Fracture (Bone)

A bone fracture (sometimes abbreviated FRX or Fx, Fx, or #) is a medical condition in which there is a break in the continuity of the bone. A bone fracture can be the result of high force impact or stress, or trivial injury as a result of certain medical conditions that weaken the bones, such as osteoporosis, bone cancer, or osteogenesis imperfecta, where the fracture is then termed pathological fracture.

Although broken bone and bone break are common colloquialisms for a bone fracture, break is not a formal orthopedic term.

Signs and symptoms

Although bone tissue itself contains no nociceptors, bone fracture is very painful for several reasons:

• Breaking in the continuity of the periosteum, with or without similar discontinuity in endosteum, as both contain multiple nociceptors.
• Edema of nearby soft tissues caused by bleeding of torn periosteal blood vessels evokes pressure pain.
• Muscle spasms trying to hold bone fragments in place

Diagnosis

A bone fracture can be diagnosed clinically, based on the history given and the physical examination performed by a healthcare professional. Usually there will be an area of swelling, abrasion, bruising and/or tenderness at the suspected fracture site.

Open fractures are obvious in the sense that bone may be exposed.

X-ray radiographs can be requested to view the bone suspected of being fractured.

In situations where x-ray alone is insufficient, a computed tomograph (CT scan) may be performed.

Treatment

Pain management

In arm fractures in children ibuprofen has been found to be equally effective as the combination of acetaminophen and codeine.

Immobilization

Since bone healing is a natural process which will most often occur, fracture treatment aims to ensure the best possible function of the injured part after healing. Bone fractures are typically treated by restoring the fractured pieces of bone to their natural positions (if necessary), and maintaining those positions while the bone heals. Often, aligning the bone, called reduction, in good position and verify the improved alignment with an X-ray is all that is needed. This process is extremely painful without anesthesia, about as painful as breaking the bone itself. To this end, a fractured limb is usually immobilized with a plaster or fiberglass cast or splint which holds the bones in position and immobilizes the joints above and below the fracture. When the initial post-fracture edema or swelling goes down, the fracture may be placed in a removable brace or orthosis. If being treated with surgery, surgical nails, screws, plates and wires are used to hold the fractured bone together more directly. Alternatively, fractured bones may be treated by the Ilizarov method which is a form of external fixator.

Occasionally smaller bones, such as phalanges of the toes and fingers, may be treated without the cast, by buddy wrapping them, which serves a similar function to making a cast. By allowing only limited movement, fixation helps preserve anatomical alignment while enabling callus formation, towards the target of achieving union.

Surgery

Surgical methods of treating fractures have their own risks and benefits, but usually surgery is done only if conservative treatment has failed or is very likely to fail. With some fractures such as hip fractures (usually caused by osteoporosis or osteogenesis Imperfecta), surgery is offered routinely, because the complications of non-operative treatment include deep vein thrombosis (DVT) and pulmonary embolism, which are more dangerous than surgery. When a joint surface is damaged by a fracture, surgery is also commonly recommended to make an accurate anatomical reduction and restore the smoothness of the joint. Infection is especially dangerous in bones, due to their limited blood flow. Bone tissue is predominantly extracellular matrix, rather than living cells, and the few blood vessels needed to support this low metabolism are only able to bring a limited number of immune cells to an injury to fight infection. For this reason, open fractures and osteotomies call for very careful antiseptic procedures and prophylactic antibiotics.

Occasionally bone grafting is used to treat a fracture.

Sometimes bones are reinforced with metal. These implants must be designed and installed with care. Stress shielding occurs when plates or screws carry too large of a portion of the bone's load, causing atrophy. This problem is reduced, but not eliminated, by the use of low-modulus materials, including titanium and its alloys. The heat generated by the friction of installing hardware can easily accumulate and damage bone tissue, reducing the strength of the connections. If dissimilar metals are installed in contact with one another (i.e., a titanium plate with cobalt-chromium alloy or stainless steel screws), galvanic corrosion will result. The metal ions produced can damage the bone locally and may cause systemic effects as well.

Some doctors further treat bones using electrical bone growth stimulation or osteostimulation or both.

Complications

Some fractures can lead to serious complications including a condition known as compartment syndrome. If not treated, compartment syndrome can result in amputation of the affected limb. Other complications may include non-union, where the fractured bone fails to heal or mal-union, where the fractured bone heals in a deformed manner.

In children

In children, whose bones are still developing, there are risks of either a growth plate injury or a greenstick fracture.

• A greenstick fracture occurs due to mechanical failure on the tension side. That is, since the bone is not as brittle as it would be in an adult, it does not completely fracture, but rather exhibits bowing without complete disruption of the bone's cortex in the surface opposite the applied force.
• Growth plate injuries, as in Salter-Harris fractures, require careful treatment and accurate reduction to make sure that the bone continues to grow normally.
• Plastic deformation of the bone, in which the bone permanently bends but does not break, is also possible in children. These injuries may require an osteotomy (bone cut) to realign the bone if it is fixed and cannot be realigned by closed methods.
• Certain fractures are known to occur mainly in pediatric age group, as fracture clavicle & supracondylar fracture of humerus.