From the Guidelines
The most common carpal fracture is the scaphoid fracture, accounting for approximately 60-70% of all carpal bone fractures. This is followed by triquetral fractures (about 15%), lunate fractures (5-10%), and hamate fractures (2-4%) 1. Pisiform, trapezium, trapezoid, and capitate fractures are relatively rare. Scaphoid fractures typically occur from a fall on an outstretched hand, with the force transmitted through the extended wrist. These fractures are particularly concerning due to the scaphoid's tenuous blood supply, which enters distally and supplies the bone in a retrograde fashion. This unique vascular pattern puts the proximal pole at high risk for avascular necrosis following fracture, especially when the fracture occurs at the waist or proximal pole.
Key Points to Consider
- Triquetral fractures often result from dorsiflexion injuries or direct blows, while hamate fractures frequently occur in athletes who use equipment with handles (like golf clubs or baseball bats) 1.
- Early recognition and appropriate management of carpal fractures is essential to prevent complications such as nonunion, malunion, and post-traumatic arthritis.
- The incidence of distal radius fractures, which are related to carpal fractures, continues to rise for all age groups, with a significant burden on society 1.
- The treatment of carpal fractures, including scaphoid fractures, requires careful consideration of the fracture pattern, patient age, and activity level to determine the best course of treatment, whether it be conservative management or surgical intervention 1.
Management and Treatment
- Successful treatment of distal radius fractures requires restoration of radial length, inclination, and tilt, as well as the realignment of the articular fracture fragments 1.
- Operative fixation resulting in <2 mm of residual articular surface step-off is usually considered necessary to avoid long-term complications, such as osteoarthritis 1.
- The American Academy of Orthopaedic Surgeons (AAOS) and the American Society for Surgery of the Hand (ASSH) have developed evidence-based clinical practice guidelines to aid practitioners in the treatment of patients with distal radius fractures 1.
From the Research
Most Common Carpal Fractures
- The scaphoid is the most commonly fractured carpal bone, representing 70% of carpal bone fractures 2
- Scaphoid fractures usually result from a forceful extension of the wrist 3
- The diagnosis of scaphoid fractures can be complicated by the presence of normal radiographs at the time of presentation, and clinical intuition can be increased by physical examination and immediately available modalities such as ultrasound within the emergency department 4
Diagnosis and Treatment
- Definitive diagnosis of scaphoid fractures should be made with computed tomography and magnetic resonance to verify the presence of displacement 4
- For nondisplaced or minimally displaced scaphoid waist and distal pole fractures, immobilization below the elbow without inclusion of the thumb is an option 5
- Early surgical intervention for nondisplaced or minimally displaced scaphoid waist fractures allows for quicker return of function, but with increased risk of surgical complications and no long-term outcomes differences compared with cast immobilization 5
- MRI is the most accurate imaging test to diagnose scaphoid fractures in patients with no evidence of fracture on initial x-rays 2
Immobilization Protocols
- Wrist immobilization is crucial for nondisplaced scaphoid waist fractures, and short arm casting was just as effective as thumb spica casting in preventing fracture displacement 6
- Immobilization protocols for nondisplaced scaphoid fractures have included the elbow, wrist, and thumb, but there is no significant difference in fracture angulation or rotation between spica and short arm casts 6