The clinical presentation varies depending on the stage of the disease from mild swelling to severe swelling and moderate deformity. Inflammation, erythema, pain and increased skin temperature (3–7 degrees Celsius) around the joint may be noticeable on examination. X-rays may reveal bone resorption and degenerative changes in the joint. These findings in the presence of intact skin and loss of protective sensation are pathognomonic of acute Charcot arthropathy.

Roughly 75% of patients experience pain, but it is less than what would be expected based on the severity of the clinical and radiographic findings.

In general, pigmented villonodular synovitis often manifests initially as sudden onset, unexplained joint swelling and pain; the joint swelling is disproportionate to the amount of pain the patient feels at first. Decreased motion and increased pain occur as the disorder progresses as well as locking of the joint. The localized form often manifests initially as a painless, slow-growing mass and progresses to the other common symptoms of PVNS. The swelling often feels warm to the touch. Diffuse PVNS symptoms are often confused with those of Rheumatoid arthritis. While pigmented villonodular synovitis can occur in both pediatric and geriatric patients, it is more common with ages 20–50.

Clinical findings include erythema, edema and increased temperature in the affected joint. In neuropathic foot joints, plantar ulcers may be present. Note that it is often difficult to differentiate osteomyelitis from a Charcot joint, as they may have similar tagged WBC scan and MRI features (joint destruction, dislocation, edema). Definitive diagnosis may require bone or synovial biopsy.

PVNS is locally aggressive and can spread to surrounding tissues, causing bone erosion and tissue damage. If not treated early, it can spread to areas outside the joint, and potentially cause permanent loss of range as well as intense pain. The disorder also has, on average, a 45% rate of recurrence.

DISH can present with spinal stiffness on forward flexion/back extension, or with mild back pain. It is symptomatic for thoracic spinal pain in approximately 80% of patients. Back pain or stiffness is worse in the morning in almost two-thirds of patients. It may also be asymptomatic and discovered as an incidental radiological abnormality. Dysphagia from cervical spine osteophyte impingement of esophagus is reported in some cases. Similar calcification and ossification may be seen at peripheral entheseal sites, including the shoulder, iliac crest, ischial tuberosity, trochanters of the hip, tibial tuberosities, patellae, and bones of the hands and/or feet.

Patients usually complain of pain in one joint, which persists for months, or even years, does not ease with exercise, steroid injection or heat treatment, shows nothing on X-ray, but shows a definite restriction of movement.

There are 3 defined stages to this disease:

- early: no loose bodies but active synovial disease;

- transitional: active synovial disease, and loose bodies;

- late: loose bodies but no synovial disease;

In the early stages of the disease it is often confused with tendinitis and/or arthritis. Once it reaches transitional the loose bodies become apparent with X-ray in greater than 70% of cases, with MRI often showing where xray fails. In experienced hands, US is also useful for the diagnosis.

In the disease, the thin flexible membrane of the synovium gradually forms blisters which calcify and enlarge. These nodules eventually break free and float around the joint space becoming larger – these add to the discomfort and stiffness of the joint.

The disease is rare and little known and there is currently no known cure. The affected tissue will show up as a semi-solid mass in a MRI scan, final diagnosis is usually confirmed by taking a biopsy.

Synovial chondromatosis occurs twice as commonly in males as females and usually in their forties. However, online communities for synovial chondromatosis patients have yielded a stark contrast, with equal representation from both genders and members diagnosed as young as late teenage/early 20s.

The disease generally affects only one of the larger weight bearing joints (hip, ankle, knee) – although the elbow, and wrist can also be affected. Rarely involves the temporal mandibular joint.

Diffuse idiopathic skeletal hyperostosis (DISH) is a non-inflammatory spondyloarthropathy which predominantly affects the spine. It is characterized by ankylosis and enthesopathy (ossification of the ligaments and entheses). It most commonly affects the thoracic and thoraco-lumbar spine, but involvement is variable and can include the entire spine.

Common deformities of the knee include:

- Genu varum

- Genu valgum

- Genu recurvatum (Knee hyperextension)

- Knee flexion deformity

- Bipartite patella

Referred pain is that pain perceived at a site different from its point of origin but innervated by the same spinal segment. Sometimes knee pain may be related to another area from body. For example, knee pain can come from ankle, foot, hip joints or lumbar spine.

Synovial chondromatosis (synonyms include synovial osteochondromatosis, primary synovial osteochondromatosis, and synovial chondrometaplasia) is a disease affecting the synovium, a thin flexible membrane around a joint. It is also known as Reichel's syndrome or Reichel-Jones-Henderson syndrome, named after Friedrich Paul Reichel, Hugh Toland Jones and Melvin Starkey Henderson.

