Treatment is usually multimodal, involving surgery, chemotherapy and radiotherapy:

- Surgery, to remove the tumor and a safety margin of healthy tissue. This is the mainstay of synovial sarcoma treatment and is curative in approximately 20–70% of patients, depending on the particular study being quoted.

- Conventional chemotherapy, (for example, doxorubicin hydrochloride and ifosfamide), to reduce the number of remaining microscopic metastases. The benefit of chemotherapy in synovial sarcoma to overall survival remains unclear, although a recent study has shown that survival of patients with advanced, poorly differentiated disease marginally improves with doxorubicin/ifosfamide treatment.

- Radiotherapy to reduce the chance of local recurrence. The benefit of radiotherapy in this disease is less clear than for chemotherapy.

As the condition is quite rare, opinions among experts about how to treat OKCs differ.

Treatment options:

- Wide (local) surgical excision.

- Marsupialization - the surgical opening of the (OKC) cavity and a creation of a marsupial-like pouch, so that the cavity is in contact with the outside for an extended period, e.g. three months.

- Curettage (simple excision & scrape-out of cavity).

- Peripheral ostectomy after curettage and/or enucleation.

- Simple excision.

- Carnoy's solution - usually used in conjunction with excision.

- Enucleation and cryotherapy

Complete surgical excision is the treatment of choice, associated with an excellent long term clinical outcome.

Patients treated with complete surgical excision can expect an excellent long term outcome without any problems. Recurrences may be seen in tumors which are incompletely excised.

Chondroblastoma has not been known to spontaneously heal and the standard treatment is surgical curettage of the lesion with bone grafting. To prevent recurrence or complications it is important to excise the entire tumor following strict oncologic criteria. However, in skeletally immature patients intraoperative fluoroscopy may be helpful to avoid destruction of the epiphyseal plate. In patients who are near the end of skeletal growth, complete curettage of the growth plate is an option. In addition to curettage, electric or chemical cauterization (via phenol) can be used as well as cryotherapy and wide or marginal resection. Depending on the size of the subsequent defect, autograft or allograft bone grafts are the preferred filling materials. Other options include substituting polymethylmethacrylate (PMMA) or fat implantation in place of the bone graft. The work of Ramappa "et al" suggests that packing with PMMA may be a more optimal choice because the heat of polymerization of the cement is thought to kill any remaining lesion.

Both radiotherapy and chemotherapy are not commonly used. Radiotherapy has been implemented in chondroblastoma cases that are at increased risk of being more aggressive and are suspected of malignant transformation. Furthermore, radiofrequency ablation has been used, but is typically most successful for small chondroblastoma lesions (approximately 1.5 cm). Treatment with radiofrequency ablation is highly dependent on size and location due to the increased risk of larger, weight-bearing lesions being at an increased risk for articular collapse and recurrence.

Overall, the success and method of treatment is highly dependent upon the location and size of the chondroblastoma.

No treatment has been found to be routinely effective. NSAIDs and COX-2 inhibitors are not generally helpful other than for general pain relief. They do not seem to help reduce effusions or prevent their occurrence. Low-dose colchicine (and some other ‘anti-rheumatic’ therapies e.g. hydroxychloroquine) have been used with some success. (Use of methotrexate and intramuscular gold have not been reported in the literature). More aggressive treatments such as synovectomy, achieved using intra-articular agents (chemical or radioactive) can provide good results, with efficacy reported for at least 1 year.

Reducing acute joint swelling:

Arthrocentesis (or drainage of joint) may be useful to relieve joint swelling and improve range of motion. Local steroid injections can also reduce fluid accumulation short-term, but do not prevent onset of episodes. These treatments provide temporary relief only. Bed rest, ice packs splints and exercise are ineffective.

A single case report of a patient with treatment-refractory IH describes the use of anakinra, an interleukin 1 receptor antagonist. At the first sign of any attack, a single 100 mg dose was given. With this dosing at onset of attacks, each episode of effusion was successfully terminated.

