Surgical Recall 69 – Hand Surgery

Bones of the hand?
Metacarpal bones
Carpal bones

What is the tip of the finger joint?
Distal InterPhalangeal joint (DIP)

What is the middle finger joint?
Proximal InterPhalangeal joint (PIP)

What is the knuckle joint?
Metacarpal Phalangeal joint (MP)

What are the intrinsic hand muscles?
Interosseous muscles

What is adduction and abduction of the fingers?
ADDuction is to the midline
ABDuction is away from the midline

What are the trauma zones of the hand?
Zone 1 – beyond PIP
Zone 2 – MP to PIP
Zone 3 – Thumb crease to MP
Zone 4 – Lower half of the palm
Zone 5 – Palmer crease and proximal

Where is “no man’s land”? Significance?
Zone 2 – distal palmer crease to just beyond the PIP joint
Flexor tendon injuries here have a poor prognosis – expert is needed to repair

What is the ulnar nerve distribution?
Half of ring finger and medial

What is the radial nerve distribution?
Back of hand, half of ring finger and lateral, NOT including tips of fingers
Lateral part of thumb

What is the median nerve distribution?
Palmer side of hand, half of ring finger and lateral.
Tips of fingers on the back

How can radial nerve motor function be tested?
– Wrist and MCP extension
– Abduction and extension of thumbs

How can the ulnar nerve motor function be tested?
– Spread fingers apart against resistance
– Check ability to cross index and middle fingers

How can the median nerve function be tested?
– Touch the thumb to the pinky (distal median nerve)
– Squeeze examier’s finger (proximal median nerve)

How can the flexor digitorum profundus apparatus be tested?
Check isolated flexion of the finger DIP joint

How can the flexor digitrum superficialis apparatus be tested?
Check isolated flexion of the figer at the MP joint

Where do the digital arteries run?
On medial and lateral sides of the digit

What hand lacerations should be left unsutured?
Human and animal bites

Should a clamp ever be used to stop a laceration bleeder on the hand?
Use pressure then tourniquet for a definitive repair if bleeding does not cease
Nerves run with blood vessels

What is a felon?
Infection of the tip of the finger pad
Treat with incision and drainage

What is a paronychia?
Infection of the side of the finger nail
Treat by incision and drainage

What is tenosynovitis?
Tendon sheath infection

What are Kanavel’s signs?
Signs of tenosynovitis
– Affected finger held in flexion
– Pain over volar aspect of affected tendon on palpation
– Swelling of affected finger (fusiform)
– Pain on passive extension

Most common bacteria in tenosynovitis and paronychia?
Staph aureus

How do you treat bites (human and animal)?
Debridement and irrigation
Administration of antibiotics
Leave wound open

Unique bacteria in human bites?
Eikenella corrodens

Unique bateria in dog and cat bites?
Pasteurella multicoida

What is the most common hand/wrist tumor?
Ganglion cyst

What is an extremely painful type of subungual tumor?
Glomus tumor
(subungual – under the nail)

What is a “boxer’s fracture”?
Fracture of the fourth or fifth metacarpal

What is a “drop finger” injury?
Laceration of the extensor tendon over the MP injury

What is the classic deformity resulting from laceration of the extensor tendon over the DIP joint?
Mallet finger

What is the classic deformity resulting from laceration of the extensor tendon over the PIP joint?
Boutonniere deformity

What fracture causes pain in the “anatomic snuffbox”?
Schapoid fracture
Visible 2 weeks later on Xray (NOT initially)
Can cause avascular necrosis
Place in cast if clinically suspected

What is the “safe position” of hand splinting?
In a C-shape, with hand slightly extended and fingers/thumb slightly flexed

What is Dupuytren’s contracture?
Fibrosis of palmar fascia, causing contracture of an inability to extend digits

What is Gamekeeper’s thumb?
Injury to the ulnar collateral ligament of the thumb

How should a subungal hematoma be treated?
Release pressure by burning a hole in the nail

What is carpal tunnel syndrome?
Compression of the median nerve in the carpal tunnel

What is the most common cause of carpal tunnel syndrome?

What are less common causes of carpal tunnel syndrome?
Median artery (persistent)
Edema of pregnancy
Neoplasm (i.e. ganlioneuroma)

Thyroid (myxedema)
Rheumatoid arthritis
Pneumatic drill usage


Symptoms of carpal tunnel syndrome?
Pain and numbness in the median nerve distribution

What are the signs of carpal tunnel syndrome?
Tinel’s sign (percussion over median nerve)
Phalen’s test (flexion of wrist)
Thenar atrophy
Wartenberg’s sign (hand resting on a surface – pinky finger rests in abduction compared to the other 4 digits)

What is the workup for CTS?
Nerve conduction study

What is the initial treatment for CTS?
Nonoperative – rest, wrist splint, NSAIDs

What are indications for surgery with CTS?
Refractory symptoms, theanr atrophy, thenar weakness

What is the surgical treatment for CTS?
Release transverse carpal ligament

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