Common symptoms include hip, knee (hip pathology can refer pain to a normal knee), or groin pain, exacerbated by hip or leg movement, especially internal hip rotation (with the knee flexed 90°, twisting the lower leg away from the center of the body). The range of motion is reduced, particularly in abduction and internal rotation, and the patient presents with a limp. Pain is usually mild. Atrophy of thigh muscles may occur from disuse and an inequality of leg length. In some cases, some activity can cause severe irritation or inflammation of the damaged area, including standing, walking, running, kneeling, or stooping repeatedly for an extended period of time. In cases exhibiting severe femoral osteonecrosis, pain is usually a chronic, throbbing sensation exacerbated by activity.

The first signs are complaints of soreness from the child, which are often dismissed as growing pains, and limping or other guarding of the joint, particularly when tired. The pain is usually in the hip, but can also be felt in the knee (referred pain). In some cases, pain is felt in the unaffected hip and leg, due to the children favoring their injured side and placing the majority of their weight on their "good" leg. It is predominantly a disease of boys (4:1 ratio). Perthes is generally diagnosed between 5 and 12 years of age, although it has been diagnosed as early as 18 months. Typically, the disease is only seen in one hip, but bilateral Perthes is seen in about 10% of children diagnosed.

Legg–Calvé–Perthes disease (LCPD, also known as Perthes disease or Legg–Perthes disease) is a childhood hip disorder initiated by a disruption of blood flow to the head of the femur. Due to the lack of blood flow, the bone dies (osteonecrosis or avascular necrosis) and stops growing. Over time, healing occurs by new blood vessels infiltrating the dead bone and removing the necrotic bone which leads to a loss of bone mass and a weakening of the femoral head. The bone loss leads to some degree of collapse and deformity of the femoral head and sometimes secondary changes to the shape of the hip socket. It is also referred to as idiopathic avascular osteonecrosis of the capital femoral epiphysis of the femoral head since the cause of the interruption of the blood supply of the head of the femur in the hip joint is unknown.

The condition is most commonly found in children between the ages of 4 and 8, but it can occur in children between the ages of 2 and 15. The main long-term problem with this condition is that it can produce a permanent deformity of the femoral head, which increases the risk of developing osteoarthritis in adults. Perthes is a form of osteochondritis which only affects the hip, although other forms of osteochondritis can affect elbows, knees, ankles, and feet. Bilateral Perthes, which means both hips are affected, should always be investigated thoroughly to rule out multiple epiphyseal dysplasia.

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

Legg–Calvé–Perthes syndrome is a degenerative disease of the head of the femur which results in bone loss and deformity. It usually presents as a chronic condition.

These conditions nearly all present with an insidious onset of pain referred to the location of the bony damage. Some, notably Kienbock's disease of the wrist, may involve considerable swelling, and Legg-Calvé-Perthes disease of the hip causes the victim to limp. The spinal form, Scheuermann's disease, may cause bending, or kyphosis of the upper spine, giving a "hunch-back" appearance.

Usually, a SCFE causes groin pain, but it may cause pain in only the thigh or knee, because the pain may be referred along the distribution of the obturator nerve. The pain may occur on both sides of the body (bilaterally), as up to 40 percent of cases involve slippage on both sides. After a first SCFE, when a second SCFE occurs on the other side, it typically happens within one year after the first SCFE. About 20 percent of all cases include a SCFE on both sides at the time of presentation.

Signs of a SCFE include a waddling gait, decreased range of motion. Often the range of motion in the hip is restricted in internal rotation, abduction, and flexion. A person with a SCFE may prefer to hold their hip in flexion and external rotation.

Elbow dysplasia is a condition involving multiple developmental abnormalities of the elbow-joint in the dog, specifically the growth of cartilage or the structures surrounding it. These abnormalities, known as 'primary lesions', give rise to osteoarthritic processes. Elbow dysplasia is a common condition of certain breeds of dogs.

