Osteoblastoclastoma

Cases of cancer in the world are constantly increasing. Among the lesions of the skeletal system, osteoblastoclastoma (giant cell tumor, osteoclastoma) is a leader in frequency - a benign tumor process, prone to malignancy, capable of damaging a variety of bones of the skeleton. [1] The primary clinical picture of the disease proceeds imperceptibly, but over time, swelling of a separate bone area attracts attention: the tumor grows gradually, painlessly. Treatment of pathology is surgical, involving the removal of osteoblastoclastoma within healthy tissues. With timely therapeutic measures, the outcome of the disease is considered encouraging.[2]

Epidemiology

For the first time, this tumor was described in detail by the French surgeon August Nelaton back in the 19th century. Giant cell mass was included in the category of fibrous osteodystrophies. Pathology was called by different terms: brown tumor, gigantoma, osteoclastoma, local fibrous osteodystrophy, giant cell sarcoma. The name osteoblastoclastoma was introduced into medical terminology by Professor Rusakov.

To date, specialists have no doubts about the tumor origin of osteoblastoclastoma, which is considered one of the most common bone neoplasms. In men and women, the disease occurs with approximately the same frequency. There are descriptions of family and hereditary pathology.

Osteoclastoma can develop at almost any age. There are known cases of tumor detection, both in one-year-old infants and in 70-year-old elderly people. According to statistics, almost 60% of patients with such a neoplasm are people aged 20-30 years.

Osteoblastoclastoma belongs to the category of solitary tumors, usually solitary. Rarely develop similar foci in adjacent bone tissues. The lesion most often extends to long tubular bones (almost 75% of cases), small and flat bones suffer somewhat less often.

Long tubular bones are affected mainly in the area of the epimetaphysis (in childhood - in the area of the metaphysis). There is no tumor germination in the tissue of the articular and epiphyseal cartilage. Less commonly, the pathology affects the area of the diaphysis (less than 1% of cases).

Osteoblastoclastoma of the facial bones accounts for more than 20% of all tumors with this localization.

Medical specialists distinguish between malignant and benign osteoblastoclastoma. In childhood, malignant pathology is rare.

Causes of the osteoclastoma

Doctors cannot point to any one clear cause of osteoblastoclastoma. It is believed that the appearance of pathology can affect:

• inflammatory processes affecting the bone and periosteum;
• traumatic injury or repeated injuries of the same area of the bone;
• repeated exposures;
• violation of bone formation during the prenatal period.

In about seven out of ten cases, osteoclastoma affects long bones, but can spread to adjacent tendon and soft tissues.

If the pathology develops in the maxillofacial region, then most often the cause is bone trauma or an infectious process - for example, after tooth extraction, extirpation. Less often, the appearance of a neoplasm is recorded in the region of the fibula and tibia, ribs and spinal column.

In women, the hands, toes, femurs, and knee joints are often affected, with the formation of a tenosynovial giant cell tumor of a diffuse form. Such a tumor has the appearance of a dense formation among the soft tissues, localized near the tendons. Gradually, the process spreads to the articular bone, damaging and destroying it.

In general, the causes of osteoblastoclastoma are:

• change in the balance of hormones;
• endocrine pathologies;
• exposure to occupational hazards, bad habits;
• irrational nutrition;
• prolonged or incorrect use of certain medications;
• parasitic lesions;
• long stay in radioactive zones.

The transformation of benign osteoblastoclastoma into a malignant tumor is possible under the influence of:

• frequent injuries of a pathologically altered bone segment;
• strong hormonal changes (for example, during pregnancy);
• repeated irradiation.

The factors listed above do not necessarily lead to the appearance of pathology, but they can have a negative impact in people predisposed to the development of osteoblastoclastoma.

Risk factors

Osteoclastoma often develops in patients older than 10 years. In children under 5 years of age, pathology is very rare.

The risk of developing a tumor increases under the influence of such factors:

• Unfavorable environmental conditions, the presence of professional and domestic hazards, intoxication, chronic infectious diseases, parasitic lesions.
• Oncological pathologies in history, previous radiation therapy (especially several courses), other exposure to radiation (including living or working in radioactively hazardous regions).
• Frequent injuries, fractures, bruises, bone fractures.
• Genetic factors, gene changes or mutations, cancer diagnoses in close relatives.
• Congenital bone defects, disorders of the skeletal structure.

