What are their complications? How long does a bone take to heal?
In this guide you will learn everything about bone fractures.
What are bone fractures:
Bone fracture is a break in the surface of a bone, either across its cortex or through its articular surface.
The mechanism of injury is defined by:
Type of external and unnatural force applied to the bone;
Natural resistance of the bone.
Clinical picture and symptoms:
The classic symptoms of a fracture are:
Swelling: pathological swelling, with an increase in volume of the structure, caused by the presence of the lymphatic fluid in the tissues (edema).
Pain: which is always present and increases with movement and palpation of the affected segment. It can be mild, moderate and severe and can be due to tearing of the periosteum (the outer layer of the bone), soft tissue injury, vascular injury, nerve injury, etc.
Deformity: caused by displacement of the bones, as often occurs in displaced fractures, and by the increase in tissue volume, caused by edema.
Abnormal mobility: Sometimes the limitation of movement is so severe that the person is unable to move the affected segment.
Loss of stability and natural movement of the compromised anatomical area.
Loss of movement in adjacent joints: When you move a limb, its closest extremity is also mobilized or rotated. In displaced fractures, this bone rupture continuity does not allow the movement of the structures adjacent to the trauma.
Crepitus: This is an abnormal rubbing sensation produced by the friction between the two fracture fragments. It can be felt mainly in displaced fractures.
Shortening: Shortening of the limbs to varying degrees is very common long bones fractures.
Bone fractures: the main causes
Every day our bones are subjected to considerable amounts of force, given by the muscle action and by the activities we constantly carry out.
The bone has its own mechanism that allows it to protect itself from forces that are unnatural to it and avoid breaking.
However, if an external force applied to the bone is too great and exceeds its mechanical strength, a fracture can occur.
External damaging forces can come from:
Chronic and repetitive movements (stress fractures);
Pathological diseases in progress, which weaken the natural bone resistance.
Bone fractures types and classification:
The bone fracture types and classification can be defined by many factors.
Depending on the area of the bone involved, fractures may be:
Diaphyseal: the central tubular region of the bone that composes its body;
Metaphyseal: the region of the bone between the diaphysis and the epiphysis;
Epiphyseal: end part of a long bone, which forms the adjacent joint.
Articular or intra-articular: when the fracture reaches the joint, it can compromise the cartilage and may create impediments to the joint movement. In that case must proceed with a fracture reduction as soon as possible;
Specific anatomical locations: for example the supracondylar fractures.
Orientation and configuration of the fracture crack:
Transverse: occur when a bone is broken perpendicular to its axis. The crack is arranged horizontally, at right angles;
Oblique: the fracture line is angled, going to form an angle of less than 90 degrees;
Spiral: the fracture line forms a spiral along the bone segment, wrapping around it;
Comminute: fracture that has three or more bone fragments;
Multi-fragmentary: characterized by two fractured bone fragments.
Type of trauma:
Direct impact trauma: when the bone fractures at the point of application of the injury force:
Impact: they may occur by a contusion and generally manifest themselves with a transverse fracture line;
Meshed - bone fragments are pushed into each other, shortening the bone;
Compression / crushing: fractures also involve surrounding soft tissues and are generally comminuted;
Penetration: fractures caused by firearms, in which the bullet damages both the external and internal components.
Indirect trauma: when the damaging force acts at a distance from the fracture site, spreading along the entire limb or along the spine until it reaches the fracture site:
Traction/avulsion: these are traumatic fractures caused by a sudden and violent muscle contraction, which causes bone detachment at the tendon insertion of the muscle itself;
Compression/impacted: produces a spiroid fracture rim;
Flexion/bending: fracture that generates a transverse fracture gap;
Lateral cut/displacement: produces a displacement of bone fragments;
Torsion: This type of fracture often occurs between the vertebrae, and is caused by an impact on the soft lining of the vertebral bodies;
Combined force or action: it is given by the combined action of one or more forces (for example bending, rotation and compression).
Violence of the traumatic event:
High energy, as may happen during car accidents;
Low energy, such as an accidental fall at home or even at work.
Skin integrity and soft tissues surrounding the fracture:
Closed: a fracture doesn’t damage the structures around the bone and doesn’t communicate with the external environment; the overlying skin and other soft tissues are intact;
Open: a fracture with a break in the overlying skin and soft tissues, leading to the fracture communicating with the external environment:
a) Internally open (from within): The sharp fracture end pierces the skin from within, resulting in an open fracture.
b) Externally open (open from outside): The object causing the fracture lacerates the skin and soft tissues over the bone, as it breaks the bone, resulting in an open fracture.
