Scaphoid fracture
Encyclopedia
A scaphoid fracture is the most common type of wrist fracture. Scaphoid fractures usually cause pain at the base of the thumb accompanied by swelling in the same area. Scaphoid fractures usually cause pain and sensitivity to palpation in the anatomic snuffbox at the base of the thumb accompanied by swelling in the same area. These are also called navicular fractures (the scaphoid also being called the carpal navicular) as navicular is the traditional name for the scaphoid bone, although this can be confused with the navicular in the foot. Treatment depends on the location of the fracture.
tenderness.
Scaphoid fractures are often diagnosed by X-rays. However not all fractures are apparent initially. Therefore people with tenderness over the scaphoid are often casted
for 7–10 days at which point a second set of X-rays is taken. If there was a hairline fracture, healing will now be apparent. Even then a fracture may not be apparent. A CT Scan can then be used to observe the snuff box area more precisely. Fractures can take between 6 and 12 weeks of casting. The Scaphoid has its own blood flow unlike other carpal bones. It receives its blood supply primarily from lateral and distal branches of the radial artery. Blood flows from the top/distal end of the bone in a retrograde fashion down to the proximal pole; if this blood flow is disrupted by a fracture, the bone may not heal. Surgery is necessary at this point to mechanically mend the bone together.
The use of MRI, if available, is preferred over CT and can give one an immediate diagnosis. Bone scintigraphy is also an effective method for diagnosis fracture which do not appear on Xray.
(AVN) is a common complication of a scaphoid fracture. Risk of AVN depends on the location of the fracture.
Non union can also occur from undiagnosed or undertreated scaphoid fractures.
Non displaced or minimally displaced waist and and distal fractures have a high rate of union with closed cast management. The choice of short arm, short arm thumb spica or long arm cast is debated in the medical literature and no clear consensus or proof of the benefit of one type of casting or another has been shown; although it it generally accepted to use a short arm or short arm thumb spica for non displaced fractures. Non displaced or minimally displaced fracture can also be treated with percutaneous or minimal incision surgery which if performed correctly has a high union rate, low morbidity and faster return to activity than closed cast management.
Diagnosis
Clinically patients present with snuff boxAnatomical snuff box
The anatomical snuffbox is a triangular deepening on the radial, dorsal aspect of the hand—at the level of the carpal bones, specifically, the scaphoid and trapezium bones forming the floor...
tenderness.
Scaphoid fractures are often diagnosed by X-rays. However not all fractures are apparent initially. Therefore people with tenderness over the scaphoid are often casted
Orthopedic cast
An orthopedic cast, body cast or surgical cast, is a shell, frequently made from plaster, encasing a limb to hold a broken bone in place until healing is confirmed...
for 7–10 days at which point a second set of X-rays is taken. If there was a hairline fracture, healing will now be apparent. Even then a fracture may not be apparent. A CT Scan can then be used to observe the snuff box area more precisely. Fractures can take between 6 and 12 weeks of casting. The Scaphoid has its own blood flow unlike other carpal bones. It receives its blood supply primarily from lateral and distal branches of the radial artery. Blood flows from the top/distal end of the bone in a retrograde fashion down to the proximal pole; if this blood flow is disrupted by a fracture, the bone may not heal. Surgery is necessary at this point to mechanically mend the bone together.
The use of MRI, if available, is preferred over CT and can give one an immediate diagnosis. Bone scintigraphy is also an effective method for diagnosis fracture which do not appear on Xray.
Complications
Avascular necrosisAvascular necrosis
Avascular necrosis is a disease where there is cellular death of bone components due to interruption of the blood supply. Without blood, the bone tissue dies and the bone collapses...
(AVN) is a common complication of a scaphoid fracture. Risk of AVN depends on the location of the fracture.
- Fractures in the proximal 1/3 have a high incidence of AVN (~30%)
- Waist fractures in the middle 1/3 is the most frequent fracture site and has moderate risk of AVN.
- Fractures in the distal 1/3 are rarely complicated by AVN.
Non union can also occur from undiagnosed or undertreated scaphoid fractures.
Treatment
Treatment of scaphoid fractures is guided by the location in the bone of the fracture (proximal, waist, distal), displacement (or instability) of the fracture, and patient tolerance for cast immobilization.Non displaced or minimally displaced waist and and distal fractures have a high rate of union with closed cast management. The choice of short arm, short arm thumb spica or long arm cast is debated in the medical literature and no clear consensus or proof of the benefit of one type of casting or another has been shown; although it it generally accepted to use a short arm or short arm thumb spica for non displaced fractures. Non displaced or minimally displaced fracture can also be treated with percutaneous or minimal incision surgery which if performed correctly has a high union rate, low morbidity and faster return to activity than closed cast management.
External links
- AAFP: Diagnosis and Management of Scaphoid Fractures
- Wheeless: Scaphoid fracture
- UMich Healthwise Knowledgebase: Scaphoid fracture
- http://sprojects.mmi.mcgill.ca/icmcradiology/radcase.aspx?IDCase=6&CaseDiag=D
- Jeffrey E. Budoff, MD: Scaphoid Fractures