General Hand Questions Flashcards
Describe the pully system of the hand
Consists of 5 annular and 3 cruciate pullys. Preventing bowstringing of the FDS and FDP tendon.
A1 pully - Lies over the MCP joint
A2 pully - Lies over the proximal phalanx
A3 pully - Lies of the PIPJ
A4 pully - Lies over middle phalnx
A5 pully - Lies of the DIPJ
C1 pully - Lies between A2-A3
C2 pully - Lies between A3-A4
C3 pully - Lies between A4-A5
Describe Trigger Finger
Inflammation of the flexor tendons caused by repetitive use. Means when finger is in flexion a node passes through the pully system. When attempting to extend node gets caught leading to the finger becoming locked.
Describe the blood supply to the hand?
Blood supply to the hand recieves contributes from both the radial and ulnur arteries.
It consists of the superficial and deep palmar archs.
Superficial - located anteriorly to the flexor tendons in the hand and deep to the palmar aponeurosis. It gives rise to the digital arteries, which supply the four fingers
Deep - located deep to the flexor tendons of the hand. It contributes to the blood supply to the digits and to the wrist joint.
Describe the blood supply of the scaphoid
The scaphoid has a retrograde blood supply from palmar and dorsal branches of the radial artery. This means that the more proximal a fracture in the scaphoid is, the more likely it is to lose its blood supply and go on to suffer avascular necrosis.
Describe the zones of the flexor side of the hand.
Zone one - Distal to FDS tendon insertion - FDP being damaged here.
Zone two - Between distal palmar crease and FDS tendon. FDP and FDS would be injured here.
Zone three - Between Distal palmar crease and carpal tunnel
Zone four - Carpal tunnel
Zone five - Proximal to carpal tunnel
Describe the borders of the anatomical snuffbox
Ulnar (medial) border: Tendon of the extensor pollicis longus.
Radial (lateral) border: Tendons of the extensor pollicis brevis and abductor pollicis longus.
Proximal border: Styloid process of the radius.
Floor: Carpal bones; scaphoid and trapezium.
Roof: Skin
Describe the contents of the anatomical snuffbox
Cephalic vein
Radial Artery
Superficial branch of the radial nerve
Where is the origin and insertion of FDP and FDS
It has two heads – one originates from the medial epicondyle of the humerus, the other from the radius. The muscle splits into four tendons at the wrist, which travel through the carpal tunnel, and attach to the base of the middle phalanx of the four digits.
Originates from the ulna and associated interosseous membrane. At the wrist, it splits into four tendons, that pass through the carpal tunnel and attach to the distal phalanges of the four fingers.