Exposure of an open fracture to the external environment makes it at high risk to infection.
Number of fracture foci:
Unifocal: there is only one outbreak of fracture;
Bifocal: there are two outbreaks of fracture;
Trifocal or plurifocal: fracture outbreaks are three or multiple, as happens in polytrauma patients.
Based on the extent of the fracture line:
a) Incomplete fracture: it involves only one surface or the cortex of the bone.
For example, greenstick fractures are seen exclusively in children.
Here the bone is elastic and usually bends due to buckling or breaking one cortex when a force is applied.
b) Complete fracture: the bone is completely broken.
Complete fracture undisplaced (without dislocation of the bone fragments) in which the fracture abutments retain their position, shape and anatomical size;
Complete fracture displaced in which there is a loss of contact between the bone fragments (lateral displacement, longitudinal displacement, axis displacement, peripheral displacement).
Aggravating factors that can cause a bone fracture:
Pathological fractures: when a bone has been weakened by a pathological condition, even minor stresses can cause a break in the structure.
They occur as a spontaneous failure of the diseased bone or from the application of a light or moderate force.
For example, as occurs in the case of some neoplastic diseases (benign or malignant), or also in other diseases that can cause skeletal fragility, such as osteoporosis, bone tumors, etc.
Stress fractures: when a low intensity force is continuously repeated over time, on a specific point of a structure, can cause a stress fracture.
They occur mostly in the lower limbs and in bones subjected to prolonged workload.
The functional overload that derives from the continuous stresses on the bone is typical of sportsmen.
For example, as occurs in some sports such as dance, running, etc.
Normally, the bone damaged by these small micro traumas tends to self-repair during periods of rest.
If an athletic gesture applies a continuous force in the same area that has previously suffered a light damage, it causes a further weakening of the structure, and, over time, the creation of a stress fracture.
Bone fractures complications:
The complications of fractures are rare but can threaten the vitality of the structure affected or cause a permanent alteration of the functional movement, up to involve the whole organism.
In case of open fractures, the risk of further complications is high (which usually brings an infection), due to the involvement of other structures surrounding the fractured bone, such as blood vessels, tissues, and nerves.
Closed fractures that do not involve other structures, especially those that are rapidly reduced, are less likely to cause serious complications.
Immediate (acute) and late complications in bone fractures:
Acute complications include all the problems that occur at the time of the trauma, or during the following days:
Hemorrhage: A common feature of all fractures and soft tissue injuries.
Rarely, internal or external bleeding is severe enough to cause an hemorrhagic shock (for example, as occurs in hip fractures and some open fractures).
Skin lesions: generally occur in displaced open fractures, in which the exposure must be immediately identified, to avoid a becoming infection.
Vascular injuries: some displaced and open fractures tear blood vessels.
Some closed fractures, particularly supra-condylar humeral fractures located both anteriorly and posteriorly, interrupt the vascular supply sufficiently to cause an ischemia (Volkmann syndrome).
The vascular lesion may not be clinically visible, even for a few hours after the injury.
Nerve Injury: bone fragments can damage nerves, if they apply a pression that compresses them, or if sharp bone fragments cut them.
If the nerve injury is caused by a prolonged compression or by a compromised nerve sheath that lines the nerve (myelin sheath), or by a temporary block of the nerve conduction (which can last from a few days to a few months), with the gradual resumption of motor and sensory activity (if the nervous structure is intact, the nerve tends to heal spontaneously).
When the lesion is total, then the nerve has been torn or cut completely, and the sensitivity and the ability to move the structure are compromised.
In this case the only plausible solution is through an immediate surgery.
Pulmonary embolism or thrombosis (DVT): in patients with hip and pelvic fractures, the risk of pulmonary embolism is high.
Pulmonary embolism is the most common fatal complication of hip and pelvic fractures.
It is mostly detected when the patient has an "air hunger syndrome", with breathing difficulty, cough, tachycardia, etc.
That’s why after a surgery treatment, a drug therapy based on heparin is generally prescribed.
It allows to make the blood more fluid and to prevent obstructions in the blood vessels.
Fat embolism syndrome: this is one of the most serious complications, the essential feature being occlusion of small vessels by fat globules.
The fat globules may originate from bone marrow or adipose tissue.
Fat embolism is more common following severe injuries with multiple fractures and fractures of major bones.
Compartment syndrome (Volkmann): it is a syndrome characterized by an increase in pressure within a circumscribed anatomical area (as occurs mostly in fractures of the radius and ulna, in humeral fractures near the elbow, in tibial plateau fractures, and with open fractures of the tibia).
