Scaphoid Fracture

By admin On Feb 28, 2024

Ovid: 5-Minute Orthopaedic Consult

Editors: Frassica, Frank J.; Sponseller, Paul D.; Wilckens, John H.

Title: 5-Minute Orthopaedic Consult, 2nd Edition

> Table of Contents > Scaphoid Fracture

Scaphoid Fracture

Simon C. Mears MD, PhD

John J. Hwang MD

Basics

Description

Fracture of the most radial (thumb side) of the carpal bones, usually as a result of a dorsiflexion injury to the wrist
The most common of the carpal fractures, estimated at 60% (1)
Frequent problems include delayed diagnosis and nonunion.
Classification:
- Chronologically: Acute or chronic
- Anatomically: In the proximal, middle, or distal third
Displaced or nondisplaced
Direction: Transverse or oblique
By mechanism: High-energy (e.g., motor vehicle accident) or simple, low-energy fall
Simple fracture or complicated fracture with associated ligament injury or dislocation.
Synonym: Navicular fracture

General Prevention

Wear wrist protectors during high-risk activities such as rollerblading and in-line skating (2).

Epidemiology

Incidence

In 1 study, the annual fracture rate was 4.3 per 10,000 people, the average age was 25 years, and 82% occurred in males (1).
Scaphoid fractures account for ~2% of all fractures and 11% of hand fractures (1).
2nd most common fracture of the wrist area after the distal radius
Rare in children (3)

Prevalence

Usually an injury of young adults (males more commonly
than females, probably because of activity level) after a fall,
athletic injury, or motor vehicle accident.

Risk Factors

Contact sports
Rollerblading and in-line skating (2)
Risk factors for nonunion:
- Proximal pole fracture
- Distal oblique or vertical fracture
- Large displacement of the fracture
- High-energy injury

Pathophysiology

The major blood supply to the proximal pole enters the bone through the distal 1/3 of the bone.
Vessel disruption causes compromise of the blood supply to the proximal pole (4).

Etiology

An axial force impacting on an outstretched hand
The scaphoid acts as a bridge between the proximal and distal rows of the carpus, making it vulnerable to fracture.

Diagnosis

Signs and Symptoms

History

Pain or clicking with wrist motion
The clinician must have a high index of suspicion to avoid missing the injury.
Patients occasionally present late (months or even years after the injury) with persistent ache, weakness, or clicking.

Physical Exam

Pain with wrist motion is common.
Swelling is variable because the fracture may or may not produce much bleeding.
Typically, palpate the snuffbox region (between the short and long extensor tendons to the thumb) (Fig. 1) and compare the findings with those of the uninjured side.
- If tenderness is found here, presume that the patient has a fracture until proven otherwise.

Tests

Lab

No laboratory tests aid in the diagnosis.

Imaging

Radiography:
- Posteroanterior, lateral, pronated oblique, and ulnar deviated posteroanterior radiographs of the wrist (scaphoid views)
- Displacement of the normal fat plane on the volar surface of the navicular is suggestive of injury.
- Carefully scrutinize radiographs for signs of ligament disruption and carpal dislocation.
  
  Fig. 1. Tenderness in the snuffbox should produce suspicion of a scaphoid fracture.
If plain radiographs are negative but examination is suggestive of fracture, additional imaging is indicated, including:
- Bone scan (in acute phase)
- CT scan with 3D reconstruction
- MRI, which is becoming the standard test because results are obtained quickly (5)

Differential Diagnosis

Ligament injury or sprain
Perilunate dislocation
Distal radius fracture
Wrist instability

Treatment

General Measures

Immobilize the wrist in a thumb spica
splint for 2 weeks if clinical suspicion of a fracture exists, even if
a fracture is not seen on initial radiographs.
The type of splint or cast used is
controversial; recommendations range from an above-the-elbow thumb
spica cast to a below-the-elbow cast that does not immobilize the thumb
(6).
Radiographs should be repeated at 10–14 days, at which time the fracture edges may be better seen.
For nondisplaced fractures, the patient
should be placed in a below-the-elbow thumb-spica cast for 6–8 weeks
and then reassessed clinically and radiographically.
Displaced fractures and proximal pole fractures require surgery.
Fractures in competitive athletes may be treated surgically to allow for earlier return to activity.

Activity

Heavy lifting or sports activities should be avoided until the fracture is healed and the patient is pain free.

