A TOPIC ABOUT CARPAL BONES FRACTURES IN GENERAL

1. CARPAL BONES
FRACTURES
PRESENTED BY:
DR AGGOUN

2. SUMMARY
I. INTRODUCTION
II. ANATOMIC RECALL
III. EPIDEMIOLOGY
IV. SCAPHOID FRACTURE
V. TRIQUETRAL FRACTURE
VI. TRAPEZIUM FRACTURE
VII. LUNATE FRACTURE
VIII. CAPITATE FRACTURE
IX. HAMATE FRACTURE
X. PISIFORM FRACTURE
XI. TRAPEZOID FRACTURE
XII. CONCLUSION

3. INTRODUCTION
There are eight carpal bones at the wrist, situated between the
radius and ulna in the forearm and the metacarpals in the hand. The
most common (and important) carpal fracture is that of the scaphoid
. Among the other carpal bones, only the triquetrum, hamate and
pisiform are likely to be fractured in isolation; other carpal fractures
are seen more commonly in conjunction with other injuries. Most
isolated carpal fractures are caused by direct trauma.

4. ANATOMIC RECALL

5. EPIDEMIOLOGY
scaphoid fracture: 50-80%
triquetral fracture: ~18%
trapezium fracture: ~3-5%
lunate fracture: 3.9%
capitate fracture: 1.9%
hamate fracture: 1.7%
pisiform fracture: 1.3%
trapezoid fracture: 0.4%

6. SCAPHOID FRACTURES
ANATOMY:
 Osteology
complex 3-dimensional structure
resembling a boat, skiff, and twisted peanut
largest bone in proximal carpal row
> 75% covered by articular cartilage

7. SCAPHOID FRACTURES
Blood supply

8. SCAPHOID FRACTURES
Biomechanics
link between proximal and distal carpal row
both intrinsic and extrinsic ligaments attach and surround the scaphoid
the scaphoid flexes with wrist flexion and radial deviation and extends during wrist extension and
ulnar deviation (same as proximal row)

9. SCAPHOID FRACTURES
Clinical presentation:

10. SCAPHOID FRACTURES
Pathology:
The usual mechanism is falling on an outstretched hand,
applying an axial load to an extended and pronated wrist
wrist in ulnar deviation .
Fractures distribution is not even:
waist of the scaphoid: 70-80%
distal pole (scaphoid tubercle): 20%
proximal pole: 10%

11. SCAPHOID FRACTURES
Classifications:
Mayo classification of scaphoid fractures (based on location of fracture line)
Herbert and Fisher classification of scaphoid fractures(based on fracture stability)
Russe Classification (based on fracture pattern)

12. SCAPHOID FRACTURES
Radiographs
recommended views
neutral rotation PA
lateral
semi-pronated (45°) oblique
scaphoid
wrist in 20 degrees of ulnar deviation
waist fractures seen best
if radiographs are negative (27%) and there is a
high clinical suspicion repeat radiographs in 14-
21 days

13. SCAPHOID FRACTURES
Bone scan MRI
CT scan ultrasound

14. SCAPHOID FRACTURES
Treatment
Nonoperative:
cast immobilization(short arm)
Indications:
stable non displaced fracture (majority of fractures)
if patient has normal radiographs but there is a high level of suspicion can immobilize in thumb spica and
reevaluate in 12 to 21 days
outcomes
scaphoid fractures with <1mm displacement have union rate of 90%

15. SCAPHOID FRACTURES
Operative
percutaneous screw fixation
Indications:
unstable fractures as shown by proximal pole fractures
displacement > 1 mm without significant angulation or deformity
non-displaced waist fractures
to allow decreased time to union, faster return to work/sport, similar total costs
compared to casting
Outcomes:
union rates of 90-95% with operative treatment of scaphoid fractures

16. SCAPHOID FRACTURES
open reduction internal fixation
indications
significantly displaced fracture patterns
15° scaphoid humpback deformity
radiolunate angle > 15° (DISI)
intrascaphoid angle of > 35°
scaphoid fractures associated with perilunate dislocation
comminuted fractures
unstable vertical or oblique fractures
Outcomes:accuracy of reduction correlated with rate of union

