Scaphoid fracture

Definition

A scaphoid fracture consists of a break of one of the four proximal carpal bones of the wrist located between the radius and the thumb.

Pathology

The fracture of the scaphoid is the most common carpal bone fracture reaching 70% due to its protruding anatomy. The scaphoid plays a critical role in the movement of the thumb and in limiting the degree of the movement of the wrist. Its fracture can have serious consequences for the function of the thumb and the entire hand. With a high energy impact a scaphoid fracture may be associated with fractures of other wrist bones or distal ulna and radius.

Classification

Scaphoid fractures may be non-displaced, when the bone fragments maintain their anatomical position, or displaced when the bone fragments have moved from their original anatomy. They also adopt names depending on the location of the break: tubercle, waist and proximal fracture. A scaphoid fracture may occur in association with a distal radius fracture.

Causes

The main cause of scaphoid fracture is a fall on the outstretched hand on the open palm. It also occurs in motor vehicle and sport accidents with high frequency in men between 15 and 30 years of age. Scaphoid fractures are common in older people due to their weaker balance.

Risk factors

Prominent risk factors for a scaphoid fracture include participation in intensive sport activities in the younger population particularly in adolescents and young men, and low energy falls in the elderly. Additional risk factors include:

Sport (Basketball, football, rugby, hockey, skiing, snowboarding)

Medical conditions (osteoporosis, menopause)

Smoking (reduces calcium absorption and predisposition to fractures)

Symptoms

The symptoms arising from a scaphoid fracture are:

Sharp pain at thumb base and wrist

Pain at the "snuff box" exacerbated with grip

Swelling at the base of the thumb

Deformity of the wrist

Bruising

Stiffness/inability to move the thumb

Diagnosis

The examination begins with the patient's medical history including previous wrist dislocations and injuries. As pain diminishes within a day or two from the incident, a fracture to the scaphoid can be easily overseen. Clinical examination of the wrist will determine:

Changes in the anatomy of the affected wrist against the healthy wrist

Tenderness when applying gentle pressure on the "snuffbox"

Pain when applying pressure on the inner side of the wrist while extending the wrist joint (specific test for scaphoid fracture)

X-rays are taken when a fracture of the scaphoid is suspected. However, this method does not always reveal the presence of a fracture. This can become visible on X-rays during the healing process of the fracture after 1-2 weeks. During this period the patient wears a splint on the wrist. Compared to X-rays, and CT scans, MRI images offer a more sensitive alternative for the detection and accurate characterisation of scaphoid fractures.

Treatment

Nonoperative treatment

The management of scaphoid fractures varies in relation to the fracture site. In case of a fracture in the lower portion of the scaphoid surgery is not required and treatment with a cast or brace is sufficient. The cast is placed either below the elbow including the thumb, or beyond the elbow. Additional conservative treatments include:

Ice pads

Administration of NSAIDs

Painkillers

Physiotherapy whilst the arm is in a cast or brace

Rehabilitation

Regardless of the type of treatment, a cast or splint is usually worn for 9-12 weeks or up to 6 months. Any physical activities that increase the risk of a fall should be avoided until complete fracture healing has been achieved. To prevent stiffness, it is critical to maintain finger movement and begin physical therapy soon after the fracture has healed or generally 6-8 weeks after surgery. A physical or occupational therapist assists with exercises to restore flexibility and strength of the wrist including fine movements of the hand and fingers. A guided educational program will educate the patient how to modify activities to avoid recurrent injuries to the wrist. Standard rehabilitative therapy also includes:

Hand elevation (to reduce swelling/pain)

Pain management with analgesics

Antiinflammatory treatment with NSAIDs Ice or heat pads

Massage

Joint mobilisation

Stretches

Electrotherapy

Return to activity plan

Prevention

The main preventative measures for a scaphoid fracture aim at reducing the risk of falls and protect the wrist if collisions occur during sport, cycling and motor biking. Common strategies are:

Postural taping

Wearing protective gear during work recreational activities

Osteoporosis treatment

Use of devices to improve elderly patient stability and avoid falls

Modification of physical activities

Exercise to improve muscle strength, flexibility and posture