided.
- Ensure the proximal retinaculum has been released
- Close skin 4/0 nylon
Complication
- Pillar pain - achy pain in palm
- Massage and hand therapy
- Ulner nerve
- Median nerve damage
Nerves at risk during a carpal tunnel release
- Palmar cutaneous branch of median nerve - enters palm superficial to retinaculum.
- Recurrent branch of median nerve - comes off median nerve distal to flexor retinaculum, curls proximally around distal border of retinaculum to supply the thenar eminence.
