The medication(s) listed below have been approved by the Food and Drug Administration (FDA) as orphan products for treatment of this condition. Learn more orphan products.

The only effective line of treatment for malignant infantile osteopetrosis is hematopoietic stem cell transplantation. It has been shown to provide long-term disease-free periods for a significant percentage of those treated; can impact both hematologic and skeletal abnormalities; and has been used successfully to reverse the associated skeletal abnormalities.

Radiographs of at least one case with malignant infantile osteopetrosis have demonstrated bone remodeling and recanalization of medullar canals following hematopoietic stem cell transplantation. This favorable radiographic response could be expected within one year following the procedure - nevertheless, primary graft failure can prove fatal.

Clinical trials of isotretinoin, etidronate with oral corticosteroids, and perhexiline maleate have failed to demonstrate effectiveness, though the variable course of the disease and small prevalence induces uncertainty.

A handful of pharmaceutical companies focused on rare disease are currently in varying stages of investigation into different therapeutic approaches for FOP.

In August 2015, U.S. Food and Drug Administration (FDA) Office of Orphan Products Development granted La Jolla Pharmaceuticals orphan drug designation for two novel compounds for FOP. The compounds are small-molecule kinase inhibitors designed to selectively block ACVR1 (ALK2).

In August 2015, Clementia Pharmaceuticals also began the enrollment of children (ages 6 and above) into its Phase II clinical trial investigating palovarotene for the treatment of FOP. Preclinical studies demonstrated that palovarotene, a retinoic acid receptor gamma agonist, blocked abnormal bone formation in animal models via inhibition of secondary messenger systems in the BMP pathway. Clementia licensed palovarotene from Roche Pharmaceuticals, which previously evaluated the compound in more than 800 individuals including healthy volunteers and patients with chronic obstructive pulmonary disease. Palovarotene received Fast Track designation from the U.S. Food and Drug Administration (FDA) and orphan designations for the treatment of FOP from both the FDA and the European Medicines Agency (EMA).

In September 2015, Regeneron announced new insight into the mechanism of disease involving the activation of the ACVR1 receptor by activin A. In 2016, the company initiated a phase 1 study of its activin antibody, REGN 2477, in healthy volunteers; a phase 2 trial in FOP patients is planned for 2017.

Another potential therapeutic approach involves allele-specific RNA interference that targets mutated mRNA for degradation while preserving normal ACVR1 gene expression.

Further investigation into the mechanisms of heterotopic bone formation in FOP could aid in the development of treatments for other disorders involving extra-skeletal bone formation.

There is no cure, although curative therapy with bone marrow transplantion is being investigated in clinical trials. It is believed the healthy marrow will provide the sufferer with cells from which osteoclasts will develop. If complications occur in children, patients can be treated with vitamin D. Gamma interferon has also been shown to be effective, and it can be associated to vitamin D. Erythropoetin has been used to treat any associated anemia. Corticosteroids may alleviate both the anemia and stimulate bone resorption. Fractures and osteomyelitis can be treated as usual. Treatment for osteopetrosis depends on the specific symptoms present and the severity in each person. Therefore, treatment options must be evaluated on an individual basis. Nutritional support is important to improve growth and it also enhances responsiveness to other treatment options. A calcium-deficient diet has been beneficial for some affected people.

Treatment is necessary for the infantile form:

- Vitamin D (calcitriol) appears to stimulate dormant osteoclasts, which stimulates bone resorption

- Gamma interferon can have long-term benefits. It improves white blood cell function (leading to fewer infections), decreases bone volume, and increases bone marrow volume.

- Erythropoietin can be used for anemia, and corticosteroids can be used for anemia and to stimulate bone resorption.

Bone marrow transplantation (BMT) improves some cases of severe, infantile osteopetrosis associated with bone marrow failure, and offers the best chance of longer-term survival for individuals with this type.

In pediatric (childhood) osteopetrosis, surgery is sometimes needed because of fractures. Adult osteopetrosis typically does not require treatment, but complications of the condition may require intervention. Surgery may be needed for aesthetic or functional reasons (such as multiple fractures, deformity, and loss of function), or for severe degenerative joint disease.

