elbow Flashcards
(149 cards)
1
Q
what (basic) account for the eblows stability
A
bony articulation and soft-tissue stabilizers
2
Q
what kind of joint is the elbow
A
Hinge joint
3
Q
what are the 2 component of the elbow joint
A
Humero-radial
Humero-ulnar
4
Q
what bones make up the basic elbow joint
A
the distal humerus, proximal radius and proximal ulna
5
Q
what make up the Humeroulnar articulation
A
between the trochlea and the trochlear notch
6
Q
what is the movement seen at the Humeroulnar articulation
A
flexion and extension
7
Q
what makes up the Humeroradial articulation
A
between the capitulum and the head of the radius
8
Q
what action is seen at the Humeroradial articulation
A
pronation/supination, flex/ext
9
Q
what makes up the Proximal radioulnar joint
A
between the head of the radius and the radial notch of the ulna
10
Q
what movement is seen at the Proximal radioulnar joint
A
pron/sup
11
Q
what movement do we see at the distal radial ulnar joint
A
pron/sup
12
Q
what makes up the distal RU joint
A
Articulation between the lateral side of head of ulna with ulnar notch of distal radius
13
Q
what separates joint cavity of distal RU joint from wrist joint
A
an Articular disc
14
Q
how much joint stability is provided by the bony architecture
A
50%
15
Q
how Congruous is the elbow joint
A
One of the most congruous joints
16
Q
how much joint stability is provided by the soft tissues of the elbow joint
A
50%
17
Q
how many degrees of freedom in a hindge joint
A
2 DF
18
Q
what movement is allowed at the elbow joint - high joint
A
flexion and extension
19
Q
Proximal and distal RU are what kind of joint
A
pivot joints (trochoid) and allow axial rotation or pivoting.
20
Q
how many joints are in the elbow
A
Anatomically there is 1 joint, the cubital complex (elbow), and 1 capsule
21
Q
what kind of movement is allowed at all of the elbow structures - all together now
A
Physiologically, the elbow movements are flexion/extension & pronation/supination
22
Q
Fibrous capsule
A
Completely encloses joints and blends with annular ligament and collateral ligament on each side
23
Q
Annular ligament
A
holds the radial head in place in radial notch
24
Q
what are the static soft tissue stabilizers of the elbow
A
Anterior capsule and collateral ligaments
25
Synovial capsule of the elbow jt
inner layer
Lines the deep surface of the annular ligament
26
synovial capsule and the proximal radio-ulnar joint
the SC Continuous with the synovial membrane of the proximal radio-ulnar joint
27
radius in the synovial membrane
Radius is able to rotate in here without tearing
28
role of the Medial and lateral ligament complexes
primary elbow stabilizers, and are thickenings of the fibrous capsule
Restrict – varus and valgus stress
29
valgus stresses cause the
Most instability
30
which is stronger the medial or lateral collateral ligament complex
medial
31
how many fat pads does the elbow have
3 fats pads - between the fibrous capsule and synovial membrane
32
3 elbow fat pads locations
Olecranon fossa – post
Coronoid fossa – ant
Radial fossa – ant
33
what is the bursa role in the elbow
Bursa role is to reduce friction of surface that are moving in each other
34
Subcutaneous olecranon bursa
between skin and olecranon process
35
Subtendinous olecranon bursa
between tendon of triceps and olecranon process
36
Bicipitoradial bursa
between biceps tendon and radial tuberosity
37
Radioulnar bursa:
between extensor digitorum, radiohumeral joint, and supinator
38
Olecranon bursitis
Inflammation of the subcutaneous olecranon bursa – olecranon bursitis or “student’s elbow”.
39
what causes Olecranon bursitis
Caused by repeated friction and pressure of the bursa.
40
Distal RU fibrous capsule- weakness.
encloses the joint – It has weak anterior and posterior bands
41
Distal RU synovial capsule
capsule lines the fibrous capsule and the proximal surface of the disc.
