Wrist imaging by venkatesh MPresentation Transcript
Distal portions of the radius and ulna, the
proximal and distal rows of carpal bones,and
the bases of the metacarpals .
The proximal row of carpal bones consists of
the scaphoid, lunate, triquetrum, and
The distal row of carpal bones contains the
trapezium, trapezoid, capitate, and hamate
The proximal carpal row is termed an
intercalated segment because forces acting
on its proximal and distal articulations
determine its position.
This aspect of the osseus anatomy becomes
important when considering the pattern of
collapse that occurs in the different types of
3joints- do not
Wrist flexion and
extension - half at
radiocarpal joint and
half at the midcarpal
Radial and ulnar
deviation - midcarpal
Pivot type of synovial joint.
Responsible for pronation and supination.
Connects ulna and radius at their distal edges
Separates DRUJ from radio-carpal joint.
Arises from the ulnar aspect of the lunate
fossa of the radius and inserts in the fovea at
the base of the ulnar styloid process
Connects ulna and radius at their distal edges
and separates DRUJ from radio-carpal joint.
Meniscal homolog - between the ulna and
Volar and dorsal radioulnar ligaments
Ulnar collateral ligament
Volar ulnolunate and ulnotriquetral ligament
Sheath of the ECU tendon
SagittalT1-weighted MR image. Note the thicker
appearance of the volar and dorsal portions of
theTFCC (arrows) on sagittal section.
The distal radioulnar joint is primarily
stabilized by theTFCC.TheTFC functions as a
cushion between the ulnar head and carpal
Many of the structures that make up the
complex are connected by fibrous bands
The radiocarpal joint is formed proximally by
the distal surface of the radius andTFC and
distally by the proximal row of carpal bones
The midcarpal compartment extends
between the proximal and distal carpal rows.
Lister’s tubercle on the dorsal radial ridge -
site of spur.
LIGAMENTS OF WRIST
EXTRINSIC LIGAMENTS INTRINSIC LIGAMENTS
Link the carpal bones to
the radius and ulna.
Figure 101-3 Anatomy of the volar ligaments. A, Diagram illustrating the volar
radiocarpal and ulnocarpal ligaments. B, Correlative coronal MR arthrogram
image. RLT, radiolunotriquetral ligament; RS, radioscaphoid (radioscapholunate)
ligament; RSC, radioscaphocapitate ligament; UC, ulnocarpal ligaments; UL,
ulnolunate ligament; UT, ulnotriquetral ligament
Normal intercarpal ligaments. A and B,Central portion.The central portions of the intercarpal
ligaments are thinner.They course along the more inferior aspect of the corresponding carpal bones as
seen on the coronal MR image in A and corresponding thin coronal histologic section in B. Note the
scapholunate ligament (white arrow in A, black arrow in B), and the lunotriquetral (arrowhead). The
scapholunate ligament may appear triangular in this central region. Also, note on the histologic
section the differing characteristics of theTFCC, with the more fibrocartilage-like articular disk (small
black arrow) and the more ligament-like peripheral ulnar attaching portion (smaller arrowheads in B),
see later discussion. C, Dorsal portion of the ligaments.The ligaments in this portion thicken and
extend more vertically, especially the scapholunate ligament. Scapholunate ligament (arrowhead),
lunotriquetral ligament (white arrow).
Limit motion and stabilize the proximal
Originate in forearm, insert onto carpal
Classified as volar or dorsal.
Volar radiocarpal ligaments are stronger and
thicker than the dorsal ligaments
Most important stabilizers of wrist motion.
Originate from the volar aspect of the styloid
process of the radius.
Radioscaphocapitate ligament (RSC)
connects the radius to the distal carpal row
and plays an important role in preventing
rotary subluxation of the scaphoid.
The second and strongest, the
radiolunotriquetral (RLT) ligament,
connects the radius to the proximal carpal
Provide stability to
in a fall on the
producing a "dorsal
Best depicted on
Coronal MR arthrogram.The dorsal
radiocarpal ligament (white arrow) is seen.
More distally the dorsal intercarpal ligament is
identified (black arrow).
Dorsal extrinsic ligaments of the wrist.
(A, B) Coronal 3D GRE images at
different levels show the dominant
dorsal carpal ligaments.
Carpal tunnel or carpal canal is the passageway
on the palmar side of the wrist that connects the
forearm to the middle compartment of the deep
plane of the palm
A total of nine flexor tendons pass through the
flexor digitorum profundus (four tendons)
flexor digitorum superficialis (four tendons)
flexor pollicis longus (one tendon)
median nerve between tendons of flexor digitorum
profundus and flexor digitorum superficialis
The ulnar canal or ulnar tunnel, also
called Guyon's canal, is a space
between flexor retinaculum and the palmar
carpal ligament (which runs between
the pisiform and the hamate ), through which
the ulnar artery and the ulnar nerve travel
into the hand.