The increase in pressure interrupts the blood circulation and the tissues of that anatomical district (tendons, ligaments, muscles, nerves) no longer receive (or partially) supplements and oxygen.
The consequence of this syndrome, if not picked up on time, brings to a tissue necrosis or death of the affected structure.
The result of the muscles affected by necrosis is a deformity and a nervous deficit, up to the total lack of sensibility.
Compartment syndrome threatens the vitality and survival of the limb, even to the point of requiring an amputation.
The therapy consists in a decompression through fasciotomy surgery.
The anterior lodge of the forearm is incised, from the elbow to the carpal tunnel.
The incision should be left open until the edema resolves; after that the anatomical compartment is closed with a suture or skin graft.
Infection: contamination of the wound with bacteria from the outside environment may lead to infection of the bone(osteomyelitis).
This is when these microorganisms invade the membrane, unleashing an inflammatory reaction, which can lead to the formation of pus.
It occurs more commonly in open fractures, particularly in those where compounding occurs from outside (external compounding).
The increasing use of operative methods in the treatment of fractures is responsible for the rise in the incidence of infection of the bone, often years later. Infection may be superficial, moderate (osteomyelitis), or severe (gas gangrene).
Long-term complications in bone fractures:
A normal consolidation of a fracture should be the result of the formation of the callus, sufficient to withstand the strain.
Once the bone consolidation and healing time has expired, the absence of evidence that the lesion has been repaired can lead to:
Instability: some fractures can lead to joint instability.
Instability can bring disabilities and increases the risk of osteoarthrosis.
Stiffness and movement reduced: fractures that extend to the surface of the joint often damage the joint cartilage.
An alteration of the cartilage surface leads to a scar, which causes osteoarthrosis and compromises the movement of the joint.
Stiffness is more likely after a prolonged immobilization.
Knees, elbows and shoulders are particularly incline to post-traumatic stiffness, especially in old age.
The main factors are given by:
partial interruption of the vascular supply;
patient-related factors that may compromise the bone healing (for example, corticosteroids or thyroid hormones);
excessive separation of bone fragments;
movement between bone fragments;
presence of soft tissues between the two bone stumps;
an extensive lesion of the external bone cortex;
infection of the bone.
Pseudarthrosis: complete and irreversible compromisation of bone healing, in which little or no callus forms and bone resorption occurs at the fracture site.
It is a pathological situation because a particular tissue called fibrous and fibrous-cartilaginous (the one that can be found in scars and vertebral discs) is formed between the fracture fragments.
The body perceives the bone fragments as if they were separate bones, therefore it tries to join them together.
Bad Consolidation: Occurs when fracture fragments heal in an incorrect position, causing clinical and aesthetic deformity.
It can occur when a fracture has not been adequately reduced and stabilized.
Through corrective osteotomies (surgical operations in which the bone is cut with the intent to correct its shape), the lesion is restored to its normal skeletal morphology and the fragments are stabilized in the desired position, through different osteosynthesis devices.
Wedge osteotomies of equal size are then performed in opposite directions, which can be used to correct a translational deformity and restore mechanical axis alignment of the lower extremity.
Osteonecrosis: Part of a fracture fragment can become necrotic, especially when the vascular supply is damaged.
Closed fractures at risk of osteonecrosis are carpal scaphoid fractures, displaced femoral neck fractures, and displaced talar neck fractures.
Arthrosis: fractures that interrupt the continuity of a joint can cause joint misalignment, resulting in instability and future degeneration of the joint cartilage.
Limb-length discrepancy: when a fracture in children involves a growth epiphyseal plate, growth itself can be affected, resulting in a shorter than the other one.
In adults, surgical repairs of a fracture, particularly hip fractures, can cause a leg length discrepancy, which can lead to a difficult deambulation and the necessity of a footbed for the shorter leg.
Algodystrophy (Sudek's disease or CRPS): it is defined as a complex regional pain syndrome.
The causes are currently unknown; it can be imputed to a presence of an initiating noxious event, or a cause of immobilization.
It affects the arms, hands, legs and feet.
CRPS describes an array of painful conditions that are characterized by a continuing (spontaneous and/or evoked) regional pain that is seemingly disproportionate to the usual course of any known trauma or other lesion.
The pain is regional and the person has a sensation of burning, stiffness, sweaty and shiny skin, edema, muscle contraction disorders, color change of the anatomical structure concerned, pain that remains present even when the painful stimulus is no longer present.
There are two types:
Type 1 CRPS (as previously mentioned) occurs following a trauma such as fractures, sprains, surgery, and repeated microtrauma.
