lecture 11: wrist and hand Flashcards
1
Q
what carpal bones are in the proximal row
A
scaphoid. lunate, triquetrum, pisiform
2
Q
what carpal bone sits on the triquetrum
A
pisiform
3
Q
what carpal bones are in the distal row
A
trapezium, trapezoid, capitate, hamate
4
Q
true or false: the capitate bone is part of the proximal roq
A
false, the distal row
5
Q
what carpal bone sits at the base of the thumb
A
the trapezium
6
Q
which carpal bone is the keystone/main anchor of the carpus
A
capitate
7
Q
be able to name the carpal bones and if they are in the distal or proximal row
A
8
Q
why is there such a tight fit of the carpal bones
A
to allow for stability
9
Q
what are the smoothest lines of the wrist called
A
gilula lines
10
Q
what percentage of force transmission occurs at the distal radius in the normal wrist
A
80%
11
Q
true or false: the scaphoid has 2 regions
A
false, 3 regions
12
Q
what are the 3 regions of the scaphoid
A
distal pole
proximal pole
wasit
13
Q
what is another name for the scaphoid bone in the wrist
A
navicular
14
Q
what region of the scaphoid is poorly vascularized
A
proximal pole
15
Q
since the proximal pole of the scaphoid is poorly vascularized, what is it susceptible to
A
avascular necrosis
16
Q
how is the scaphoid frequently fractured
A
by fall on hyperextended radially deviated wrist
17
Q
true or false: the scaphois is frequently fractured by fall on hyperextended ulnar deviated wrist
A
false, radially
18
Q
where can you palpate the scaphoid
A
snuff box
19
Q
what bone is considered an important stabilizer of the carpus (not the scaphoid)
A
lunate
20
Q
what carpus bone has very little movement
A
luante
21
Q
true or false: the lunate has very limited movement
A
true
22
Q
true or false: the scaphoid bone is the only bone vulnerable to avascular necrosis
A
false , the lunate as well
23
Q
what is keinbocks disease
A
condition where the blood supply to one of the small bones in the wrist, the lunate, is interrupted.
24
Q
true or false: the lunate is also vulnerable to avascular necrosis
A
true (keinbocks disease)
25
what are the regions of the hamate
proximal pole and hook and body
26
what carpus bone is the site of attachment of the flexor retinaculum
hammate
27
true or false: the capitate is the site of attachment of the flexor retinaculum
false, the hamate is
28
where can you palpate the hamate
near base of pinky
29
what is the bone that is saddle shaped at the base of the thumb
trapezium
30
what two carpus bones contribute to the anterior orientation of the thumb
trapezium and scaphoid
31
the trapezium and the scaphoid together contribute to what and why is that important
to the anterior orientation of the thumb
(important for grasp)
32
what is the larges carpal bone
capitate
33
where is the capitate located
orientated at the base of the long finger
34
what bone is the stable base for the index finger
trapezoid
35
what bone is located at the base of the index finger important for pimch
trapezoid
36
true or false: the capitate bone is important for pinch
false, the trapezoid
37
what carpal bone articulates with the fibrocartiligenous disc and pisiform
triquetrum
38
true or false; the pisiform is a sesamoid bone
true
39
what are the 3 main joints of the wrist
distal radioulnar joint (DRUJ)
radoiocarpal joint
mid-carpal joint
40
what is the force transmission at the radius-carpus during radial deviation
87%
41
what is the force transmission at the ulna-carpus during rotatio
37%
42
what is the force transmission at the mid carpal (neutral) of the scaphotrapezium-trapezoid
31%
43
what are the bony parts of the radoiocarpal joint
radius and the proximal carpal row
44
in the radoiocarpal joint, the radius articulates with what carpal boens
scaphoid and lunate
45
what motions does the radoiocarpal joint contribute to
flexion, extension and radial-ulnar deviation
46
what is the primary function of the distal radioulnar joint
forearm pronation and supination
47
what does the distal radioulnar joinnt facilitate
load transmission between radius-hand and ulna
48
true or false: the radio carpal joint facilitates load transmission between radius-hand and ulna
false, the distal radioulnar joint does
49
extrinsic ligaments of the wrist are orientaed towards where
midline
50
what does it mean for a wrist ligament to be extrinsic
from radius/ulna to carpal bones
(oriented towards the midline)
51
are the intrinsic or extrinsic ligs v shaped
