The scaphoid bone, a small, boat-shaped bone located on the thumb side of the wrist, connects the two rows of smaller carpal bones. This position allows it to coordinate movement and provide stability for the entire wrist joint. An injury to this bone can significantly impact wrist motion and hand function.
Distinctive Pain and Tenderness
A broken scaphoid causes pain and tenderness on the thumb side of the wrist, below the base of the thumb. This discomfort often intensifies when pressure is applied to a soft depression on the back of the hand, known as the anatomical snuffbox. Tenderness in this area indicates a potential scaphoid fracture.
The pain can range from a dull ache to a more intense sensation. It commonly worsens with wrist movements, particularly those involving gripping, pinching, pushing, or pulling objects. Some individuals might experience pain radiating through the hand or discomfort when moving their thumb.
The initial pain may not be severe, leading many to mistake the injury for a simple wrist sprain. This mild presentation can delay seeking medical attention, which can impact healing. The precise location and nature of the pain, especially in the anatomical snuffbox, are important for suspecting a scaphoid fracture.
Other Physical Indicators
Beyond pain, a scaphoid fracture often presents with other signs in the wrist. Swelling is common, which may be localized around the thumb side of the wrist or more generalized across the wrist. This swelling can sometimes lead to a feeling of fullness in the anatomical snuffbox.
Bruising may also be present, though it is not always immediate or prominent. The subtle nature of these initial physical signs can contribute to the injury being overlooked. Over time, a decrease in grip strength often develops, making it difficult to perform tasks that require holding or squeezing objects.
Fine motor skills can also be impaired, affecting daily activities. These additional indicators, when combined with the characteristic pain, help identify a potential scaphoid fracture. These symptoms might develop gradually rather than appearing immediately after the injury.
How the Injury Occurs
Scaphoid fractures typically result from forceful impacts to the wrist. The most frequent cause is a fall onto an outstretched hand (FOOSH), particularly when the wrist is hyperextended. This mechanism transmits force directly through the wrist bones, making the scaphoid vulnerable to a break.
The angle and intensity of the impact during a fall influence whether a scaphoid fracture occurs. While FOOSH injuries are the primary cause, scaphoid fractures can also happen during activities like contact sports or motor vehicle collisions. These high-energy events can also generate enough force to fracture the scaphoid bone.
When to Consult a Healthcare Professional
Given the subtle initial symptoms, it is important to seek medical attention if wrist pain persists after an injury, even if it seems mild. The scaphoid bone has a limited blood supply, particularly to its proximal pole (the part closer to the forearm). A fracture can disrupt this blood flow, increasing the risk of complications such as non-union (where the bone fails to heal) or avascular necrosis (where part of the bone tissue dies due to lack of blood).
Delayed diagnosis and treatment can lead to long-term issues like chronic pain, stiffness, reduced wrist function, and even arthritis. If a scaphoid fracture is suspected, immobilize the wrist using a splint or cast and avoid putting weight through it until a medical professional can evaluate the injury. Prompt assessment helps ensure proper management and improves the likelihood of a successful recovery.