1. Pain due to neuroma formation following transection of the palmar cutaneous branch (PCB) of the median nerve

a) branches of PCB may cross interthenar crease

b) avoid using magnification and making incisions lightly to the ulnar side of interthenar crease

c) treated by ligating this branch where it originates from the median nerve in the forearm (results in a small area of numbness at the base of the thenar eminence)

2. neuroma of the dorsal sensory branch of the radial nerve

a) caused by extending the incision proximally and radially

b) maybe treated by neurolysis of neuroma

3. Injury to the recurrent motor branch of the median nerve

a) anomaly may cause the nerve to lie above or to pierce TCL

b) avoided by: staying to the ulnar side of the midline

4. direct injury to the median nerve

5. volar displacement and entrapment of median nerve in healing edges of TCL

6. hypertrophic scar causing compression of the median nerve

a) usually caused by an incision crossing the wrist perpendicular to the flexion crease

b) avoid by not crossing flexion crease,or in cases where necessary(e.g.,in releasing Guyon’s canal entrapment of the ulnar nerve, in tenosynovectomy for rheumatoid arthritis, or in dealing with an anomalous superficialis or palmaris muscle) by crossing wrist obliquely at 45° angle directed toward the ulnar side

7. failure to improve symptoms

a) incorrect diagnosis: if EMG or NCV is not done pre-op, they should be done after surgical failure (to R/O e.g., cervical root involvement [look for posterior myotome involvement], or genneralized peripheral neuropathy)

b) incomplete transection: the most common cause for failure if the diagnosis is correct(also the possibility of accessory ligament or fascial band proximal to TCL in cases where the division was complete). When this is identified on re-exploration, 75% of patients will be cured or improved after division is completed

8. joint stiffness: caused by excessively long immobilization of wrist and fingers

9. injury to superficial palmar arch (arterial): usually results from “blind” distal division of TCL

10. bowstringing of flexor tendons

11. complex regional pain syndrome AKA reflex sympathetic dystrophy: exact incidence is unknown, reported in 4 of 132 patients in one series (probably too high, most surgeons will see only one or two cases in their career). Treatment with IV phentolamine has been suggested, but most cases are self-limited after ≈ 2 weeks

12. infection: usually causes exquisite tenderness

13. hematoma: also usually quite painful and tender