Osteitis is inflammation of bone. More specifically, it can refer to one of the following conditions:

- Osteomyelitis, or "infectious osteitis", mainly "bacterial osteitis")

- Alveolar osteitis or "dry socket"

- Condensing osteitis (or Osteitis condensans)

- Osteitis deformans (or Paget's disease of bone)

- Osteitis fibrosa cystica (or Osteitis fibrosa, or Von Recklinghausen's disease of bone)

- Osteitis pubis

- Radiation osteitis

- Osteitis condensans ilii

- Panosteitis, a long bone condition in large breed dogs

- In horses, pedal osteitis is frequently confused with laminitis.

Culture and sensitivity of the wound site determines the choice of antibiotic. Repeated culture and sensitivity testing is often carried out in OM since the treatment is prolonged and antibiotic resistance may occur, when a change in the drug may be required.

Osteomyelitis often requires prolonged antibiotic therapy for weeks or months. A PICC line or central venous catheter can be placed for long-term intravenous medication administration. It may require surgical debridement in severe cases, or even amputation.

Initial first-line antibiotic choice is determined by the patient's history and regional differences in common infective organisms. A treatment lasting 42 days is practiced in a number of facilities. Local and sustained availability of drugs have proven to be more effective in achieving prophylactic and therapeutic outcomes. Open surgery is needed for chronic osteomyelitis, whereby the involucrum is opened and the sequestrum is removed or sometimes saucerization can be done. Hyperbaric oxygen therapy has been shown to be a useful to the treatment of osteomyelitis.

Prior to the widespread availability and use of antibiotics, blow fly larvae were sometimes deliberately introduced to the wounds to feed on the infected material, effectively scouring them clean. In 1875, American artist Thomas Eakins depicted a surgical procedure for osteomyelitis at Jefferson Medical College, in a famous oil painting titled "The Gross Clinic".

There is tentative evidence that bioactive glass may also be useful in long bone infections. Support from randomized controlled trials, however, is not available as of 2015.

Once PVNS is confirmed by biopsy of the synovium of an affected joint, a synovectomy of the affected area is the most common treatment. Bone lesions caused by the disorder are removed and bone grafting is performed as needed. Because diffuse PVNS has a relatively high rate of recurrence, radiation therapy may be considered as a treatment option. In some cases, a total joint replacement is needed to relieve symptoms when PVNS causes significant joint destruction.

Pathologic fracture of the mandible is a possible complication of OM where the bone has been weakened significantly.

Normally, asymptomatic cases are not treated. Non-steroidal anti inflammatory drugs and surgery are two typical options for the rest.

Treatment consists of rest, non-weightbearing and painkillers when needed. A small study showed that the nonsteroidal anti-inflammatory drug ibuprofen could shorten the disease course (from 4.5 to 2 days) and provide pain control with minimal side effects (mainly gastrointestinal disturbances). If fever occurs or the symptoms persist, other diagnoses need to be considered.

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.

Evidence for bone spurs found in the fossil record is studied by paleopathologists, specialists in ancient disease and injury. Bone spurs have been reported in dinosaur fossils from several species, including "Allosaurus fragilis", "Neovenator salerii", and "Tyrannosaurus rex".

The exact cause is unknown. Some doctors believe it is caused by abnormal metabolism of fat. Others think it may be caused by repetitive inflammation. Some feel that blood within the joint may cause the inflammatory change. Risk factors for PVNS developing are not yet understood. Very little research has been carried out. However, a common theme in patients is a trauma experienced to the joint prior to the onset of symptoms.

Evidence for periostitis found in the fossil record is studied by paleopathologists, specialists in ancient disease and injury. Periostitis has been seen in the late Cretaceous-Eocene crocodile "Borealosuchus formidabilis", once known as "Leidyosuchus". In one study, periostitis was the most common pathology in this species, with 134 instances of the condition out of 7,154 bones the scientists examined showing evidence for the condition. Periostitis has also been documented in dinosaurs, including a forelimb referred to the long-necked "Camarasaurus grandis", as well as the shoulder blade of a horned dinosaur.

