Generality
Exostoses are the benign formations of new bone, which can be generated on the surface of the bones of the human body.
To determine the appearance of an exostosis can be a repeated irritative phenomenon, a trauma, an infection or a genetic mutation; however, in a not inconsiderable number of cases, these benign neo-formations of bone are due to unknown reasons.
There are numerous types of exostoses, including: exostosis of the ear canal, buccal exostosis, heel spurs, multiple hereditary exostoses, osteochondroma, osteoma of the paranasal sinuses and sub-nail exostoses.
Exostoses can be symptomatic or asymptomatic; when they are symptomatic, the associated manifestations depend on the anatomical site concerned.
Diagnosed by X-rays, exostoses require treatment when they are responsible for symptoms that affect the patient's quality of life.
What is an Esostosi?
Exostosis is the medical term that, together with the synonym osteoma, describes all those benign formations of new bone, which can originate on the surface of the bones of the human body .
The word exostosis, therefore, includes all the possible bony growths of a benign nature that can be generated on the surface of a bone, including the so-called osteophytes (or bone spurs ) and osteochondromas .
- Osteophyte is the name of a bone formation similar to a claw or a thorn of a rose, which can form near the joints, following chronic irritation or long-lasting erosion processes.
- Osteochondroma, on the other hand, is the medical term that defines exostoses with the site of appearance on the cartilaginous portion of those bones that include a layer of cartilage.
Exostoses: the most common sites
All bones in the human body can be subject to exostosis.
However, there are bones that, due to their location or for reasons not yet clarified, are more affected than others; more specifically, among the bones most subject to the phenomenon of exostosis, there are:
- The bones that make up the external auditory canal;
- Ankle bones;
- The calcaneus, one of the 7 bones of the tarsus of the foot;
- The jaw or jaw;
- The long bones of the limbs (humerus, radius, ulna, phalanges of the hands, femur, tibia and fibula);
- The bones constitute the paranasal sinuses (sphenoid, ethmoid etc.).
Causes
To cause an exostosis can be:
- A chronic erosive and / or irritative process affecting a very specific anatomical portion . This is what happens in exostoses that appear in the vicinity of a suffering joint of a form of arthritis (eg: Heberden nodules in the hands) or in exostoses that grow near the bony insertion of a tendon or a ligament (eg: heel spurs );
- An injury or injury to the bone on which the abnormal growth occurs . Exostoses due to this type of cause are those affecting particular bones such as the maxilla or the jaw;
- Exposure continues to certain environmental factors . This is the case of the exostoses that grow on the bones of the ear canal of people whose ears are continually exposed to water and wind;
- A genetic anomaly . There are forms of hereditary exostoses and forms of exostoses that arise following a spontaneous mutation of DNA, during embryonic development (therefore, mutations that occur after conception, but long before birth).
The cases of exostoses due to an alteration of the DNA (no matter whether inherited or acquired during embryonic development) take the generic name of multiple hereditary exostoses;
- An osteomyelitis . In medicine, the word "osteomyelitis" identifies the infection and the consequent inflammation of a bone and its medullary cavity.
It should be noted that, in spite of what has just been reported, many cases of exostoses appear due to unknown causes (ie their appearance cannot be attributed to a phenomenon or a precise episode).
Common types of exostoses
The most common and described types of exostoses are:
- The exostoses of the ear canal ;
- The heel spur ;
- Multiple hereditary exostoses ;
- The osteoma of the paranasal sinuses ;
- Buccal exostoses ;
- Sub-nail exostosis ;
- Osteochondroma .
EXPOSURES OF AUDITIVE CONDUCT
Also known as the surfer's ear, the auditory exostosis is the condition resulting from the growth of a bone growth on the surface of the bones forming the external auditory canal (it is the canal of the external ear, which begins at the level of the auricle and leads to the eardrum).
Currently, doctors have not yet identified the precise cause of auditory ostostosis; however, having detected a high incidence of this condition in people practicing water sports such as surfing, sailing, etc., they believe that it represents a causal factor determining the repeated exposure of the external auditory canal to water and wind (NB: this explains also the expression "surfer's ear").
Exostoses of the ear canal can affect one or both ears and can degenerate into hearing loss.
CALCANEOUS PLUG
Also known as the heel spur, the heel spur is the exostosis of the heel.
