Wrist and Hand

Volar thickening of joint capsule. Centers long flexor tendon. Guards against hyperextension. Augments/extends proximal phalanx' small articular surface

What do the palmar ligaments do?

Ulnar nerve Ulnar artery Palmar cutaneous branch of median nerve.

What does not go through the carpal tunnel?

The palmar metacarpal arteries, which anatomose with the common palmar digital arteries.

What does the deep palmar arch of the radial artery give rise to?

It forms the superficial palmar arch and branches into common palmar digital arteries, which branch into proper palmar digital arteries.

What does the superficial arch of the ulnar artery give rise to?

Holds heads of metacarpals together.

What does the transverse metacarpal ligament do?

Tendons of flexor digitorum superficialis Tendons of flexor digitorum profundus Flexor pollicis longus Main branch of median nerve.

What goes through the carpal tunnel?

Part of the proximal attachment of the superficial group of flexor muscles. Attaches to medial epicondyle of humerus.

What is the common flexor tendon?

Between abductor pollicis longus and flexor carpi radialis

Where do you feel the radial pulse?

From the ulnar artery in the cubital fossa

Where does the common interosseous artery arise?

Midcarpal: most radial abduction, wrist extension Radiocarpal: most ulnar deviation, wrist flexion

Movement at radiocarpal joint vs. midcarpal joint

Inflammation of extensor pollicis brevis and abductor pollicis longus as thy glide over radial styloid process. Pain, swelling over radial styloid.

De Quervain's tenosynovitis

Convex (scaphoid, lunate) along concave (radius, ulna) Also movement at midcarpal joint.

Describe bones in wrist movement

Medial: EPL tendon Lateral: EPB, APL tendons Floor: scaphoid, trapezium

What are the boundaries of the anatomical snuffbox?

Base (proximal) Shaft Head (distal)

What are the parts of a phalanx?

Deep muscles in the respective forearm compartments.

What do the anterior and posterior interosseous arteries supply?

Passive opening of fingers when wrist is flexed Passive closing of fingers when wrist is extended Extremely important in pt with C6 spinal cord injury

Tenodosis grasp

Radial nerve injury in upper arm. Happens w/humerus fracture Paralysis of muscles of posterior compartments (wrist/digit extensors)

Wrist drop

Ulnar nerve injury at wrist Distal lesions, compression in Guyon's canal. Loss of sensation on ulnar side, innervation to intrinsic muscles. Unopposed action of extrinsic causes MP hyperextension, PIP/DIP flexion

Guyon tunnel syndrome

From fall on palm. Poor blood supply so may take months to heal. Avascular necrosis of proximal fragment may cause degenerative joint disease of wrist. May need to fuse carpals surgically.

Scaphoid fracture

Median band to base of middle phalanx Lateral bands (2) to base of distal phalanges. Interossei and lumbricals attach to lateral bands.

What are the parts of the extensor expansion hood?

Extrinsic: strong, forceful movements Intrinsic: fine, delicate movements

Movement and intrinsic vs extrinsic muscles

Stabilize joints and guard against excessive lateral deviation.

What do the collateral ligaments of the MC and IP joint capsules do?

1. Brachial artery 2. Radial artery (lateral side of forearm, hand) 3. Radial recurrent artery 4. Superficial branch of the radial a. 5. Deep branch of the radial a.

1-5

Ulnar nerve injury at level of elbow Associated with epicondyle fracture, compression in cubital fossa Numbness, tingling in cutaneous distribution of ulnar nerve "Clawing" of hand.

Cubital tunnel syndrome

Aponeurosis around dorsum, sides of head of metacarpal and proximal phalanx. Elaboration of extensor digitorum tendon. Non-contractile. Holds extensor tendon in middle of digit. ED contracts: hood is pulled proximally. MP flexion is blocked; PIP/DIP simulataneously extend. ED relaxes: lumbricals flex MP while extending PIP/DIP

Describe the extensor expansion hood.

Superficial branch of radial artery + lateral part of superficial arch of ulnar artery Deep branch of ulnar artery + medial part of deep palmar arch of radial artery Palmar metacarpal arteries (radial) + common palmar digital arteries (ulnar)

Describes the anastomoses of the hand

Benign, slowly progressive condition causing contracture of palmar fascia. No clear etiology or pathogenesis

Dupuytren contracture

Flexor retinaculum/transverse carpal ligament: prevents bowstringing of extrinsic flexor tendons. Extensor retinaculum: prevents bowstringing of extrinsic extensor tendons Collateral ligaments: lateral stability Articular disc: btwn ulna, proximal carpals. Gliding surface, cushions forces transmitted through ulnacarpal axis.

Explain the role of the flexor retinaculum, extensor retinaculum, radial/ulnar collateral ligaments, articular discs.

Extensor carpi radialis longus Extensor carpi radialis brevis Extensor carpi ulnaris

Extensors acting on wrist

Flexor carpi radialis Flexor carpi ulnaris

Flexors acting on wrist

Repeated forceful flexion and extension of wrist strains attachment of common extenson tendon, producing inflammation of periosteum of lateral epicondyle.

Lateral epicondylitis

Palmaris longus Absent in 10-15% of population Medial epicondyle of humerus to Fascia of palm Wrist flexion Median nerve

Nothing?

Power grip: extension of wrist increases distance over which flexors act, producing stronger grasp. Tenodesis: flexion at the wrist results in weaker, more insecure grip

Power grip vs. tenodesis

Tendon of abductor pollicis longus Radial artery Tendon of flexor carpi radialis Median nerve Tendon of palmaris longus Four tendons of flexor digitorum superficialis Ulnar artery Ulnar nerve Tendon of flexor carpi ulnaris

Superficial structures at wrist: lateral to medial.

Extensor digitorum Extensor indicis Extensor digiti minimi Extensor pollicis longus Extensor pollicis brevis Abductor pollicis longus Extensor carpi ulnaris

What does the posterior interosseous nerve innervate?

1. Brachial artery 6. Ulnar artery 7. Anterior/posterior ulnar recurrent arteries 8. Common interosseous artery 9. Posterior interosseous artery 10. Anterior interosseous artery 11. Superficial palmar arch 12. Deep branch of the ulnar a.

6-12

Between individual carpal bones in each row Plane joints with minimal movement

Describe intercarpal joints

Median nerve injury at level of elbow. Impaired PIP/DIP flexion in digits 1-3. Impaired MP flexion in digits 2-3. Impaired PIP flexion in digits 4-5. Spared flexion of DIP of digits 4-5

Hand of benediction