A bone fracture 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 a minimal trauma
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 properly termed a pathologic
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 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
Damage to adjacent structures such as nerves or vessels, spinal cord and nerve roots, or
cranial contents can cause other specific signs and symptoms.
Pathophysiology
The natural process of healing a fracture starts when the injured bone and surrounding
tissues bleed, forming a fracture hematoma.
The blood coagulates to form a blood clot situated between the broken fragments.
Within a few days blood vessels grow into the jelly-like matrix of the blood clot.
The new blood vessels bring phagocytes to the area, which gradually remove the non-viable
material.
The blood vessels also bring fibroblasts in the walls of the vessels and these multiply
and produce collagen fibres.
In this way the blood clot is replaced by a matrix of collagen.
Collagen's rubbery consistency allows bone fragments to move only a small amount unless
severe or persistent force is applied.
At this stage, some of the fibroblasts begin to lay down bone matrix in the form of collagen
monomers.
These monomers spontaneously assemble to form the bone matrix, for which bone crystals are
deposited in amongst, in the form of insoluble crystals.
This mineralization of the collagen matrix stiffens it and transforms it into bone.
In fact, bone is a mineralized collagen matrix; if the mineral is dissolved out of bone, it
becomes rubbery.
Healing bone callus is on average sufficiently mineralized to show up on X-ray within 6 weeks
in adults and less in children.
This initial "woven" bone does not have the strong mechanical properties of mature bone.
By a process of remodeling, the woven bone is replaced by mature "lamellar" bone.
The whole process can take up to 18 months, but in adults the strength of the healing
bone is usually 80% of normal by 3 months after the injury.
Several factors can help or hinder the bone healing process.
For example, any form of nicotine hinders the process of bone healing, and adequate
nutrition will help the bone healing process.
Weight-bearing stress on bone, after the bone has healed sufficiently to bear the weight,
also builds bone strength.
Although there are theoretical concerns about NSAIDs slowing the rate of healing, there
is not enough evidence to warrant withholding the use of this type analgesic in simple fractures.
Effects of smoking Smokers generally have lower bone density
than non-smokers, so have a much higher risk of fractures.
There is also evidence that smoking delays bone healing.
Some research indicates, for example, that it delays tibial shaft fracture healing from
a median healing time of 136 to a median healing time of 269 days.
This means that the fracture healing time was approximately doubled in smokers.
Although some other studies show less extreme effects, it is still shown that smoking delays
fracture healing.
Diagnosis
A bone fracture can be diagnosed clinically based on the history given and the physical
examination performed.
Imaging by X-ray is often performed to view the bone suspected of being fractured.
In situations where x-ray alone is insufficient, a computed tomograph or MRI may be performed.
Classification
By cause Traumatic fracture - This is a fracture due
to sustained trauma.
e.g.- Fractures caused by a fall, road traffic accident, fight etc.
Pathological fracture - A fracture through a bone which has been made weak by some underlying
disease is called pathological fracture.
e.g.- a fracture through a bone weakened by metastasis.
Osteoporosis is the most common cause of pathological fracture.
Periprosthetic fracture - A fracture at the point of mechanical weakness at the end of
an implant Orthopedic
In orthopedic medicine, fractures are classified in various ways.
Historically they are named after the doctor who first described the fracture conditions.
However, there are more systematic classifications in place currently.
All fractures can be broadly described as: Closed fractures: are those in which the skin
is intact Open fractures: involve wounds that communicate
with the fracture, or where fracture hematoma is exposed, and may thus expose bone to contamination.
Open injuries carry a higher risk of infection.
Other considerations in fracture care are displacement and angulation.
If angulation or displacement is large, reduction of the bone may be required and, in adults,
frequently requires surgical care.
These injuries may take longer to heal than injuries without displacement or angulation.
Compression fractures: usually occurs in the vertebrae, for example when the front portion
of a vertebra in the spine collapses due to osteoporosis.
Other types of fracture are: Complete fracture: A fracture in which bone
fragments separate completely.
Incomplete fracture: A fracture in which the bone fragments are still partially joined.