Often, the environmental factor is not considered as the main reason, and it is completely in vain: environmental problems have a direct impact on the quality of air, food products, and the water regime of the area, which invariably affects the state of health. The adverse effects of ultraviolet radiation are noted if a person visits beaches and outdoor pools for a long time and regularly, gets sunburned.

The influence of carcinogens and radiation is also found in many hazardous industries associated with chemicals such as nickel, asbestos, sulfuric acid, arsenic, as well as with the processing of metals and plastics.

Pathogenesis

Giant cell tumor is a complex histologically benign bone lesion that rarely recurs, although it is definitely a source of "benign" metastases and often transforms into a sarcoma after irradiation. In the absence of a clear histogenetic origin, giant cell tumor is named for its specific histological appearance. 
The typical morphological description is a benign mononuclear stromal cell lesion with a large number of benign osteoclast-like giant cells. Immunohistochemical and molecular studies of osteoclastoma tissues demonstrate two populations of stromal cells, one consisting of proliferating spindle cells that represent markers of osteoblastic origin,  [3]while  [4] the other population consists of polygonal cells that stain for CD14+/CD68+ monocyte/macrophage antigens. [5] 

The main pathogenetic features of osteoblastoclastoma:

• the tumor includes two cell types: multinucleated giant and small uninuclear cells;
• most commonly affected are the distal femur, proximal tibia, distal radius, and pelvis and scapula (most rarely the vertebral column);
• the lesion is predominantly isolated and solitary;
• the tumor is located in the epiphysis or metaphysis, which is significantly swollen, deformed in the form of a large tubercle or hemisphere;
• the pathological process reaches the articular cartilage and is interrupted;
• the neoplasm increases in all directions, however, the main growth is noted along the long bone axis to the diaphysis;
• the transverse dimension diametrically increases more than three times;
• with a cellular variant of osteoblastoclastoma, the neoplasm consists of chambers separated from each other by complete and partial barriers (like soap suds or irregular honeycombs);
• there is a divergence of the cortical substance, swelling from the inside, thinning, without periosteal layers;
• if the osteoclastoma is of considerable size, then the cortical substance resolves, the neoplasm is surrounded by a thin shell capsule, consisting of the walls of the surface chambers;
• in the osteolytic variant, there is no chamber pattern, the bone defect is homogeneous;
• the marginal defect is saucer-shaped;
• there is resorption of the cortical layer, sharpening of the crust on the lesion line, without undermining and periosteal layers;
• the defect has clear contours;
• pathological fractures are observed in 12% of patients.

Osteoclastoma affects areas rich in myeloid bone marrow. Often pronounced curvature and shortening of the bone are found - in particular, with belated diagnosis and treatment. In most cases, the tumor is located eccentrically, with the destruction of the vast majority of the condyles of the bone. X-ray shows the achievement of the subchondral bone layer. In almost half of the cases, the entire articular end of the bone is affected, which swells, the cortical layer is destroyed, the lesion goes beyond the bone limits.

To date, osteoblastoclastoma is rarely considered as a benign tumor: it is classified as an aggressive neoplasm, primarily because of its unpredictability and high probability of malignancy.

Symptoms of the osteoclastoma

Clinical manifestations in childhood and old age are almost the same. The first signs are not detected immediately, since at first osteoblastoclastoma develops hidden, and it is possible to determine it only almost a year after the onset of development.

Experts divide the symptoms into general and local. General signs usually accompany malignant osteoblastoclastoma, and local signs are present with a benign neoplasm.

General signs do not depend on the location of the affected bone:

• severe pain in the area of tumor growth;
• palpatory crunching, indicating the growth of the neoplasm and the destruction of the bone segment;
• the appearance of a network of vessels over the pathological focus;
• a steady increase in bloating;
• increased pain as the neoplasm grows;
• violation of muscle and joint function near the affected area;
• enlargement of nearby lymph nodes;
• general malaise, fatigue;
• increase in body temperature;
• loss of appetite, weight loss;
• apathy, powerlessness.

Local manifestations are "tied" to the site of the affected bone. For example, if osteoblastoclastoma develops in any of the jaws, then facial symmetry is gradually broken. The patient begins to experience difficulties with speech, chewing, sometimes the teeth become loose and fall out. In severe cases, necrotic areas, fistulas are formed.