17. SCAPHOID FRACTURES
Complications
1. Scaphoid Nonunion
2. Osteonecrosis
3. Malunion
4. Subchondral bone penetration with arthrosis due to prominent hardware
5. SNAC wrist (scaphoid nonunion advanced collapse)

18. TRIQUETRAL FRACTURES
Triquetral fractures are carpal bone fractures generally
occurring on the dorsal surface of the triquetrum. The
triquetral may be fractured by means of impingement
from the ulnar styloid, shear forces, or avulsion from
strong ligamentous attachments. They are the second
commonest carpal bone fracture, after the scaphoid.

19. TRIQUETRAL FRACTURE
Clinical presentation
Commonest history is trauma to the outstretched hand with carpal extension
pain is usually on the ulnar aspect of the wrist, exacerbated by extension/flexion of the wrist
swelling over the dorsum of the hand with a tender dorsal aspect of triquetrum may be found on exam
Pathology
The usual injury mechanism is falling onto an outstretched hand in ulnar deviation. Less commonly, it may
may be caused by a direct blow to the dorsum of the hand, a situation where commonly other carpal
fractures are seen.

20. TRIQUETRAL FRACTURES
There are three fracture patterns often observed, dorsal
avulsion fractures, triquetral body fractures and volar avulsion
fractures . Dorsal avulsion fractures account for about 95% all
triquetral fractures, most of the remainder are body fractures
.
Treatment and prognosis
Surgical intervention is rarely required, but a persistently
symptomatic chip fracture may require excision.

21. TRAPEZIUM FRACTURES
Trapezium fractures are uncommon carpal bone injuries. They can either occur in isolation or
combination with another carpal bony injury.
They can be broadly classified into ridge (most common ) and
body fractures.
Mechanism
They often occur as a result of a high energy trauma and usually involve either
direct or indirect axial loading . These are most commonly transverse loading
injuries in the setting of an adducted thumb in which the first metacarpal is
driven into the trapezium .
Trapezial ridge fractures may result from a direct blow to the volar surface,
dorsoradial impaction or an avulsion injury. Fractures of the trapezial body result
from an axial loading or shearing force through the first carpometacarpal joint.

22. TRAPEZIUM FRACTURES
Trapezial fractures are often associated with a fracture of the first metacarpal
base and/or subluxation or dislocation of the first carpometacarpal joint.
Trapezial ridge fractures may be associated with wrist injuries, including
distal radial fractures.
Non displaced fractures can sometimes be occult. A Robert’s
AP view, with the hand in full pronation, is a good way of
visualizing the trapezium on plain radiographs
Treatment and prognosis
Displaced fractures may require open reduction and internal
fixation, typically performed with Kirschner wires or screws.

23. LUNATE FRACTURES
Lunate fractures are a carpal injury that if left untreated, can result in significant
carpal instability.
Pathology
Lunate fractures are often secondary to axial loading of the head capitate bone,
this is seen in forceful hyperextension with ulnar deviation
The lunate is an important stabilizer of the wrist, fractures can lead to ligamentous
injury and overall volar intercalated segment instability. There may be other
associated injuries that require further investigation via cross-sectional imaging .

24. LUNATE FRACTURES
Treatment and prognosis
Isolated fractures without displacement or subluxation can be managed conservatively, however
fractures that possess joint subluxation are unstable and require surgical intervention 2.
Around 20% of patients possess a single-vessel supply to their lunate hence there is an increased
possibility of avascular necrosis, the remaining cohort typically has a two-vessel supply and
intraosseous anastomosis

25. CAPITATE FRACTURES
Capitate fractures are an uncommon carpal fracture. They rarely occur in isolation
and are often associated with greater arc injuries.
Pathology
Capitate fractures are most commonly due to high-energy,
hyperextension forces
Radiographic features
Capitate fractures will rarely occur in isolation, they can be
subtle due to boney overlap, and are most commonly
transverse body fractures. These can be subtle on projectional
radiography and best appreciated on cross-sectional imaging

