CARPAL BONES FRACTURES GENERALITES.pptx

A TOPIC ABOUT CARPAL BONES FRACTURES IN GENERAL

1. CARPAL BONES FRACTURES Presented by: Dr aggoun

2. SUMMARY INTRODUCTION ANATOMIC RECALL EPIDEMIOLOGY SCAPHOID FRACTURE TRIQUETRAL FRACTURE TRAPEZIUM FRACTURE LUNATE FRACTURE CAPITATE FRACTURE HAMATE FRACTURE PISIFORM FRACTURE TRAPEZOID FRACTURE 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 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 Scaphoid Nonunion Osteonecrosis Malunion Subchondral bone penetration with arthrosis due to prominent hardware 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 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 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.

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