The long-term-outlook for people with osteopetrosis depends on the subtype and the severity of the condition in each person.The severe infantile forms of osteopetrosis are associated with shortened life expectancy, with most untreated children not surviving past their first decade. seems to have cured some infants with early-onset disease. However, the long-term prognosis after transplantation is unknown. For those with onset in childhood or adolescence, the effect of the condition depends on the specific symptoms (including how fragile the bones are and how much pain is present). Life expectancy in the adult-onset forms is normal.

Treatment in fibrous dysplasia is mainly palliative, and is focused on managing fractures and preventing deformity. There are no medications capable of altering the disease course. Intravenous bisphosphonates may be helpful for treatment of bone pain, but there is no clear evidence that they strengthen bone lesions or prevent fractures. Surgical techniques that are effective in other disorders, such as bone grafting, curettage, and plates and screws, are frequently ineffective in fibrous dysplasia and should be avoided. Intramedullary rods are generally preferred for management of fractures and deformity in the lower extremities. Progressive scoliosis can generally be managed with standard instrumentation and fusion techniques. Surgical management in the craniofacial skeleton is complicated by frequent post-operative FD regrowth, and should focus on correction of functional deformities. Prophylactic optic nerve decompression increases the risk of vision loss and is contraindicated.

Managing endocrinopathies is a critical component of management in FD. All patients with fibrous dysplasia should be evaluated and treated for endocrine diseases associated with McCune–Albright syndrome. In particular untreated growth hormone excess may worsen craniofacial fibrous dysplasia and increase the risk of blindness. Untreated hypophosphatemia increases bone pain and risk of fractures.

Biophosphonates are drugs that are used to prevent bone mass loss and are often used to treat osteolytic lesions. Zoledronic acid (Reclast) is a specific drug given to cancer patients to prevent the worsening of bone lesions and has been reported to have anti-tumor effects as well. Zoledronic acid has been clinically tested in conjunction with calcium and vitamin D to encourage bone health. Denosumab, a monoclonal antibody treatment RANKl inhibitor that targets the osteocyte apoptosis regualtory RANKL gene, is also prescribed to prevent bone metastases and bone lesions. Most biophosphonates are co-prescribed with disease-specific treatments, such as chemotherapy or radiation for cancer patients.

There is no cure or approved treatment for FOP. Attempts to surgically remove the bone result in explosive bone growth. While under anesthesia, people with FOP may encounter difficulties with intubation, restrictive pulmonary disease, and changes in the electrical conduction system of the heart. Activities that increase the risk of falling or soft tissue injury should be avoided, as even minor trauma may provoke heterotopic bone formation.

Giant osteoclasts can occur in some diseases, including Paget's disease of bone and bisphosphonate toxicity.

Specific treatment for enchondroma is determined by a physician based on the age, overall health, and medical history of the patient. Other considerations include:

- extent of the disease

- tolerance for specific medications, procedures, or therapies

- expectations for the course of the disease

- opinion or preference of the patient

Treatment may include:

- surgery (in some cases, when bone weakening is present or fractures occur)

- bone grafting - a surgical procedure in which healthy bone is transplanted from another part of the patient's body into the affected area.

If there is no sign of bone weakening or growth of the tumor, observation only may be suggested. However, follow-up with repeat x-rays may be necessary. Some types of enchondromas can develop into malignant, or cancerous, bone tumors later. Careful follow-up with a physician may be recommended.

Bone lesions in multiple myeloma patients may be treated with low-dose radiation therapy in order to reduce pain and other symptoms. Used in combination with immunochemotherapy, radiation therapy can be used to treat certain cancers when aimed at areas of bone lesion and softened bone.

The disease has been reported to affect 3 per 1000 infants younger than 6 months in the United States. No predilection by race or sex has been established. Almost all cases occur by the age of 5 months. The familial form is inherited in an autosomal dominant fashion with variable penetrance. The familial form tends to have an earlier onset and is present at birth in 24% of cases, with an average age at onset of 6.8 weeks. The average age at onset for the sporadic form is 9–11 weeks.

Cortical hyperostosis is a potential side effect of long-term use of prostaglandins in neonates.