Figure 21 Normal clenched fist view. With a tight fist, the contracting
tendons and muscles create a force within the wrist that drives the
capitate (C) proximally toward the scapholunate joint.
In wrists with a lax or disrupted scapholunate ligament, the joint will
In this case, the S-L interval did not abnormally widen.
The three carpal arcs: smooth curves joining
the surfaces of the carpal bones
-The first arc is a smooth curve outlining the
proximal convexities of the scaphoid, lunate
-The second arc traces the distal concave
surfaces of the same bones
-Third arc follows the main proximal
curvatures of the capitate and hamate.
An arc is disrupted if it cannot be traced
A break in one of the arcs indicates a fracture
or the disruption of a ligament leading to a
subluxation or dislocation
The joint spaces of the wrist have a width of 2
mm or less. Only the radiocarpal joint is
The carpometacarpal joints are slightly
narrower than the midcarpal joints.
The capitolunate joint is considered the
baseline joint width to which other joint
spaces can be compared.
Carpal joints should be symmetrical.
Furthermore, when viewed in profile
(tangentially), the cortical margins of the
bones constituting that joint should be
Bone edges that are not viewed in profile do
not display this parallelism
Drawing the longitudinal axes of some of the
carpal bones on a lateral radiograph and
measuring the angles between them is a
good method of determining the wrist bones-
The three most important axes are those
through the scaphoid, the lunate and the
capitate, drawn on the lateral radiograph.
The true axis of the scaphoid is the line
through the midpoints of its proximal and
Since the midpoint of the proximal pole is
often difficult to appreciate, an almost
parallel line can be used that is traced along
the most ventral points of the proximal and
distal poles of the bone
The axis of the lunate runs through the
midpoints of the convex proximal and
concave distal joint surfaces and can best be
drawn by finding the perpendicular to a line
joining the distal palmar and dorsal borders
of the bone
Normal: 30 - 60
Questionably abnormal: 60 - 80?
Abnormal: > 80-This indicates instability of the wrist.
The lunate has a trapezoidal shape, as the
sides converge from the proximal surface to
the distal surface, which are grossly parallel.
If the lunate is tilted, it becomes triangular in
shape.Awareness of this fact prevents thinking
the lunate might be dislocated based only on its
appearance, that in fact changes with its
So it may be dislocated with tilting or just be
Schematic representation of the lunate shape
in different positions
The capitate axis joins the midportion of the
proximal convexity of the third metacarpal
and that of the proximal surface of the
Normal: Abnormal: > 30- indicates instability
of the wrist.
The posteroanterior view of the distal forearm reveals
anatomic variations in the length of the radius and the
ulna, known as ulnar variance or Hulten variance.
As a rule, the radial styloid process exceeds the length
of the articular end of the ulna by 9 to 12 mm.
At the site of articulation with the lunate, however,
the articular surfaces of the radius and the ulna are on
the same level, yielding neutral ulnar variance
Occasionally, the ulna projects more proximally—
negative ulnar variance (or ulna minus variant); or
more distally—positive ulnar variance (or ulna plus
To quantify shortening of the
Comparison with the
contralateral side is necessary
STEP 1 – Obtain the long axis of
the Radius & extend the line
distally into the carpus
STEP 2 - Perpendicular line
drawn through the radial
STEP 3 - Another perpendicular
line drawn through the distal
articular process of ulna
Distance between the 2 parallel
lines = Radial Length
Radial Length = 12 mm
Describes the angulation of the distal radial articular
surface in the coronal plane
Important for predicting functional outcome
STEP 1 – Obtain the long axis of the Radius & extend the
line distally into the carpus
STEP 2 -The distal tip of the radial styloid and the ulnar
the distal radial articular surface are joined by a second line
STEP 3 - A perpendicular from the long axis of the radius is
placed to intersect the second line.The angle between
these two lines is the Radial inclination
Normal Radial Inclination = 16° - 28° (Mean = 22°)
Carpal height is the distance between the base
of the third metacarpal and the distal radial
articular surface as determined on a
PA radiograph of the wrist
--Measurement of carpal height allows
comparative quantification of carpal collapse in
an individual patient over time.
--The carpal height ratio allows comparison
between individuals and it is the carpal height
divided by the length of the third metacarpal.
Parameter MeanValue Range
0.54 ± 0.03
Height Ratio 1.57 ± 0.05
UlnarVariance 1 – 2 mm 0 – 2 mm
Radial Inclination 22 ° 16° – 28 °
Radial Length 12 mm 10 – 18 mm
PalmarTilt 11° 11° – 45°
There are two deep fat planes that are useful
in the radiographic evaluation of wrist
trauma: the pronator quadratus fat pad and
the scaphoid fat pad.
The pronator quadratus fat pad lies
between the pronator quadratus muscle and
the volar tendon sheaths. It is seen on the
lateral radiograph of the wrist as a linear or
crescentshaped lucency just anterior to the
distal radius and ulna.