Type 2 CRPS occurs following an injury to a nerve branch.
Osteomyelitis: it is an inflammatory process that affects both the external and the internal component of the bone, including the bone marrow.
The most common cause is bacterial or fungal.
The infection causes the formation of abscesses.
The pus thus formed finds its way out through the area of least resistance.
The developed abscess spreads through the soft tissues and outwards, forming a breast that breaks the skin, or slips down, towards the shaft, between the cortex and the periosteum.
Post-traumatic aseptic avascular necrosis: due to an insufficiency or lack of blood supply, all the cells of a portion of the bone tissue die, not for causes associated with infections or the introduction of bacteria that damage the structure.
In severe cases it leads to bone collapse.
Bone fractures treatment:
The main goal of the fractures treatment is to guarantee the complete and physiological bone consolidation, without any alteration of the morphology, allowing the complete recovery of the functionality of the joints, muscles, and all the adjacent structures.
Therapy and treatment are essentially two:
Conservative therapy is usually used for non-displaced, incomplete, and compression fractures.
It is composed by three phases:
1. Fracture Reduction:
Usually performed under general anesthesia, it consists in correcting the displacement of the fracture stumps, returning them to their anatomical position.
In some cases the fragments decomposition does not allow an adequate reduction procedure, and an attempt is therefore made to place in a position as favorable as possible.
The doctor manually repositions the bones in the correct physiological position and, if this is not possible, special tools such as continuous traction are used.
For example femoral shaft fracture traction in children, balanced skeletal shaft femoral fractures traction in adults, etc.
Once the fracture fragments have been repositioned, they must be hold in that position until the fracture has healed itself, otherwise it may shift due to muscle action and gravity.
Some of the most common methods of restraint are, for example, cast showers for the arm and leg, or a functional brace, which allows the mobility of the contiguous joints, while the fracture is still consolidating.
3. Physiotherapy and rehabilitation:
The physiotherapy and rehabilitation program include:
Active and passive movements of all joints of the injured limb;
Physical therapies, massages and muscle strengthening to improve muscle tone and performance;
Functional rehabilitation exercises of the limb with the aim to restore generic and specific movements of the patient's daily life activities.
Surgical therapy is performed when the previous reductions have not given an effective result or in case of specific problems, for example:
Loss of reduction;
Displaced fractures within the joint (joint fractures);
The operation consists in opening the fracture site, removing any obstacles between the injured bone heads (muscles, soft structures, etc.) and making an osteosynthesis, immobilizing the bones with various implants based on the surgeon's choice:
On the other hand, during the external fixation operation, rigid wires are inserted, which penetrate the bone, in opposite poles to the fracture site, joined with an external fixation system that acts as a bridge.
It is adopted in cases of open/exposed fractures.
Most common tests done to diagnose bone fractures:
The most used technique to diagnose bone fracture, joint disorders and traumatic conditions, is the conventional radiography.
The radiologist should obtain at least two separate views, anteroposterior and lateral, and for each view should include two adjacent joints.
This reduces the risk to miss a fracture (as occurs in micro fractures of children, and it is often necessary to obtain an x-ray of the contralateral limb), a dislocation, or other associated injuries to a remote site far from the apparent primary lesion.
In some cases, special projections are required (for example an oblique image), depending on the clinical situation of the bone examined.
The radiography allows the doctor to:
Confirm the clinical diagnosis;
Better study the anatomy of the fracture;
Better study the fracture fragments displacement;
Detect further cracks and stress fractures;
Detect bone dislocations (dislocations);
Plan the treatment;
Ascertain post-reduction status of fractures.
Magnetic resonance imaging (MRI):
MRI evaluation is mostly used during traumatic bone and soft tissue conditions diagnosis.
With this technique is possible to have a full evidence of bone contusions and microfractures that aren't shown with a conventional radiography or computed tomography.
It allows to have a clear separation of the different tissues including muscles, tendons, ligaments, vessels, nerves, cartilage and bone.
While MRI has many advantages, there are also some disadvantages.
Cerebral aneurysm clips;
The presence of metallic objects, such as ferromagnetic surgical clips:
Metallic objects create "holes" in the image, distorting the image.
Computed tomography (CT) scan:
Tomography is an x-ray of a section of the body that allows for more accurate visualization of lesions that are too small to be seen on conventional x-rays or that show anatomical details obscured by overlying structures.
CT is indispensable in the evaluation of many traumatic conditions, various bone and soft tissue tumors, but also useful for evaluating the bone healing process.