26. CAPITATE FRACTURES
Treatment and prognosis
In general, conservative management is warranted for fractures that are non-displaced, fractures that
display a high level of displacement require surgical fixation .
Like the scaphoid, there is a risk of avascular necrosis at the proximal pole given its poor vascularity due to a
a retrograde blood supply .
Complications
In very rare circumstances, during a scaphoid and capitate fracture, the proximal aspect of the capitate can
rotate 90 degrees into the sagittal plane, this is known as scaphocapitate syndrome , which could be better
described as a trans-scaphoid, trans-capitate peri-lunar fracture-dislocation that reduces to result in an
inversion of the proximal aspect of the capitate.

27. HAMATE FRACTURES
Hamate fractures are an uncommon form of carpal bone fractures and only
account for 1-2% of such fractures.
Hamate fractures usually get subdivided into two broad groups: hook fractures
and body fractures.
Classification of hamate fractures:
type 1: hook of hamate fracture
type 2: body of hamate fracture
type 2a: coronal (may be dorsal oblique or splitting fracture)
type 2b: transverse fracture

28. PISIFORM FRACTURES
uncommon fracture of the carpal bones.
Plain radiograph
Some can be occult on plain film. The pisotriquetral joint is best seen in the lateral
view with 30 degrees supination or using the carpal tunnel view.
They are usually managed by immobilization in either a plaster cast or a wrist splint.
In certain circumstances, placement of a pin-screw or excision is performed.

29. TRAPEZOID FRACTURES
Trapezoid fractures are the least common carpal fracture. They typically occur as the
result of an axial force through the second metacarpal.
The trapezoid is in a relatively immobile, and protected location hence the rarity of
an isolated fracture. Given the wedged shape and weaker dorsal ligamentous
support, fractures will dislocate in the dorsal direction . It is often associated with a
second metacarpal fracture.
Treatment and prognosis
Treatment varies from conservative management to open reduction internal fixation,
failure to recognize can lead to functional problems such as decreased grasp power

30. CONCLUSION
Fractures of the carpal bones, which make up the wrist joint, are relatively common injuries,
Early diagnosis and treatment are crucial for optimal healing and to minimize complications.
Different fractures in the carpal bones have different prognoses and require individualized treatment
plans.
Physical therapy is often essential for regaining full wrist function after healing.
Some fractures may lead to long-term issues like pain, stiffness, and reduced grip strength.

31. 1. Kaewlai R, Avery LL, Asrani AV, Abujudeh HH, Sacknoff R, Novelline RA. Multidetector CT of carpal injuries: anatomy, fractures,
and fracture-dislocations. Radiographics : a review publication of the Radiological Society of North America, Inc. 28 (6): 1771-84.
doi:10.1148/rg.286085511 - Pubmed
2. Scalcione LR, Gimber LH, Ho AM, Johnston SS, Sheppard JE, Taljanovic MS. Spectrum of carpal dislocations and fracture-
dislocations: imaging and management. AJR. American journal of roentgenology. 203 (3): 541-50. doi:10.2214/AJR.13.11680-
Pubmed
3. You JS, Chung SP, Chung HS, Park IC, Lee HS, Kim SH. The usefulness of CT for patients with carpal bone fractures in the
emergency department. Emergency medicine journal : EMJ. 24 (4): 248-50. doi:10.1136/emj.2006.040238 - Pubmed
4. Bhat AK, Kumar B, Acharya A. Radiographic imaging of the wrist. Indian journal of plastic surgery : official publication of the
Association of Plastic Surgeons of India. 44 (2): 186-96. doi:10.4103/0970-0358.85339 - Pubmed
5. Pan T, Lögters T, Windolf J, Kaufmann R. Uncommon Carpal Fractures. Eur J Trauma Emerg Surg. 2016;42(1):15-27.
doi:10.1007/s00068-015-0618-5 - Pubmed
REFERENCES