1. Fractures and dislocations of the wrist
Dr Ihab Rassem
Lecturer of radiology Ain Shams University
Cairo, Egypt

2. Radiographic views Dorsovolar (PA) Lateral
Dorsovolar with ulnar deviation (scaphoid)
Supinated oblique (pisiform, pisotriquetral joint)
Pronated oblique (triquetral)
Carpal tunnel (hook of hamate, pisiform, volar trapezium)

5. Dorsovolar with ulnar deviation

6. Supinated oblique

7. Pronated oblique view

8. Carpal Tunnel view

9. Carpal bones fractures

10. Scaphoid fracture Most common carpal bone to be fractured Age 15-30
Fall on outstretched arm
Classification
Distal pole and tubercle 5-10%
Proximal pole 15-20% (nonunion & AVN)
Waist 70-80%

12. Scaphoid fracture

14. PA with ulnar deviation

15. Nonunited scaphoid fracture

16. Scaphoid fracture seen in MRI

17. AVN of scaphoid

18. Fracture of triquetral
Usually a subtle fracture
Best seen in the lateral or pronated oblique view.

23. Hamate fractures
Usually arise due to direct blow to the volar aspect of the wrist
Two types
Fracture of the hook (hamulus) of hamate:
Fracture of the body of hamate
Hook of hamate is seen in dorsovolar view as a cortical ring. Absence, indistinctness, or sclerosis of this ring suggests hamulus fracture (eye sign)
Carpal tunnel view is also helpful may may be difficult due to pain

27. Fracture of pisiform bone
Rare
Results from fall on the outstretched hand or use of the hand as a hammer to strike an object
May be isolated or co-exist with other bone fractures
Best seen in supinated oblique or carpal tunnel view

29. Fractrue of the capitate
Results from fall on outstretched hands or form direct blow
Usually associated with other carpal bone injuries particularly scaphoid fracture and perilunate dislocation
Waist (neck) of capitate is the most common site

30. PA view
Tomogram

32. Fracture of the lunate bone
Usually result from fall on the dorsiflexed wrist or ecessive push on the heal of the hand
Often associated with perilunate dislocation.
More commonly occur as a pathologic fracture in the setting of Kienböck disease

33. Kienböck Disease Avascular necrosis of the lunate bone,
May be related to repeated trauma
May be related to negative ulnar variance
Classification
Stage I: radiograph normal, transverse linear fracture on tomography
Stage II: increased density with some flattening on the radial side
Stage III: marked decrease in height of lunate with proximal migration of capitate
Stage IV:radiocarpal joint osteoarthritis

35. Stage I

36. Stage II

37. Stage III

38. Stage IV

39. Fracture of the trapezium
Most commonly loading injury in the setting oa adducted thumb where the first metacarpal is driven into trapezium
Associated with fracture of the 1st metacarpal base and subluxation or dislocation of 1st carpometacarpal joint

41. Fracture trapezoid Rare fracture.
Associated with dislocation of the 2nd metacarpal bone

43. Carpal bones dislocations

44. Normal anatomical relations
Lateral view with wrist in neutral position: radius, lunate, capitate, 3rd metacarpal should be in the same line.

46. Normal anatomical relations
Dorsovolar view with wrist in neutral postion: 3 smooth unbroken arcs should be seen (Gilula arcs)
Arc I: proximal articular surfaces of the scaphoid,lunate,& triquetrum
Arc II: distal concavities of scaphoid, lunate, & triquetrum
Arc III: proximal convexities of capitate & hamate

48. Vulnerable zones theory
Dislocations around the lunate can occur in two patterns.
Lesser arc injury pattern: consist of pure ligamentous injuries leading to dislocations
Greater arc injury pattern: consist of dislocation in addition to fracture of one or more of the bones around the lunate (scaphoid, trapezium, capitate, hamate, triquetrum).
In cases of greater arc injury you mention the prefix trans- followed by the name of the fractured bone then the dislocation e.g. trans- scaphoid perilunate dislocation

49. Greater arc =blue lesser arc = red

50. Dislocations around the lunate
Occur in sequential stages according to the severity of trauma
Stage I: Scapholunate dissociation; rotatory subluxation of scaphoid
Stage II: perilunate dislocation
Stage III: midcarpal dislocation
Stage IV: lunate dislocation

51. Dislocations around the lunate

52. Scapholunate dissociation
Results from injury of the scapholunate ligament
Radiographicaly diagnosed by Terry Thomas sign due to widening of the space between the scaphoid and lunate more than 2 mm

53. Terry Thomas sign

54. Rotatory subluxation of scaphoid
Related condition to scapholunate dissocaition where there is in addition rotation of the scaphoid along its long axis
Radiographically diagnosed by signet ring sign: volar tilt of the scaphoid makes it appear foreshortened with its tuberosity seen end on giving a cortical ring.
Radiographs in dorsovolar view should be in the neutral position or with ulnar tilt for this sign to be reliable one

55. Neutral position signet ring sign
Radial tilt Normal scaphoid

57. Perilunate dislocation
On lateral view:
Dorsal or volar dislocation of the capitate.
Lunate remains in articulation with the radius although there may be some degree of tilt
On dorsovolar view
Crowdening of the proximal and distal carpal rows
Break in arcs II and III at the site of the capitate

59. Lunate dislocation On lateral view On dorsovolar view
Axis of lunate is titled away from the articular surface of radius (spilled tea cup sign)
Capitate remains in normal alignment with radius and 3rd metacarpal
On dorsovolar view
Disruption of arc II while arc III remains intact

62. DISI

63. VISI

64. Thank you