It is extremely useful for defining the presence of the fracture and its extension (or dislocation), of various intra-articular anomalies (such as damage to the articular cartilage or the presence of non-calcified osteo-cartilaginous bodies) and of the adjacent soft tissues.
It can also detect any small bone fragments that have been displaced in the joints after an injury, a fractured vertebral body, and any concomitant spinal cord injuries.
Scintigraphy is a test that detects the distribution in the body through a radioactive agent injected into the vascular system.
Its main feature that all other imaging techniques haven't, is the ability to visualize the entire skeleton all in once.
Traumatic conditions such as, tumors, arthritis, infections, and metabolic bone disease are the right indications for a skeletal scintigraphy.
During traumatic conditions, a scintigraphy is extremely useful in the early diagnosis of stress fractures.
These fractures may not be visible on conventional radiographs or even tomographic studies.
Bone fractures healing and repair process:
Right after a bone fracture, the body immediately starts a healing process to repair it through specific sequences, restoring the injured structure to its original state.
As already mentioned, the basic rule to ensure that a bone is completely restored is to keep each fracture segment together and in contact.
The two fracture segments must not make any movement, otherwise the bone and the adjacent structures healing process would be compromised (if the repair process fails, a false joint forms between the fracture stumps, defined as pseudoarthrosis).
According to the subject, the healing and repairing processes are:
1. Inflammation stage:
The inflammation begins immediately after the injury.
It reaches its peak within a few hours and lasts until 1 week after the fracture.
At the beginning of the lesion, blood drops out from the torn vessels, resulting in a hematoma (a lot of blood in a confined site) around the fracture and between the injured stumps.
The surrounding areas, alarmed by the damaged cells, release a series of chemical agents, which cause a dilatation of the vessels near the lesion, which release a liquid (inflammatory exudate), to spread throughout the area.
The inflammatory exudate is full of specific immune cells, responsible of the thickening of the fluid which, converting it into a gel, completely cover the wound.
The swelling and the pain resulting from the damage are always part of our body's "defense plan", which tries to hydrostatically block the fracture.
In this way he warns us that he wants to protect the injured area and that we must move it as little as possible, so he has the possibility to repair it without obstacles.
As the gel begins to form, the blood vessels become more narrow, and as the blood supply decreases, the lymphatic ducts are also closed, to prevent the spread of infection.
Other types of immune system cells, which act as scavengers, are called to the injured area, and clean it of infectious agents and debris.
Then they remove all damaged tissues, bone fragments, and blood that has leaked from the torn blood vessels.
In short, the organism places the damaged site in quarantine.
This process lasts up to 48 hours after the damaging event.
The best way to help our body in this phase, is to apply the strategy called PRICE:
As the inflammatory response subsides, necrotic tissue (dead cells) and exudates are reabsorbed and the bone repair phase begins.
2. Repair phase:
The repair phase lasts about 2-3 weeks.
In this phase some specialized cells begin to produce a new bone matrix, the temporary callus of the fracture.
The callus is the first sign of union visible on radiography, usually 3 weeks after the fracture.
In this stage, new blood vessels are generated to form new bone between the fracture lines.
Immobilization (e.g. a cast) is required to allow the blood vessel formation.
These cells begin to proliferate, differentiate, and produce the fracture callus made up of fibrous (such as the tendon and ligament tissue), cartilaginous (such as the tissue that makes up the nose), and bone tissue.
Callus fills and surrounds the fracture site, and in the early stages of healing phase, can be divided into hard or bony callus, and softer fibrous and cartilaginous callus.
The bone initially formed in the periphery of the callus is called the hard callus, while the soft callus is formed in the central regions.
The bone gradually replaces the internal tissues, enlarging the hard callus, increasing the fracture fragments stability.
The stability of the fracture fragments progressively increases, thanks to the formation of the internal and external callus.
However, at this stage, unfortunately, the healing is not yet complete.
The fracture callus is still weak compared to the normal bone physiology and it only gains full strength during the remodeling phase.
The repair phase can be defined completed, when the pain ceases, the end part of the fractured bone can be moved and the diagnostic examination does not detect any movement of the bone stumps.
3. Remodeling Phase:
The remodeling phase aims to the definitive replacement of the newly formed bone with lamellar bone tissue, reducing the size of the callus, and restoring the normal vascular supply.
In this last phase the strength of the bone returns to being almost like the "healthy" contralateral one and the possibility of a new fracture decreases.
In the last stages of the remodeling phase, after all bone tissue has been replaced, the superfluous bone is resorbed and the new trabecular bone is formed.
The transition of the fracture callus to woven bone and the process of mineralization, which stiffens and strengthens the newly formed bone, may last for months or even years.
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