In the animal kingdom there also exists a non-pathological form of osteosclerosis, resulting in unusually solid bone structure with little to no marrow. It is often seen in aquatic vertebrates, especially those living in shallow waters, providing ballast as an adaptation for an aquatic lifestyle. It makes bones heavier, but also more fragile. In those animal groups osteosclerosis often occurs together with bone thickening (pachyostosis). This joint occurrence is called pachyosteosclerosis.

An osteoclast (from the Greek words for "bone" (ὀστέον), and "broken" (κλαστός)) is a type of bone cell that breaks down bone tissue. This function is critical in the maintenance, repair, and remodelling of bones of the vertebral skeleton. The osteoclast disassembles and digests the composite of hydrated protein and mineral at a molecular level by secreting acid and a collagenase, a process known as "bone resorption". This process also helps regulate the level of blood calcium.

An odontoclast (/odon·to·clast/; o-don´to-klast) is an osteoclast associated with absorption of the roots of deciduous teeth.

Fibrous dysplasia is a disorder where normal bone and marrow is replaced with fibrous tissue, resulting in formation of bone that is weak and prone to expansion. As a result, most complications result from fracture, deformity, functional impairment, and pain. Disease occurs along a broad clinical spectrum ranging from asymptomatic, incidental lesions to severe disabling disease. Disease can affect one bone (monostotic) or multiple (polyostotic), and may occur in isolation or in combination with cafe-au-lait skin macules and hyperfunctioning endocrinopathies, termed McCune-Albright syndrome. More rarely, fibrous dysplasia may be associated with intramuscular myxomas, termed Mazabraud's syndrome. Fibrous dysplasia is very rare, and there is no known cure. Fibrous dysplasia is not a form of cancer.

Osteosclerosis is a disorder that is characterized by abnormal hardening of bone and an elevation in bone density. It may predominantly affect the medullary portion and/or cortex of bone. Plain radiographs are a valuable tool for detecting and classifying osteosclerotic disorders. It can manifest in localized or generalized osteosclerosis. Localized osteosclerosis can be caused by Legg–Calvé–Perthes disease, sickle-cell disease and osteoarthritis among others. Osteosclerosis can be classified in accordance with the causative factor into acquired and hereditary.

Five bisphosphonates are currently available. In general, the most commonly prescribed are risedronic acid, alendronic acid, and pamidronic acid. Etidronic acid and other bisphosphonates may be appropriate therapies for selected patients but are less commonly used. None of these drugs should be used by people with severe kidney disease.

- Etidronate disodium The approved regimen is once daily for six months; a higher dose is more commonly used. No food, beverage, or medications should be consumed for two hours before and after taking. The course should not exceed six months, but repeat courses can be given after rest periods, preferably of three to six months duration.

- Pamidronate disodium in intravenous form: the approved regimen uses an infusion over four hours on each of three consecutive days, but a more commonly used regimen is over two to four hours for two or more consecutive or nonconsecutive days.

- Alendronate sodium is given as tablets once daily for six months; patients should wait at least 30 minutes after taking before eating any food, drinking anything other than tap water, taking any medication, or lying down (patient may sit).

- Tiludronate disodium are taken once daily for three months; they may be taken any time of day, as long as there is a period of two hours before and after resuming food, beverages, and medications.

- Risedronate sodium tablet taken once daily for 2 months is the prescribed regimen; patients should wait at least 30 minutes after taking before eating any food, drinking anything other than tap water, taking any medication, or lying down (patient may sit).

- Zoledronic acid is given as an intravenous infusion; a single dose is effective for two years. This is recommended for most people at high risk with active disease.

Osteochondrodysplasia is a general term for a disorder of the development of bone and cartilage.

Bone disease refers to the medical conditions which affect the bone.

Curettage is performed on some patients, and is sufficient for inactive lesions. The recurrence rate with curettage is significant in active lesions, and marginal resection has been advised. Liquid nitrogen, phenol, methyl methacrylate are considered for use to kill cells at margins of resected cyst.

The goal of treatment is to relieve bone pain and prevent the progression of the disease. These medications are usually recommended for people with Paget's disease who:

- have bone pain, headache, back pain, or a nerve-related symptom (such as "shooting" pains in the leg) that is directly associated with the disease;

- have elevated levels of serum alkaline phosphatase (ALP) in their blood;

- display evidence that a bone fracture will occur;

- require pretreatment therapy for affected bones that require surgery;

- have active symptoms in the skull, long bones, or vertebrae (spine);

- have the disease in bones located next to major joints, placing them at risk of developing osteoarthritis;

- develop hypercalcemia that occurs when a person with several bones affected by Paget's disease and a high serum alkaline phosphatase level is immobilized.

