L6.3 - Wrist and hand joints

Question 1

Wrist joint aka Radiocarpal Joint

1) What type of joint?
2) Ligaments
3) BS
4) NS
5) Movements

Answer 1

1) Condyloid joint (shallow convex and concave surfaces)
2) Med, lat collateral lig., palmar and dorsal radiocarpal, palmalr and dorsal radioulnar
3) Branches of palmar and dorsal carpal arches from Ulnar and radial arteries
4) Anterior (branch of median)/posterior (branch of radial) interosseous , deep branch of ulnar
5) Radial and ulnar deviation, Flex/Ex

Question 2

Role of palmar and dorsal radiocarpal lig.

Answer 2

Orientated obliquely to stop proximal carpal slipping over to ulnar side

Question 3

How does flexion and extension occur at the wrist joint?

Answer 3

When muscles of Radial deviation (abduction) and ulnar deviation (adduction) cancel each other out

Question 4

Wrist joint - radial deviation is abduction or adduction?

Answer 4

Abduction

Question 5

Wrist joint - muscles involved in flexion?

Answer 5

All forearm flexors except PT, PQ and one extensor APL

Question 6

Wrist joint - muscles involved in extension?

Answer 6

8 muscles - ECRL, ECRB, ECU, ED, EI, ECM, EPL, EPB

Question 7

Wrist joint - muscles involved in radial deviation?

Answer 7

APL, FCR, ECRL

Question 8

Wrist joint - muscles involved in ulnar deviation?

Answer 8

ECU, FCU

Question 9

Ulnar vs radial deviation which has a greater degree of action at 1) Wrist joint 2) Midcarpal joint

Answer 9

1) Ulnar

2) Radial - not restricted by styloid process of radius

Question 10

Intercarpal joints

1) What type of joint?
2) Ligaments
3) BS
4) NS
5) Movements

Answer 10

1) Plane
2) Anterior, posterior, interosseous
3) Palmar and dorsal arches
4) Anterior interosseous, deep branch of ulna
5) Gliding between carpals

Question 11

Is the joint capsule of the ICJ same as the wrist joints?

Answer 11

No it is the same as CMC joints

Question 12

What role does the interosseous lig. of the ICJ do?

Answer 12

Turns carpal bones into function units

• scaphoid, lunate, triquetrium is one unit
• capitate and hamate is one unit

Question 13

Midcarpal joints

1) What type of joint?
2) Movements

Answer 13

1) Functional joint that is convex-concave condyloid type joint
2) Flexion/extension, radial deviation, ulnar deviation

Question 14

CMC and IMC joints are in one synovial sheath

1) CMC joint type? IMC joint type?
2) Ligaments
3) BS
4) NS

Answer 14

1) CMC - 1 = Saddle, 2,3 = Plane, 4,5 = Hinge, IMC = All plane
2) CMC, IMC, Interoesseous, collateral (CMC
3) Palmar arterial arches, dorsal and palmar metacarpal arteries
4) Ant, post interosseous, deep ulnar

Question 15

MCP and IP Joints

1) Type of joint?
2) Actions?
3) BS
4) NS
5) Ligaments

Answer 15

1) MCP - Condyloid, IP - Hinge
2) MCP - F/E, Ab/Ad, IP- F/E
3) BS: Palmar arterial arch
4) NS: Median and Ulnar nerves
5) Collateral lig, Transverse metacarpal lig (holds medial 4 digits, stops excess ab and lies deep to base of FDS and FDP), Palmar (volar) plate, Dorsal plate

Question 16

Skier’s thumb/Gamekeeper’s thumb?

Answer 16

Rupture of medial collateral lig. from forced abduction and extension of thumb
*Add Policis tendon can get impinged there aka stener lesion

Question 17

Boutonniere deformity aka buttonhole deformity

Answer 17

Boutonniere deformity is a deformed position of the fingers or toes, in which the joint nearest the knuckle (the proximal interphalangeal joint, or PIP) is permanently bent toward the palm while the farthest joint (the distal interphalangeal joint, or DIP) is bent back away (PIP flexion with DIP hyperextension).

Question 18

Which synovial sheath is ulna bursa continuous with?

Answer 18

Little finger

Question 19

Are there sheaths where lumbricals muscles attach?

Answer 19

No

Question 20

Which synovial sheath is radial bursa continous with?

Answer 20

Thumb

Question 21

What kind of fibres are volar plates? Annular or cruciform?

Answer 21

Annular

*Cruciform lig. are found between volar plates and forms a tunnel in flexion

Question 22

De Quervain’s tenosynovitis

Answer 22

Painful condition affecting the tendons on the thumb side of your wrist. It will probably hurt when you turn your wrist, grasp anything or make a fist. Cause is idiopathic.

Question 23

Digital tenovaginitis stenosans aka Trigger Finger

Answer 23

Inflammation in fibrous sheath

Question 24

Tinel’s test

Answer 24

It is performed by lightly tapping (percussing) over the median nerve to elicit a sensation of tingling or “pins and needles” in the distribution of the nerve - allows us to distinguish whether patient has carpal tunnel syndrome

Question 25

If median nerve was compressed, what happens to the action at the thumb?

Answer 25

Opposition cannot be done

Question 26

What is Saturday night palsy?

Answer 26

Saturday night palsy from falling asleep with one’s arm hanging over the arm rest of a chair, compressing the radial nerve at the spiral groove - leads to wrist drop and numbness at the dorsum of the hand

Question 27

F/E of wrist, which one is greater?

Answer 27

Flexion - styloid process of radius prevents overextension of wrist