Transient synovitis causes pain in the hip, thigh, groin or knee on the affected side. There may be a limp (or abnormal crawling in infants) with or without pain. In small infants, the presenting complaint can be unexplained crying (for example, when changing a diaper). The condition is nearly always limited to one side. The pain and limp can range from mild to severe.

Some children may have a slightly raised temperature; high fever and general malaise point to other, more serious conditions. On clinical examination, the child typically holds the hip slightly bent, turned outwards and away from the middle line (flexion, external rotation and abduction). Active and passive movements may be limited because of pain, especially abduction and internal rotation. The hip can be tender to palpation. The log roll test involves gently rotating the entire lower limb inwards and outwards with the patient on his back, to check when muscle guarding occurs. The unaffected hip and the knees, ankles, feet and spine are found to be normal.

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.

Transient synovitis of the hip (also called toxic synovitis; see below for more synonyms) is a self-limiting condition in which there is an inflammation of the inner lining (the synovium) of the capsule of the hip joint. The term irritable hip refers to the syndrome of acute hip pain, joint stiffness, limp or non-weightbearing, indicative of an underlying condition such as transient synovitis or orthopedic infections (like septic arthritis or osteomyelitis). In everyday clinical practice however, irritable hip is commonly used as a synonym for transient synovitis. It should not be confused with sciatica, a condition describing hip and lower back pain much more common to adults than transient synovitis but with similar signs and symptoms.

Transient synovitis usually affects children between three and ten years old (but it has been reported in a 3-month-old infant and in some adults). It is the most common cause of sudden hip pain and limp in young children. Boys are affected two to four times as often as girls. The exact cause is unknown. A recent viral infection (most commonly an upper respiratory tract infection) or a trauma have been postulated as precipitating events, although these are reported only in 30% and 5% of cases, respectively.

Transient synovitis is a diagnosis of exclusion. The diagnosis can be made in the typical setting of pain or limp in a young child who is not generally unwell and has no recent trauma. There is a limited range of motion of the hip joint. Blood tests may show mild inflammation. An ultrasound scan of the hip joint can show a fluid collection (effusion). Treatment is with nonsteroidal anti-inflammatory drugs and limited weight-bearing. The condition usually clears by itself within seven to ten days, but a small group of patients will continue to have symptoms for several weeks. The recurrence rate is 4–17%, most of which is in the first six months.

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.

Juvenile rheumatoid arthritis presents gradually with early morning stiffness, fatigue, and weight loss.

Transient synovitis is a reactive arthritis of the hip of unknown cause. People are usually able to walk and may have a low grade fever. They usually look clinically nontoxic or otherwise healthy. It may only be diagnosed once all other potential serious causes are excluded. With symptomatic care it usually resolves over one week.

Repeated, periodic joint effusions of the knee. Usually one knee is affected but sometimes both knees. Other joints may also be involved along with the knee. Effusions are large, restricting range of motion but significant pain is not a feature. There is usually stiffness. Tenderness of the joint may or may not be present. Aspirated synovial fluid is usually sterile but will sometimes show elevated cell count (>100 cells/mL) with 50% being polymorphonuclear leukocytes.

Onset of effusions are sudden with no particular trigger or stimulus. Each episode lasts for a few days to about a week and recurs in cycles of 7 to 11 days with extremes of 3 days to 30 days also reported. Sometimes the joint may begin to swell again as soon as the fluid has subsided. Where both knees are affected concurrently, as one joint ceases to swell the other may become involved.

The cycle of joints swellings have been reported as being very regular, even predictable. This has been a characteristic feature of IH in many case reports. However, over the longer-term especially, these cycles of effusion and recovery may not be as constant as first reported.

In women, many cases seem to begin at puberty. Episodes of knee swelling may coincide the menstrual cycle. In nearly all case reports, pregnancy seems to suppress the condition but after birth, during lactation, it returns.

In the main, patients are mostly free of other symptoms. Fever is rare. There no signs of local inflammation or lymphatic involvement. Laboratory tests are generally normal or within reference limits.

Synovitis causes joint tenderness or pain, swelling and hard lumps, called nodules. When associated with rheumatoid arthritis, swelling is a better indicator than tenderness.

