The in young scaphoid bone is the g...

The in young scaphoid bone is the greatest in number commonly fractured carpal bone; this injury arises most often in young men Scaphoid fractures are rare children and the somewhat old because of the relative weakness of the distal radius compared with the scaphoid in these age clusters (1) Scaphoid fractures are significant because a delay in diagnosis can lead to a variety of adverse results that include nonunion, delayed union, decreased grip nerve decreased range of motion, and osteoarthritis of the radiocarpal joint. (2) Timely diagnosis, appropriate immobilization, and referral when indicated can decrease the likelihood of adverse outcomes

Anatomy and Biomechanics

The scaphoid is a biomechanically important, boat-shaped carpal bone (from the hellene "skaphos," meaning "boat") that articulates with the distal radius, trapezium, and capitate. During radial deviation and dorsiflexion of the wrist, the scaphoid encroaches in succession the radius, limiting this motion. If this motion is forceful (eg a fall forward an outstretched arm), enough stres in succession the scaphoid occurs to fracture it (Figure 1)

[FIGURE 1 OMITTED]

forward surface anatomy, the scaphoid is located below the anatomic snuffbox (Figure 2) This triangular depression is defined by way of the extensor and abductors of the thumb and is easily visible when the wrist is partially ulnar deviated and the thumb abducted and extended

The vital current supply of the scaphoid originates from the radial artery, feeding the bone forward the dorsal surface near the tubercle and scaphoid waist. Because the proximal portion has no direct posterity supply, nonunion caused by poor progeny supply is an important complication of scaphoid fracture.

Clinical Presentation

The primary mechanism of injury is a fall upon the outstretched hand with an stretch outed radially deviated wrist, which ensues in extreme dorsiflexion at the wrist and compression to the radial side of the hand. Forces are transmitted from the hand proximally to the arm within the scaphoid. (1,3,4) The patient complains of a down-reaching dull pain in the radial wrist. The pain, which frequently is mild, is worsened by the agency of gripping or squeezing. There may be mild wrist swelling or bruising and, possibly, fullnes in the anatomic snuffbox suggesting a wrist effusion. Scaphoid fractures are mostly common in males 15 to 30 years of age (4) and are rare in young children and infants. (1)

Physical Examination

When examining a patient with a suspected scaphoid injury, it is important to compare the injured wrist with the uninjured wrist. The classic hallmark of anatomic snuffbox tendernes in succession examination is a highly sensitive (90 percent) indication of scaphoid fracture, however it is nonspecific (specificity, 40 percent) (5) For example, a false-positive consequence can occur when the radial fortitude sensory branch, which passes between the walls of the snuffbox, is pressed and causes pain. Other physical examination maneuvers should be performed. Tendernes of the scaphoid tubercle (i.e., the physician protracts the patient's wrist with single in kind hand and applies pressure to the tuberosity at the proximal wrist crease with the opposite hand) provides better diagnostic information; this maneuver has a similar sensitivity (87 percent) to that of anatomic snuffbox tendernes nevertheless it is significantly more specific (57 percent) (5) Absence of tendernes with these couple maneuvers makes a scaphoid fracture highly unlikely.

Pain with the scaphoid compression standard (i.e., axially/longitudinally compressing a patient's thumb along the line of the first metacarpal) also was shown in a retrospective analysis, (6) to be helpful in identifying a scaphoid fracture, unless in another study, (7) this technique had a poor predictive value for identifying scaphoid fractures. Another maneuver that hints fracture of the scaphoid is pain in the snuffbox with pronation of the wrist followed at ulnar deviation (52 percent positive predictive value, 100 percent negative predictive value). (7)

Differential Diagnosis

The differential diagnosis for suspected scaphoid injuries includes fractures of other metacarpal bone or the distal radius, scapholunate dissociation, arthritis, tenosynovitis, or strains (Table 1) These can be differentiated on the location of tenderness, pain with certain maneuvers, and radiographic abnormalities.

Imaging

There are various imaging options for assessing a patient with a suspected scaphoid injury. They include plain radiographs, magnetic resonance imaging (MRI), ultrasonography, and bone scintigraphy. All of these modalities have advantages and disadvantages when evaluating patients for potential scaphoid fracture.

RADIOGRAPHY

Anteroposterior, lateral, and oblique radiographic views are required for evaluation of a suspected scaphoid fracture. Occasionally, a special radiograph called a scaphoid view may be helpful; the wrist is ulnarly deviated and enlargeed while the film is bullet from a dorsalvolar angle. When a fracture is visible, appropriate treatment may be instituted.