Carpal Tunnel Syndrome

Question 1

Contents of Carpal tunnel

Answer 1

• Median nerve
• 4 tendons of FDP and FDS
• Flexor pollucis longus

Question 2

Boundaries of carpal tunnel

Answer 2

• Laterally - trapezium
• Medially - hamate
• Superior - flexor retinaculum
• Floor - carpal groove
• Attachements of flexor retinaculum - scaphoid, hamate, trapezium, pisiform

Question 3

Muscles that the median nerve innervates in hand and forearm

Answer 3

Forearm:
* Pronator teres
* Flexor carpis radialis
* Palmaris longus
* Flexor digitorum superficialis
* Flexor digitorum profundus (median nerve portion)

Hand = LOAF
* Lateral 2 lumbricles
* Opponens pollucis
* Abductor pollucis brevis
* Flexor pollucis brevis

Question 4

What is Tinels test

Answer 4

• Tapping/perucssion over median nerve under flexor retinaculum
• If tingling/pain during = +ve

Question 5

Phalens test

Answer 5

• Flex wrist at 90 degree angle
• 30-60s
• If causes tingling/pain = +ve

Question 6

What is hand of benediction?

Answer 6

• Appears when trying to make fist
• Caused by median nerve injury/entrapment at elbow or wrist
• Flexed ring and little finger but others extended
• Due to lateral FDP and 2 lumbricles paralysed

Question 7

RF for carpal tunnel syndrome

Answer 7

• Female
• Increasing age
• Obesity
• Previous wrist surgery

Conditons: diabetes, hypothyroidism, RA, pregnancy

Question 8

First line treatment for carpal tunnel syndrome

Answer 8

• Wrist splint - esp at night
• Hand therapy - exercises
• Corticosteroid injections
• NSAIDs? - evidence limited

Question 9

Surgery for carpal tunnel

Answer 9

• If still symptomatic despite conservative management:
• Carpal tunnel release surgery - decompress via cutting through flexor retinaculum

Question 10

If patient cannot oppose thumb after carpal tunnel surgery, which nerve has been damaged?

Answer 10

• Recurrent branch - median nerve
• Supplies LOAF

Question 11

Presentation carpal tunnel

Answer 11

• Pain/numbness/parasthesia in median nerve territory
• Palm spared - palmar cutaenous branch branches proximal and passess over flexor retinaculum
• Worse at night
• Relieved by hanging affected arm over bed or shaking it

Question 12

Later stages carpal tunnel signs

Answer 12

• Weakness thumb abduction - denervation atrophy of thenar muscles
• Wasting thenar eminence

Question 13

Differentials for carpal tunnel

Answer 13

• Cervical radiculopathy - C6 but will have neck pain
• Pronator teres syndrome - median nerve squished by muscle - will extend to proximal forearm, sensation in palm reduced
• Flexor carpi radialis tenosynovitis - tenderness at base of thumb

Question 14

Complications of CTS

Answer 14

• Recurrence
• Persistent symptoms
• Infection
• Scar formation
• Nerve damage
• Trigger thumb