Reducing frequency and severity of IH episodes:

Case reports indicate some success using long-term, low-dose colchicine (e.g. 0.5 mg to 1 mg daily). A recent single case report has shown hydroxychloroquine (300 mg daily) to be effective too.

Small-sized clinical trials have shown positive results with (1) chemical and (2) radioactive synovectomy. (1) Setti et al. treated 53 patients with rifampicin RV (600 mg intra-articular injections weekly for approximately 6 weeks) with good results at 1 year follow-up. (2) Top and Cross used single doses of intra-articular radioactive gold in 18 patients with persistent effusions of mixed causes including 3 with IH. All 3 patients with IH responded well to treatment at one-year follow-up.

Treatment is frequently by means of removal of the loose bodies and of a partial or full synovectomy (removal of the synovium)

Full synovectomy is a moderately major operation and involves completely exposing the joint and removing the affected tissue. Partial synovectomy is normally done arthroscopically. Synovectomies are normally carried out by shaving the lining of the knee but there are other ways of achieving this by either freezing the synovium or by the use of radiation treatment.

The need for further procedures is greater than 25% although normally the frequency of the required removal of loose bodies is reduced by the previous synovectomy. There have been documented cases of malignant transformation however this is rare.

Whilst the condition can be described as a ‘benign growth’ it seldom affects more than one joint, and does not usually affect surrounding tissue.

Treatment of rheumatoid nodules is rarely a priority for people with rheumatoid arthritis. However, surgical removal is often successful, even if there is a tendency for nodules to regrow. Of the drug therapies commonly used in rheumatoid arthritis, methotrexate has the disadvantage of tending to make nodules worse. TNF inhibitors do not have a very reliable effect on nodules. B cell depletion with rituximab often leads to disappearance of nodules but this is not guaranteed.

Besides the frequent choice to leave the cyst in place, surgical treatments remain the primary elective option for treatment of ganglion cysts. The progression of ganglion surgery worldwide is to use an arthroscopic or mini-opening method. Alternatively, a hypodermic needle may be used to drain the fluid from the cyst (via aspiration) and a corticosteroid may be injected after the cyst is empty; however, if the fluid has thickened, owing to the passage of time, this treatment is not always effective.

There is a recurrence rate of approximately 50% following needle drainage (via aspiration) of ganglion cysts.

One common and traditional method of treatment for a ganglion cyst was to strike the lump with a large and heavy book, causing the cyst to rupture and drain into the surrounding tissues. Historically, a Bible was the largest or only book in any given household, and was often employed for this treatment. This led to the former nickname of "Bible bumps" or "Gideon's disease" for these cysts. This treatment risks injuring the patient.

RS3PE responds excellently to low dose corticosteroids, with sustained and often complete remission. Non-steroidal anti-inflammatory drugs (NSAIDs) have also been used. Hydroxychloroquine has proven effective in some cases.

Complications of treatment may include joint stiffness and scar formation. Recurrence of the lesion is more common following excision of a volar ganglion cyst in the wrist. Incomplete excision that fails to include the stalk or pedicle also may lead to recurrence, as will failing to execute a layered closure of the incision.

Because any medication that could reduce the inflammation of CPPD bears a risk of causing organ damage, treatment is not advised if the condition is not causing pain.

For acute pseudogout, treatments include intra-articular corticosteroid injection, systemic corticosteroids, non-steroidal anti-inflammatory drugs (NSAIDs), or, on occasion, high-dose colchicine. In general, NSAIDs are administered in low doses to help prevent CPPD. However, if an acute attack is already occurring, higher doses are administered. If nothing else works, hydroxychloroquine or methotrexate may provide relief.

Research into surgical removal of calcifications is underway, however this still remains an experimental procedure.

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.