extrinsic
52
are the volar ligaments or dorsal ligaments of the extrinsic ligaments on the wrist stronger
volar ligaments are stronger
53
what is the function of the extrinsic wrist ligaments
stabilize the carpus during extension (force transmission during weight bearing)
54
what are the static stabilizers of the DRUJ
TFCC
ECU (including sheath)
interosseous membrane
55
what are the dynamic stabilizers of the DRUJ
pronator quadratus
pronator teres
biceps brachii (inserion tuberosity of the radius and deep fascia of FA)
supinator (intertion lateral, proximal shft of radius)
56
what are the 4 things that make up the TFCC
dorsal radioulnar ligament (DRUL)
palmar radioulnar ligament (PRUL)
ECU
articular disk
57
what does the article disk of the TFCC function
increases the surface area of distal ulna and shock absorption
58
what are the 4 functions of the TFCC
stabilization of the DRUJ and ulnar side of carpus
cushion ulna on carpus
allows axial loading of ulna on forearm
increases articular surface of carpus
59
true or false: The TFCC stabilizes the DRUJ and radial side of the carpus
false, ulnar
60
where is the mid carpal joint formed
between two carpal rows (b/w distal and proximal)
61
what does the mid carpal joint contribute to
flexion
extension
radial-ulnar deviation
62
how is the mid carpal joint stabilzied
stabilization via ligaments and capsule
63
accord to garcia ellas, 2013, which joint is more important: the mid carpal or radoiocarpal joint
midcarap
64
true or false: the proximal row has no tendinous inserions
true
65
where does wrist mvovment start
distal row of carpus
66
explain wrist movement and how mid carpal is more important that radoiocarpal joint
proximal row has no tendinous insertions
wrist movement starts at distal row of carpis
movement pulls mid carpal ligaments taut, creates a compressive load and moves proximal row
67
what is the orientation of the intrinsic ligaments of the wrist
transverse orientation
68
what does it mean to be an intrinsic ligament of the wrist
carpal to carpal
69
what are the two important intrinsic ligaments
scapholunate (interesses) ligament
lunotriquetral interosseous ligament
70
in an xray, if there is space between the scaphoid and lunate, what ligament is ruptured
scapholunate
71
what is the most common wrist ligament injury
SL ligament (scapholunate)
72
true or false: The SL lig rupture is most common wrist ligament injury
true
73
what is a common cause of carpal instability and the most common wrist lig injury
SL ligament rupture
74
true or false: there is higher SL lig tensile force in flexion
false, extension
75
in what position is there higher SL ligament tensile force
extension
76
what is the common name of an Scapholunate ligament tear
terry thomas sign (space between scaphoid and lunate)
77
what are the two types of intrinsic ligament dissociation
volar
(volar intercalary segment instability(
dorsal
(dorsal intercalary segment instability)
78
explain volar intercalary segment instability
L-T ligament rupture (plus dorsal radoiocarpal and volar radiocarpal)
=lunate points in a volar direction
79
explain dorsal intercalary segment instability
SL ligament rupture (plus scaphotrapeziumtrapezoid or dorsal inter carpal)
-lunate points in a dorsal direction
80
VISI is associated with LT or SL ligament rupture
LT
81
DISI is associated with LT or SL ligament rupture
SL ligament
82
in the study of incidence of carpal instability two years after fall on outstretched hand, what percentage had clinical evidence of carpal instability
44%
83
in the study of incidence of carpal instability two years after fall on outstretched hand, 44% had clinical evidence of carpal instability, of those 44% how many had scapho-lunate dissocaiteion
24%
84
what happens if you get an untreated scapholunate ligament injury
scapholunate advanced collapse (SLAC wrist)
=capitate will descend and fill in the empty spot
85
are ligaments the only wrist stabilizers
no , we are able to surpass the tensile strength of wrist ligaments without rupture
86
true or false: scapholunate ligament is more than just a passive restraint
true
87
explain how the scapholunate ligament is more than just a passive restraint
there are mechanoreceptors in ligaments that signal joint perturbation and influence surrounding muscles
=reactions are protection
88
the centre of rotation in the wrist goes through what bone
capitate
89