Similar to a claw or a pink thorn, the heel spur is usually the result of the continuous repetition of phenomena that irritate the insertion of the Achilles tendon on the heel (in this case, the exostosis will be located on the posterior front of the foot) or the insertion of the plantar fascia on the heel (in this situation, instead, the exostosis will be located on the inferior-posterior portion of the foot).
Statistics say that the heel spur is more common in:
- People who have the habit of wearing shoes that "beat" on the back of the heel or that significantly modify the arch of the foot (eg: heeled shoes, in the case of women);
- People who practice sports like road racing, where it is possible to develop inflammation of the plantar fascia ( plantar fasciitis );
- Individuals who by their nature have an Achilles tendon that is narrower than normal;
- Obese or overweight subjects.
MULTIPLE HEREDITARY EXOSTOSIS
The aforementioned multiple hereditary exostosis is a genetic disease, which causes the formation of different bony growths in various bones of the human body.
Hereditary condition in 50% of cases and acquired during the course of embryonic development in the remaining percentage, the multiple hereditary exostosis preferably affects the long bones of the leg, the shoulders and the shoulder blades.
Multiple hereditary exostoses tend to go unnoticed up to 5-6 years of age, a period in which the patient begins to develop the first abnormal bone growths.
OSTEOMA OF THE PARANASAL SENSES
The paranasal sinuses are the 4 cavities filled with air with seat inside the cheeks and forehead, and resulting from the particular arrangement of the ethmoid cranial bones ( ethmoid sinuses), sphenoid ( sphenoid sinuses), frontal ( frontal sinuses) and maxillary ( maxillary sinuses).
The paranasal sinuses serve to: improve the perception of odors, amplify the sounds and the voice emitted by the vocal cords, make the skull less heavy and humidify-heat-purify the inspired air.
The osteoma of the paranasal sinuses is the condition that can arise due to the effect of an exostosis on one of the ethmoid bone, the sphenoid bone, the frontal bone and the jaw bone.
Due to completely unknown causes, the osteoma of the paranasal sinuses can be an obstacle to the passage of inhaled air and the drainage of mucus .
EXOSTOSI BUCCALE
Buccal exostosis is the medical expression that defines the benign bone formations that can be generated inside the mouth, or on the jaw or jaw.
As a rule, at the origin of the buccal exostosis episodes there is a trauma or injury to the gingiva (obviously involving the underlying bone structure).
Buccal exostosis is more common in adolescence.
SUB-UNGUEAL EXOSTOSIS
Also known as exostoses of the nail bed, the sub-nail exostosis is the condition resulting from the formation of an abnormal growth on the bone surface immediately below the so-called nail bed (ie the characteristic portion of the fingers and toes, on which the 'nail).
In general, at the origin of the sub-nail exostosis episodes there is a trauma to the part of the finger that develops the anomaly.
Statistics in hand, sub-nail exostosis is a phenomenon that doctors find most often at the expense of the first toe, that is, the toe.
Adolescents suffer most frequently from exostoses of the nail bed.
osteochondroma
As already exposed to the readers, an osteochondroma is an exostosis which forms on the cartilaginous surface of a bone; this means that osteochondroma is an abnormal bone growth, covered, unlike normal exostoses, by a layer of cartilage.
Also known as osteo-cartilaginous exostosis, osteochondroma most often affects the bones of the lower limbs, the pelvic bones (particularly those involved in the hip joint) and the scapula .
Among the various types of exostoses recognized and described in the medical literature, osteochondroma is the common; in this regard, epidemiological investigations report that about 2% of the general population would suffer from osteochondroma.
Currently, the causes of osteochondromas are unknown; experts, however, believe that some skeletal developmental anomalies affect the formation of these osteo-cartilaginous growths, as the subjects most affected are children and adolescents (ie a category of person in the full phase of bone growth).
Symptoms and Complications
Exostoses can be completely symptom-free conditions - so that the diagnosis in such situations is often the result of chance - or conditions characterized by a more or less complex symptomatology .
The same type of exostoses (eg, heel spurs) may be responsible for symptoms in one individual and completely asymptomatic in another.