There are no prospective randomized controlled trials studying therapies for relapsing polychondritis. Evidence for efficacy of treatments is based on case reports and series of small groups of patients.

For mild cases limited to joint pain or arthritis, oral nonsteroidal anti-inflammatory drugs (NSAIDs) may be used. Other treatments typically involve medications to suppress the immune system. Corticosteroids are frequently used for more serious disease. Steroid-sparing medications such as azathioprine or methotrexate may be used to minimize steroid doses and limit the side effects of steroids. For severe disease cyclophosphamide is often given in addition to high dose intravenous steroids.

Baker's cysts usually require no treatment unless they are symptomatic. It is very rare that the symptoms are actually coming from the cyst. In most cases, there is another disorder in the knee (arthritis, meniscal (cartilage) tear, etc.) that is causing the problem. Initial treatment should be directed at correcting the source of the increased fluid production. Often rest and leg elevation are all that is needed. If necessary, the cyst can be aspirated to reduce its size, then injected with a corticosteroid to reduce inflammation. Surgical excision is reserved for cysts that cause a great amount of discomfort to the patient. A ruptured cyst is treated with rest, leg elevation, and injection of a corticosteroid into the knee.

Baker's cysts in children, unlike in older people, nearly always disappear with time, and rarely require excision.

Ice pack therapy may sometimes be an effective way of controlling the pain related to Baker's cyst. Heat is also commonly used. A knee brace can offer support giving the feel of stability in the joint.

Rest and specific exercise

Many activities can put strain on the knee, and cause pain in the case of Baker's cyst. Avoiding activities such as squatting, kneeling, heavy lifting, climbing, and even running can help prevent pain. Despite this, some exercises can help relieve pain, and a physiotherapist may instruct on stretching and strengthening the quadriceps and/or the patellar ligament.

Treatment includes supportive care with analgesics and anti-inflammatory agents. Exercise should be limited as it increases pain and extends the area of infarction. Symptoms usually resolve in weeks to months, but fifty percent of sufferers will experience relapse in either leg.

Synovitis symptoms can be treated with anti-inflammatory drugs such as NSAIDs. An injection of steroids may be done, directly into the affected joint. Specific treatment depends on the underlying cause of the synovitis.

Treatment is usually with intravenous antibiotics, analgesia and washout and/or aspiration of the joint. Draining the pus from the joint is important and can be done either by needle (arthrocentesis) or opening the joint surgically (arthrotomy).

Empiric antibiotics for suspected bacteria should be started. This should be based on gram stain of the synovial fluid as well as other clinical findings. General guidelines are as follows:

- Gram positive cocci - vancomycin

- Gram negative cocci - Ceftriaxone

- Gram negative bacilli - Ceftrioxone, cefotaxime, or ceftazidime

- Gram stain negative and immunocompetent - vancomycin

- Gram stain negative and immunocompromised - vancomycin + third generation cephalosphorin

- IV drug use (possible pseudomonas aeruginosa) - ceftazidime +/- an aminoglycoside

Once cultures are available, antibiotics can be changed to target the specific organism.

After a good response to intravenous antibiotics, patients can be switched to oral antibiotics. The duration of oral antibiotics varies, but is generally for 1-4 weeks depending on the offending organism.

In infection of a prosthetic joint, a biofilm is often created on the surface of the prosthesis which is resistant to antibiotics. Surgical debridement is usually indicated in these cases. A replacement prosthesis is usually not inserted at the time of removal to allow antibiotics to clear infection of the region. Patients that cannot have surgery may try long-term antibiotic therapy in order to suppress the infection.

Close follow up with physical exam & labs must be done to make sure patient is no longer feverish, pain has resolved, has improved range of motion, and lab values are normalized.

Fibrosarcoma occurs most frequently in the mouth in dogs . The tumor is locally invasive, and often recurs following surgery . Radiation therapy and chemotherapy are also used in treatment. Fibrosarcoma is also a rare bone tumor in dogs.