with a distal radius fracture, which movement would be more problematic
extension because it has a greater contribution of radiocapral
90
during flexion, explain the joint contribution of the radoiocarpal and mid carpal
40% radiocapral
60% mid carpal
91
during extension, explain the joint contribution of the radoiocarpal and mid carpal
33.5% mid carpal
66.5% radoiocarpal
92
there is a higher contribution from radoiocarpal or midcarpal during extension
radoiocarpal
93
explain the movement of the carpals during flexion
distal and proximal carpal rows both move into flexion
94
explain the movement of the carpals during extension
distal and proximal carpal rows both move into extension
95
explain the symbolic movement of wrist flexion and extension
carpal rows act like 2 cylinders rolling in the same direction
96
explain the carpal kinematics during radial deviation
1) proximal row flexes and translates ulnarly
2) lunate pronates
3) triquetrum rides proximally and dorsally on hamate
97
explain the carpal kinematics during ulnar deviateion
1) proximal row extends and translates radially
2) lunate supinates
3) triquetrum rides distally and volarly on hamate
98
a terry thomas sign is a radiographic indicator of what
scapholunate ligament rupture
99
there is greater mobility with what finger bones
with ring and little finger metacarpals
100
why is there different metacarpal lengths
cascade/convergence
=natural cascade towards base of thumb
101
what are the 3 arches of the hand
fixed transverse proximal arch
movile distal transverse arch
longitudinal arch
102
where is the fixed transverse proximal arch
mid point = capitate
103
the proximal transverse arch is fixed or movile
fixed
104
the distal transverse arch is fixed or mobile
mobile
105
what is the midpoint of the mobile distal transverse arch
3rd metacarpal
106
which is mobile: the distal or proximal transverse arch
distal
107
along what metacarpal does the longitudinal arch of the hand lie
3rd metacarpal
108
since the metacarpals are different lengths what does that mean
there is a volar arch
109
what type of joint is the MCP (in fingers)
condylyar
110
what are the movements possible for MCP
flexion/extension
abduction/adduction
111
what type of joint are the PIP and DIP joints
hinge
112
what are the movements possible at the PIP and DIP joints
flexion and extension
113
true or false; the finger joints are synovial
true
114
what are the finger ligaments
ulnar and radial collateral ligaments (cord and accessory(
volar (palmar plate)
115
in which position are the collateral ligaments of the finger most taut
PIP and DIP closed pack position is in full extension
collaterals at MCP are tight when flexion
116
what is the MCP ROM (in fingers) during flexion extension
flexion: 90
extension 0
117
what is the PIP ROM during flexion extension
flexion: 100
extension: 0
118
what is the DIP ROM during flexion
flexion: 80
extension 00
119
true or false: the MCP gets 100 degrees of flexion
false, the MCP gets 90
the PIP gets 100
120
which joint has most flexion ROM: the MCP< PIP or DIP
PIP
121
according to evans, whas is the minimal DIP flexion needed
70
122
thumb makes up what percentage of hand function
60%
123
what type of joint is the MCP joint at the thumb
biaxial joint
124
what are the motions possible at the MCP joint of the thumb
flexion/extension
abduction/adduction
125
what type of joint is the IP joint at the thumb
hinge joint
126
what are the movements possible at the IP joint of the thumb
flexion/exnesion
127
what type of joint is the CMC of the thumb
saddle joint
128
what movements are possible at the CMC joint of the thumb
flexion/extension
abduction/adduction
circumfuction and opposition
129
what is the normal ROM in the MCP joint of the thumb
flexion: 55 degrees
hyperextension: 10 degrees
130
what is the normal ROM of the IP joint of the thumb
flexion: 80
extension: 0
131
what is the normal ROM of palmar abduction of the thumb
45 degrees
132
what are the dynamic stabilizers of the CMC joint of the thumb
ADD
APD
OPP
FPB
APL
FPL
EPB
EPL
133
what are the static stabilizers of the CMC
16 ligaments
most important arte palmar oblique (beak) ligament and dorsoradial ligament
134
with more lateral pinch force, what happens do the CMC joint contract force
it increases
135
what can happens with erosive chagnes with osteoarthritic
CMC subluxation
136
what is shoulder sign indicative of