90% of giant cell tumors show a typical epiphyseal location. The tumor often extends to the articular subchondral bone or even rests on the cartilage. The joint and/or its capsule are rarely affected. In rare cases where osteoclastoma occurs in a child, the lesion is likely to be located in the metaphysis. [6]The most common sites,  [7] in descending order, are the distal femur, proximal tibia, distal radius, and sacrum. [8] 50% of osteoclastomas occur in the knee area. Other common sites include the head of the fibula, proximal femur, and proximal humerus. Pelvic localization is rare.  Multicentricity or synchronous occurrence of osteoclastoma in different skeletal locations is known to occur, but is extremely rare  [9]. , [10][11][12]

If osteoblastoclastoma develops in the leg area, the patient's gait changes, over time, the muscles on the damaged lower limb atrophy, walking becomes difficult. In some cases, dystrophic bone processes occur, the bone becomes thinner. Pathological fractures occur, accompanied by severe pain and tissue swelling. There may be complications in the form of hemorrhages, hematomas, necrosis of soft tissues.

If osteoclastoma develops in the region of the humerus or femur, then the motor skills of the finger phalanges and, in general, the function of the affected limb are impaired.

With the malignancy of the tumor process, the patient's condition worsens. The following signs are noteworthy:

• pain in the affected area of the bone intensifies;
• neoplasm is steadily increasing;
• bone tissues are destroyed, the zone of such destruction expands;
• the tumor focus loses its clear boundaries;
• the cortical layer is destroyed.

Such changes can only be seen by a specialist when performing instrumental diagnostics.

Benign osteoblastoclastomas are distinguished by a gradual latent or oligosymptomatic course. The pain syndrome occurs only during the progression of the pathology, after a few months the patient begins to be disturbed by pain with irradiation. In many patients, the first indication of disease is a pathological fracture. At diagnosis, about 12% of patients with osteoclastoma present with a pathologic fracture. [13]The presence of a pathological fracture is  [14] thought to indicate more aggressive disease with a higher risk of local recurrence and metastatic spread. [15]

With malignancy of osteoblastoclastoma, a previously inconspicuous tumor becomes painful, signs of irritation of the nerve endings are found. If the neoplasm is primarily malignant, then there are severe, debilitating pains, with a rapidly growing neurological picture.

Osteoclastoma in children

Clinical signs of different forms of benign osteoblastoclastoma are often not the same. Cystic forms do not manifest themselves symptomatically for a long time, and in 50% of cases they are detected only after the development of a pathological fracture. The tumor process is detected with a strong intraosseous proliferation of tissue, with the occurrence of pain. The protrusion of the bone site occurs only with pronounced growths: the patient has an expanded venous network, limited articular mobility. The lytic form of osteoblastoclastoma is characterized by faster growth, early onset of pain, but contractures occur less frequently.

Most often in childhood, osteoblastoclastoma affects the upper metaphyses of the shoulder and femur. Somewhat less often, the lesion is found in the lower femoral metaphysis, tibia and fibula. In the lytic form, destruction of the epiphyseal cartilage is possible with further spread to the epiphysis, without penetration into the joint (the articular cartilage remains intact). In the active cystic form, tumor growth is noted in the central part of the diaphysis, with a sharp thinning of the cortical layer and bone swelling.

Osteoclastomas in childhood  are predominantly benign, but they can also cause significant bone destruction. With the germination of the epiphyseal cartilage, the growth of the limb area slows down, pathological fractures, false joints with a pronounced bone defect and pain syndrome may occur.

In a malignant process, a neoplasm is formed according to the type of osteogenic sarcoma: rapid growth and pronounced bone destruction are characteristic. For a distinctive diagnosis, children undergo a histological examination.

Stages

Specialists distinguish between the lytic and cellular-trabecular stage of development of osteoblastoclastoma.

1. The cellular-trabecular stage is characterized by the formation of foci of bone tissue destruction, separated by partitions.
2. The lytic stage is characterized by the formation of a continuous destructive focus, which is localized asymmetrically with respect to the central bone axis. As the neoplasm grows, it can spread to the entire bone diameter.

A typical sign of osteoblastoclastoma is the separation of the destructive focus from the healthy part of the bone. The medullary canal is delimited from the neoplasm with the help of the closing plate.