Though articular cartilage damage is not life-threatening, it does strongly affect the quality of life. Articular cartilage damage is often the cause of severe pain, swellings, strong barriers to mobility and severe restrictions to the patient's activities. Over the last decades, however, surgeons and biotech ventures[who?] have elaborated promising procedures[which?] that contribute to articular cartilage repair. These procedures do not, however, treat osteoarthritis.

Osteomyelitis (OM) is an infection of bone. Symptoms may include pain in a specific bone with overlying redness, fever, and weakness. The long bones of the arms and legs are most commonly involved in children while the feet, spine, and hips are most commonly involved in adults.

The cause is usually a bacterial infection and rarely a fungal infection. It may occur via spread from the blood or from surrounding tissue. Risks for developing osteomyelitis include diabetes, intravenous drug use, prior removal of the spleen, and trauma to the area. Diagnosis is typically suspected based on symptoms. This is then supported by blood tests, medical imaging, or bone biopsy.

Treatment often involves both antimicrobials and surgery. In those with poor blood flow, amputation may be required. With treatment outcomes are often generally good when the condition has only been present a short time. About 2.4 per 100,000 people are affected a year. The young and old are more commonly affected. Males are more commonly affected than females. The condition was described at least as early as the 300s BC by Hippocrates. Before the availability of antibiotics the risk of death was significant.

Calcitonin, also called calcitonin-salmon, is a synthetic copy of a polypeptide hormone secreted by the ultimobranchial gland of salmon. Miacalcin is administered by injection, three times per week or daily, for 6–18 months. Repeat courses can be given after brief rest periods. Miacalcin may be appropriate for certain patients, but is seldom used. Calcitonin is also linked to increased chance of cancer. Due to the increased risk of cancer, the European Medicines Agency (EMA) recommended that calcitonin be used only on a short-term basis for 3 conditions for which it had previously been approved in the European Union: Paget's disease, acute bone loss resulting from sudden immobilization, and hypercalcemia caused by cancer.

The EMA said it based its recommendations on a review of the benefits and risks of calcitonin-containing medicines. Conducted by the agency's Committee for Medicinal Products for Human Use (CHMP), the review encompassed available data from the companies that market these drugs, postmarketing safety data, randomized controlled studies, 2 studies of unlicensed oral calcitonin drugs, and experimental cancer studies, among other sources.

CHMP found that "a higher proportion of patients treated with calcitonin for long periods of time develop cancer of various types, compared with patients taking placebo." The increase in cancer rates ranged from 0.7% for oral formulations to 2.4% for the nasal formulation. CHMP concluded that the benefits of calcitonin for osteoporosis did not exceed the risks. The nasal spray's only indication is for osteoporosis, thus justifying the drug's removal from the market.

As a solution for injection or infusion, calcitonin should be administered for no more than 4 weeks to prevent acute bone loss resulting from sudden immobilization, and normally for no more than 3 months to treat Paget's disease, the EMA said. The agency did not specify a time frame for the short-term use of calcitonin for treating hypercalcemia caused by cancer.

A systematic review reported that there is some evidence that rinsing with chlorhexidine (0.12% or 0.2%) or placing chlorhexidine gel (0.2%) in the sockets of extracted teeth reduces the frequency of dry socket. Another systematic review concluded that there is evidence that prophylactic antibiotics reduce the risk of dry socket (and infection and pain) following third molar extractions of wisdom teeth, however their use is associated with an increase in mild and transient adverse effects. The authors questioned whether treating 12 patients with antibiotics to prevent one infection would do more harm overall than good, in view of the potential side effects and also of antibiotic resistance. Nevertheless, there is evidence that in individuals who are at clear risk may benefit from antibiotics. There is also evidence that antifibrinolytic agents applied to the socket after the extraction may reduce the risk of dry socket.

Some dentists and oral surgeons routinely debride the bony walls of the socket to encourage hemorrhage (bleeding) in the belief that this reduces the incidence of dry socket, but there is no evidence to support this practice. It has been suggested that dental extractions in females taking oral contraceptives be scheduled on days without estrogen supplementation (typically days 23–28 of the menstrual cycle). It has also been suggested that teeth to be extracted be scaled prior to the procedure.