Most primary lesions are related to osteochondrosis, which is a disease of the joint cartilage and specifically Osteochondritis dissecans (OCD or OD), the separation of a flap of cartilage on the joint surface. Other common causes of elbow dysplasia included ununited anconeal process (UAP) and fragmented or ununited medial coronoid process (FCP or FMCP).

Osteochondritis dissecans is difficult to diagnose clinically as the animal may only exhibit an unusual gait. Consequently, OCD may be masked by, or misdiagnosed as, other skeletal and joint conditions such as hip dysplasia. The problem develops in puppyhood although often subclinically, and there may be pain or stiffness, discomfort on extension, or other compensating characteristics. Diagnosis generally depends on X-rays, arthroscopy, or MRI scans. While cases of OCD of the stifle go undetected and heal spontaneously, others are exhibited in acute lameness. Surgery is recommended once the animal has been deemed lame, before then non-surgical control is usually used.

Failure to treat a SCFE may lead to: death of bone tissue in the femoral head (avascular necrosis), degenerative hip disease (hip osteoarthritis), gait abnormalities and chronic pain. SCFE is associated with a greater risk of arthritis of the hip joint later in life. 17-47 percent of acute cases of SCFE lead to the death of bone tissue (osteonecrosis) effects.

In osteochondritis dissecans, fragments of cartilage or bone become loose within a joint, leading to pain and inflammation. These fragments are sometimes referred to as joint mice. OCD is a type of osteochondrosis in which a lesion has formed within the cartilage layer itself, giving rise to secondary inflammation. OCD most commonly affects the knee, although it can affect other joints such as the ankle or the elbow.

People with OCD report activity-related pain that develops gradually. Individual complaints usually consist of mechanical symptoms including pain, swelling, catching, locking, popping noises, and buckling / giving way; the primary presenting symptom may be a restriction in the range of movement. Symptoms typically present within the initial weeks of stage I; however, the onset of stage II occurs within months and offers little time for diagnosis. The disease progresses rapidly beyond stage II, as OCD lesions quickly move from stable cysts or fissures to unstable fragments. Non-specific symptoms, caused by similar injuries such as sprains and strains, can delay a definitive diagnosis.

Physical examination typically reveals fluid in the joint, tenderness, and crepitus. The tenderness may initially spread, but often reverts to a well-defined focal point as the lesion progresses. Just as OCD shares symptoms with common maladies, acute osteochondral fracture has a similar presentation with tenderness in the affected joint, but is usually associated with a fatty hemarthrosis. Although there is no significant pathologic gait or characteristic alignment abnormality associated with OCD, the patient may walk with the involved leg externally rotated in an attempt to avoid tibial spine impingement on the lateral aspect of the medial condyle of the femur.

The condition is usually characterized by a sudden onset of knee pain, worse at night. Examination reveals tenderness of the medial femoral condyle, joint effusion, and occasional locking of the knee joint.

Elbow Dysplasia is a significant genetically determined problem in many breeds of dog, often manifesting from puppyhood and continuing for life. In elbow dysplasia, the complex elbow joint suffers from a structural defect, often related to its cartilage. This initial condition, known as a "primary lesion", causes an abnormal level of wear and tear and gradual degradation of the joint, at times disabling or with chronic pain. Secondary processes such as inflammation and osteoarthritis can arise from this damage which increase the problem and add further problems of their own.

The term "Colles fracture" is classically used to describe a fracture at the distal end of the radius, at its cortico-cancellous junction. However, now the term tends to be used loosely to describe any fracture of the distal radius, with or without involvement of the ulna, that has dorsal displacement of the fracture fragments. Colles himself described it as a fracture that “takes place at about an inch and a half (38mm) above the carpal extremity of the radius” and “the carpus and the base of metacarpus appears to be thrown backward”. The fracture is sometimes referred to as a "dinner fork" or "bayonet" deformity due to the shape of the resultant forearm.

Colles' fractures can be categorized according to several systems including Frykman, Gartland & Werley, Lidström, Nissen-Lie and the Older's classifications.