Forms

Depending on the clinical and radiological information and morphological features, the following basic types of osteoblastoclastomas are distinguished:

• The cellular appearance is found predominantly in middle-aged and elderly patients. The neoplasm develops slowly, eventually revealing itself as a dense swelling with a nodular surface, without the possibility of restriction from a healthy bone. When localized in the jaw area, the latter acquires a spindle shape. The position of the teeth does not change. The tissue covering the cellular osteoblastoclastoma is anemic. Radiologically, a shadow is distinguished from a large number of cavity and cellular formations, fenced off by barriers. There is no reaction from the periosteum.
• The cystic form of osteoblastoclastoma initially causes pain. When probing the tumor, some areas are pliable, there is a symptom of "parchment crunch". The bone over the neoplasm becomes thinner, has a smooth, convex, domed shape. On x-ray, the focus resembles an odontogenic cyst or ameloblastoma.
• The lytic type of pathology is relatively rare, mainly in patients of childhood and adolescence. The growth is growing fast enough. Against the background of thinning of the cortical layer, pains appear: at first they begin to disturb at rest, then - when probing the affected area. Expansion of the vasculature over the tumor site is noted. With the localization of the pathological focus in the jaw region, the teeth are bent, loosened. Possible pathological fractures. On the radiograph there is a structureless zone of enlightenment.

According to the degree of malignancy, osteoblastoclastoma is divided into benign (without cellular atypism), primary malignant and malignant (transformed from a benign tumor).

Depending on the localization, the following types of pathology are distinguished:

• The peripheral form of osteoblastoclastoma in the upper jaw does not have any special morphological features, it is located on the gums.
• The central form is located inside the bone structure and, unlike the peripheral form, has hemorrhagic zones, which cause the brown tint of the neoplasm. The tumor is represented by one conglomerate.
• Osteoblastoma of the lower jaw is located in the thickness of the bone tissue, in the zone of molars and premolars. The growth of the neoplasm occurs over several years (on average - 3-10 years), accompanied by a dysfunction of the temporomandibular joint.
• Osteoclastoma of the upper jaw is manifested by the appearance of a protrusion of the affected jaw area, loosening of the teeth, and asymmetry of the face. Tumor enlargement is slow and painless.
• Osteoblastoclastoma of the femur is the most common localization, affecting the zone of bone growth: the greater trochanter, neck and head of the femur. The lesser trochanter is less commonly affected (in isolation). Pathology is accompanied by pain, bone deformity, pathological fractures.
• Osteoblastoclastoma of the ilium often develops at its base. It is also possible to damage the Y-shaped cartilage with the destruction of the horizontal branch of the pubic bone or the descending branch of the ischium. Pathology proceeds at first asymptomatically, then pains appear during exercise, lameness.

Complications and consequences

The most unfavorable consequence of benign osteoblastoclastoma is its malignancy, or malignancy. Malignant giant cell tumor is rare; analysis of studies revealed an incidence of 1.6% of primary malignant neoplasms and 2.4% of secondary malignant neoplasms. Infiltrative growth is detected, the nearest lymph nodes are affected, and metastases may spread. [16]

Malignant giant cell osteoblastoma is capable of producing metastases of the following types:

• hot (rapidly developing, actively destroying surrounding tissues);
• cold (without a definite development, existing for a long time in an inactive state, but having the ability to transform into "hot" ones);
• mute (existing in an anabiotic state and detected by chance).

Malignant osteoblastoclastoma can occur in three variants:

1. A primary malignant tumor retains the basic type of structure, however, there is an atypicality of mononuclear elements and the presence of mitosis in them.
2. Malignancy of a primary benign tumor with the development of spindle cell or osteogenic sarcoma.
3. Malignancy after previous treatment - in particular, after non-radical interventions or irrational radiation therapy. In such a situation, polymorphic cell sarcoma with pulmonary metastasis most often develops.

It is generally accepted that malignant osteoclastoma is a high-grade sarcoma; [17] however, research evidence suggests that malignant osteoclastoma behaves like a low to moderate grade sarcoma. [18] Metastases occur in 1–9% of patients with osteoblastoclastoma, and some earlier studies have correlated the incidence of metastases with aggressive growth and local recurrence. [19], [20]

After carrying out surgical interventions, patients with disability or its loss are assigned the appropriate disability group.