dorsal radial dislocation of 1st MC (CMC)
tilting in dorsal radial direction
137
what are the extrinsic musculotendinous structure flexors
flexor digi superficualis (FDS)
flexor digi profundus (FDP)
flexor pol longus (FPL)
palmaris longus (PL)
138
what position would allow for optimal differential glide of FDS and FDP
hook fist
=flexion of PIP and DIP with no flexion of MCP
139
what position would allow for optimal glide of FDS
straight fist
=fexion of MCP and PIP but extension of DIP
140
what position would allow optimal glide of FDP
full fist (full flexion)
141
true or false: the full fist allows optimal glide of the FDS
false, FDP
142
hook fist allows optional differential glide of what
FDP FDS
143
straight fist allows optimal glide of what
FDS
144
full fist allows optimal flide of what
FDP
145
what are the extrinsic musculotendinous structures for extension and abduction
extensor digitorum communis (EDC)
indiex proprius
extensor digiti mini
extensor pollicis longus/brevis
abductor pollicis longus
146
what fingers have individual extensor tendons
indépendant active extension of the index and little fingers
147
true or false: active extension of the long and ring fingers is difficultt when the MCP joints of index and little fingers are flexed
true
148
what is the juncture tendinae
the tendons of the extensor digital to the fingers are connected to one another by the junctura tendinae
149
what is the function of the juncturae tendinae
increase extension to individual fingers
if one of two fingers passively flexed at MP, pulls EDC of other fingers along
150
what muscles make up the thenar eminence
flexor pollicus brevis
opponens pollicus
abductor pollicis brevis
adductor polices
151
what muscles make up the hypothenar eminence
flexor digiti minimi
opponents digiti minimi
abductor digiti minimi
152
what are the intrinsics of the hand
lumbricals and itnerosseus structures
153
explain the diamond of stack during flexion and extension
during flexion, diamondss is larger
during extension, diamond is tighter
154
explain boutineires deformity
disruption of central slip insertion (causes slip in the volar direction of the lateral bands)
=PIP flexion and DIP extension
155
why does MP flexion cause IP extension
because the lateral slips of the EDC tighten and pull the lateral bands
(flexion of MPs and etension of PIP/DIP)
156
EXPLAIN FINGER movement segment during digital flexion
extrinsic FDS initiates flexion at the PIP joint
extrinsic FDP then flexes the DIP joint
intrinsics then flex MP joint
157
explain finger movement segment during digital extension
extrinsic EDC extends MP joint
intrinsic lumbricals and interosseus muscles extend PIP and DIP joint
158
explain the tenodesis pattern
wirst Extension = finger flexion
wrist flexion = finger extension
159
what are the 3 functions of the retinacular system (flexor retinaculum)
prevent bowstringing of flexor tendons
maintains capral arch
optimizes flexor forces
160
what structure forms the roof of the carpal tunnel
flexor retinaculum
161
what needs to be cut open in carpal tunnel syndrome surgery
flexor retinaculum
162
what is the function of the extensor retinculum
functions as a pulley for the extensor tendons
maintains constant moment arm
163
what is the test for DeQuervains tendonitis
finklesteins test
164
what is the finklesteins tes
to test for dequervains syndrome
=wrist ulnar deviation and thumb flexion
165
what is dequervains syndrome
swelling of the tendons that run along the thumb side of the wrist and attach to the base of the thumb
(abductor pollicus longus and extensor polloicus brecvis)
1st dorsal comparement of the extensor retinaculum
166
what is the function of the the digital flexor tendon pulley system
prevents bowstringing
=increase torque and decrease excursion
167
how can a patient optimize FDS glide
make a straight fist
168
what are the fucntions of the pulley excision
there are 4 normal annular bullies facilitate normal flexion
169
what are the 3 most useful pulleys
a2, a4 and a3
170
what bands make up the diamond of stack in fingers
lateral bands
171
the lateral bands in the finger make up a shape, what is that shape called
diamond of stack
172
what three structures contribute to form the lateral and central bands of the fingers
EDC (extensor digi)
interossei
lumbricals
173
flexion of MCP and simultaneous extension of PIP/DIP relies mostly on what muscels
intrinsics (ex : lumbricals)