Osteoporosis is due to causal factors like atrophy of disuse and gonadal deficiency. Hence osteoporosis is common in post menopausal women and in men above 50 yrs. Hypercorticism may also be causal factor, as osteoporosis may be seen as a feature of Cushing's syndrome.

Osteogenesis imperfecta is a rare condition in which bones break easily. There are multiple genetic mutations in different genes for collagen that may result in this condition. It can be treated with some drugs to promote bone growth, by surgically implanting metal rods in long bones to strengthen them, and through physical therapy and medical devices to improve mobility.

The treatment should be tailored to the cause involved and the severity of the disease process. With oral osteoporosis the emphasis should be on good nutrient absorption and metabolic wastes elimination through a healthy gastro-intestinal function, effective hepatic metabolism of toxicants such as exogenous estrogens, endogenous acetaldehyde and heavy metals, a balanced diet, healthy lifestyle, assessment of factors related to potential coagulopathies, and treatment of periodontal diseases and other oral and dental infections.

In cases of advanced oral ischaemic osteoporosis and/or ONJ that are not bisphosphonates related, clinical evidence has shown that surgically removing the damaged marrow, usually by curettage and decortication, will eliminate the problem (and the pain) in 74% of patients with jaw involvement. Repeat surgeries, usually smaller procedures than the first, may be required. Almost a third of jawbone patients will need surgery in one or more other parts of the jaws because the disease so frequently present multiple lesions, i.e., multiple sites in the same or similar bones, with normal marrow in between. In the hip, at least half of all patients will get the disease in the opposite hip over time; this pattern occurs in the jaws as well. Recently, it has been found that some osteonecrosis patients respond to anticoagulation therapies alone. The earlier the diagnosis the better the prognosis. Research is ongoing on other non-surgical therapeutic modalities that could alone or in combination with surgery further improve the prognosis and reduce the morbidity of ONJ. A greater emphasis on minimizing or correcting known causes is necessary while further research is conducted on chronic ischaemic bone diseases such as oral osteoporosis and ONJ.

In patients with bisphosphonates-associated ONJ, the response to surgical treatment is usually poor. Conservative debridement of necrotic bone, pain control, infection management, use of antimicrobial oral rinses, and withdrawal of bisphosphonates are preferable to aggressive surgical measures for treating this form of ONJ. Although an effective treatment for bisphosphonate-associated bone lesions has not yet been established, and this is unlikely to occur until this form of ONJ is better understood, there have been clinical reports of some improvement after 6 months or more of complete cessation of bisphosphonate therapy.

The first three cases of bisphosphonate-associated osteonecrosis of the jaw were spontaneously reported to the FDA by an oral surgeon in 2002, with the toxicity being described as a potentially late toxicity of chemotherapy. In 2003 and 2004, three oral surgeons independently reported to the FDA information on 104 cancer patients with bisphosphonate-associated osteonecrosis of the jaw seen in their referral practices in California, Florida, and New York. These case series were published as peer-reviewed articles — two in the "Journal of Oral and Maxillofacial Surgery" and one in the "Journal of Clinical Oncology". Subsequently, numerous instances of persons with this ADR were reported to the manufacturers and to the FDA. By December 2006, 3607 cases of people with this ADR had been reported to the FDA and 2227 cases had been reported to the manufacturer of intravenous bisphosphonates.

The International Myeloma Foundation's web-based survey included 1203 respondents, 904 patients with myeloma and 299 with breast cancer and an estimate that after 36 months, osteonecrosis of the jaw had been diagnosed in 10% of 211 patients on zoledronate and 4% of 413 on pamidronate. A population based study in Germany identified more than 300 cases of osteonecrosis of the jaw, 97% occurring in cancer patients (on high-dose intravenous bisphosphonates) and 3 cases in 780,000 patients with osteoporosis for an incidence of 0.00038%. Time to event ranged from 23–39 months and 42–46 months with high dose intravenous and oral bisphosphonates. A prospective, population based study by Mavrokokki "et al.". estimated an incidence of osteonecrosis of the jaw of 1.15% for intravenous bisphosphonates and 0.04% for oral bisphosphonates. Most cases (73%) were precipitated by dental extractions. In contrast, safety studies sponsored by the manufacturer reported bisphosphonate-associated osteonecrosis of the jaw rates that were much lower.

