About 25% of people over the age of 50 experience knee pain from degenerative knee diseases.

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.

In the United States, more than US $3 billion is spent each year on arthroscopic knee surgeries that are known to be ineffective in people with degenerative knee pain.

Any condition resulting in decreased peripheral sensation, proprioception, and fine motor control:

- Diabetes mellitus neuropathy (the most common in the U.S. today, resulting in destruction of foot and ankle joints), with Charcot joints in 1/600-700 diabetics. Related to long-term poor glucose control.

- Alcoholic neuropathy

- Cerebral palsy

- Leprosy

- Syphilis ("tabes dorsalis"), caused by the organism "Treponema pallidum"

- Spinal cord injury

- Myelomeningocele

- Syringomyelia

- Intra-articular steroid injections

- Congenital insensitivity to pain

- Peroneal muscular atrophy

In reality, both of these mechanisms probably play a role in the development of a Charcot joint.

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.

The exact cause is unknown. Mechanical factors, dietary and long term use of some antidepressants may be of significance. There is a correlation between these factors but not a cause or effect. The distinctive radiological feature of DISH is the continuous linear calcification along the antero-medial aspect of the thoracic spine. The disease is usually found in people in their 60s and above, and is extremely rare in people in their 40s and 30s. The disease can spread to any joint of the body, affecting the neck, shoulders, ribs, hips, pelvis, knees, ankles, and hands. The disease is not fatal, however some associated complications can lead to death. Complications include paralysis, dysphagia (the inability to swallow), and pulmonary infections. Although DISH manifests in a similar manner to ankylosing spondylitis, these two are totally separate diseases. Ankylosing spondylitis is a genetic disease with identifiable marks, and affects organs. DISH has no indication of a genetic link, and does not affect organs other than the lungs, which is only indirect due to the fusion of the rib cage.

Long term treatment of acne with vitamin derived retinoids, such as etretinate and acitretin, have been associated with "extraspinal" hyperostosis.

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.

The exact cause is unclear. Proposed factors include wearing overly tight shoes, family history, and rheumatoid arthritis. Some state that footwear only worsens a problem caused by genetics.

This condition, which occurs in adolescents and adults, can be associated with previous trauma.

The true cause is not known. Most commonly, hallux rigidus is thought to be caused by wear and tear of the first metatarsophalangeal 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.

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.

Although the condition is degenerative, it can occur in patients who are relatively young, particularly active sports people who have at some time suffered trauma to the joint (turf toe). A notable example is NBA star Shaquille O'Neal who returned to basketball after surgery.

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.

Identified risk factors for plantar fasciitis include excessive running, standing on hard surfaces for prolonged periods of time, high arches of the feet, the presence of a leg length inequality, and flat feet. The tendency of flat feet to excessively roll inward during walking or running makes them more susceptible to plantar fasciitis. Obesity is seen in 70% of individuals who present with plantar fasciitis and is an independent risk factor.

Studies have suggested a strong association exists between an increased body mass index and the development of plantar fasciitis in the non-athletic population; this association between weight and plantar fasciitis has not been observed in the athletic population. Achilles tendon tightness and inappropriate footwear have also been identified as significant risk factors.

Bone mineral density decreases with increasing age. Osteoporotic bone loss can be prevented through an adequate intake of vitamin C and vitamin D, coupled with exercise and by being a non-smoker. A study by Cheng et al. in 1997, showed that greater bone density indicated less risk for fractures in the calcaneus.

Plantar fasciitis is the most common type of plantar fascia injury and is the most common reason for heel pain, responsible for 80% of cases. The condition tends to occur more often in women, military recruits, older athletes, the obese, and young male athletes.

Plantar fasciitis is estimated to affect 1 in 10 people at some point during their lifetime and most commonly affects people between 40–60 years of age. In the United States alone, more than two million people receive treatment for plantar fasciitis. The cost of treating plantar fasciitis in the United States is estimated to be $284 million each year.

Risk factors for developing shin splints include:

- Excessive pronation at subtalar joint

- Excessively tight calf muscles (which can cause excessive pronation)

- Engaging the medial shin muscle in excessive amounts of eccentric muscle activity

- Undertaking high-impact exercises on hard, noncompliant surfaces (ex: running on asphalt or concrete)

- Smoking and low fitness level

While medial tibial stress syndrome is the most common form of shin splints, compartment syndrome and stress fractures are also common forms of shin splints. Females are 1.5 to 3.5 times more likely to progress to stress fractures from shin splints. This is due in part to females having a higher incidence of diminished bone density and osteoporosis.

In the horse it occurs at the horse's fetlock. The sesamoid bones lie behind the bones of the fetlock, at the back of the joint, and help to keep the tendons and ligaments that run between them correctly functioning.

Usually periostitis (new bone growth) occurs along with sesamoiditis, and the suspensory ligament may also be affected. Sesamoiditis results in inflammation, pain, and eventually bone growth.

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.

Ankle sprains can occur through either sports or activities of daily living, and individuals can be at higher or lower risk depending on a variety of circumstances including their homeland, race, age, sex, or profession In addition, there are different types of ankle sprains such as eversion ankle sprains and inversion ankle sprains. Overall, the most common type of ankle sprain to occur is an inversion ankle sprain, where excessive plantar flexion and supination cause the anterior talofibular ligament to be affected. A study showed that for a population of Scandinavians, inversion ankle sprains accounted for 85% of all ankle sprains Most ankle sprains occur in more active people, such as athletes and regular exercisers.

Calcaneal fractures are often attributed to shearing stress adjoined with compressive forces combined with a rotary direction (Soeur, 1975). These forces are typically linked to injuries in which an individual falls from a height, involvement in an automobile accident, or muscular stress where the resulting forces can lead to the trauma of fracture. Overlooked aspects of what can lead to a calcaneal fracture are the roles of osteoporosis and diabetes.

Unfortunately, the prevention of falls and automobile accidents is limited and applies to unique circumstances that should be avoided. The risk of muscular stress fractures can be reduced through stretching and weight-bearing exercise, such as strength training. In addition, footwear can influence forces that may cause a calcaneal fracture and can prevent them as well. A 2012 study conducted by Salzler showed that the increasing trend toward minimalist footwear or running barefoot can lead to a variety of stress fractures including that of the calcaneus.

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