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 humans, these conditions may be classified into three groups:

1. Spinal: Scheuermann's disease (of the interspinal joints) which is a curve in the thoracic spine.

2. Articular: Legg-Calvé-Perthes disease (or, avascular necrosis of the femoral head in the hip), Köhler's disease (of the tarsal navicular bone of the foot), Panner's disease (of the capitulum of the elbow), and Freiberg's infraction (of the second or third metatarsal of the foot and less frequently the first or fourth; sometimes called Freiberg's Infraction or Freiberg's disease)

3. Non-articular: This group includes Sever's disease (of the calcaneus, or heel), and Kienbock's disease of the hand, and other conditions not completely characteristic of the osteochondrosis, such as Osgood-Schlatter's disease (of the tibial tubercle) and Osteochondritis dissecans.

It is more common in females over the age of 50 with possible risk factors of corticosteroid use, Lupus, alcoholism, pancreatitis, sickle cell anemia, and rheumatoid arthritis.

This disorder is rare, and is characterised by an asymmetrical limb deformity due to localized overgrowth of cartilage, histologically resembling osteochondroma. It is believed to affect the limb bud in early fetal life. The condition occurs mostly in the ankle or knee region and it is always confined to a single limb. This usually involves only the lower extremities and on medial side of the epiphysis. It is named after researcher David Trevor.

The fracture is most commonly caused by people falling onto a hard surface and breaking their fall with outstretched hand (FOOSH)–falling with wrists flexed would lead to a Smith's fracture. Originally it was described in elderly and/or post-menopausal women. It usually occurs about three to five centimetres proximal to the radio-carpal joint with posterior and lateral displacement of the distal fragment resulting in the characteristic "dinner fork" or "bayonet" like deformity. Colles fracture is a common fracture in people with osteoporosis, second only to vertebral fractures.

Children with autosomal dominant MED experience joint pain and fatigue after exercising. Their x-rays show small and irregular ossifications centers, most apparent in the hips and knees. A waddling gait may develop. Flat feet are very common.

The spine is normal but may have a few irregularities, such as scoliosis. There are very small capital femoral epiphyses and hypoplastic, poorly formed acetabular roofs. Knees have metaphyseal widening and irregularity while hands have brachydactyly (short fingers) and proximal metacarpal rounding. By adulthood, people with MED are of short stature or in the low range of normal and have short limbs relative to their trunks. Frequently, movement becomes limited at the major joints, especially at the elbows and hips. However, loose knee and finger joints can occur. Signs of osteoarthritis usually begin in early adulthood.

Children with recessive MED experience joint pain, particularly of the hips and knees, and commonly have deformities of the hands, feet, knees, or vertebral column (like scoliosis). Approximately 50% of affected children have abnormal findings at birth (such as club foot or twisted metatarsals, cleft palate, inward curving fingers due to underdeveloped bones and brachydactyly, or ear swelling caused by injury during birth). Height is in the normal range before puberty. As adults, people with recessive MED are only slightly more diminished in stature, but within the normal range. Lateral knee radiography can show multi-layered patellae.

In many cases there is pain and discomfort in a joint which increases over time. While it can affect any bone, about half of cases show multiple sites of damage. Avascular necrosis primarily affects the joints at the shoulder, knee, and hip. The classical sites are: head of femur, neck of talus and waist of the scaphoid.

Avascular necrosis most commonly affects the ends of long bones such as the femur (the bone extending from the knee joint to the hip joint). Other common sites include the humerus (the bone of the upper arm), knees, shoulders, ankles and the jaw.

Hip dysplasia can range from barely detectable to severely malformed or dislocated.

The congenital form, teratologic or non-reducible dislocation occurs as part of more complex conditions.

The condition can be bilateral or unilateral:

- If both hip joints are affected one speaks of "bilateral" dysplasia. In this case some diagnostic indicators like asymmetric folds and leg-length inequality do not apply.

