![]() ![]() There is a fracture (arrow) at the base of the fourth metacarpal (4). Hamate body fractures are commonly associated with fourth and fifth metacarpal base fractures. Hamate fractures can be occult in 60% of cases by radiography alone, and may necessitate CT scanning if clinically warranted. The overlying soft tissues are swollen (arrowheads). There may be a fracture (long arrow) at the base of the fourth metacarpal base. The joint spaces at the fourth and fifth CMC joints appear narrowed (short arrows). PA, oblique and lateral views of the wrist. The dorsal fragment has a tendency to dorsally sublux along with the base of the fourth and fifth metacarpals, as seen here.Ĭase 2-06. This is a type 2a fracture of the hamate. Type 2 can be further subdivided into coronal (2a) and transverse (2b) fractures. Hamate fractures are subdivided into 2 types, hook (type 1) and body (type 2) fractures. There is fracture of the hamate with dorsal dislocation of the dorsal fragment. Oblique view of the wrist and axial CT scan of the wrist. In the immature skeleton, distal radius fractures are the predominant fractures of the wrist. Scaphoid and other carpal bone fractures are infrequent in children, possibly because the bones are incompletely ossified and are cushioned by cartilage. There is a non-displaced waist of scaphoid fracture (arrow) seen only on the PA projection. PA, oblique, lateral, and scaphoid views of the wrist of a child. The scaphoid bone is the most commonly fractured of the carpal bones, and constitutes 68.2% of carpal fractures. Fractures of the proximal pole constitute 10% of all scaphoid fractures and have the highest complication rate of non-union and proximal pole AVN. MRI is a reasonable alternative, particularly when soft tissue injuries are also suspected. When radiographs are normal or equivocal, and scaphoid fracture is still suspected, CT may be a useful next step. Although not helpful in this case, the scaphoid view should be routinely obtained when scaphoid fracture is suspected.Ĭoronal CT images definitively show the scaphoid fracture traversing the waist. Scaphoid view of the wrist does not show the fracture. There is a subtle minimally displaced fracture (arrows) just proximal to the waist of the scaphoid, seen only on the PA projection. PA, lateral and oblique views of the wrist. A type of scaphoid malunion is the humpback deformity which occurs when there is increased flexion angulation of the scaphoid this results in poorer clinical outcomes.Ĭase 2-03. This same principle can be applied to the femoral head and talus. Due to the extensive articular cartilage, vascular supply can be more easily compromised and result in osteonecrosis of the proximal pole. Fractures of the scaphoid usually occur at the waist and may require ulnar deviation for detection on x-ray. Scaphoid view shows the fracture through the waist of the scaphoid. PA, Oblique, and Lateral views of the wrist. Non-displaced scaphoid waist fractures can be treated conservatively with good result. To illustrate this, 30% of waist (middle third) fractures develop delayed or nonunion, however proximal pole fractures develop these complications in the majority of cases. For this reason, in general more proximal fractures are likely to develop more complications. Delayed union, non-union and osteonecrosis of the proximal pole are potential complications and depend on how proximal the fracture site is relative to the entrance of the artery at the waist of the scaphoid which is somewhat variable. Fall on an outstretched hand with dorsiflexion is the mechanism of injury. Waist fractures constitute 70% of scaphoid fractures. The scaphoid view is the best projection for scaphoid waist fractures. The scaphoid view is obtained by placing the wrist in ulnar deviation and angling the x-ray beam towards the forearm, in order to project the scaphoid longitudinally onto the x-ray detector. There is a transverse fracture (arrow) across the waist of the scaphoid. The fracture is not visible on the other views. There is linear lucency (arrow) through the waist of the scaphoid evident on the oblique view, consistent with fracture. PA, oblique, and lateral radiographs of the wrist. ![]()
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