This document provides an overview of imaging of the wrist joint. It begins with an introduction to the anatomy of the wrist joint and the role of x-ray and MRI in evaluation. Specific anatomical structures are then described such as the carpal arcs, axes, angles, ligaments and neurovascular structures. Common pathologies are discussed including tears of the triangular fibrocartilage complex (TFCC), scapholunate dissociation, lunate dislocations, and Kienbock's disease. Imaging appearances of these conditions on x-ray, ultrasound and MRI are presented. Other topics covered include ulnar variance, carpal tunnel syndrome, Guyon's canal syndrome, and intersection syndromes.

1. Imaging of Wrist joint
DR RAKIB AHMAD WANI
PG III YEAR

2. Introduction
• This joint is a complex joint in upper limb
• Consists of articulations of Radius, ulna,
carpus and carpo-metacarpal bones
• To evaluate and interpret wrist images one
should be fully aware of the anatomy
• X ray serves as basic tool while MRI serves to
answer the issues of soft tissues

3. Anatomy
• Wrist joint is formed by
Distal radio-ulnar joint,
Radio-carpal and Mid-
carpal joint
• Sigmoid notch of radius
articulates with ulna

4. X ray wrist

5. Parallelism and symmetry
• Joint spaces of wrist joint
are more or less
symmetrical
• Average width of joint
spaces are 2mm or less
• Capitato-lunate serves
as standard space to
which others should be
compared.

6. Carpal arcs
• Three arcs should be
drawn
• 1st is formed by
convexities of Scaphoid,
lunate and Triquitrum
bones
• 2nd is formed by inner
concavities of same bones
• 3rd is formed by proximal
curvature of Capitate and
hamate.

7. Asymmetry
• Any asymmetry in the
joint space and loss of
parallelism points that
some disruption has
occurred
• Depending on which
arch or which joint
space is widened,
pathology lies in the
same compartment

8. Asymmetry

9. Angles and Axes of Carpals
• Scaphoid axis : is formed
by proximal and distal
poles
• Lunate axis : is drawn
perpendicular to proximal
convex and distal concave
surface
• Capitato-lunate angle : >
30 is abnormal
• Scapho-lunate angle: 30-
60 is normal; 60-80 is
questionable and > 80 is
abnormal

10. Axes and Angles

11. Flexor retinaculum
• Is a rectangular fibrous
band and forms roof of
carpal tunnel
• Radially attached to
ridge of trapezium and
on ulnar aspect to hook
of hamate
• On ulnar aspect it forms
Guyon canal

12. Flexor retinaculum

13. Guyon’s canal
• Is a fibro-osseous
tunnel that contains
ulnar neuro-vascular
bundle
• Landmarks are deep to
FCU, Lateral to Pisiform
and at the hook of
hamate

14. Extensor Tendons
• On dorsal aspect,
tendons are divided
into 6 compartments
• Lister tubercle is
important landmark
that separates II and III
compartment.

16. Triangular Fibro-Cartilage complex
• It is a complex structure
has various parts :
Triangular fibro-
cartilage ; Radio-ulnar ;
ulno-carpal; Meniscal
homologue; ECU
tendon and ulnar
collateral ligament.

18. TFCC

19. TFCC

20. RU ligaments

21. Inter-carpal ligaments
• These are stabilizers of the wrist joint and are
divided into extrinsic and intrinsic parts.
• Intrinsic : Scapho-lunate, Luno-triquetral are
important ones .
TFCC.
• Extrinsic: volar, Dorsal, RCL and UCL

22. Inter-carpal ligaments
• The two important
ligaments are in the
proximal row : scapho-
lunate and luno-
triquitrum.
• The first one is
pyramidal and latter is
horse shoe in shape

23. Pathologies

24. TFCC Tear
• It can be traumatic in
young in radial end and
degenerative in elderly at
ulnar end
• Presents with ulnar side
wrist pain
• Seen as fluid intensity
signal along the ulna
• Discontinuity of complex
is seen on MR
arthrogram.