Diagnostics of the osteoclastoma

For the diagnosis of osteoblastoclastoma, it is necessary to use the following methods:

• questioning the patient, careful examination and palpation of the affected area of the bone, studying the anamnesis;
• laboratory and instrumental diagnostics, morphological studies.

When determining the anamnesis of the pathology, the doctor pays attention to the first manifestations of the tumor, the presence and nature of pain, previous illnesses and injuries, previous treatment, and features of the general condition. It is also important to clarify the state of the urinary, reproductive, respiratory system, liver and kidneys, lymph nodes, to make an ultrasound diagnosis of internal organs.

Absolutely all patients are prescribed blood and urine tests, determining indicators of protein and fractions, sialic acids, phosphorus and calcium. It is necessary to determine the enzymatic activity of phosphatases, conduct a diphenyl test, evaluate C-reactive protein, etc. It should be noted that laboratory parameters for bone tumors are usually nonspecific, but can help in differential diagnosis. For example, with malignant osteoblastoclastoma, changes such as leukocytosis, accelerated ESR, a decrease in blood protein and non-hemoglobin iron, an increase in sialic acids and alkaline phosphatase are possible. Oxyproline, hexokinase appears in the urine. In the blood serum, the levels of phosphorus and calcium increase.

The generally accepted studies for suspected osteoblastoclastoma include survey and sight x-rays, tomography. On the radiograph, it is possible to clarify the localization, scale, nature of the disease process, to determine its prevalence to the surrounding organs and tissues. Computed tomography allows you to explore deep pathological destruction, determine the size of the focus within the bone limits. However, magnetic resonance imaging is still considered more informative: according to the information obtained during the study, doctors can collect a spatial image, including a three-dimensional picture.

During the morphological study, the material that is obtained during aspiration and trepanobiopsy, or the removed bone areas along with osteoblastoclastoma, is studied. A puncture biopsy is carried out using special needles, and the tumor is punctured under X-ray observation. 

In the process of X-ray examination of long tubular bones in patients, an osteolytic destructive focus is found, localized according to an eccentric type in the region of the epiphysis. In dynamics, the pathology diverges towards the articular cartilage, as well as to the bone metaphysis, and can occupy the entire diameter (which is typical for osteoblastoclastoma of the head of the fibula and radius). The cortical layer is strongly thinned, swollen, partial destructions are often found. In a benign process, there is no periosteal reaction. The restriction between the neoplasm and the spongy substance is blurred, there is no clarity. The sclerotic border is absent in most cases.

When the spine is affected, the tumor in 80% of cases is located in the vertebral body. The body with an arch and processes can be affected, sometimes several vertebrae, costal sections, sacroiliac joint are involved in the pathological process. Destructive foci can have a cellular structure, or lytic.

When studying layered images on CT, the destruction of the arch with transverse processes is determined, which cannot be seen on an ordinary x-ray. The use of MRI allows us to consider the effect of the tumor on the spinal cord. [21], [22]

Primary malignant osteoblastoclastoma on x-ray is defined as a lytic destructive focus with blurred boundaries. In some cases, the structure is coarse-meshed. There is a "swelling" of the affected bone area, a strong thinning of the cortical layer with its further destruction. The cortical plate is heterogeneous from the inside. Possible periosteal reaction.

With malignancy of an initially benign osteoblastoclastoma, a large-mesh, small-mesh or lytic structure of the destructive focus is found. The affected bone area is "swollen", the cortical layer is strongly thinned, with uneven outlines along the inner side. Possible cortical fracture. Periosteal reaction (weak visor of Codman) has the character of bulbous periostitis.

To identify possible metastasis, sonography is prescribed to help examine the condition of the internal organs. 

The final stage in the diagnosis of a bone tumor is represented by histological identification and cytological examination of smears. The material is taken by conducting a biopsy (open or puncture).

Differential diagnosis

Benign osteoblastoclastomas require differentiation from all pathologies that show evidence of bone cyst or tissue lysis on x-ray. Among these pathologies:

• fibrous dysplasia;
• lytic osteogenic sarcoma;
• parathyroid osteodystrophy;
• focus of bone tuberculosis;
• aneurysmal bone cyst.