Hallux rigidus or stiff big toe is degenerative arthritis and stiffness due to bone spurs that affects the MTP joint at the base of the hallux (big toe).

Hallux flexus was initially described by Davies-Colley in 1887 as a plantar flexed posture of phalanx relative to the metatarsal head. About the same time, Cotterill first used the term "hallux rigidus".

When plantar fasciitis occurs, the pain is typically sharp and usually unilateral (70% of cases). Heel pain is worsened by bearing weight on the heel after long periods of rest. Individuals with plantar fasciitis often report their symptoms are most intense during their first steps after getting out of bed or after prolonged periods of sitting. Improvement of symptoms is usually seen with continued walking. Rare, but reported symptoms include numbness, tingling, swelling, or radiating pain. Typically there are no fevers or night sweats.

If the plantar fascia continues to be overused in the setting of plantar fasciitis, the plantar fascia can rupture. Typical signs and symptoms of plantar fascia rupture include a clicking or snapping sound, significant local swelling, and acute pain in the sole of the foot.

In 1988, Hattrup and Johnson described the following radiographic classification system:

Grade I - mild changes with maintained joint space and minimal spurring.

Grade II - moderate changes with narrowing of joint space, bony proliferation on the metatarsophalangeal head and phalanx and subchondral sclerosis or cyst.

Grade III - Severe changes with significant joint space narrowing, extensive bony proliferation and loose bodies or a dorsal ossicle.

The symptoms of bunions include irritated skin around the bunion, pain when walking, joint redness and pain, and possible shift of the big toe toward the other toes. Blisters may form more easily around the site of the bunion as well.

The presence of bunions can lead to difficulties finding properly fitting footwear and may force a person to buy a larger size shoe to accommodate the width the bunion creates. If the bunion deformity becomes severe enough, the foot can hurt in different places even without the constriction of shoes. It is then considered as being a mechanical function problem of the forefoot.

Fibrous ankylosis is a fibrous connective tissue process which results in decreased range of motion. Symptoms present as bony ankylosis, in which osseous tissue fuses two bones together reducing mobility, which is why fibrous ankylosis is also known as false ankylosis.

Pathology may be the result of trauma, disease, chronic inflammation, or surgery.

Some research suggests fibrous ankylosis may precede the development of bony ankylosis

In medicine, an enthesopathy refers to a disorder involving the attachment of a tendon or ligament to a bone. This site of attachment is known as the entheses.

If the condition is known to be inflammatory, it can more precisely be called an enthesitis.

A bunion is a deformity of the joint connecting the big toe to the foot. The big toe often bends towards the other toes and the joint becomes red and painful. Onset is gradual. Complications may include bursitis or arthritis.

The exact cause is unclear. Proposed factors include wearing overly tight shoes, family history, and rheumatoid arthritis. Diagnosis is generally based on symptoms and supported by X-rays. A similar condition of the little toe is referred to as a bunionette.

Treatment may include proper shoes, orthotics, or NSAIDs. If this is not effective for improving symptoms, surgery may be done. It affects about 23% of adults. Females are affected more often than males. Usual age of onset is between 20 and 50 years old. The condition also becomes more common with age. It was first clearly described in 1870.

Plantar fasciitis is a disorder that results in pain in the heel and bottom of the foot. The pain is usually most severe with the first steps of the day or following a period of rest. Pain is also frequently brought on by bending the foot and toes up towards the shin and may be worsened by a tight Achilles tendon. The condition typically comes on slowly. In about a third of people both legs are affected.

The causes of plantar fasciitis are not entirely clear. Risk factors include overuse such as from long periods of standing, an increase in exercise, and obesity. It is also associated with inward rolling of the foot and a lifestyle that involves little exercise. While heel spurs are frequently found it is unclear if they have a role in causing the condition. Plantar fasciitis is a disorder of the insertion site of the ligament on the bone characterized by micro tears, breakdown of collagen, and scarring. As inflammation plays a lesser role, many feel the condition should be renamed plantar fasciosis. The diagnosis is typically based on signs and symptoms with ultrasound sometimes used to help. Other conditions with similar symptoms include osteoarthritis, ankylosing spondylitis, heel pad syndrome, and reactive arthritis.

Most cases of plantar fasciitis resolve with time and conservative methods of treatment. Usually for the first few weeks people are advised to rest, change their activities, take pain medications, and stretch. If this is not sufficient physiotherapy, orthotics, splinting, or steroid injections may be options. If other measures do not work extracorporeal shockwave therapy or surgery may be tried.