25. TFCC Tear

27. Palmer classification
• class 1
a) central perforation
b) Ulnar avulsion with or
without ulnar fracture
c) Avulsion of Ulno-
triquetral and ulno-
ilunate ligament
d) Radial avulsion of TFCC
• Class 2
a) TFCC wear with thinning
without perforation
b) TFCC wear with
ulnar/lunate/triquetral
chondromalacia
c) TFCC perforation with
chondromalacia
d) Luno-triquetral perf with
2a/2b or 2c
e) Any of above with ulno-
carpal arthritis

28. Scapho-lunate dissociation
• Is aka rotatory
subluxation of scaphoid.
• Refers to abnormal
orientation of scaphoid
and lunate and is due to
injury to the scapho-
lunate ligament
• Relative flexion of
scaphoid with relative
extension of lunate is
typical pattern
• On x ray widened
Scapho-lunate interval
of >4mm is seen
• Increase in Scapho-
lunate angle >60 degree
• On MRI examination, It
is seen as discontinuity
of the Scapho-lunate
ligament along with
joint effusion.

29. SL dissociation
Terry Thomas sign MRI imaging

30. SL Tear Grading

31. Lunate Dislocations
• These are uncommon traumatic wrist
injuries .
• Lunate is displaced and rotated volarly.
• Occurs due to fall on out-stretched hand.
• Lunate shows “Piece of Pie sign”
• Rest of the bones are well aligned with
maintained symmetry.

32. LD

33. Peri-lunate dislocation
• Are potentially closed wrist injuries and
involve the carpus relative to lunate
• involves scapho-lunate and Luno-
triquetral ligaments
• In this pathology, the Capitate (apple)
doesn’t sit in the concavity of Lunate
(Cup)

35. Dorsal and Volar intercalated
segment instability
• DISI is the form of
instability involving
wrist joint in which
Lunate is displaced
dorsally.
• Disruption of the
scapho-lunate ligament
• Due to wrist trauma
• SL angle of >60 degree
• CL angle >30 degree
• VISI is less common
in which lunate is
displaced palmarly
• Ligament injured is
Luno-triquetral
ligament
• SL <30 degrees
• CL >30 degree

36. DISI

37. VISI

38. Ulnar variance
• It is defined as the relative length of distal end of ulna
wrt radius
• If ulna is shorter than radius it is called Negative ulnar
variance
• If ulna is longer than radius it is called positive ulnar
variance
• If both are equal it is called neutral variance
• On radiographs Positive variance is when the level of
the ulna is >2.5 mm beyond the radius margin at the
distal radio-ulnar joint and negative variance is when
the ulna is ≤2.5 mm than the radius at the DRUJ

39. Ulnar variance
Positive Negative

40. Ulnar impaction syndrome
• Occurs in association with
positive ulnar variance
• May occur with distal
radial fracture
• Consequent bone signal
changes are seen in distal
ulna, radial side of
triquetrum and ulnar side
of lunate
• TFCC and luno-triquetrum
tear is seen on MRI

41. Ulnar impaction syndrome

42. Ulnar impingement syndrome
• Occurs in association with
Negative ulnar variance
• shortened distal ulna
results in contraction of
the extensor pollicis
brevis, abductor pollicis
longus, and pronator
quadratus muscles which
prevents normal
buttressing of the
radioulnar joint.
• Seen as edema where
ulna converges on radius

43. Ulnar impingement syndrome

44. AVN of Scaphoid bone
• Trauma of scaphoid
bone leads to AVN
• It has peculiar blood
supply where in
proximal pole receives
blood supply in
retrograde fashion
• It mnifests as sclerosis
of bone on wrist
radiographs

45. AVN of scaphoid

46. Kienbock disease
• Is associated with negative ulnar variance
together with a susceptible blood vessel
• Is defined as osteonecrosis of the lunate
where cortical blood supply is compromised
and results in infarction of the bone with
surrounding hyperemia
• Sclerosis with negative ulnar variance is seen
• Bone signal changes are seen along the central
and radial aspect of lunate

47. Kienbock disease

48. Stahl classification of Kienbock disease
• stage I: normal radiograph
• stage II: increased radio density of the lunate
with possible decrease of lunate height on the
radial side only
• stage III
– IIIa: lunate collapse, no scaphoid rotation
– IIIb: lunate collapse, fixed scaphoid rotation
• stage IV: degenerative changes around lunate

