Hand and Wrist Lecture

Question 1

Which joint is between the carpals and metacarpals?

Answer 1

carpometacarpal joint

Question 2

Which type of joint is between the metacarpals and phalanges?

Answer 2

metacarpophalangeal joint

Question 3

What joint is between phalanges (fingers)?

Answer 3

interphalangeal joint

Question 4

What joint is between the radius, scaphoid, and lunate?

Answer 4

radiocarpal joint

Question 5

What joint is between the distal carpal row and the proximal carpal row?

Answer 5

midcarpal joint

Question 6

When flexing the wrist, what percetage of flexion occurs at the radiocarpal join and percentage at the midcarpal joint?

Answer 6

• radopcarpal joint = 40%
• midcarpal joint = 60%

Question 7

When extending the wrist joint, what percentage of extension is at the midcarpal joint, and which percentage is at the radiocarpal joint?

Answer 7

• midcarpal joint = 33%
• radiocarpal joint = 67%

Question 8

At which joint does most of the abduction and adduction of the wrist occur?

Answer 8

midcarpal joint

Question 9

How many degrees of abduction (radial deviation) can be obtained at the wrist join?

Answer 9

15-20 degrees

Question 10

How many degrees of adduction (ulnar deviation) can be obtained at the wrist joint?

Answer 10

30-45 degrees

Question 11

What is the degrees of ulnar deviation greater than the degrees obtained for radial deviation?

Answer 11

The styloid of the radius blocks radial deviation at 20 degrees abducted.

Question 12

True or False:

The extensor tendons form a immoveable hood over the MP and IP joints of the fingers called the extensor expansion.

Answer 12

false - extensor tendons form a MOVEABLE hood over the MP and IP joints of the fingers called the extensor expansion.

Question 13

True or False:

the arrangement of both extensor muscles and intrinsic hand muscles that attach to this dorsal digital expansion enable the uncoupling of flexion and extension.

Answer 13

True

Question 14

What does the extensor hood mechanism allow?

Answer 14

this mechanism allows the long extensor tendos to strongly extend the MP joint and allows extension of IP joints when MP joints are flexed by lumbricals, which also attach to the “hood” part of the extensor expansion

Question 15

What muscle is responsible for the “power grip”, which is the powerful movement of digits 1-5?

Answer 15

flexor digitorum profundus

Question 16

True or False:

As the median nerve reaches the carpal tunnel, it moves from a position between f.d. superficialis and f.d. profundus, to a position superficial to f.d. superficialis.

Answer 16

TRUE

Question 17

What is contained within the carpal tunnel?

Answer 17

• median nerve
• flexor pollicis longus
• flexor carpi radialis
• flexor retinaculum
• flexor digitorum superficialis
• flexor digitorum profundus

Question 18

What wrist bones encircle half of the carpal tunnel?

Answer 18

• hamate
• capitate
• trapezoid
• trapezium

Question 19

What artery and nerve is found in Guyon’s canal?

Answer 19

ulnar nerve and artery

Question 20

What is the cause of Dupuytren’s Contracture?

Answer 20

Progressive shortening and thickening of the palmar fascia that pulls the 4th and 5th digits into partial flexion.

Tends to be hereditary.

Question 21

What are the 5 fascial compartments of the hand and wrist?

Answer 21

• hypothenal compartment
• thenar compartment
• central compartment
• adductor compartment
• interosseous compartment

Question 22

Which long flexor tendons have a synovial sheath?

Answer 22

• flexor digitorum superficialis
• flexor digitorum profundus
• flexor pollicis longus

Question 23

Is the flexors pollicis longus’ synovial sheath separate from the ulnar bursa?

Answer 23

Yes

Question 24

The long tendons of f.d. superficialis and profundus enter a common flexor sheath (ulnar bursa) beneath the flexor retinaculum. Each of their 4 tendons then enter its own separate synovial sheath. This synovial sheath is within a fibrous digital sheath. The synovial sheath for digit 5 is continuous with the ulnar bursa.

Question 25

What condition can be caused by an infection in the digital synovial sheaths?

Answer 25

Tensosynovitis \*\* Infections in the digital synovial sheaths can cause inflammation of the tendon and synovial sheath. For the 5th digit, such an infection can spread into the carpal tunnel and into the forearm because the digital synovial sheath is continuous with the ulnar bursa \*\*

Question 26

Which 3 muscles form the thenar eminence?

Answer 26

* abductor pollicis brevis * flexor pollicis brevis * superficial head * deep head * opponens pollicis

Question 27

Which 4 muscles make up the intrinsic thenar muscles (thumb) of the palmar aspect of the hand (anterior)?

Answer 27

* abductor pollicis brevis * flexor pollicis brevis * superficial head * deep head * opponens pollicis * adductor pollicis * oblique head * transverse head

Question 28

Which 3 muscles form the hypothenar eminence of the palmar aspect of hand (anterior)?