Intermittent hydrarthrosis (IH), also known as "periodic synoviosis", "periodic benign synovitis", or "periodic hydrarthritis", is a chronic condition of unknown cause characterized by recurring, temporary episodes of fluid accumulation in the knee. While the knee is mainly involved, occasionally other joints such as the elbow or ankle can additionally be affected. Fluid accumulation in the joint can be extensive causing discomfort and impairing movement, although affected joints are not usually very painful. While the condition is chronic, it does not appear to progress to more destructive damage of the joint. It seems to affect slightly more women than men.

Episodes of swelling last several days or longer, can occur with regular or semi-regular frequency, typically one or two episodes per month. Between periods of effusion, knee swelling reduces dramatically providing largely symptomless intervals. Unlike some other rheumatological conditions such as rheumatoid arthritis, laboratory findings are usually within normal ranges or limits.

Clear treatment options have yet to be established. NSAIDs and COX2-inhibitors are generally not effective. Where this condition has been correctly diagnosed, various anti-rheumatic drugs as well as colchicine may be trialled to find the most effective option. More aggressive intra-articular treatment such chemical or radio-active synovectomy can also be helpful although benefits beyond 1 year have not been reported in literature.

Synovitis is the medical term for inflammation of the synovial membrane. This membrane lines joints that possess cavities, known as synovial joints. The condition is usually painful, particularly when the joint is moved. The joint usually swells due to synovial fluid collection.

Synovitis may occur in association with arthritis as well as lupus, gout, and other conditions. Synovitis is more commonly found in rheumatoid arthritis than in other forms of arthritis, and can thus serve as a distinguishing factor, although it is also present in many joints affected with osteoarthritis. Long term occurrence of synovitis can result in degeneration of the joint.

Trapeziometacarpal osteoarthritis, also known as carpometacarpal (CMC) osteoarthritis (OA) of the thumb or osteoarthritis at the base of the thumb, is a reparitive joint disease affecting the first carpometacarpal joint (CMC1). This joint is formed by the trapezium bone of the wrist and the first metacarpal bone of the thumb. Because of its relative instability, this joint is a frequent site for osteoarthritis. Carpometacarpal osteoarthritis (CMC OA) of the thumb occurs when the cushioning cartilage of the joint surfaces wears away, resulting in damage of the joint.

The main complaint of patients is pain. Pain at the base of the thumb occurs when moving the thumb and might eventually persist at rest. Other symptoms include stiffness, swelling and loss of strength of the thumb. Treatment options include conservative and surgical therapies.

The primary and most common symptom in patients with CMC OA of the thumb is pain. Pain at the base of the thumb is mainly experienced when moving the thumb or when applying pressure with the thumb. However, in advanced stages of CMC OA, pain might persist at rest. Another prominent symptom is loss of strength of the thumb. Patients struggle to grab or hold an object due to weakening of the thumb. For example, tying a knot or holding a saucepan becomes increasingly difficult.

If patients present themselves with similar symptoms, physicians should also consider De Quervain syndrome, rheumatoid arthritis or flexor carpi radialis and flexor pollicis longus tendinopathy as a possible cause.

Typical signs of CMC OA can be observed from the outside of the hand. For example, the area near the base of the thumb can be swollen and could appear inflamed. Advanced stages of CMC OA can eventually lead to deformity of the thumb. This deformity, also called a ‘zigzag’ deformity, is characterized by a deviation of the thenar eminence towards the middle of the hand, whilst the thumb phalanges overextend. Also a grinding sound, known as crepitus, can be heard when the CMC1 joint is moved.

The disorder is more common in older adults. The disease is often occult until crystal deposits are coincidentally detected and diagnosed by a pathologist in various orthopedic specimens. It may be asymptomatic, or it can be associated with osteoarthritis, or it can present as an acute or chronic inflammatory arthritis that causes pain in one or more joints. The white blood cell count is often raised.

The arthritis is usually polyarticular (i.e., it leads to an inflammation of several joints in the body), although it may begin as monoarticular (i.e., confined to just one joint). CPPD crystals tend to form within articular tissues. In theory, any joint may be affected, but statistics show that the knees are the most commonly affected joints, as well as wrists and hips.

In many instances, patients may also have signs of carpal tunnel syndrome. This condition can also be associated with Milwaukee shoulder syndrome.