Prevention of alveolar osteitis can be exacted by following post-operative instructions, including:

1. Taking any recommended medications

2. Avoiding intake of hot fluids for one to two days. Hot fluids raise the local blood flow and thus interfere with organization of the clot. Therefore, cold fluids and foods are encouraged, which facilitate clot formation and prevent its disintegration.

3. Avoiding smoking. It reduces the blood supply, leading to tissue ischemia, reduced tissue perfusion and eventually higher incidence of painful socket.

4. Avoiding drinking through a straw or spitting forcefully as this creates a negative pressure within the oral cavity leading to an increased chance of blood clot instability.

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.

In humans, excessive forces caused by sudden bending upwards of the big toe, high heels, or a stumble can contribute to sesamoiditis. Once the sesamoid bone is injured it can be very difficult to cure, because every time you walk you put additional pressure on the sesamoid bone. Treatment in humans consists of anti-inflammatory medication, cortisone injections, strapping to immobilize the big toe, and orthotics with special accommodations to keep pressure off the affected bone.

In horses, sesamoiditis is generally caused by excess stress on the fetlock joint. Conformation that promotes sesamoiditis include long pasterns, or horses with long toes and low heels.

Periostitis, also known as periostalgia, is a medical condition caused by inflammation of the periosteum, a layer of connective tissue that surrounds bone. The condition is generally chronic, and is marked by tenderness and swelling of the bone and an aching pain.

Enthesitis is inflammation of the entheses, the sites where tendons or ligaments insert into the bone. It is also called enthesopathy, or any pathologic condition involving the entheses. The entheses are any point of attachment of skeletal muscles to the bone, where recurring stress or inflammatory autoimmune disease can cause inflammation or occasionally fibrosis and calcification. One of the primary entheses involved in inflammatory autoimmune disease is at the heel, particularly the Achilles tendon.

It is associated with HLA B27 arthropathies like ankylosing spondylitis, psoriatic arthritis, and reactive arthritis. Symptoms include multiple points of tenderness at the heel, tibial tuberosity, iliac crest, and other tendon insertion sites.

The bone edema in arthitis mutilans can be treated with TNF inhibitors in the short term: a 2007 study found that the bone edema associated with psoriatic arthritis (of which arthitis mutilans is a subtype) responded to TNF inhibitors with "dramatic" improvement, but the study was not determinative of whether TNF inhibitors would prevent new bone formation, bone fusion, or osteolysis (bone resorption).

Although a 2011 research article stated that disagreements between hand surgeons and rheumatologists remain regarding the indications, timing and effectiveness of rheumatoid hand surgery, arthritis mutilans may be successfully treated by iliac-bone graft and arthrodesis of the interphalangeal joints and the metacarpophalangeal joint in each finger.

If a dry socket occurs, the total healing time is increased. Postoperative pain is also worse than the normal discomfort which accompanies healing following any minor surgical procedure. The pain may last for seven to forty days.

Treatment options include modified activity with or without weight bearing; immobilization; cryotherapy; anti-inflammatory medication; drilling of subchondral bone; microfracture; removal or reattachment of loose bodies; mosaicplasty and osteoarticular transfer system (OATS) procedures. The primary goals of treatment are:

1. Enhance the healing potential of subchondral bone;

2. Fix unstable fragments while maintaining joint congruity; and

3. Replace damaged bone and cartilage with implanted tissues or cells that can grow cartilage.

The articular cartilage's capacity for repair is limited: partial-thickness defects in the articular cartilage do not heal spontaneously, and injuries of the articular cartilage which fail to penetrate subchondral bone tend to lead to deterioration of the articular surface. As a result, surgery is often required in even moderate cases where the osteochondral fragment has not detached from the bone (Anderson Stage II, III).

If the ringbone is close to a joint, the prognosis for the horse's continued athletic use is not as good as if the ringbone is not near a joint. Ringbone that is progressing rapidly has a poorer prognosis as well.

Horses that are not performing strenuous work, such as jumping or working at speed, will probably be usable for years to come. However, horses competing in intense sports may not be able to continue at their previous level, as their pastern joints are constantly stressed.