Answer 28

* flexor digiti minimi * abductor digiti minimi * opponens digiti minimi \* palmaris brevis lies superficial

Question 29

What is the proximal/distal attachments, actions, innervation, and blood supply of the opponens pollicis?

Answer 29

Proximal Attachment: * flexor retinaculum * tubercles of scaphoid and trapezium Distal Attachment: * lateral side of 1st metacarpal Actions: * oppose thumb * medially rotate 1st metacarpal Innervation: * recurrent branch of median nerve Blood Supply: * superficial palmar branch of the radial artery

Question 30

What is the proximal/distal attachments, actions, innervation, and blood supply of the abductor pollicis brevis?

Answer 30

Proximal Attachment: * flexor retinaculum * tubercles of scaphoid and trapezium Distal Attachment: * lateral side of base of proximal phalanx of thumb Actions: * abduct thumb * aid in opposition Innervation: * recurrent branch of median nerve Blood Supply: * superficial palmar branch of the radial artery

Question 31

What is the proximal/distal attachments, actions, innervation, and blood supply of the flexor pollicis brevis?

Answer 31

Proximal Attachment: * flexor retinaculum * tubercles of scaphoid and trapezium Distal Attachment: * lateral side of base of proximal phalanx of thumb Actions: * flexes thumb Innervation: * recurrent branch of median nerve (superficial head) * deep branch of ulnar nerve (deep head) Blood Supply: * superficial palmar branch of the radial artery

Question 32

What is the proximal/distal attachments, actions, innervation, and blood supply of the adductor pollicis?

Answer 32

Proximal Attachment: * bases of 2nd and 3rd metacarpals * capitate * adjacent carpals Distal Attachment: * medial side of base of proximal phalanx of thumb Actions: * adducts thumb toward lateral border of palm Innervation: * deep branch of ulnar nerve Blood Supply: * deep palmar arterial arch

Question 33

What is the proximal/distal attachments, actions, innervation, and blood supply of the abductor digiti minimi?

Answer 33

Proximal Attachment: * pisiform Distal Attachment: * medial side of base of proximal phalanx of 5th digit Actions: * abducts 5th digit * aids in flexion of 5th proximal phalanx Innervation: * deep branch of ulnar nerve Blood Supply: * ulnar artery

Question 34

What is the proximal/distal attachments, actions, innervation, and blood supply of the flexor digiti minimi (brevis)?

Answer 34

Proximal Attachment: * hook of hamate and flexor retinaculum Distal Attachment: * medial side of base of proximal phalanx of 5th digit Actions: * flexes proximal phalanx of digit 5 Innervation: * deep branch of ulnar nerve Blood Supply: * ulnar artery

Question 35

What is the proximal/distal attachments, actions, innervation, and blood supply of the opponens digiti minimi?

Answer 35

Proximal Attachment: * hook of hamate * flexor retinaculum Distal Attachment: * medial border of 5th metacarpal Actions: * brings 5th metacarpal anterior and rotates it to bring it into opposition with thumb Innervation: * deep branch of ulnar nerve Blood Supply: * ulnar artery

Question 36

What are the lumbrical intrinsic (short) muscles of the hand?

Answer 36

* _1st and 2nd Lumbricals_ * ​attached to lateral 2 tendons of flexor digitorum pollicis * median nerve * _3rd and 4th Lumbricals_ * attached to medial 3 tendons of flexor digitorum pollicis * deep branch of ulnar nerve They insert on the lateral sides of the extensor expansions of digits 2-5. They flex the metacarpophalangeal joints and extend interphalaneal joints (via the extensor expansion and extensor hood) of digits 2-5.

Question 37

What do the lumbrical intrinsic (short) muscles of the hand do?

Answer 37

flex the metacarpophalageal joins and extend interphalangeal joints (via the extensor expansion and extensor hood) of digits 2-5

Question 38

How many palmar interossei (PAD) intrinsic (short) muscles of the hand are there?

Answer 38

* 3 of them * attach to palmar surfaces of 2nd, 4th, and 5th metacarpals * insert at bases of proximal phalanges and the extensor expansions of digits 2nd, 4th, and 5th digits * P.A.D. -\> adduct 2nd, 4th, and 5th fingers toward axial line; also assist lumbricals * innervated by deep branch of ulnar nerve

Question 39

How many dorsal interossei (DAB) intrinsic (short) muscles are there?

Answer 39

* 4 of them * attach to adjacent sides of 2 metacarpals * insert at bases of proximal phalanges and the extensor expansions of digits 2-4 * D.A.B. -\> abduct 2nd-4th fingers toward axial line; also assist lumbricals * innervated by deep branch of ulnar nerve

Question 40

What nerve innervates the dorsal interossei (DAB) intrinsic (short) muscles of the hand?

Answer 40

deep branch of ulnar nerve

Question 41

What nerve innervates the palmar interossei (PAD) intrinsic (short) muscles of the hand?

Answer 41

deep branch of ulnar nerve