It is a common belief that if you can move an injured limb, it cannot be broken. This assumption is often incorrect, especially when dealing with the complex structure of the hand. The hand’s intricate design includes many small bones supported by an extensive network of soft tissues. This structure can allow a surprising degree of movement even after a fracture has occurred, meaning mobility is not a reliable test for determining a broken bone.
Understanding Hand Bone Anatomy and Stability
The hand is an exceptionally complex structure, containing 27 bones, which is nearly a quarter of all the bones in the human body. These bones are divided into three groups: the carpals in the wrist, the metacarpals in the palm, and the phalanges in the fingers and thumb. This multitude of small bones, rather than a few large ones, provides the hand with its remarkable flexibility and dexterity.
A dense web of ligaments and tendons surrounds and supports these bones, providing inherent stability. Ligaments connect bone to bone, while tendons connect muscle to bone, transmitting the force necessary for movement. Because the hand has so many supporting structures, a fracture in one small bone may not destabilize the entire structure. This allows the surrounding tissues to maintain some ability to move the digits.
Why Movement Does Not Rule Out a Break
The ability to move a finger or the hand after an injury largely depends on the type and stability of the fracture. A fracture does not always mean the bone is completely severed or displaced into two separate pieces. Many hand fractures are considered stable, meaning the bone fragments remain in good alignment or are barely out of place.
For example, a non-displaced fracture, sometimes referred to as a hairline or stress fracture, involves a break that does not cause the bone ends to separate. In these cases, the surrounding tendons and muscles still have an intact bony structure, even if cracked, to pull against. This allows the soft tissues to transmit force across the fracture site, resulting in limited, painful, but still present movement.
Critical Signs That Indicate a Fracture
Since movement is not a clear sign of a non-fracture, it is important to look for other symptoms that strongly suggest a broken bone. Pain specifically focused over a small area of a bone, known as point tenderness, is a reliable indicator of a fracture. The body’s immediate response to a bone injury is often rapid swelling, or edema, as fluid rushes to the damaged tissue.
Bruising, or ecchymosis, may appear as small blood vessels rupture and leak blood into the surrounding tissues. While swelling and bruising can also occur with sprains, a visible deformity, such as a finger that looks crooked or shortened, is a strong indication of a displaced fracture. Another concerning sign is a grinding sensation or sound, called crepitus, which can occur when broken bone ends rub against each other during attempted movement.
Immediate Steps and When to Seek Medical Help
If a hand injury is severe enough to cause significant pain, swelling, or any of the signs mentioned, immediate action is necessary. First, remove any jewelry, especially rings, from the injured hand before swelling begins or worsens. The hand should then be gently immobilized using a makeshift splint or rolled towel to prevent unnecessary movement that could worsen the injury.
To help manage swelling and pain, the hand should be elevated above the level of the heart, and ice should be applied to the affected area for up to 20 minutes at a time. Seek urgent medical attention immediately if there is an obvious deformity, numbness or tingling, or if the pain is severe and persistent. A medical professional will use an X-ray to confirm the diagnosis, determine the fracture type, and ensure the bone is correctly aligned for proper healing.