When an exostosis is symptomatic, the manifestations of the condition are closely related to the site of the outgrowth; for example:
- A symptomatic heel spur is typically responsible for pain in the back or bottom of the heel (especially during activities such as walking or running) and a feeling of soreness in the skin tissues surrounding the abnormal bone growth;
- A symptomatic buccal exostosis is a source of pain in the mouth and problems when brushing your teeth;
- A symptomatic multiple hereditary exostosis is characterized by the presence of: limbs of different length (heterometry of the limbs), arched arms and / or legs, short stature, sense of joint stiffness, painful bones during movement of the related joints and compression of the nerves and / or blood vessels passing near abnormal bone formations;
- An exostosis of the symptomatic ear canal causes hearing loss and, if left untreated, total loss of hearing ability;
- A symptomatic exostosis of the paranasal sinuses produces problems of drainage of the mucus, hinders the air entering from the nostrils and, if in proximity of some important nerve, causes the crushing of the latter, resulting painful.
Complications
Although they are formations of a benign nature, exostoses can still be the cause of complications. For example:
- The exostosis of the ear canal can cause complications such as: hearing loss and tendency to develop recurrent ear infections (they are due to the water that accumulates and stagnates in the ear canal, following the altered anatomy of the latter) ;
- If it grows near blood vessels, the osteochondroma can promote the appearance of vascular complications, including: false aneurysm (or pseudoaneurysm ), phlebitis and acute ischemia .
- Multiple hereditary exostoses can be complicated when one of the bony growths becomes malignant (in these situations, the resulting malignant tumor is an example of osteosarcoma).
Did you know that ...
According to statistics, the evolution in malignant terms of a bone growth due to multiple hereditary exostoses would concern between 1 and 6 patients per 100; fortunately, therefore, this is an uncommon phenomenon.
Diagnosis
In order to diagnose exostoses, an X-ray examination of the anatomical portion involved is essential.
If there is any doubt about the benign nature of the outgrowth detected, the execution of a bone biopsy is clear .
For those suffering from multiple hereditary exostoses, the diagnosis of the genetic condition in question is possible even before birth (NB: doctors search for this disease only when one of the parents of the possible future patient is a carrier; otherwise, is not a routine test, as could be, for example, that related to Down syndrome).
Therapy
Very often, the presence of an exostosis does not require any therapy.
The use of some kind of treatment occurs only when the exostosis is symptomatic or, worse, is the cause of complications .
How much an exostosis requires a therapy (therefore, in the cases in which it is responsible for problems that compromise the quality of life), the type of therapy adopted depends on the localization of the anomalous bone growth and the severity of the symptoms.
Examples of Therapy
EXODOSIS OF THE AUDITOR CHANNEL
When the auditory canal exostosis requires therapy, the latter consists of a surgical operation, known as canaloplastica, whose purpose is to remove the anomalous bone growth and restore the normal anatomy of the external ear canal of the ear.
Did you know that ...
People at risk of developing the surfer's ear (eg surfers, sailors, sailors, etc.) can effectively prevent this type of exostosis by using ear plugs or a helmet that protects the ears from exposure to water and wind.
CALCANEOUS PLUG
For the treatment of symptomatic cases of heel spurs, there are two types of therapeutic approach: a therapeutic approach of a conservative nature, which represents the first line treatment, and a therapeutic approach of a surgical nature, which instead constitutes the treatment reserved exclusively for patients on which the aforementioned conservative therapies have been ineffective.
- The conservative treatment of heel spurs includes: rest from all those activities that could cause heel pain, taking anti - inflammatories, applying ice on the painful area, stretching and strengthening exercises for the leg muscles (obviously from the lower limb affected by the exostoses), physiotherapy and use of shoes that preserve the health of the heel (for a woman, the use of heeled shoes should be avoided);
- The surgical treatment of heel spurs, on the other hand, consists in the removal of the exostosis, followed by a period of rest and physiotherapy rehabilitation.
MULTIPLE HEREDITARY EXOSTOSIS
When it is a source of symptoms, multiple hereditary exostoses require the use of a surgical therapy aimed at:
- Remove all exostoses that compress the nerves and / or the neighboring blood vessels;
- Remove any exostoses that show signs of malignancy;
- Correct the deviations of the limbs;
- Correct the heterometry of the limbs as much as possible.
Prognosis
While for symptomatic exostoses the prognosis is normally benign, for the symptomatic exostoses the predictions on the evolution of the condition are uncertain, less obvious.
Even when subjected to the most adequate treatments, in fact, some exostoses could recur after some time, becoming the protagonist of recurrences .