The pronator quadratus fat pad.The pronator quadratus fat stripe
is seen on the lateral radiograph of the wrist as a linear or
crescent-shaped lucency just anterior to the distal radius and ulna
(arrowheads). Fractures involving the distal radius or ulna often
show volar displacement (arrows), blurring, irregularity, or
obliteration of this fat plane
The scaphoid fat plane or fat stripe is a
triangular or linear collection of fat that is
bounded by tendons of the abductor pollicis
longus and the extensor pollicis brevis and by
the radial collateral ligament.
This fat plane is seen on the PA radiograph as
a lucent stripe extending from the radial
styloid to the trapezium and almost
paralleling the radial aspect of the scaphoid
Scaphoid fat stripe. (A)The normal fat stripe is seen
the lateral aspect of the scaphoid (arrows).
(B) A non-displaced fracture of the scaphoid is
associated with obliteration of the fat stripe (circle).
The long flexor and extensor tendons,many
of the major ligaments, and the retinacula
of the wrist and hand can be assessed with
At sonography, peripheral nerves are
depicted as multiple parallel hypoechoic
areas (groups of fascicles) surrounded by
echogenic perineurium and/or epineurium
Normal sonographic appearance of tendons in the wrist. (a)
Longitudinal sonogram of the flexor surface of the wrist depicts the
flexor digitorum superficialis (FDS) tendon at its junction with the muscle.
Note the typical linear fibrillar appearance of the tendon. (b)Transverse
sonogram at the same level as a shows the musculotendinous
junctions of the flexor digitorum superficialis (FDS) and flexor
digitorum profundus (FDP).The tendons appear as hypoechoic fibrils in
echogenic fascicles surrounded by an echogenic epitendineum.
Transverse sonogram shows the extensor surface of
the wrist at the level of the distal carpal row, with a
normal small volume of anechoic synovial fluid in the
tendon sheath between the extensor tendons.
Normal sonographic appearance of nerves. (a)Transverse sonogram of
the median nerve in the distal forearm shows multiple hypoechoic
groups of fascicles surrounded by the echogenic perineurium and
epineurium, as well as an unusually prominent but normal median artery.
(b) Longitudinal sonogram of the median nerve shows parallel
hypoechoic groups of nerve fascicles
and the median nerve, which lies deep to the flexor digitorum
superficialis (FDS) muscle in the distal forearm.
2 most important are ;
2. Lunatotriquetral ligaments.
Disruption of these may result in pain,
instability, and carpal dissociation.
Injury to the triangular fibrocartilage may
occur in association with injuries to these
Forearm is placed prone
Wrist is positioned over a volar-placed pad or
rolled towel to achieve slight flexion
Scapholunate ligament on transverse
sonograms - compact triangular echogenic
fibrillar structure between lunate and
scaphoid, just distal to the Lister tubercle
Absence of a sonographically detectable
ligament does not necessarily indicate injury
With the wrist in the same position, the
dorsal lunatotriquetral ligament can be
located by passing the transducer slightly to
the ulnar side.
Appears as a compact echogenic fibrillar
structure between the lunate and triquetrum
(11)Transverse sonogram shows the dorsal aspect of the
proximal carpal row, just distal to the level of the Lister tubercle.
Note the echogenic fibrillar appearance of the dorsal scapholunate
ligament, which underlies the extensor digitorum (ED) tendons.
(12)Transverse sonogram at the same level as 11 but on the ulnar
side of the dorsal carpus shows the echogenic dorsal aspect of
the lunatotriquetral ligament and, above it, the extensor digiti
minimi (EDM) tendon.
Normal sonographic appearances of the carpal tunnel. (a)Transverse
sonogram over the carpal tunnel shows the hypoechoic flexor
retinaculum (arrowheads) with the median nerve immediately beneath
it.The long flexor tendons of flexor digitorum superficialis (FDS) and
flexor digitorum profundus (FDP) are located deep to the nerve. Note the
presence of a normal variant median artery (curved arrow) alongside the
median nerve. (b) Extended-field-of-view transverse sonogram of the
carpal tunnel shows the bones that mark its boundaries.
Transverse sonogram of the Guyon canal, obtained by
using the linear-array transducer in sector mode for a
wider field of view, shows the presence of a normal
variant accessory muscle that may be associated with
compression of the adjacent ulnar nerve.
Sonographic examination of the ulnar surface of
the wrist. (a) Photograph shows the correct
position of the transducer. (b) Longitudinal
sonogram shows the echogenic triangular
fibrocartilage deep to the extensor carpi ulnaris
Extensor retinaculum - strong fibrous band
that extends obliquely across the dorsum of
Has deep attachments along its course which
divide its surface into six separate
compartments numbered from radial (I) to
Each tunnel contains a single synovial sheath
that surrounds one or more extensor
Relationships of the 6compartments of the extensor
tendons (I−VI) with the Lister tubercle (arrow).