- In unilateral dysplasia only one joint shows deformity, the contralateral side may show resulting effects. In the majority of unilateral cases the left hip has the dysplasia.

If the joint is fully dislocated a false acetabulum often forms (often higher up on the pelvis) opposite the dislocated femoral head position.

In acetabular dysplasia the acetabulum (socket) is too shallow or deformed. The center-edge angle is measured as described by Wiberg. Two forms of femoral dysplasia are coxa vara, in which the femur head grows at too narrow an angle to the shaft, and coxa valga, in which the angle is too wide.

A rare type, the "Beukes familial hip dysplasia" is found among Afrikaners that are members of the Beukes family. The femur head is flat and irregular. People develop osteoarthritis at an early age.

Femoroacetabular Impingement (FAI), or hip impingement syndrome, may affect the hip joint in young and middle-aged adults and occurs when the ball shaped femoral head rubs abnormally or does not permit a normal range of motion in the acetabular socket. Damage can occur to the articular cartilage, or labral cartilage (soft tissue bumper of the socket), or both. Treatment options range from conservative to arthroscopic to open surgery.

It is a congenital subluxation or dislocation of the ulna's distal end, due to malformation of the bones. Sometimes, minor abnormalities of other bone structures, often caused by disease or injury, such as a fracture of the distal end of the radius with upward displacement of the distal fragment. The deformity varies in degree from a slight protrusion of the lower end of the ulna, to complete dislocation of the inferior radio-ulnar joint with marked radial deviation of the hand. Severe deformities are associated with congenital absence or hypoplasia of the radius.

The male:female rate of this disorder is 1:4. The incidence is unknown, and there is no described racial predominance. Even though Madelung's Deformity is considered a congenital disorder, symptoms sometimes aren't seen until adulthood. In most cases, symptoms find their onset during midchildhood. At this age, the relatively slower growth of the ulnar and palmar part of the radius, leads to an increasingly progressive deformity. Pain and deformity are the main symptoms patients present with. Typical clinical presentation consists of a short forearm, anterior-ulnar bow of the radius and a forward subluxation of the hand on the forearm. As mentioned before, the severity of the disorder varies greatly, which also leads to a spectrum of presentation.

Tibial plateau fractures typically presents with knee effusion, swelling of the knee soft tissues and inability to bear weight. The knee may be deformed due to displacement and/or fragmentation of the tibia which leads to loss of its normal structural appearance. Blood in the soft tissues and knee joint (hemarthrosis) may lead to bruising and a doughy feel of the knee joint. Due to the tibial plateau's proximity to important vascular (i.e. arteries, veins) and neurological (i.e. nerves such as peroneal and tibial) structures, injuries to these may occur upon fracture. A careful examination of the neurovascular systems is imperative. A serious complication of tibial plateau fractures is compartment syndrome in which swelling causes compression of the nerves and blood vessels inside the leg and may ultimately lead to necrosis or cell death of the leg tissues.

Proximal femoral focal deficiency (PFFD), also known as Congenital Femoral Deficiency (CFD), is a rare, non-hereditary birth defect that affects the pelvis, particularly the hip bone, and the proximal femur. The disorder may affect one side or both, with the hip being deformed and the leg shortened.

It is commonly linked with the absence or shortening of a leg bone (fibular hemimelia) and the absence of a kneecap. Other linked birth defects include the dislocation or instability of the joint between the femur and the kneecap, a shortened tibia or fibula, and foot deformities.

Trevor disease can often mimic posttraumatic osseous fragments, synovial chondromatosis, ostechondroma, or anterior spur of ankle. It is not possible to distinguish DEH from osteochondroma on the basis of histopathology alone. Special molecular tests of the genes EXT1, EXT2 are used for the analysis of genetic expressions. These are within normal ranges in DEH, while they are lower in ostechondroma (owing to a mutation). These tests are expensive and the diagnosis is often made on clinical and radiological findings. Synovial chondromatosis occurs in a much older age group and can be ruled out on this basis.