In such cases, there is a crack in the osseous tissue that does not completely traverse the
width of the bone.
Linear fracture: A fracture that is parallel to the bone's long axis.
Transverse fracture: A fracture that is at a right angle to the bone's long axis.
Oblique fracture: A fracture that is diagonal to a bone's long axis.
Spiral fracture: A fracture where at least one part of the bone has been twisted.
Comminuted fracture: A fracture in which the bone has broken into several pieces.
Impacted fracture: A fracture caused when bone fragments are driven into each other.
Avulsion fracture: A fracture where a fragment of bone is separated from the main mass.
Anatomical location An anatomical classification may begin with
specifying the involved body part, such as the head or arm, followed with more specific
localization.
Fractures that have additional definition criteria than merely localization can often
be classified as subtypes of fractures that merely are, such as a Holstein-Lewis fracture
being a subtype of a humerus fracture.
However, most typical examples in an orthopedic classification given in previous section cannot
appropriately be classified into any specific part of an anatomical classification, as they
may apply to multiple anatomical fracture sites.
Skull fracture Basilar skull fracture
Blowout fracture - a fracture of the walls or floor of the orbit
Mandibular fracture Nasal fracture
Le Fort fracture of skull - facial fractures involving the maxillary bone and surrounding
structures in a usually bilateral and either horizontal, pyramidal or transverse way.
Spinal fracture Cervical fracture
Fracture of C1, including Jefferson fracture Fracture of C2, including Hangman's fracture
Flexion teardrop fracture - a fracture of the anteroinferior aspect of a cervical vertebral
Clay-shoveler fracture - fracture through the spinous process of a vertebra occurring
at any of the lower cervical or upper thoracic vertebrae
Burst fracture - in which a vertebra breaks from a high-energy axial load
Compression fracture - a collapse of a vertebra, often in the form of wedge fractures due to
larger compression anteriorly.
Chance fracture - compression injury to the anterior portion of a vertebral body with
concomitant distraction injury to posterior elements
Holdsworth fracture - an unstable fracture dislocation of the thoracolumbar junction
of the spine
Rib fracture Sternal fracture
Shoulder fracture Clavicle fracture
Scapular fracture
Arm fracture Humerus fracture
Supracondylar fracture Holstein-Lewis fracture - a fracture of the
distal third of the humerus resulting in entrapment of the radial nerve.
Forearm fracture Ulnar fracture
Monteggia fracture - a fracture of the proximal third of the ulna with the dislocation of
the head of the radius Hume fracture - a fracture of the olecranon
with an associated anterior dislocation of the radial head
Radius fracture Essex-Lopresti fracture - a fracture of the
radial head with concomitant dislocation of the distal radio-ulnar joint with disruption
of the interosseous membrane.
Distal radius fracture Galeazzi fracture - a fracture of the radius
with dislocation of the distal radioulnar joint
Colles' fracture - a distal fracture of the radius with dorsal displacement of the wrist
and hand Smith's fracture - a distal fracture of the
radius with volar displacement of the wrist and hand
Barton's fracture - an intra-articular fracture of the distal radius with dislocation of the
radiocarpal joint.
Hand fracture Scaphoid fracture
Rolando fracture - a comminuted intra-articular fracture through the base of the first metacarpal
bone Bennett's fracture - a fracture of the base
of the first metacarpal bone which extends into the carpometacarpal joint.
Boxer's fracture - a fracture at the neck of a metacarpal
Pelvic fracture Fracture of the hip bone
Duverney fracture - an isolated pelvic fracture involving only the iliac wing.
Femoral fracture Hip fracture
Patella fracture Crus fracture
Tibia fracture Pilon fracture
Tibial plateau fracture Bumper fracture - a fracture of the lateral
tibial plateau caused by a forced valgus applied to the knee
Segond fracture - an avulsion fracture of the lateral tibial condyle
Gosselin fracture - a fractures of the tibial plafond into anterior and posterior fragments
Toddler's fracture - an undisplaced and spiral fracture of the distal third to distal half
of the tibia
Fibular fracture Maisonneuve fracture - a spiral fracture of
the proximal third of the fibula associated with a tear of the distal tibiofibular syndesmosis
and the interosseous membrane.