Radial boundary by tendons of 1st
Ulnar boundary by EPL
Proximally by the radial styloid, and
distally by the base of the thumb
Floor is formed by the scaphoid
proximally and the trapezium distally.
It contains the radial artery and
The extensor pollicis longus tendon (III) crosses the tendons of the 2nd compartment to reach
The anatomic snuff-box (arrow) is a triangular space delimited by the tendons of the 1st and 3rd
Lies within the carpal tunnel
Located immediately beneath the retinaculum,
just to the radial side of the superficial row of
flexor digitorum tendons
Rigid boundaries Increase in volume of
contents or decrease in size of tunnel
On transverse sonograms, the nerve appears
elliptic in outline and seems to become
progressively flatter as it passes through the
Transverse sonogram of the volar wrist
shows the median nerve (blue shade)
and the multiple flexor tendons (yellow
shade) of the normal carpal tunnel.
Transverse sonogram of the volar wrist
shows the median nerve (blue shade)
and the multiple flexor tendons (yellow
shade) of the normal carpal tunnel.
Transverse sonogram of the
volar wrist shows the median
nerve (blue shade) and the
multiple flexor tendons
(yellow shade) of the normal
Longitudinal sonogram of the volar wrist shows the
median nerve (blue shade) and the flexor tendons
(yellow shade) of the normal carpal tunnel.
Longitudinal sonogram of the volar wrist shows the
median nerve (blue shade) and the flexor tendons
(yellow shade) of the normal carpal tunnel.
The most useful bony landmarks to identify
the proximal carpal tunnel are the pisiform
at its ulnar side and the scaphoid at its
Distal carpal tunnel - delimited by the
trapezium and the hamate
As the ultrasound beam interacts with
multiple parallel interfaces such as ligament
or tendon fibers, the beams may be reflected
away from the transducer if the probe is not
held exactly perpendicular to the structure.
This effect results in anisotropy artifact
(ie, an apparent area of reduced echogenicity
in the ligament or tendon on the acquired
Anisotropy artifact.Transverse sonograms of the extensor surface of the
wrist show the extensor digitorum(ED) and extensor pollicis longus (EPL)
tendons, clearly and without artifact on the image obtained with the
probe held exactly perpendicular to the tendons (a), but with a
significant loss of echogenicity on the image obtained with the probe
held at an oblique angle to the tendons (b).
Rocking the transducer backward and
forward over the ligament or tendon in the
longitudinal axis (also referred to as heel-
toeing) helps depict the normal echogenic
CT should be performed if conventional
radiographs provide insufficient detail about
radiocarpal articular step-off and gap
Computed tomography (CT)-protocol
Two- to 3-mm axial and direct coronal or sagittal
images for conventional studies. Axial images at
1- and 0.5-mm intervals for coronal and sagittal
reformatting or three-dimensional reconstruction.
MR imaging has provided us with new
insights into the difficult anatomy of the wrist
by allowing improved visualization of the
relationship of the muscles, ligaments,
tendons and bone
Its multiplanar and exquisite soft tissue
contrast capabilities allow for depiction of
subtle osseous and soft tissue pathology.
Carpal tunnel syndrome
Neoplastic lesions of the wrist and hand
Magnetic resonance imaging (MRI)
Field of view: 8 to 12 cm
Coil: wrist coil or flat 5-inch coil (motion studies)
Patient position: arm at side when possible;
otherwise, arm above head
Supine with arms by the side of patient
Larger patients - arm above head.
Wrist in pronation with fingers slightly
Long axis of distal radius & central
metacarpal axis in neutral position with
T1WI in axial, coronal and sagittal planes.
FSET2- axial and coronal.
STIR or fat satT2 FSE axial and coronal for tenosynovitis,
ganglia, carpal tunnel syndrome and neoplasms.
GRE coronal sequences for ligaments and fluid.
3D SPGR for anatomy ofTFCC & intrinsic ligaments .
T1 and STIR / fat satT2 for bones.
Anatomy of the volar ligaments. A, Diagram illustrating the volar radiocarpal and ulnocarpal ligaments. B,
Correlative coronal MR arthrogram image. RLT, radiolunotriquetral ligament; RS, radioscaphoid
(radioscapholunate) ligament; RSC, radioscaphocapitate ligament; UC, ulnocarpal ligaments; UL,
ulnolunate ligament; UT, ulnotriquetral ligament.
IV gadolinium for synovitis, wrist masses, and in
evaluating the vascularity of the scaphoid or
lunate in avascular necrosis (AVN).
Kinematic wrist devices to track carpal row
motion with radial and ulnar deviation of the
A saline / gadolinium mixture
3 to 4 mL injected into the radiocarpal
Intra-articular gadolinium distends the joint
Most efficacious method of diagnosing
Fat-saturatedT1-weighted images obtained
in all three imaging planes.
At least one additional fat satT2 in coronal
Gadolinium is injected IV.
