Carpal Tunnel Syndrome Flashcards
What are the borders of the carpal tunnel?
The carpal tunnel is formed by two layers, the deep carpal arch and the flexor retinaculum.
Formed laterally by scaphoid and the trapezium tubercule
Formed medially by psiform and the hook of hamate.
The roof is the flexor retinaculum.
What are risk factors for carpal tunnel syndrome
Pregnancy, obesity, females, previous injury to wrist. DM, RA,
Symptoms and clinical signs
Pain numbness and parasthesia over median nerve distrubution. Pain typically worse at night.
Weakness of thumb abduction. Wasting of thenar eminence. Ape Hand.
Tinnels and phalens test. durkans sign.
Managment of carpal tunnel syndrome
Night splint.
Hand physiotherapy.
Corticosteroid injections.
Activity modification
NSAIDS
What are risks of carpal tunnel syndrome?
Pain, infection, bleeding, scarring
Damage to nerves
Damage to palmar cutaneous nerve (altered sensation over palm)
Damage to median nerve
Damage to vessels
Superficial palmar arch
Pillar pain
Ongoing lack of function
Ongoing compressive symptoms
Recurrence
Further surgery
Complex regional pain syndrome
What are the differentials of carpal tunnel syndrome
Pronator teres impingment.
C6 Radiculopathy
What is the kaplan criteria
(1) age over 50 years,
(2) duration greater than 10 years,
(3) constant paresthesia,
(4) stenosing flexor tenosynovitis,
(5) positive Phalen’s test in less than 30 seconds.
How would you expose
Mark incision
Using Kaplan’s cardinal line + line along the radial border of the ring finger
Extend line downwards to proximal wrist crease
Then follow incision lines down to subcutaneous fat
Superficial dissection
Dissect through subcutaneous fat
Insert a West retractor to keep tissues under maximal tension
Expose and dissect through palmar fascia
Deep Dissection
Expose the transverse carpal ligament
Make a small incision through the ligament
Then insert a Macdonald underneath ligament to protect median nerve
Describe how the nerves of the hand
Recurrent motor branch affected)
Is affected as given off AFTER the carpal tunnel
Get weakness to the LOAF muscles (Radial 2 Lumbricals, Opponens Pollicis, APB. Flexor Pollicis Brevis)
Digital Branches
Affected - get numbness / paraesthesia to radial 3.5 digits
Palmar Cutaneous Branch
NOT affected
Branches from median nerve around 5cm proximal to carpal tunnel
Supplies skin over thenar eminence - which is then preserved
What is important to ask in History of carpal tunnel syndrome
Site, onset, worse at night, aggrevating symptoms. Parasethesia, change in hands they have notcied. Weakness in hand.
PMH: Diabetes, hypothyroidism, are they pregnant, RA
Social Hx: Smoke, hand dominance, occupation
What would you look for in carpal tunnel syndrome?
Look: Wasting, scarring, obvious deformity
Feel: NV Status of hand, change in muscle bulk,
Move: Check ROM in hand, test strength of median nerve thumb abduction.
Tinels: Taping over area of carpal tunnel reproduces the pain and tingling, tap on the palm in between the pisiform and the tubercle of the trapezium
Phalens Test: Upside down Prayer sign, reproduce symptoms
Durkans test: Compress over area of carpal tunnel