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

Typical symptoms include pain, refusing to walk or bear weight and limping -bruising and deformity are absent. On clinical examination, there can be warmth and swelling over the fracture area, as well as pain on bending the foot upwards (dorsiflexion). The initial radiographical images may be inconspicuous (a faint oblique line) and often even completely normal. After 1–2 weeks however, callus formation develops. The condition can be mistaken for osteomyelitis, transient synovitis or even child abuse. Contrary to CAST fractures, non-accidental injury typically affect the upper two-thirds or midshaft of the tibia.

Other possible fractures in this area, occurring in the cuboid, calcaneus, and fibula, can be associated or can be mistaken for a toddler's fracture. In some cases, an internal oblique radiography and radionuclide imaging can add information to anterior-posterior and lateral views. However, since treatment can also be initiated in the absence of abnormalities, this appears to have little value in most cases. It could be useful in special cases such as children with fever, those without a clear trauma or those in which the diagnosis remains unclear. Recently, ultrasound has been suggested as a helpful diagnostic tool.

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.

Clutton's joints is a term describing the finding of symmetrical joint swelling seen in patients with congenital syphilis. It most commonly affects the knees, presenting with synovitis and joint effusions (collections of fluid within the joint capsules) lasting up to a year. It has also been reported affecting the ankles, elbows, wrists and fingers. It is usually painless, although pain in the absence of trauma can occur in a few cases. There is usually no disability associated with the joint swelling, and recovery is usually complete. It occurs between 5 and 20 years of age in both sexes.

The condition was described in 1886 by Henry Hugh Clutton in "The Lancet".

Postarthroscopic glenohumeral chondrolysis (PAGCL) is a rare complication of arthroscopic surgery and involves chondrolysis wherein the articular cartilage of the shoulder undergoes rapid, degenerative changes shortly after arthroscopic surgery.

Individuals affected by RS3PE typically have repeated episodes of inflammation of the lining of their synovial joints and swelling of the end portion of the limbs. The arms and hands are more commonly affected than the legs and feet. Both sides are usually involved though RS3PE can affect only one side in certain cases.

Bupivacaine, lidocaine, ropivacaine and levobupivacaine are all toxic to cartilage and their intra-articular infusions can lead to this toxic effect. Intra-articular pain pumps with local anesthetics have been implicated as a potential cause.

Calcium pyrophosphate dihydrate (CPPD) crystal deposition disease, also known as pseudogout and pyrophosphate arthropathy is a rheumatologic disorder with varied symptoms and signs arising from the resultant accumulation of crystals of calcium pyrophosphate dihydrate in the connective tissues. The alternative names emphasize particular aspects of the clinical or radiographic findings. The knee joint is the most commonly affected.

Toddler's fractures or childhood accidental spiral tibial (CAST) fractures are bone fractures of the distal (lower) part of the shin bone (tibia) in toddlers (aged 9 months-3 years) and other young children (less than 8 years). The fracture is found in the distal two thirds of the tibia in 95% of cases, is undisplaced and has a spiral pattern. It occurs after low-energy trauma, sometimes with a rotational component.

Remitting seronegative symmetrical synovitis with pitting edema (abbreviated RS3PE or sometimes RSPE) is a rare syndrome identified by symmetric polyarthritis, synovitis, acute pitting edema (swelling) of the back of the hands and/or feet, and a negative serum rheumatoid factor. If no underlying disorder can be identified (idiopathic RS3PE), this entity has an excellent prognosis and responds well to treatment.

RS3PE typically involves the joints of the extremities, specifically the metacarpophalangeal and proximal interphalangeal joints, wrists, shoulders, elbows, knees and ankles.

It is more common in older adults, with the mean age between 70 and 80 years in most studies.

It occurs more often in men than in women with a 2:1 ratio.

It is unknown how common this condition is.

Symptoms include: pain on weight bearing, frequently after only a short time. The nature of the pain varies widely among individuals. Some people experience shooting pain affecting the contiguous halves of two toes. Others describe a feeling like having a pebble in their shoe or walking on razor blades. Burning, numbness, and paresthesia may also be experienced. The symptoms progress over time, often beginning as a tingling sensation in the ball of the foot.

Morton's neuroma lesions have been found using MRI in patients without symptoms.

Dactylitis or sausage digit is inflammation of an entire digit (a finger or toe), and can be painful.

The word dactyl comes from the Greek word "daktylos" meaning "finger". In its medical term, it refers to both the fingers and the toes.