Passive or active motion to exercise the
patient to create a joint effusion and to
obtain an arthrographic effect
Imaging done 15 minutes after injection to
enhance vascularized or inflamed tissue
Used when direct techniques are
Coronal MR 3DT1W gradient-echo image
obtained after Intravenous Injection Of A
Gadolinium-based Contrast material
After intraarticular contrast injection into the
radiocarpal joint in another patient illustrates
high signal contrast extending through aTFC
defect into the DRUJ
Most common injury to the wrist caused by a
fall on an outstretched hand.
The classic Colles’ fracture is a transverse
fracture, with or without comminution, with
or without intraarticular extension,
accompanied by impaction and dorsal
displacement of the distal surface of the
Colles’ fracture. (A) PA oblique and (B) lateral views show
a metaphyseal fracture of the radius (arrows) in mild dorsal
angulation with associated ulna styloid tip avulsion fracture
The scaphoid is the most commonly
fractured carpal bone in adults, accounting
for 70% of all carpal injuries
Scaphoid fractures may be difficult to detect
Imaging of scaphoid fractures requiresAP, lateral, and
scaphoid views. Displacement or obliteration of the
navicular fat stripe is a useful sign for subtle
Radionuclide scans, MRI, or CT may be useful for
detecting subtle fractures and evaluating
Complications: delayed union (failure to unite in 3
months), nonunion, malunion, AVN (most common
with proximal pole fractures), radioscaphoid
impingement, and arthrosis.
(A) Locations of
1, tubercle; 2, distal
articular surface; 3,
distal third; 4, waist;
5, proximal pole. (B)
(arrows) lead to
fracture is more
X-ray in a 22-year-old man with acute trauma of the right wrist is suggestive of a scaphoid
fracture (b) Longitudinal US obtained in the lateral direction clearly shows cortical
discontinuity (c) STIR MR image obtained - diffuse high-signal-intensity alteration of the
bone marrow of the scaphoid (straight arrows) and discontinuity of the cortex.
Humpback deformity of the
scaphoid results from angulation of the
proximal and distal parts of a scaphoid in the
setting of scaphoid fracture through the waist
It is important to identify as it can result in
progressive collapse of the scaphoid with
non-union, and even if eventual union is
achieved, destabilisation of the wrist
At first, there is angulation between
fragments; next, the two fragments settle
or impact into each other; and finally an
exostosis (curved arrow) or bony
prominence (the humpback deformity)
develops dorsally at the fracture site.
Usually occurs after a fracture through the
waist or proximal pole (in 30 %).
Preiser disease - NontraumaticAVN
Chronic AVN - diminished signal intensity
with all pulse sequences, with or without
associated bone collapse
Gad is helpful in determining the likelihood of
AVN of the proximal pole - enhancement
implies vascularised vital tissue
STIR– hyperemia of distal pole marrow
T2W - Low signal intensity of the
proximal pole of the scaphoid
(arrows) consistent with AVN.
Patient had no history of trauma, and
no fracture line was evident.
T1W – Fracture line and AVN
AVN of lunate.
Negative ulnar variance is associated
Subchondral bone adjacent to the radial
articular surface is relatively avascular.
Repeated trauma and compression fractures.
Transverse microfractures may be seen
pathologically to precede frank AVN.
Progression to lunate collapse and proximal
migration of the capitate bone results in loss
of normal carpal structure.
Frontal view of the hand
and wrist demonstrates
and collapse of the lunate
(blue arrows) in Kienbock's
CoronalTi-W - abnormally low signal
intensity in the lunate, compression of
subchondral bone, and preservation
of normal articular cartilage (arrow).
Represent Kienbock disease.
appear as slight
distortion of the
pattern of the
The triquetrum is the second most commonly
injured carpal bone (3 to 4% of all carpal bone
Isolated fractures of the capitate, trapezium,
and trapezoid are infrequent.
Fracture of the body of the triquetrum. (A) A conventional
lateral x-ray may not show this rare type of triquetral
injury. It is better diagnosed with (B), computed
Fracture of the distal radial metaphysis or
epiphysis, with or without articular
involvement, demonstrating palmar
displacement or angulation.
Barton’s Fracture is a marginal fracture of the
dorsal rim of the radius that displaces along
with the carpus, producing a fracture-
A variant of the Barton’s fracture involves the
palmar rim of the distal end of the radius and
may be more common than its dorsal
It is sometimes referred to as a reverse
Barton’s or a palmar Barton’s fracture.
Barton’s fracture. (A) Lateral and (B) AP oblique views
show a marginal fracture of the dorsal rim of the
radius that is displaced along with the carpus,
producing a fracture-subluxation.
Reverse Barton’s fracture. (A) Lateral and (B) PA views
demonstrate a volar rim fracture with palmar displacement of the
carpus with the rim fragment (arrow), consistent with a fracture
Fracture of the base of the thumb metacarpal. (A) A Bennett’s
fracture is consistent with a two-part fracture-dislocation (circle).