Le Fort fracture of ankle - a vertical fracture of the antero-medial part of the distal fibula
with avulsion of the anterior tibiofibular ligament.
Bosworth fracture - a fracture with an associated fixed posterior dislocation of the proximal
fibular fragment which becomes trapped behind the posterior tibial tubercle.
The injury is caused by severe external rotation of the ankle.
Combined tibia and fibula fracture Trimalleolar fracture - involving the lateral
malleolus, medial malleolus and the distal posterior aspect of the tibia
Bimalleolar fracture - involving the lateral malleolus and the medial malleolus.
Pott's fracture
Foot fracture Lisfranc fracture - in which one or all of
the metatarsals are displaced from the tarsus Jones fracture - a fracture of the proximal
end of the fifth metatarsal March fracture - a fracture of the distal
third of one of the metatarsals occurring because of recurrent stress
Calcaneal fracture
OTA/AO classification
The Orthopaedic Trauma Association Committee for Coding and Classification published its
classification system in 1996, adopting a similar system to the 1987 AO Foundation system.
In 2007, they extended their system, unifying the 2 systems regarding wrist, hand, foot
and ankle fractures.
Other systems There are other systems used to classify different
types of bone fractures: "Denis classification" for spinal fractures
"Frykman classification" for forearm fractures "Gustilo open fracture classification"
"Letournel and Judet Classification" for Acetabular fractures
"Neer classification" for humerus fractures Seinsheimer classification, Evans-Jensen classification,
Pipkin classification and Garden classification for hip fractures
Treatment
Treatment of bone fractures are broadly classified as surgical or conservative, the latter basically
referring to any non-surgical procedure, such as pain management, immobilization or other
non-surgical stabilization.
A similar classification is open versus closed treatment, in which open treatment refers
to any treatment in which the fracture site is surgically opened, regardless of whether
the fracture itself is an open or closed fracture.
Pain management In arm fractures in children, ibuprofen has
been found to be as effective as a 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, and maintaining those positions while the bone heals.
Often, aligning the bone, called reduction, in good position and verifying 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.
Splinting results in the same outcome as casting in children who have a distal radius fracture
with little shifting.
Surgery Surgical methods of treating fractures have
their own risks and benefits, but usually surgery is done only if conservative treatment
has failed, is very likely to fail, or likely to result in a poor functional outcome.
With some fractures such as hip fractures, surgery is offered routinely because non-operative
treatment results in prolonged immobilisation, which commonly results in complications including
chest infections, pressure sores, deconditioning, deep vein thrombosis 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 the recrudescent nature of bone infections.
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, galvanic corrosion will
result.
The metal ions produced can damage the bone locally and may cause systemic effects as
well.
Electrical bone growth stimulation or osteostimulation has been attempted to speed or improve bone
healing.
Results however do not support its effectiveness.
Complications
Some fractures can lead to serious complications including a condition known as compartment
syndrome.
If not treated, compartment syndrome can eventually require 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.
Complications of fractures can be classified into three broad groups depending upon their
time of occurrence.
These are as follows - Immediate complications - occurs at the time
of the fracture.
Early complications - occurring in the initial few days after the fracture.
Late complications - occurring a long time after the fracture.
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 to realign the bone if it is fixed and cannot
be realigned by closed methods.
Certain fractures are known to occur mainly in the pediatric age group, such as fracture
of the clavicle & supracondylar fracture of the humerus.
See also Stress fracture
Distraction osteogenesis Rickets
Catagmatic H. Winnett Orr, US Army surgeon who developed
Orthopedic plaster casts References
External links First Aid for Fractures Wildernessmanuals.com
Fracture and Dislocation Compendium Orthopaedic Trauma Association
Authoritative information in orthopaedic surgery American Association of Orthopedic Surgeons
Radiographic Atlas of Fracture After the Injury Children's Hospital Of Philadelphia