Hyperostosis is an excessive (pathological) proliferation of unchanged bone tissue. It can occur as an independent process or be a symptom of other diseases. The symptoms are determined by the primary pathology. Hyperostosis may be accompanied by deformation of one or more bones of the skeleton, or it may not manifest clinically in any way and be detected only during special studies (radiography, MRI, radionuclide examination). The tactics of treatment of hyperostosis depends on the underlying disease.
Hyperostosis – excessive bone overgrowth, in which an increase in the mass of bone tissue per unit volume is determined. It can occur compensatorily (with increased load on the limb) or be a symptom of a number of diseases. By itself, hyperostosis does not pose a danger to the patient, but it can signal pathological processes that require serious therapy. Depending on the underlying disease in which hyperostosis is observed, oncologists, phthisiologists, endocrinologists, pulmonologists, gastroenterologists, venereologists, orthopedists, rheumatologists and other specialists can treat this pathology.
Usually, with hyperostosis, tubular bones are affected. The bone tissue thickens and grows in the periosteal and endosteal direction. At the same time, depending on the nature of the underlying pathology, two options may be observed. The first is the defeat of all elements of bone tissue: the periosteum, spongy and cortical matter are compacted and thickened, the number of immature cellular elements increases, the architectonics of the bone is disrupted, the bone marrow atrophies and is replaced by bone growths or connective tissue. The second is a limited lesion of the spongy substance with the formation of foci of sclerosis.
Taking into account the prevalence, local and generalized hyperostoses are distinguished. Local hyperostosis within one bone can develop with constant physical overload of a certain segment of the limb. This form of hyperostosis also occurs in some malignant tumors and systemic diseases. In addition, local hyperostosis is observed in Morgagni-Morel-Steward syndrome, a disease that can be observed in women of menopausal age.
The group of generalized hyperostoses includes cortical infantile hyperostosis (Caffey-Silverman syndrome) – a disease with an unknown pathogenesis that develops in young children, and cortical generalized hyperostosis – a hereditary disease that is transmitted by autosomal recessive type and manifests itself during puberty. Another generalized hyperostosis is Kamurati-Engelmann disease, transmitted by autosomal dominant type.
Types of hyperostosis
Marie-Bamberger syndrome (systemic ossifying periostosis, hypertrophic osteoarthropathy) is an overgrowth of bone tissue described by the Austrian therapist Bamberger and the French neurologist Marie. It is manifested by multiple, usually symmetrical hyperostoses that occur in the area of the forearms, shins, metatarsals and metacarpal bones. It is accompanied by a characteristic deformation of the fingers: the phalanges thicken in the form of “drumsticks”, the nails take the form of “watch glasses”. A patient with hyperostosis is concerned about pain in the bones and joints. Vegetative disorders (redness and pallor of the skin, sweating) and recurrent arthritis of the metacarpal, elbow, ankle, wrist and knee joints with an erased clinical picture are also observed. It is possible to enlarge the nose and thicken the skin on the forehead.
Hyperostosis in Marie-Bemberger syndrome develops a second time, as a reaction of bone tissue to a violation of the acid-base balance and a chronic lack of oxygen. The cause of the syndrome is malignant tumors of the lungs and pleura, chronic inflammatory lung diseases (pneumoconiosis, tuberculosis, chronic pneumonia, chronic obstructive bronchitis, etc.), intestinal and kidney diseases, as well as congenital heart defects. Less often observed with cirrhosis of the liver, lymphogranulomatosis and echinococcosis. In some cases, hyperostosis occurs spontaneously, without connection with any disease.
Radiography of the shins, forearms and other affected segments reveals symmetrical thickening of the diaphyses due to the formation of smooth, even periosteal layers. At the initial stages, the density of layers is less than that of the cortical layer. Subsequently, the layers become denser and merge with the cortical layer. With successful treatment of the underlying disease, the manifestations of Marie-Bemberger syndrome decrease and may even disappear completely. NSAIDs are used to reduce pain during exacerbation.
Women of menopausal and post-menopausal age suffer from frontal hyperostosis. Hyperostosis is manifested by thickening of the inner plate of the frontal bone, obesity and the appearance of male sexual characteristics. The cause of the occurrence has not been clarified, it is assumed that hyperostosis is provoked by hormonal changes during menopause. The disease develops gradually. At first, patients are concerned about persistent compressive headache. The pain is localized in the forehead or the back of the head and does not depend on the change in the position of the head. Due to constant pain, patients with hyperostosis often become irritable and suffer from insomnia.
Subsequently, body weight increases, obesity occurs, often accompanied by increased hair growth on the face and in the trunk area. Other manifestations of frontal hyperostosis include type II diabetes mellitus, fluctuations in blood pressure with a tendency to increase, palpitations, shortness of breath and menstrual irregularities, which, unlike the usual menopause, are not accompanied by hot flashes. Over time, there is an aggravation of nervous disorders, sometimes there are depressions.
The diagnosis of frontal hyperostosis is made on the basis of characteristic symptoms and skull radiography data. Radiographs reveal bone growths in the area of the frontal bone and the Turkish saddle. The inner plate of the frontal bone is thickened. During spine x-ray, bone growths are often also detected. When studying the level of hormones in the blood of patients with hyperostosis, an increased amount of adrenal cortex hormones, adrenocorticotropin and somatostatin is determined.
Treatment of frontal hyperostosis is carried out by endocrinologists. A low-calorie diet is prescribed, patients are recommended to maintain a regime of sufficient motor activity. With a persistent increase in blood pressure, antihypertensive drugs are indicated, with diabetes mellitus – drugs for correcting blood sugar levels.
Infantile cortical hyperostosis
This hyperostosis was first described by Roscke in 1930, however, a more detailed description of the disease was performed by Silverman and Caffey in 1945. The causes of development are not exactly clarified, there are theories regarding hereditary and viral origin, as well as about the connection of the disease with hormonal balance disorders. Hyperostosis occurs only in infants. The beginning resembles an acute infectious disease: there is an increase in temperature, the child loses appetite, becomes restless. Acceleration of ESR and leukocytosis are detected in the blood. On the face and limbs of patients with hyperostosis, dense swellings appear without signs of inflammation, sharply painful on palpation. A characteristic feature of infantile hyperostosis is a “moon-shaped face” caused by swelling in the lower jaw area.
According to the radiography of the clavicles, short and long tubular bones, as well as the lower jaw, lamellar periosteal layers are revealed. The spongy substance is sclerosed, compact thickened. According to the results of radiography of the lower leg, an arcuate curvature of the tibia can be determined. General restorative therapy is prescribed. The prognosis for infantile cortical hyperostosis is favorable, all symptoms spontaneously disappear within a few months.
Cortical generalized hyperostosis
Hyperostosis is hereditary, inheritance occurs in an autosomal recessive type. It is manifested by a lesion of the facial nerve, exophthalmos, deterioration of vision and hearing, thickening of the collarbones and an increase in the chin. Symptoms occur after reaching adolescence. Radiographs reveal cortical hyperostoses and osteophytes.
Systemic diaphyseal congenital hyperostosis
This hyperostosis was described at the beginning of the XX century by the Austrian surgeon Egelmann and the Italian doctor Kamurati. It belongs to the number of genetic diseases, inheritance occurs according to the autosomal dominant type. Hyperostosis develops in the area of the diaphysis of the tibial, humeral and femoral bones. Other bones are less often affected. There is joint stiffness and a decrease in muscle volume.