(B)A Rolando’s fracture is consistent with a comminuted
(three-part) fracture (circle).
In the skeletally immature, a stress reaction
can develop primarily at the distal radial
growth plate and to a lesser degree in the
distal end of the ulna.
Gymnastics is the major cause of it
The physeal plate shows irregularity, cystic
change, and widening, consistent with a
Salter–Harris type I or II injury.There may be
adjacent bone fragmentation.
“Gymnast’s wrist (SH I injury).” (A) PA and (B) lateral wrist
views demonstrate widening of the physis of the radius (arrows)
secondary to chronic stress reaction in a gymnast.
Carpal instability occurs when there is
symptomatic malalignment between the
rows of carpal bones and between the carpal
bones and the radius.
Figuratively speaking, the proximal carpal
row is termed an intercalated segment
because forces acting on its proximal and
distal articulations determine its position.
DISI is short for dorsal intercalated segmental
The intercalated segment is the proximal
carpal row identified by the lunate.The term
'intercalated segment' refers to it being the
part in between the proximal segment of the
wrist consisting of the radius and the ulna and
the distal segment, represented by the distal
carpal row and the metacarpals.
Volar intercalated segmental instability or
palmar flexion instability is when the lunate is
tilted palmarly too much.
Common dislocations of the wrist are the
lunate and perilunate dislocations.
The key to differentiation between both is
what is centered over the radius.
If the capitate is centered over the radius and
the lunate is tilted out, it is a lunate
If however the lunate centers over the distal
radius and the capitate is dorsal, we are
dealing with a perilunate dislocation
LEFT: Lunate dislocation: capitate is centered over
the radius and lunate is tilted out.
RIGHT: Perilunate dislocation: lunate is centered
over the radius and capitate is tilted out dorsally.
Loss of mechanical linkage between scaphoid
Usually relates to complete disruption of
the scapholunate interosseous ligament (SLIL)
Frontal Conventional Radiographic Signs:
TerryThomas Sign (AKA David Letterman sign)
Increased scapholunate joint space when compared
to contralateral side
Any asymmetric gap measuring greater than 5 mm is
diagnostic of SLD.
Scaphoid Ring Sign
A radio-dense ring seen over the distal scaphoid
representing rotary subluxation and foreshortening of
Lateral Plain Film Signs
> 70 degrees suggestive of dorsal intercalated
segment instability (DISI)
Seen when scaphoid is in abnormal flexion;
normal “C”-shaped line formed by palmar margins
of scaphoid and radius form an acute angle as
palmar outline of scaphoid intersects outline of
radial styloid, forming sharper “V”-shape
Younger patients Older patients
Occur near radial attachment In vascular zone near ulnar attachment
Ulnar negative variance Ulnar positive variance
Associated with ulno lunate impaction
oTears of the TFC should be suspected in
patients with Ulnar-sided wrist pain and
oTFCC tears also can involve instability of the
CoronalT1,T2W,GRE, STIR or fat satT2 FSE
3D SPGR sequences for radio-ulnar and ulno-
Biconcave disc - homogeneous low to
intermediate signal intensity.
Full-thickness defects of theTFCC
Degenerative tears of theTFC - linear band of
increased signal intensity onT1W and GRE
With complete tears the signal extends to
proximal and distal articular surfaces.
In partial tears signal will extend only to one
articular surface, usually the proximal surface
High signal onT2W or GRE - consistent with
synovial fluid trapped in the defect.
Fluid collecting in the DRUJ is an important
secondary sign, but the presence of fluid
signal alone is not indicative of a tear ofTFCC
MR arthrography with either a radiocarpal or
distal radioulnar joint injection will reveal
contrast extending through and outlining the
Triangular fibrocartilage tears. Radial-sided tears coronal 2DT2* gradient-echo image (A)
andT2 FSE image with fat saturation (B) demonstrate fluid signal intensity in the radial
aspect of theTFC (arrow), which extend to the radiocarpal and distal radioulnar joint (DRUJ)
articular surfaces. Fluid is seen in the DRUJ.
(C) Coronal ‘‘hi-res’’T1 FSE image after
intraarticular contrast injection into the
radiocarpal joint in another patient
illustrates high signal contrast
extending through aTFC defect into
the DRUJ (black arrow).
