MSK Hand Flashcards
How many bones are in the hand?
27
8 carpal bones
5 metacarpals
14 phalanges (5 prox, 4 middle, 5 distal)
Tendons in the hand create a “pulley system”
Extensor system: extensor digitorum communis inserts into _____
Flexor system: Two-tendon pulley systems made up of ____ and _____
terminal portions of digits 2 to 5
FDP and FDS (distal phalange and middle phalange respectively)
ROM of the digits? Flexion: MCP: PIP: DIP: Thumb: MCP: IP:
F: 90 PIP 90 DIP 90 THumb - MCP 50 - IP 90
ROM of the digits: Extension: MCP: PIP: DIP: Thumb: MCP: IP:
MCP 30
PIP 0
DIP 0-10
THumb:
- MCP 0
- IP 20
ROM of the digits
Abduction:
Finger:
Thumb:
F 20
Th: 70
ROM of the digits
Adduction:
Finger:
Thumb:
F 0 - return from abduction
T 0 - return from abduction
Name the 5 finger flexors
- FDP
- 2 and 3 - AIN from median C8/T1
- 4 and 5 - Ulnar C8/T1 - FDS (median n C7-T1)
- Lumbricals
- 1st and 2nd - Median C8/T1)
- 3rd and 4th - Ulnar C8/T1 - Dorsal and palmar interossea (ulnar C8/T1)
- Flexor Digiti minimi (ulnar C8/T1)
define apposition and opposition of the thumb
Opposition: approximation of the palmar aspect of the tumb and fifth digit
Apposition: approximation between the thumb and other digit not using the palmar aspect.
Name the 3 finger extensors
- Ext Dig Communis (PIN Radial C7/8)
- Extensor indicis proprius (PIN Radial C7/8)
- Extensor digiti minimi (PIN Radial C7/8)
Name the 2 finger abductors
DAB - dorsal interossei ABDuct
- 4 dorsal interossei (ulnar C8/T1)
- Abductor digiti minimi (Ulnar C8/T1)
Name the finger adductors
PAD - palmar interossei ADDuct
3 palmar interossei - ulnar nerve C8/T1
Name the 4 thumb flexors
- flexor pollicis brevis (superficial head: median nerve; deep head ulnar nerve)
- flexor pollicis longus (AIN - median C8/T1)
- Opponens pollicis (median nerve C8/T1)
- Adductor pollicis (ulnar nerve C8/T1)
Name the 3 thumb extensors
Ext pollicis longus (PIN Radial C7/8)
Ext pollicis brevis (PIN Radial C7/8)
Abd pollicis longus (PIN Radial C7/8)
name the 2 thumb abductors
Abd pollicis longus (PIN Radial C7/8)
Abd pollicis brevis (median C8/T1)
Name the muscle responsible for thumb adduction
adductor pollicis (ulnar C8/T1)
Name the 4 muscles responsible for opposition of the thumb to the 5th digit
opponens pollicis (median C8/T1)
flexor pollicis brevis, superficial head (median C8/T1)
Abductor pollicis brevis (median C8/T1)
Opponens digiti minimi (ulnar nerve C8/T1)
_____ is due to thickening and contraction of the palmar fascia due to fibrous proliferation
dupuytrens contracture
Dupuytrens contracture has also been called ____-
Vikings disease
Dupuytrens contracture is commonly associated with (4)
- DM
- alcoholism
- epileptics
- pulmonary TB
Dupuytrens contracture is typically seen in ____
men > 40 years old
Pathology?
painless nodules in the distal palmar crease. These nodules are initially nontender and may become tender as the disease progresses. The involved finger is drawn into flexion as the nodules thicken and contract.
Dupuytrens contracture
Dupuytrens contracture commonly is seen as flexion at the _____ joint involving the _____ digit
MCP joint involving the ring finger (fourth digit)
Treatment of dupuytrens contracture?
CSI injection
ultrasound
splinting
massage
______ is repetitive trauma that causes an inflammatory process to the flexor tendon sheath of the digits. This process forms a nodule in the tendon, resulting in abnormal gliding through the pulley system. As the digit, flexes, the nodule passes under the pulley system and gets caught onthe narrow annular sheath. as a result, the finger is locked in a flexed position
Stenosis tenosynovitis (trigger finger)
trigger finger (stenosis tenosynovitis) is commonly associated with (4
- DM
- RA
- repetitive trauma
- gout
seen in persons > 40 years old
MCP and PIP collateral ligamentous injuries occur in what position?
Valgus or varus stress with the finger in extended position
MCP and PIP volar plate injuries occur how?
hyperextesnion with dorsal dislocation, which is usually reducible
How do you test the tone of the ulnar collateral ligament
test by placing a valgus stress at the MCP joint of the thumb.
_____ injury is also known as gamekeepers thumb or skiers thumb
MCP ulnar collateral ligament injury
Skiers thumb or gamekeepers thumb may occur with chronic laxity or acute disruption of ____
ulnar collateral ligament.
____ occurs after forcful radial deviation of the proximal phalanx at the MCP joint of the 1st MT
Gamekeepers thumb, skiers thumb
complex tears of the ulnar collateral ligament in gamekeepers thumb can lead to entrapment of ______.
Also known as _____
adductor aponeurosis in the MCP joint
Stener’s lesion
complex tears of the UCL in gamekeepers thumb may lead to entrapment of the adductor abponeurosis in the MCP joint. This is known as Steners lesion.
Name the 3 grades of injury
i - pain and no increased motion
II increased opening with pain on stressing
III no pain, continued motion while stressing.
Instability in UCL/gamekeepers thumb is indicated by radial deviation > _____ in extension and > _____ in flexion on plain films
> 40 degrees in extension
> 20 degrees in flexion
_____ is a complete or incomplete injury to the flexor tendons of the hand
flexor digitorum injury (jersey finger)
spontaneous jersey finger may be seen in ____
RA
Mechanism of injuy in athelets with jersey finger?
when a players finger ggets caught in the jersey of another when attempting to grab him. the profundus tendon is avulsed from its insertion and possible accompanied by a bony fragment - usually the 4th digit
____ occurs with sudden passive flexion of the DIP joint when the finger is extended, causing a rupture of the extensor tendon
Mallet finger - AKA baseball finger
Treatment of mallet finger?
splinting of the DIP in extension for 6-8 weeks with a stack splint or custom-made splint. ** must maintain the finger in extension at all times. Will need weekly visits to assess full finger flexion. At the end of 6 weeks, gentle active flexion with night splintin should be done for 2-4 more weeks.
surgical repair is reserved for poor healing or if an avulsed fragment involves greater than 1/3 of the joint
What is Bennetts fracture?
oblique fracture-subluxation at the base of the thumb metacarpal
What is rolandos fracture?
fracture at the base of the thumb metacarpal that may be classified as a T, Y, or comminuted configurations
An avulsed metacarpal fragment in Bennetts fracture may sublux secondary to the proximal pull of the _____ muscle
abductor pollicis longus muscle
A metacrapal neck or shaft fracture is also known as ____
boxers fracture
____ is a fracture of the metacarpal neck/shaft usually seen after a person strikes a wall or another person
MC neck or shaft fracture - boxers fracture
boxers fracture may be seen in any digit but is commonly seen in ______
5th digit