Sacciform recess is the proximal extension of the synovial capsule and it accommodates twisting during pron/sup
42
what makes up the medial complex
Formed by the Medial Collateral Ligament (MCL) or ulnar collateral ligament (UCL)
43
role of the medial complex
resist valgus stress
44
where is the medial complex coming from
Originates on the central part of anteroinferior medial epicondyle, just posterior to the axis of rotation for flexion/ext
45
3 bundles of the medial complex
anterior, posterior, and transverse
46
Anterior bundle of the medial complex characteristics
strongest and stiffest - most important component of ligamentous complex,
47
when does the ant bundle of the medial complex stabilize the elbow
primarily stabilizes elbow from 30° to 120°
48
portions of the anterior bundle of the medial complex
anterior band
posterior band
deep middle portion
49
anterior band of the ant bundle of the medial complex is taut when
taut close to extension
(stabilizes from ± 30 to 60°)
50
Deep middle portion of the anterior bundle of the medial complex
isometric during movement - positioned along the ulnohumeral joint axis
51
Posterior band of the anterior bundle of the medial complex
taut in flexion (stabilizes from 60° to 120° flexion)
52
Posterior bundle - the medial bundle
less defined thickening of capsule – functions as a corestraint with anterior bundle, taut at terminal elbow flexion
53
Transverse bundle runs from
from the tip of the olecranon to just distal to the coronoid (variably present, little role in elbow stability)
- not seen in everyone
54
Radial head role in support
Radial head is a secondary ulnohumeral joint stabilizer to valgus loads
55
Flexor and pronator muscles - as support
originate at the medial epicondyle and provide additional support on the medial side of the elbow
56
most common Medial complex injuries
Chronic attenuation and Posttraumatic
57
what type of people is chronic attenuation often seen in
throwing players
58
what is chrontic attenuation
combination of valgus and external rotation force, stretching over time
59
what is Posttraumatic
usually after a fall onto an outstretched hand (FOOSH) - associated injuries include fractures of radial head, olecranon, or medial epicondyle
60
the Lateral Collateral Ligament (LCL) is composed of which ligamnets
composed of radial collateral ligament, lateral ulnar collateral ligament, annular ligament, and accessory lateral collateral ligament
y shaped
61
lateral ulnar collateral ligament is a key stablizer for what
is key stabilizer for varus stress and posterolateral stability
62
where does the radial collateral ligament run
lateral humerus at the elbow axis of rotation and courses distally inserting into annular ligament
63
where does the lateral ulnar collateral ligament run too
lateral epicondyle to ulna (proximal)
64
what muscle does the RCl give rise too
origin for the supinator muscle
65
LCL is the primary restraint to
maintain ulnohumeral and radiocapitellar joints in a reduced position when elbow is loaded in supination
66
what is is called when there is an insuffiency in the LCL
posterolateral rotatory instability (PLRI),
67
what is posterolateral rotatory instability (PLRI),
commonly posttraumatic and is a combination of axial compression, external rotation, and valgus force
68
what are the 2ndary restraints of the elbow
the extensor muscles
69
posterolateral elbow rotatory instability requires insufficiency of
ligaments and muscular origins about the lateral elbow
70
Annular ligament runs from
from anterior margin of radial notch of ulna around the radial head to the posterior margin of radial notch (covered with hyaline cartilage)
71
Quadrate ligament runs from
from neck of radius to the inferior surface of radial notch of ulna
72
when does the qaurate ligament get taut
Anterior fibers = forearm supination
posterior fibers= during pronation
73
Shafts of radius and ulna are connected by
interosseous membrane (IM) (syndesmosis) and oblique cord (OC)
74
what muscles interest into the IO
FDP, FPL, APL, EPB, EPL, EI
75
what joint does the IO provide support too
RUJ
76
IM resists what kind of displacement
IM resists proximal displacement of radius on ulna during pushing movements
77
what kind of displacement does the oblique cord resist
OC resists distal displacement of radius during pulling movements
78
Distal RU joint - ligaments
Anterior radioulnar ligament
Posterior radioulnar ligament
triangular fibrocartilage complex (TFCC),
79
Anterior and posterior radioulnar ligament properties
both are weak - therefore we need support for other areas (triangluar)
80
triangular fibrocartilage complex (TFCC) is made up of what
extensor carpi ulnaris, interosseous ligament, pronator quadratus, and associated forearm muscles
81
Blood for Cubital Complex
elbow anastomosis via collateral branches from brachial artery and recurrent branches from radial and ulnar arteries
82
Blood for DRUJ
anterior and posterior interosseous arteries
83
Nerve Supply for Cubital Complex
articular branches primarily from musculocutaneous, median, and radial nerves
84
Nerve Supply for DRUJ
articular branches of anterior and posterior interosseous nerves
85
Elbow movement
flexion and extension
sup and pro
86
what joints do pronation and supination
in radio-capitellar and proximal and distal RU joints.
87
what jts do Flexion/extension
ulnohumeral and radio-capitellar joint.