Chronic peripheral (TFCC) synovitis.Coronal
T2-weighted MR image. Marked thickening
and fluid signal is seen along the ulnar
attachments and ulnar aspect of theTFCC
Entrapment syndrome due
to compression of median nerve at the wrist
Anatomic variants - narrow tunnel, presence of
the median artery, abnormal and accessory
tendons and muscles
Susceptibility of the nerve to pressure -
diabetes, systemic neuropathies
Systemic and endocrine disorders - Pregnancy,
Space-occupying lesions within the tunnel
A normal nerve does not exclude the diagnosis
Nerve appears swollen at the proximal tunnel
and flattened at the distal tunnel
“Notch sign” - An abrupt nerve calibre change
at the entrance of the carpal tunnel
Nerve becomes uniformly hypoechoic with loss
of the fascicular pattern - Intraneural edema or
Hyperemic blood flow in the longitudinal
perineural plexus and within intraneural
Long-axis 12−5 MHz US image of the median nerve showing the notch sign at a higher
Corresponding schematic drawing illustrates the main nerve shape abnormalities
in carpal tunnel disease. Note the swelling portion (arrows) of the median nerve (MN) at the
distal radius, proximal to the level of compression (arrowheads) and the nerve flattening deep
to the transverse carpal ligament (curved arrow)
Carpal tunnel syndrome. Median nerve (MN) appears increasingly swollen and hypoechoic
(open arrows) with absent fascicular pattern
Observe the normal size of the nerve at the forearm (white arrowheads) between the FDS and
At proximal carpal tunnel level, the notch sign (open arrowheads), indicates the compression
point. More distally, at the distal carpal tunnel, the nerve remains flattened and hypoechoic
Width over 1.0 cm is suspect for and any
measurement over 1.5 cm is consistent with
CarpalTunnel Syndrome, if suspected
Compare to the contralateral side if unilateral
involvement is suspected or one side is more
symptomatic than the other.
If one nerve is significantly larger than the
other, regardless of measurements, this
Method for calculating the bulging of the transverse carpal ligament.A line (dashed line) is
drawn to join the tubercle (star) of the trapezium (Tra) and the hook (asterisk) of the hamate
(Ham).Then, a perpendicular (continuous white line) to this line is drawn to reach the most
prominent portion of flexor retinaculum (arrowheads). When this latter line measures 4 mm, it
indicates abnormal bulging of the ligament
Bowing ratio –TH line divided by perpendicular line - >0.15 suggests increased pressure /
volume in tunnel
Quantitative indexes in
carpal tunnel syndrome -
pressure may often lead to
an increased convexity of
the transverse carpal
ligament that is normally
straight or slightly convex
Besides assessing the median nerve and the
transverse carpal ligament, extrinsic causes
for nerve entrapment can also be identified
Most patients with carpal tunnel syndrome
are affected by tenosynovitis of flexor
A variety of SOLs can be encountered within
the carpal tunnel.
Carpal tunnel syndrome in tenosynovitis
of the flexor tendons
Long-axis US image of the median nerve
at the distal radius
demonstrates abnormally increased
fluid effusion (asterisks) surrounding
flexor tendons (ft), resulting in palmar
and compression of the median nerve
(MN) at the entrance of the tunnel
Long-axis colour Doppler US image
of the median nerve (MN)
demonstrates blood flow signals
(arrowheads) from the longitudinal
perineural plexus and the
intranervous branches as a result of
hyperemic changes related
with the inflammation
Carpal tunnel syndrome. Sagittal US scans show swelling of the proximal portion of the
median nerve (arrows) in the right wrist (RT) in a 45-year-old woman. Color Doppler US
shows increased vascularity in the swollen part of the nerve. Compare with the normal
median nerve (arrowheads) in the left wrist (LT).
Palm ganglion with median nerve compression.Transverse US scan of the median nerve
at wrist level shows an anechoic ganglion (arrows) compressing the median nerve
(arrowheads) in a 60-year-old man.
Carpal tunnel syndrome in a 52-year-old man with rheumatoid arthritis. Longitudinal (a)
and transverse (b) 10-13-MHz US images obtained at the distal radius show abnormally
increased effusion (*) surrounding the flexor tendons (FT), resulting in palmar
displacement and compression of the median nerve (MN) at the entrance to the tunnel
Changes seen in median nerve-
Median nerve shape – flattening , swelling ,
Diffuse swelling or segmental enlargement.
Increased signal intensity in median nerve inT2*
or STIR sequences - Due to oedema or
Palmar bowing of flexor retinaculum.
Deep palmar bursitis
Soft tissue masses
Post gad- Enhancement due to nerve edema or lack
of enhancement due to ischemia.
Bowing of retinaculum – Bowing ratio
Inflamed synovium and tendon sheaths are hypo on
T1 and hyper onT2 and STIR sequences.
(a) AxialT2-weighted MR image proximal
to the transverse carpal ligament
demonstrates enlargement of and
increased signal intensity within the
median nerve (arrow). R = radial aspect.
(b)AxialT2-W MR image obtained more
distally in a patient with symptoms of CTS
demonstrates relative flattening of the
median nerve (arrow).
relative flattening at the level
Entrapment of ulnar nerve in Guyon’s canal
Causes : fracture or mass lesions.
Normal nerve- low signal.
Guyon tunnel syndrome.Transverse (left) and sagittal (top right) US scans show a well-defined
hypoechoic nodule (arrowheads) in the wrist, compressing the ulnar nerve (arrows) in a 48-
year-old man in whom leiomyoma was diagnosed. Color Doppler image (bottom left) shows
the ulnar nerve (A) located between the tumor and ulnar artery.
