Scaphoid Fractures Diagnosis & Management
Scaphoid fractures are the most commonly fractured carpal bone, accounting for 2-3% of all fractures and ~10% of all hand fractures (Duckworth, 2012). They account for approximately 60% of all carpal fractures (Hove, 1999). There is a male predominance with low-energy falls being the most common etiology although men are more likely to sustain their fracture after a high-energy injury. Approximately 65% of injuries occur at the waist, with another 25% occuring in the proximal third.
History and Physical. Scaphoid fractures tend to occur in young and middle aged men. As patients age, the distal radial metaphysis is much more likely to fail than the scaphoid. The typical mechanism involves falling onto a hyperextended wrist with radial deviation (Ring, 2000). The hand and wrist should be observed for any signs of soft tissue swelling, effusion, ecchymosis or deformities. Strength, range of motion and a thorough neurovascular exam should be performed. Comparison should be made to the unaffected wrist.
Image 1. Illustration of scaphoid and retrograde blood flow (courtesy teachmeanatomy.info)
Imaging. The initial imaging modality of choice remain radiographs. Standard wrist xrays include AP, lateral and oblique views. Dedicated scaphoid series can also be obtained if clinical concern is high enough (Cheung, 2006). A PA view in ulnar deviation will give the so-called ‘scaphoid view’. A 45० pronation view can also be obtained. Overall, plain radiographs are about 70% sensitive for scaphoid fractures (Gabler, 2001). If the clinical suspicion is high enough despite normal appearing initial radiographs, a thumb spica splint or cast is usually administered. Repeat radiographs at approximately 2 weeks are usually recommended. Ultrasound has a growing but largely undefined role in the initial evaluation of potential scaphoid fractures. In one chinese study, ultrasound was 80% sensitive and specific compared to 36% and 40% respectively for xrays (Jain, 2018).
Image 2. AP wrist radiograph demonstrating a chronic scaphoid waist fracture.
Image 3. Oblique radiograph of the wrist showing acute, displaced scaphoid waist fracture
Image 4. CT of the wrist demonstrating chronic, displaced non-union scaphoid fracture (same patient from Image 2)
Classification. The Herbert and Fisher classification is commonly used to describe scaphoid fractures. Herbert classification B2 is the most common at 36.4% (Duckworth, 2012).
Figure 1. Herbert and Fisher Classification for scaphoid fractures.
Management. The majority of scaphoid fractures are nondisplaced or minimally displaced and can be treated with immobilization for 8-12 weeks in a thumb spica cast (Kawamura, 2008). The healing rate of nondisplaced waist scaphoid fractures with cast immobilization is 88% to 95%, provided that treatment is started within 3 weeks after injury (Cooney, 1980). There is no consensus on long arm vs short arm casting. In patients with normal radiographs, but a high degree of clinical suspicion, patients should be placed in a thumb spica splint with repeat radiographs in roughly 2 weeks. Some surgeons recommend early ORIF even for nondisplaced fractures to avoid complications such as more frequent office visits to check whether the cast fits properly, more frequent radiographs to assess fracture alignment, potential skin breakdown, prolonged immobilization until complete healing has occurred, stiffness of immobilized joints, and a longer time to healing.
Figure 2. Proposed management algorithm for suspected scaphoid fracture (Kawamura)
Summary. Scaphoid fractures are the most common carpal bone fracture and they tend to occur in young men. A careful clinical exam, including anatomic snuff box tenderness, axial compression and volar palpation of the scaphoid tubercle are very sensitive in evaluating for a scaphoid fracture. Radiographs are the initial imaging study of choice, however only 70% sensitive. MRI and CT are utilized in the appropriate patient and the role of ultrasound remains unclear. In the acute setting in which initial radiographs are unremarkable but clinical suspicion is high, the patient should be placed in a thumb spica splint with repeat radiographs in approximately 2 weeks. Management of nondisplaced scaphoid fractures is generally nonoperative, although consultation with a hand or orthopedic surgeon is recommended. In patients with displaced fractures, proximal pole fractures or non-union, surgical management is indicated.
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