88
Flexion/extension axis
Axis of rotation passes through the capitellum in line with the bottom of the trochlear sulcus (red line)
89
Supination/pronation axis
Axis passes through the center of the radial head and extends through the radial border of the distal ulna
90
Extension degress
0
5-10 hyperextension
91
what limits extension
Limited by bony contact and tension of anterior muscles and ligaments
92
how much active flexion can we get
145
93
how much passive flexion can we get
160
94
what is passive flexion limited by
limited by bony contact and posterior soft tissue tension
95
what is active tension lmited by
limited by apposition of contracting anterior muscles
96
is the distal humerous concave or convex
convex
trochlea & capitulum
97
Proximal ulna has concave feature
trochlear notch
98
Proximal radius has concave feature
radial head
99
flexion artho
anterior (volar) roll and glide of ulna and radius on humerus
- look at the fist
100
extension artho
posterior (dorsal) roll and glide of ulna and radius on humerus
101
Movements of proximal RUJ
pronation and supination
102
movement seen in the cubital complex during pronation and supination
Rotation (spin) of the head of radius about its axis in the osseofibrous ring (i.e., on the capitulum)
103
what does volar mean
anterior
104
range of supination and pronation
90-degrees
105
supination is restricted by
Limited by tension in interosseous membrane and volar capsule of the distal RU joint
106
what do the radius and ulna look like in supination
parallel
107
in pronation what do the radius and ulna look like
the cross each other
108
what restricts pronation
bony contact of the radius and the ulna ring(capitulm) and tension in dorsal band of distal RU joint
109
what is moving in pronation and supination at the proximal RUJ
convex radial head on the concave radial notch of the ulna
110
pronation at proximal RUJ
anterior roll and posterior glide of radial head on proximal ulna
111
supination at the proximal RUJ
posterior roll and anterior glide of radial head on proximal ulna
112
Distal RUJ cave and vex
Medial aspect of radius is concave AP (ulnar notch); radial aspect of distal ulna is convex AP
113
Distal RUJ pronation
anterior roll and glide of distal radius on ulnar head
114
Distal RUJ supination
posterior roll and glide of distal radius on ulnar head
115
do we do joint mobilzation and play in open or closed packed ppositions
open
116
Open-packed position Humeroulnar joint
70° of elbow flexion, 10° supination
117
Open-packed position Humeroradial joint
full extension and supination
118
Open-packed position Radioulnar joints
proximal- 35° of supination, 70° elbow flexion
distal - 10° supination
119
Close-packed position Humeroulnar joint
full elbow extension
120
Close-packed position Humeroradial joint
90° of flexion, 5° of supination
121
Close-packed position Radioulnar joints
5° of supination
122
during extension what do the olecranon and epis form
a stright line
123
during flexion what do the olecranon and epis form
isosceles triangle
124
Elbow flexion contractures develop when
rapidly when elbow is immobilized for extended period of time (6 weeks)
125
traumatic compressive forces what is most likely to fracture
Radial head and coronoid process are liable to fracture
126
is the elbow often dislocated
2nd most common joint dislocated
Dislocations may be simple (not fracture) or complex (with fractures)
127
what is more common Posterior or anterior dislocation
post
128
Posterior dislocation what direction does the ulna and humerus move
posterior - ulna
anterior - humerous
129
what normally causes a Posterior dislocation
due to fracture of coronoid process or humeral condyles (compressive force with extended elbow)
130
Associated fractures with elbow dislocations are more common in what population
children (bone fusion occurs ~ 14 to 17)
elderly due to fragile bones
131
In children where do we see associated fractures
fracture-separation of proximal radial epiphysis, or fracture dislocation of the humeral condyles
132
carrying angle - created by what
formed by the orientation of the trochlear groove
the distal projection of the medial edge of the trochlear compared to the lateral edge
the lateral orentation of the ulnar shaft
133
what is the average carrying angle
14
larger in females
134
is carrying angle present in fleexion and extension
not flexion just extesnion
135
where is the supinator crest
distal to the trochlear groove
136
what attaches at the supinator creast
laterasl portion of the UCL and supinator muscle
137
is the radial head concave or convex
concave
138
how many joints does the triceps cross
2
139
what are stronger elbow flexors or extensors
Elbow extensors are weaker than the elbow flexors by around 30%, and the dominant side is around 5-10% stronger than the non-dominant side.
140
Common Extensor Tendon comes from what side of the humerous
lateral epicondyle
141
what is in the common extensor tendon
Extensor carpi radialis brevis (Deep radial n.)
Extensor digitorum (PIN)
Extensor digiti minimi (PIN)
Extensor carpi ulnaris (PIN)
142
Lateral epicondylitis
Principally ECRB
May involve radioulnar bursa
143
Radial Nerve Entrapments
Posterior interosseous n. (comes off deep branch of radial n.) runs between 2 heads of supinator muscle through the Arcade of Frohse (present in 30% of population), which is a possible site of entrapment
144
Intermediate layer of the forearm
Flexor digitorum superficialis
145
Common Flexor Tendon comes from what part of the humerous
medial epicondyle
146
Common Flexor Tendon- muscles
Pronator teres
Flexor carpi radialis
Palmaris longus
Flexor carpi ulnaris
Flexor digitorum superficialis
147
Medial Epicondylitis
Inflammation of medial epicondyle and common wrist flexor tendon
148
Median Nerve Entrapment
Median and anterior interosseous nerves pass through the 2 heads of pronator teres
The 2 heads are joined by the tendinous arch of the FDS, and nerve can be entrapped there
149
Ulnar Nerve Entrapment
In tunnel entrance - space formed by medial intermuscular septum and covering layer of fascia (arcade of Struthers), pink
In tunnel exit: between two origins of flexor carpi ulnaris (Osborne’s lig), blue