Guyon tunnel syndrome: ganglion. Transverse US scans of the wrist show an
anechoic ganglion (G) compressing the ulnar nerve (arrowheads) at wrist level.The
ulnar nerve is located between the ulnar artery and ganglion.
Ulnar lunate abutment syndrome is associated
with ulnar positive variance (Fig. 9-55).
Ulnar wrist pain that often is exaggerated by
ulnar deviation of the wrist.
Radiographs show ulnar positive variance and
sclerosis or cystic change in the lunate and
Features are more easily demonstrated with
MRI for early bone, cartilage, and triangular
PA radiograph demonstrates ulnar positive variance (line),
prominent ulnar styloid, and sclerotic changes in the lunate and
triquetrum caused by cartilage loss (open arrows).
(A)T1-weighted image shows low signal intensity in
the lunate and adjacent triquetrum. (B) Gradient echo
coronal shows displacement of the radial aspect of
the triangular fibrocartilage (open arrow) and a
peripheral tear (black arrow).
De Quervain tenosynovitis involves the first
dorsal extensor compartment.
Patients present with pain and restriction of the
extensor pollicis brevis and abductor pollicis
The condition is most common in women 30 to
50 years of age
MRI or ultrasound may be used to confirm the
diagnosis.The region of the radial styloid may
have abnormal signal intensity as the result of
chronic tendon thickening
De Quervain tenosynovitis. Coronal fast spin-
echo fat-suppressedT2-weighted image
demonstrates marrow edema in the radial
styloid and thickening (arrow) of the adjacent
Resulting from the intraarticular presence of
calcium pyrophosphate dihydrate (CPPD)
The condition may be asymptomatic, in
which case the only radiologic finding may be
Characterized by calcification of the articular
cartilage and fibrocartilage; the tendons,
ligaments, and joint capsule may exhibit
calcifications as well
A dorsovolar radiograph shows chondrocalcinosis of the
triangular fibrocartilage, cystic changes in the scaphoid
and lunate, and narrowing of the radiocarpal joint.
Synovitis - increased
US - thickened,
articular tissue that
Dorsal wrist - noncompressible
hypoechogenicity, likely representing a
capsule (arrowheads) , synovial
Increased signal on fluid-sensitive sequences
in areas invested by synovium.
Advanced stages - synovium becomes
hypertrophied beginning at bare areas of the
Bare area - Intra-articular cortical bone
within the joint capsule, lined by synovium
but devoid of hyaline articular cartilage.
An inflammatory pannus - increased signal
on fluid-sensitive sequences - difficult to
differentiate from effusion
Enhancement of the synovium occurs rapidly
between 60 and 120 seconds
After this period, equilibrium occurs between
the synovium and the effusion in which the
Gd diffuses from the synovium into the
(A) CoronalT1-W - Heterogeneous low-signal intensity within the scaphoid and lunate.
heterogeneous low signal in the distal radioulnar joint and ulna styloid recess in a patient with
RA. (black arrowheads).
(B)Coronal fat-suppressedT1W post contrast - Pannus enhancement in the ulna styloid recess
and distal radioulnar joint in a patient with RA (white arrowheads). Note the erosions of the
waist of the triquetral bone. A subchondral cyst
is noted at the base of the lunate.
(A) AxialT2-W - large tophus displacing the
extensor carpi ulnaris tendon dorsally
(B) CoronalT1-W - gouty tophus (double
arrowheads) and thick inflamed synovium along the
extensor carpi ulnaris tendon sheath (arrowhead).
Cystic swelling overlying a joint or tendon
sheath with/without septations
Secondary to the protrusion of encapsulated
Extending toward the adjacent joint.
Usually symptomatic, due to increased
ligamentous pressure or compressed nerve
More on dorsal side (70%), scapholunate region
MRI and US: equally effect in detection
US: initial imaging procedure due to dynamic
capabilities, lower cost.
with point to
US image -an
Edema or inflitration of the adjacent tissues is
Low onT1 and high onT2.
May be loculated with fibrous septations.
Subperiosteal ganglion. a (arrowheads) arising from
the periosteum of the ulna and gradually sinking
into the ulnar head (curved arrow) as a result of the
pressure absorption of the bone below the enlarging
Note the extensor carpi ulnaris tendon (straight
arrow) displaced and compressed between the
ganglion and the retinaculum.
b Oblique radiographic view and c transverse T2w
tSE MR imaging correlation confi rm a deep bone
erosion (curved arrow) in the ulnar head.
Intersection syndrome occurs slightly
proximal to de Quervain tenosynovitis .
A bursa may form between the extensor
carpi radialis longus and brevis and the
abductor pollicis longus and extensor pollicis
Patients with intersection syndrome are
frequently involved in racket sports and
present with pain, weak grip, and crepitation
Axial fat-suppressedT2-weighted image
demonstrating a fluid-filled bursa (arrow).