Special Therapy

Physical Therapy

Physical therapy maintains finger ROM during immobilization and helps regain wrist motion after immobilization.

Surgery

Displaced fractures should be treated with reduction and screw fixation.
- Cannulated screws that are headless and have variable threads currently are used for fixation.
- These screws can gain compression of the fracture site without protrusion of the screw from the edge of the bone.
- The use of a cannulated screw with a guide wire aids in correct screw placement.
- Cannulated screws may be placed percutaneously.
Chronic fractures or nonunions should be treated with reduction and fixation plus bone grafting.
Salvage procedures for late-stage
arthritis seen after untreated fractures include excision of the
proximal row of carpal bones or partial wrist fusion.

P.367

Follow-up

Disposition

Issues for Referral

Displaced fractures
Associated fractures and dislocations
High-energy injuries

Prognosis

>90% of nondisplaced fractures heal (6)
No benefit has been found for treating nondisplaced fractures with surgery (7).
No differences have been found between the dorsal and volar approach to scaphoid fixation (8).
Displaced fractures:
- Higher nonunion rate if treated closed (9)
- Good outcomes with surgical reduction and fixation (10)
Treatment of scaphoid nonunions with
vascularized bone grafting and internal fixation seems to have the
highest rate of healing (11).

Complications

Nonunion
AVN of the proximal pole
Reflex sympathetic dystrophy
Arthritis
Wrist instability

Patient Monitoring

Patients with acute fractures are reviewed clinically
and radiographically every 2–4 weeks until the fracture is healed and
rehabilitation has been completed.

References

1. Hove LM. Epidemiology of scaphoid fractures in Bergen, Norway. Scand J Plast Reconstr Surg Hand Surg 1999;33:423–426.

2. Brudvik C, Hove LM. Childhood fractures in Bergen, Norway: Identifying high-risk groups and activities. J Pediatr Orthop 2003;23:629–634.

3. Elhassan BT, Shin AY. Scaphoid fracture in children. Hand Clin 2006;22:31–41.

4. Gelberman RH, Menon J. The vascularity of the scaphoid bone. J Hand Surg 1980;5A:508–513.

5. Kumar
S, O’Connor A, Despois M, et al. Use of early magnetic resonance
imaging in the diagnosis of occult scaphoid fractures: The CAST Study
(Canberra Area Scaphoid Trial). N Z Med J 2005;118:U1296.

6. Burge P. Closed cast treatment of scaphoid fractures. Hand Clin 2001;17:541–552.

7. Dias JJ, Wildin CJ, Bhowal B, et al. Should acute scaphoid fractures be fixed? A randomized controlled trial. J Bone Joint Surg 2005;87A: 2160–2168.

8. Polsky MB, Kozin SH, Porter ST, et al. Scaphoid fractures: Dorsal versus volar approach. Orthopaedics 2002;25:817–819.

9. Ring D, Jupiter JB, Herndon JH. Acute fractures of the scaphoid. J Am Acad Orthop Surg 2000;8: 225–231.

10. Rettig ME, Kozin SH, Cooney WP. Open reduction and internal fixation of acute displaced scaphoid wrist fractures. J Hand Surg 2001;26A:271–276.

11. Munk
B, Larsen CF. Bone grafting the scaphoid nonunion: A systematic review
of 147 publications including 5,246 cases of scaphoid nonunion. Acta Orthop Scand 2004;75:618–629.

Miscellaneous

Codes

ICD9-CM

814.01 Scaphoid fracture

Patient Teaching

Patients should be informed of the
difficulty of making the diagnosis of an acute fracture and the need
for prophylactic immobilization if snuffbox tenderness is present.
The risk of delayed union or nonunion should be discussed.

Activity

Patients should be advised not to attempt pushing or lifting while wearing a cast.

Prevention

Wrist protectors are thought to prevent wrist injury and should be used for rollerblading or in-line skating (2).

FAQ

Q: How is a scaphoid fracture diagnosed?

A:
Patients with traumatic wrist pain should be assessed carefully for
fracture. Good-quality radiographs should be taken acutely. If
negative, the patient should be immobilized and then reassessed in 2
weeks or assessed with MRI scanning.

Q: Why is it important that nondisplaced scaphoid fractures be diagnosed?

A:
If untreated, nondisplaced fractures may become displaced and lead to
scaphoid nonunion, requiring surgery. When nondisplaced fractures are
treated with immobilization, results are excellent.