49. Kienbock disease
Stage II AP Stage II Lateral

50. Carpal coalition
• Refers to failure of separation of two or more
carpal bones
• Lunate and triquetrum are most common
• It may be osseous, cartilaginous or fibrous
• Associated with Holt oram, turner syndrome
etc

51. Carpal coalition

52. Carpal Tunnel Syndrome
• Results from the compression of Median Nerve in carpal tunnel
• Nocturnal ascending pain emanating from the wrist, is typical
• sensory symptoms affect the first three digits and, depending on
innervation patterns, the radial aspect of the fourth digit
• Positive Tinel test: paresthesias elicited by tapping the median
nerve at the wrist
• Occurs due to
mechanical overuse (considered the most common association)
osteoarthritis
trauma
acromegaly
• Ganglion cysts, primary nerve sheath tumors
synovial hypertrophy in rheumatoid arthritis

53. USG CTS
criteria
• Palmar bowing of Flexor
retinaculum of >2mm
• Flattening of nerve distally
with increased thickness
proximally
• Normal Cross section area is
9-11mm sq
• Difference of > 2mm sq at
CT and pronator quadratus
has high sensitivity
Image

54. Images

55. USG

56. MRI for CTS
• In carpal tunnel syndrome, MRI can demonstrate
palmar bowing of the flexor retinaculum,
enlargement of the median nerve at the level of
the pisiform, and flattening of the median nerve
at the level of the hook of hamate.
• Other signs are edema or loss of fat within the
carpal tunnel, and increased size or edema of the
nerve on fluid-sensitive sequences, and, in some
cases, contrast enhancement of the nerve

57. MRI

60. Fibrolipomatous hamartoma of MN
• It is a benign neoplasm
of median nerve
• Proliferation of fibro-
adipose tissue of sheath
• Imaging features are co-
axial cable like
appearance on axial and
spaghetti like on
coronal images

62. Guyon’s canal syndrome
• Results from compression
of ulnar nerve.
• Hook of hamate fracture,
Ganglion cyst are its
causes.
• On x ray hook of hamate
fracture is seen.
• On USG ganglion cyst,
lipoma or ulnar artery
thrombus is seen and on
MRI these findings are
seen with better accuracy

63. De Quervain TS
• Aka washerwoman’s
sprain
• Occurs due to
inflammation of EPB
and APL tendons
• On USG Thickening of
tendons with fluid in
extensor compartment
and increased flow on
CDI in peri-tendonous
region

65. MRI
• More sensitive and
specific
• Increased fluid in
tendon sheath
• Thickened edematous
retinaculum with peri
tendenous edema
• Sometimes features of
tendonosis are also
seen

66. Proximal intersection syndrome
• Is overuse tenosynovitis around the
intersection of 1st and 2nd compartment
extensor tendons
• Seen in weight lifters, skiers etc
• Fluid is seen within the involved tendons with
loss of hyper echoic plane between the
tendon compartments
• On MRI peri tendenous edema is noted 4cm
proximal to lister’s tubercle

67. Proximal intersection syndrome
USG MRI

68. Distal intersection syndrome
• Relates to teno-synovitis of EPL tendon where
it crosses the ECRB and ECRL tendon
• Crossover is located just distal to lister’s
tubercle
• Over us, trauma and RA are etiologic factors
• Edema is noted in peri-tendenous region at
intersection point

69. Images

70. Ganglion cyst
• is a non malignant
cystic mass and result
from myxoid
degenration of
connective tissue
assoiated with joint
capsule and tendon
sheath
• Seen as anechoic cyst
with PAE on USG and
cystic signal on MRI

72. Value of axial and coronal images
Axial
• Distal RU joint
• Carpal tunnel and contents
• Flexor and extensor tendons
• Ulnar nerve and median
nerve pathologies
Coronal
• TFCC
• Ulnar Variance
• Scapho-lunate and Luno-
triquetral ligaments
• Fractures
• AVN
• Arthropathies

73. Summary
History and clinical findings should be available
Assess the congruity of bones on bones, Look for
any asymmetry
Look for ulnar variance
Look for any bone marrow edema/effusion
Asses inter-carpal ligaments and TFCC
Look carefully for any pathology of
carpal/Guyon’s canal
Findings should be noted to reach to a specific
diagnosis

74. Thank
You