If there are large and progressive bone lesions, osteoblastoclastoma should be suspected. This tumor is characterized by the absence of surrounding bone osteoporosis, a destructive process from the metaphysis, and late penetration of the pathology into the epiphysis.

It is possible to distinguish parathyroid osteodystrophy from osteoblastoclastoma only with the use of radiography and biochemical studies.

Difficulties may arise in the course of diagnosing osteoblastoclastoma of long bones, as well as in differentiating the disease from osteogenic sarcoma or cystic formations (bone or aneurysmal).

Localization of the aneurysmal cyst is mainly the diaphysis or metaphysis. With eccentric localization of such a cyst, local bone swelling is noted, a thin cortical layer: the neoplasm is elongated along the bone, may contain calcareous particles. With central localization, the metaphysis or diaphysis is symmetrically swollen, which does not happen with osteoblastoclastoma.

In childhood, osteoblastoclastoma can be confused with the monoosseous type of fibrous osteodysplasia. In this situation, the bone is deformed, shortened (sometimes lengthened), but does not swell, as with osteoblastoclastoma. Fibrous osteodysplasia affects mainly the metaphysis and diaphysis of tubular bones. The cortical layer can thicken, sclerotic areas are formed around the destruction zones. The development process is painless, slow.

If osteoblastoclastoma affects the lower jaw, then the pathology should be differentiated from odontoma, bone fibroma, adamantinoma, tooth-containing cyst.

Treatment of the osteoclastoma

The goal of treatment is to minimize morbidity and maximize the functionality of the affected bone; Traditionally, this treatment was performed by scraping inside the lesion with tamponing of the cavity. New techniques such as cementation using bone cement are promising as they help with reconstruction and reduce local recurrences. [23]

Completely get rid of osteoblastoclastoma is possible only surgically: the tumor is removed, preventing further damage to the bone.

Osteoclastomas of small size are carefully scraped out with a special curette. The formed bone defect is replaced by autotransplantation. With a significant size of the tumor, bone resection is performed, followed by plasty. [24].  [25]. [26]

Due to the high rate (25-50%) of local recurrences after curettage and bone grafting, surgeons have been encouraged to improve their surgical procedures using chemical or physical adjuvants such as liquid nitrogen, acrylic cement, phenol, hydrogen peroxide, topical chemotherapy or radiation therapy.. [27]Topical adjuvant therapy has  [28] been shown to help control relapse rates. [29]

If the patient is contraindicated for any reason for surgery, then he is prescribed radiation therapy. With the help of irradiation, it is possible to stop the growth of the neoplasm and destroy its structure. [30]

It is also possible to use the following methods:

• Intralesional administration of steroids. This technique is relatively new and has not been used for very long. Through injections, it is possible to achieve positive results with small osteoblastoclastomas: the tumor decreases in size. Sometimes, at the end of treatment, the focus acquires greater radiopacity, compared with the surrounding bone area.
• Introduction of alpha-interferon. Based on the theory of the vascular origin of osteoblastoclastoma, experts have introduced into practice the injection of alpha-interferon. This remedy has an anti-angiogenic ability - that is, it slows down the growth of blood vessels. This technique has become effective in about 50% of patients, but it is used relatively rarely, due to a large number of side effects - such as headache, general deterioration of well-being, severe fatigue and disability.

For the treatment of malignant (primary or secondary) osteoblastoclastoma, only surgical intervention is used, which includes tumor resection along with the bone site. Before and after the operation, the patient is prescribed radiation and chemotherapy.

Inoperable osteoclastomas (eg, some tumors of the sacrum and pelvis) can be treated with transcatheter embolization of their blood supply. 

• Anti-RANKL Therapy

Giant cells overexpress a key mediator in osteoclastogenesis: the RANK receptor, which in turn is stimulated by the cytokine RANKL, which is secreted by stromal cells. Research into denosumab, a monoclonal antibody that specifically binds to RANKL, has led to impressive treatment results, leading to its approval by the US Food and Drug Administration (FDA). [31]Denosumab is  [32] primarily intended for patients at high risk of relapse after initial surgery and local recurrence.