Although the majority of cases of ONJ have occurred in cancer patients receiving high dose intravenous bisphosphonates, almost 800 cases have been reported in oral bisphosphonate users for osteoporosis or Pagets disease. In terms of severity most cases of ONJ in oral bisphosphonate users are stage 1–2 and tend to progress to resolution with conservative measures such as oral chlorhexidine rinses.

Owing to prolonged embedding of bisphosphonate drugs in the bone tissues, the risk for BRONJ is high even after stopping the administration of the medication for several years.

This form of therapy has been shown to prevent loss of bone mineral density (BMD) as a result of a reduction in bone turnover. However, bone health entails quite a bit more than just BMD. There are many other factors to consider.

In healthy bone tissue there is a homeostasis between bone resorption and bone apposition. Diseased or damaged bone is resorbed through the osteoclasts mediated process while osteoblasts form new bone to replace it, thus maintaining healthy bone density. This process is commonly called remodelling.

However, osteoporosis is essentially the result of a lack of new bone formation in combination with bone resorption in reactive hyperemia, related to various causes and contributing factors, and bisphosphonates do not address these factors at all.

In 2011, a proposal incorporating both the reduced bone turnover and the infectious elements of previous theories has been put forward. It cites the impaired functionality of affected macrophages as the dominant factor in the development of ONJ.

In a systematic review of cases of bisphosphonate-associated ONJ up to 2006, it was concluded that the mandible is more commonly affected than the maxilla (2:1 ratio), and 60% of cases are preceded by a dental surgical procedure. According to Woo, Hellstein and Kalmar, oversuppression of bone turnover is probably the primary mechanism for the development of this form of ONJ, although there may be contributing co-morbid factors (as discussed elsewhere in this article). It is recommended that all sites of potential jaw infection should be eliminated before bisphosphonate therapy is initiated in these patients to reduce the necessity of subsequent dentoalveolar surgery. The degree of risk for osteonecrosis in patients taking oral bisphosphonates, such as alendronate (Fosamax), for osteoporosis is uncertain and warrants careful monitoring. Patients taking dexamethasone and other glucocorticoids are at increased risk.

Matrix metalloproteinase 2 may be a candidate gene for bisphosphonate-associated osteonecrosis of the jaw, since it is the only gene known to be associated with bone abnormalities and atrial fibrillation, both of which are side effects of bisphosphonates.

Treatment of Gorham's disease is for the most part palliative and limited to symptom management.

Sometimes the bone destruction spontaneously ceases and no treatment is required. But when the disease is progressive, aggressive intervention may be necessary. Duffy and colleagues reported that around 17% of patients with Gorham's disease in the ribs, shoulder, or upper spine experience extension of the disease into the chest, leading to chylothorax with its serious consequences, and that the mortality rate in this group can reach as high as 64% without surgical intervention.

A search of the medical literature reveals multiple case reports of interventions with varying rates of success as follows:

Cardiothoracic (heart & lung):

- Pleurodesis

- Ligation of thoracic duct

- Pleurperitoneal shunt

- Radiation therapy

- Pleurectomy

- Surgical resection

- Thalidomide

- Interferon alpha-2b

- TPN (total parenteral nutrition)

- Thoracentesis

- Diet rich in medium-chain triglycerides and protein

- Chemotherapy

- Sclerotherapy

- Transplantation

Skeletal:

- Interferon alpha-2b

- Bisphosphonate (e.g. pamidronate)

- Surgical resection

- Radiation therapy

- Sclerotherapy

- Percutaneous bone cement

- Bone graft

- Prosthesis

- Surgical stabilization

- Amputation

To date, there are no known interventions that are consistently effective for Gorham's and all reported interventions are considered experimental treatments, though many are routine for other conditions. Some patients may require a combination of these approaches. Unfortunately, some patients will not respond to any intervention.