A bone fracture is a partial or complete disruption in the continuity of the bone structure. While bones are remarkably strong and flexible, they have a breaking point when subjected to excessive force or trauma. Skeletal injuries are common across all ages. Understanding which bones are most susceptible offers insight into injury prevention and management.
The Most Frequently Broken Bone
The most frequently fractured bone in the human body is the clavicle, commonly known as the collarbone. This S-shaped long bone connects the arm to the trunk of the body, providing structural support to the shoulder. Its prominent, relatively thin structure, which lies just beneath the skin, contributes to its high vulnerability to fracture. It is the only long bone in the body that lies horizontally.
Clavicle fractures account for approximately 5% of all adult fractures and a higher percentage of breaks in children and adolescents. The bone’s function is to transmit forces from the upper limb to the main body skeleton, which often causes it to fail under extreme load. The middle third of the clavicle, known as the midshaft, is the thinnest and least supported area, where about 80% of all clavicle fractures occur.
The Mechanics of Clavicle Fractures
A clavicle fracture often results from the transmission of force that exceeds the bone’s structural capacity. The most common cause is a fall onto the outer part of the shoulder or a fall onto an outstretched hand. In these scenarios, the impact force travels up the arm to the shoulder and is shunted into the clavicle, causing it to break. This mechanism is frequently seen in high-impact activities and contact sports.
The clavicle acts to keep the shoulder girdle away from the chest wall, meaning it bears the brunt of compressive forces. Direct impact to the collarbone, such as a tackle or a blow during a car accident, can also cause a break. In newborns, a clavicle fracture can occur as a result of birth trauma. When the midshaft breaks, the ends of the bone often displace due to muscle pull, with one fragment being pulled upward by the sternocleidomastoid muscle.
Other Common Skeletal Injuries
While the clavicle is the most commonly fractured single bone, other skeletal areas are also frequently injured. The distal radius, the larger of the two forearm bones near the wrist, is a common site for a break, often called a Colles’ fracture. This injury typically occurs when a person instinctively extends their arm to brace a fall, transmitting impact force directly through the wrist.
Forearm fractures, involving the radius and ulna, are frequent in children. Ankle fractures, involving the tibia, fibula, or both, are also very common, often resulting from twisting motions or high-impact accidents. Unlike the clavicle, which often breaks from a fall on the shoulder or hand, ankle breaks frequently involve rotational stress on the joint.
Initial Diagnosis and Recovery
Following a suspected break, diagnosis begins with a physical examination and is confirmed with X-rays, which show the bone fragments and the degree of displacement. Most midshaft clavicle fractures that are not significantly displaced are managed non-surgically, primarily through immobilization. A simple arm sling or a shoulder immobilizer is preferred over a figure-of-eight brace, as it is better tolerated by patients.
Surgical intervention is reserved for fractures with significant shortening, defined as more than 2 centimeters, or those that are severely displaced and threaten the skin or surrounding nerves. The procedure, often called open reduction and internal fixation, uses a plate and screws to realign and stabilize the bone fragments.
For adults, the bone typically takes between 6 to 12 weeks to heal, with non-surgical cases requiring the sling for about six weeks. Complete functional recovery, including rehabilitation to restore full strength and range of motion, often takes between three to five months.