In cats, fibrosarcoma occurs on the skin. It is also the most common vaccine-associated sarcoma. In 2014, Merial launched Oncept IL-2 in Europe for the management of such feline fibrosarcomas.

Non-steroidal anti-inflammatory drugs (NSAIDs) can give significant relief of the symptoms. Treatment of lung cancer or other causes of hypertrophic osteoarthropathy results in regression of symptoms for some patients.

While there is a wide age range at clinical presentation (12–85 years), most patients come to clinical attention at 55 years (mean). There is no gender difference.

Plica syndrome treatment focuses on decreasing inflammation of the synovial capsule. A nonsteroidal anti-inflammatory drug (NSAID) is often used in conjunction with therapeutic exercise and modalities. Iontophoresis and phonophoresis have been utilized successfully against inflammation of the plica and synovial capsule. Failing these, surgical removal of the plica of the affected knee may be necessary.

Villonodular synovitis is a type of synovial swelling.

Types include:

- Pigmented villonodular synovitis (PVNS)

- Giant cell tumor of the tendon sheath (GCTS)

Though they have very different names, they have the same histology, and stain positive for CD68, HAM56, and vimentin.

They are sometimes discussed together.

Medication is the main method of managing pain in TMD, mostly because there is little if any evidence of the effectiveness of surgical or dental interventions. Many drugs have been used to treat TMD pain, such as analgesics (pain killers), benzodiazepines (e.g. clonazepam, prazepam, diazepam), anticonvulsants (e.g. gabapentin), muscle relaxants (e.g. cyclobenzaprine), and others. Analgesics that have been studied in TMD include non-steroidal anti-inflammatory drugs (e.g. piroxicam, diclofenac, naproxen) and cyclo-oxygenase-2 inhibitors (e.g. celecoxib). Topical methyl salicylate and topical capsaicin have also been used. Other drugs that have been described for use in TMD include glucosamine hydrochloride/chondroitin sulphate and propranolol. Despite many randomized control trials being conducted on these commonly used medications for TMD a systematic review carried out in 2010 concluded that there was insufficient evidence to support or not to support the use of these drugs in TMD. Low-doses of anti-muscarinic tricyclic antidepressants such as amitriptyline, or nortriptyline have also been described. In a subset of people with TMD who are not helped by either noninvasive and invasive treatments, long term use of opiate analgesics has been suggested, although these drugs carry a risk of drug dependence and other side effects. Examples include morphine, fentanyl, oxycodone, tramadol, hydrocodone, and methadone.

Botulinum toxin solution ("Botox") is sometimes used to treat TMD. Injection of botox into the lateral pterygoid muscle has been investigated in multiple randomized control trials, and there is evidence that it is of benefit in TMD. It is theorized that spasm of lateral pterygoid causes anterior disc displacement. Botulinum toxin causes temporary muscular paralysis by inhibiting acetylcholine release at the neuromuscular junction. The effects usually last for a period of months before they wear off. Complications include the creation of a "fixed" expression due to diffusion of the solution and subsequent involvement of the muscles of facial expression, which lasts until the effects of the botox wear off. Injections of local anesthetic, sometimes combined with steroids, into the muscles (e.g. the temoralis muscle or its tendon) are also sometimes used. Local anesthetics may provide temporary pain relief, and steroids inhibit pro-inflammatory cytokines. Steroids and other medications are sometimes injected directly into the joint (See Intra-articular injections).

The main goal of treatment is to identify and eradicate the underlying infectious source with the appropriate antibiotics if still present. Otherwise, treatment is symptomatic for each problem. Nonspecific urethritis may be treated with a short course of tetracycline. Analgesics, particularly NSAIDs, are used. Steroids, sulfasalazine and immunosuppressants may be needed for patients with severe reactive symptoms that do not respond to any other treatment. Local corticosteroids are useful in the case of iritis.