Surgery

Various studies show that wide resection is associated with a reduced risk of local recurrence compared to intralesional curettage and may increase relapse-free survival from 84% to 100%. [33].  [34].  [35] However, a wide resection is associated with a higher rate of surgical complications and results in functional impairment, which usually requires reconstruction. [36].  [37]. [38]

If osteoblastoclastoma is localized in long tubular bones, then it is possible to use such surgical interventions:

• Marginal removal with allo or autoplasty is performed with benign osteoblastoclastoma, slowly developing, with a cellular structure, located on the periphery of the epimetaphysis. Can be fixed with metal screws.
• If the tumor process extends to the diametrical middle of the bone, 2/3 of the condyle and part of the diaphysis with the articular area are removed. The defect is filled with a cartilage allograft. Use strong coupling bolts and screws. The connection of the allograft and the cortical layer of the host bone is performed obliquely, in order to avoid subsidence of the joint.
• If the epimetaphysis is destroyed, or there is a pathological fracture, then a segmental resection is performed with articular isolation and replacement of the defect with an allograft. Fixed with a rod on the cement.
• In case of a pathological fracture and malignancy of osteoblastoclastoma in the proximal femur, a total hip arthroplasty is performed.
• When removing articular end segments at the knee joint, transplantation of the allo-half-joint is used with the use of strong fixation. Perhaps individual total arthroplasty with a titanium elongated stem and further radiation therapy.
• If an aggressive tumor is localized in the area of the distal end of the tibia, resection with osteoplastic arthrodesis of the ankle is performed. When the talus is damaged, bone extirpation is used with lengthening arthrodesis according to Zatsepin.
• If the pathological focus is localized in the cervical vertebral region, anterior access to the vertebrae is practiced. Anterolateral approach is possible with careful exposure of the pharynx and anterior side of the vertebrae to the cranial base.
• The level of Th ₁ -Th ₂  use anterior access with oblique sternotomy to the third intercostal space. Vessels are gently shifted down. If the focus is located in the 3rd-5th thoracic vertebra, an anterolateral approach and resection of the third rib are performed. The scapula moves back without cutting off the muscles. Difficulties may arise when accessing the anterior surfaces of the upper sacral vertebrae. Anterolateral retroperitoneal right access, accurate separation of vessels and ureter are used.
• If a severe destruction of the vertebrae is detected, or the spread of the tumor to the arches in the thoracic and lumbosacral spine, transpedicular-translaminar fixation is performed with the removal of the affected vertebrae and autoplasty.
• If osteoblastoclastoma is located in the pubic and ischial bones, the affected area is removed within the boundaries of healthy tissues without bone grafting. If the bottom and roof of the acetabulum are affected, removal is indicated with further osteoplastic replacement of the defect.
• If the sacrum and L ₅  are destroyed, perform posterior removal of the affected parts and stabilization with transpedicular fixation. Next, the neoplasm is removed by the retroperitoneal method, followed by bone grafting.

Prevention

There are no specific preventive measures to prevent the occurrence of osteoblastoclastoma. For the purpose of prevention, experts recommend regularly undergoing an X-ray examination every 1-2 years for the timely detection of such tumors and their treatment.

If a person finds himself with any bone induration, then he needs to immediately consult a doctor: a general practitioner, orthopedist, oncologist, traumatologist, vertebrologist.

Additional medical advice includes:

• avoid injuries, intoxications, eat right and fully, keep physical activity;
• consult a doctor in a timely manner, including for diseases of the musculoskeletal system;
• be sure to visit a doctor and undergo a diagnostic examination if any neoplasm of unknown origin appears.

Forecast

In patients with osteoblastoclastoma, the outcome of the disease depends on many factors, such as the characteristics of the development of the tumor, its malignancy or benignness, localization, spread, timeliness of treatment, etc. In recent years, the results of the treatment of malignant bone tumors have become much more progressive. Doctors use a combined approach, if necessary, use intensive polychemotherapy. At the same time, the percentage of fifty recovered patients is more than 70%.

Experts say about a positive prognosis, if osteoblastoclastoma is completely removed promptly, there are no relapses. Whenever possible, surgeons always try to perform organ-preserving operations, with simultaneous bone grafting, and only in some cases we are talking about mutilating interventions, after which a person can no longer perform certain actions: one has to change his lifestyle. In such situations, doctors understand the term "recovery" as "the absence of tumor processes." Such patients require subsequent long-term rehabilitation, orthopedic, and sometimes psychological help.