Summary
The scaphoid is a carpal bone located at the base of the thumb. It is the most frequently fractured carpal bone, accounting for up to 15% of wrist fractures.
The most common mechanism of injury is axial load across a hyper-extended and radially deviated wrist, often occurring in falls in the elderly or from contact sports. Transverse fracture patterns are considered more stable than vertical or oblique oriented fractures.
| Fracture type | % of scaphoid fractures | Management |
|---|---|---|
| Proximal third |
Common (25%) Higher risk for avascular necrosis |
|
| Waist | Most common (65%) | |
| Distal third |
10% overall More common in children due to growth plate evolution |
Potential complications
Avascular necrosis is a common and concerning complication of a scaphoid fracture. It occurs as a result of disruption in the blood supply, which enters through the distal pole and travels to the proximal pole. Risk of avascular necrosis depends on the location of the fracture: proximal third > middle third > distal third.
The most frequent fracture site is the middle third. However, the proximal third has the highest rate of avascular necrosis (~30%).
Non-union can also occur from undiagnosed or undertreated scaphoid fractures, secondary to disruption of the blood supply. If not treated correctly, non-union of the scaphoid fracture can lead to wrist osteoarthritis.
Arthritis of the wrist can occur over time due to the above pathologies. Symptoms may include:
- aching in the wrist
- decreased range of motion of the wrist
- pain during activities, such as lifting or gripping.
Arthritis is treated with anti-inflammatory medications and, in some cases, wearing a splint when an individual feels pain in the wrist. In severe cases, that don’t respond to initial treatment regimes, steroid injections to the wrist may help alleviate pain. If these treatments not work, surgery may be considered.
Resources
- Scaphoid / scaphoid fracture
Source: Wheeless' Textbook of Orthopaedics - Scaphoid fracture
Source: Orthobullets - Owens BD, Wolf JM. Incidence estimates and demographics of scaphoid fracture in the US population. J Hand Surg Am. August 2010, 35(8): 1242-5.
- Duckworth AD, Jenkins PJ, Aitken SA, et al. Scaphoid fracture epidemiology. J Trauma Acute Care Surg. 2012;72(2):E41-E45. doi:10.1097/ta.0b013e31822458e8
Accessed from the Emergency Care Institute website at https://aci.health.nsw.gov.au/networks/eci/clinical/tools/scaphoid-fracture