HEELing The Scaphoid

Scaphoid Bone (aka Navicular) 
 Inspired by the North Carolina Tar Heels #5 - Kendall Marshall

Why do we care about a fractured scaphoid?

• First and foremost, because this injury, endured by Carolina's point guard, "K-butter," could ruin the Tar Heels' quest for a National Championship in the 2012 NCAA Basketball Tournament.
• Risk of Avascular Necrosis - the scaphoid receives limited blood supply from the palmar carpal branch of the radial artery which first supplies the distal aspect of the bone before supplying the proximal pole of the scaphoid. 
• As diagnosis of a fractured scaphoid is often not radiologically apparent on first exam, one must retain a high index of suspicion for this injury.
• Nonunion as a result of poor blood flow from disruption of the palmar carpal vessel (branch of the radial artery). This can result in permanent arthritis and disrupted range of motion due to abnormal articulations within the wrist, primarily the lunate and the radius.  
• This complication could thwart/ruin an athlete's career in the long-term. Thus, one must exercise prudence when discussing treatment modalities and return to play with athletes. 

The Scaphoid:

• The scaphoid is the largest carpal bone and sits in the proximal row of carpal bones, on the radial side.
• Most commonly fractured carpal bone, representing 10% of all hand fractures and 60-70% of all carpal fractures (1).
• The most famous carpal bone (and likely the only carpal bone able to be named) in North Carolina
• Typically a fracture is the result of a fall on an outstretched hand (FOOSH) such as Kendall Marshall's tragic fall in the second round game of the NCAA tournament versus Creighton

Diagnosis of Fracture:

• Suspect in any patient status-post FOOSH
• Classically presents with pain in the anatomic snuff box

• Patient may also have pain distal to Lister's Tubercle (the bony prominence on the distal radius)
• PA, Lateral, and Scaphoid (PA view with wrist in pronation and ulnar deviation) view x-rays .
• Limitations:  x-rays often do not initially reveal a fracture and are negative in 25% of cases, according to some studies (2, 4).
• Ultrasound!  The Emergency Ultrasound Podcast guest Dr. Mark Goodman did a fantastic (and entertaining) job explaining the methods and evidence behind ultrasound as an imaging modality in scaphoid fractures.
• Findings suggestive of fracture:  cortical discontinuity, periosteal elevation, effusion. 
• A study out of Carolinas Medical Center demonstrated promising results of Emergency Medicine physicians identifying hand fractures (carpal and phalangeal) utilizing ultrasound (3).
• Advantages:  Cheap, easy, quick imaging with no ionizing radiation.
• Disadvantages:  The hard evidence for ultrasound in diagnosis of carpal fracture is still not incredibly robust.
• MRI and bone scan may also be utilized although these modalities are expensive and time consuming.

Treatment:

• Early immobilization, ice, analgesics, and evaluation by a physician
• Non-Displaced (<1 mm)
• Immobilization with thumb spica splint/cast (4).
• Distal:  Treat with short-arm thumb spica cast for 4-6 weeks
• Midbody/Proximal:  Long-arm thumb spica cast for 6 weeks then a short-arm thumb spica cast
• Midbody Fracture Immobilization - 10-12 weeks
• Proximal Fracture Immobilization - 12-20 weeks
• Follow up is crucial as nonunion remains a threat. Consider consult to hand surgeon
• Displaced (>1 mm)
• Surgery -  Open reduction internal fixation (ORIF) or percutaneous fixation with a screw or wire to fix the scaphoid in proper anatomic alignment.
•  Expedites return to play/work (4).
• It requires an average of twelve weeks to achieve union of the scaphoid.
• Also consider surgery in patients with carpal instability, evidence of nonunion during follow-up, osteonecrosis, or in patients with a possible scapholunate dissociation (4).

References:
1.  Geissler WB.  Carpal fractures in athletes.  Clin Sports Med. 2001;20(1):167.

2.  Phillips TG, Reibach AM, Slomiany WP.  Diagnosis and management of scaphoid fractures. Am Fam Physician. 2004;70(5):879.
3.  Tayal V, Antoniazzi J, Pariyadath M, Norton J. Prospective Use of Ultrasound Imaging to Detect Bony Hand Injuries in Adults JUM September 1, 2007vol. 26 no. 9 1143-1148

4.  Burroughs, K.  Scaphoid Fractures.  http://www.uptodate.com.ezproxylocal.library.nova.edu/contents/scaphoid-fractures?source=search_result&search=scaphoid&selectedTitle=1~40  Accessed on 25 March 2012.