findings from a literature review of the best ways to manage a common injury of the wrist DIAGNOSIS AND TREATMENT OF SCAPHOID FRACTURE

SCAPHOID FRACTURES account for 71% of carpal bone fractures, and between 2% and 7% of all orthopaedic fractures (Nishihara 2000). This type of injury also accounts for one in every 10,000 attendances annually in UK emergency departments (EDs) (Tai and Ramachandran 2005). Between 5% and 12% of scaphoid fractures are related to other fractures (Malik et al 2010). The scaphoid is one of the eight carpal bones that make up the wrist. It is the largest carpal bone in the proximal row, and crosses between this and the distal row (Purcell 2010). About 80% of scaphoid fractures occur through the middle third, or waist, of the bone, while 10% involve the distal third and 10% the proximal third (Raby et al 1999). Blood supply to the scaphoid is provided by a subdivision of the radial artery from the distal end of the scaphoid. Because blood flows in a distal-to-proximal direction, the proximal portion of the scaphoid is vulnerable to inadequate blood supply when fractures occur, which in turn makes it susceptible to avascular necrosis (Ramponi 2012). Between 2% and 9% of patients with fractured scaphoid develop avascular necrosis (Allen 1983), which can result in reduced grip strength (Waldman 2014). The scaphoid plays an important part in wrist dynamics and, due to its unique anatomy, it can articulate with all five surrounding bones. For example, it articulates with the radius forming the radiocarpal joint, and with the trapezium and the trapezoid and capitate bones to aid articulation between the proximal and distal rows of the carpus (McNally and Gillespie 2004). The scaphoid also flexes with wrist flexion and wrist radial deviation. This means that, if the scaphoid’s anatomy is disorganised, wrist movements can become severely compromised, and the risks of decreased function and degenerative arthritis are raised (Gillion 2001). The most common cause of scaphoid fracture is a fall onto an outstretched hand (McNally and Gillespie 2004), which can force the bone back against the dorsal lip of the radius (Purcell 2010). Because the scaphoid bridges the carpal rows, there is also a risk of fracture in a hyperextension injury (Larsen 2002). Hyperextension at the wrist is the cause of 97% of scaphoid fractures while forced flexion causes 3% (Ritchie and Munter 1999). Ossification of the scaphoid bone begins in people aged between five and six years, and is complete by the age of between 13 and 15. Before ossification is complete, the scaphoid is almost entirely cartilaginous, which explains the rarity of fracture in children (Nishihara 2000). According to Hegeman et al (2004), 85% of older patients have low bone mineral density and 51% Correspondence [email protected]