Between 4% and 7% of people have heel pain at any given time and about 80% of these cases are due to plantar fasciitis. Approximately 10% of people have the disorder at some point during their life. It becomes more common with age. It is unclear if one sex is more affected than the other.

Enthesopathies may take the form of spondyloarthropathies (joint diseases of the spine) such as ankylosing spondylitis, plantar fasciitis, and Achilles tendinitis. Enthesopathy can occur at the elbow, wrist, carpus, hip, knee, ankle, tarsus, or heel bone, among other regions. Further examples include:

- Adhesive capsulitis of shoulder

- Rotator cuff syndrome of shoulder and allied disorders

- Periarthritis of shoulder

- Scapulohumeral fibrositis

- Synovitis of hand or wrist

- Periarthritis of wrist

- Gluteal tendinitis

- Iliac crest spur

- Psoas tendinitis

- Trochanteric tendinitis

Ankylosis or anchylosis (from Greek ἀγκύλος, bent, crooked) is a stiffness of a joint due to abnormal adhesion and rigidity of the bones of the joint, which may be the result of injury or disease. The rigidity may be complete or partial and may be due to inflammation of the tendinous or muscular structures outside the joint or of the tissues of the joint itself.

When the structures outside the joint are affected, the term "false ankylosis" has been used in contradistinction to "true ankylosis", in which the disease is within the joint. When inflammation has caused the joint-ends of the bones to be fused together, the ankylosis is termed "osseous" or complete and is an instance of synostosis. Excision of a completely ankylosed shoulder or elbow may restore free mobility and usefulness to the limb. "Ankylosis" is also used as an anatomical term, bones being said to ankylose (or anchylose) when, from being originally distinct, they coalesce, or become so joined together that no motion can take place between them.

In 2014, there was a rare case of Ankylosis, wherein a six-year old girl was able to open her mouth only a couple millimeters after one of her jaw joints got fused. Liliana Cernecca was the patient's name. She underwent a surgery at King's College Hospital in London, during which her jaw was operated on and unlocked.She was said to be one of the youngest patients to have undergone this surgery.

Hammer toe most frequently results from wearing poorly fitting shoes that can force the toe into a bent position, such as excessively high heels or shoes that are too short or narrow for the foot. Having the toes bent for long periods of time can cause the muscles in them to shorten, resulting in the hammer toe deformity. This is often found in conjunction with bunions or other foot problems (e.g., a bunion can force the big toe to turn inward and push the other toes). It can also be caused by muscle, nerve, or joint damage resulting from conditions such as osteoarthritis, rheumatoid arthritis, stroke, Charcot–Marie–Tooth disease, complex regional pain syndrome or diabetes. Hammer toe can also be found in Friedreich's ataxia (GAA trinucleotide repeat).

Sesamoiditis occurs on the bottom of the foot, just behind the big toe. There are normally two sesamoid bones on each foot; sometimes sesamoids can be , which means they each comprise two separate pieces. The sesamoids are roughly the size of jelly beans. The sesamoid bones act as a fulcrum for the flexor tendons, the tendons which bend the big toe downward.

Symptoms include inflammation and pain.

Sometimes a sesamoid bone is fractured. This can be difficult to pick up on X-ray, so a bone scan or MRI is a better alternative.

Among those who are susceptible to the malady are dancers, catchers and pitchers in baseball, soccer players, and football players.

A hammer toe or contracted toe is a deformity of the proximal interphalangeal joint of the second, third, or fourth toe causing it to be permanently bent, resembling a hammer. Mallet toe is a similar condition affecting the distal interphalangeal joint.

Claw toe is another similar condition, with dorsiflexion of the proximal phalanx on the lesser metatarsophalangeal joint, combined with flexion of both the proximal and distal interphalangeal joints. Claw toe can affect the second, third, fourth, or fifth toes.

Symptoms can vary from an ache or pain and swelling to the local area of the ankles, or a burning that surrounds the whole joint. With this condition, the pain is usually worse during and after activity, and the tendon and joint area can become stiffer the following day as swelling impinges on the movement of the tendon. Many patients report stressful situations in their lives in correlation with the beginnings of pain which may contribute to the symptoms.

In traumatic heterotopic ossification (traumatic myositis ossificans), the patient may complain of a warm, tender, firm swelling in a muscle and decreased range of motion in the joint served by the muscle involved. There is often a history of a blow or other trauma to the area a few weeks to a few months earlier. Patients with traumatic neurological injuries, severe neurologic disorders or severe burns who develop heterotopic ossification experience limitation of motion in the areas affected.