McCance Patho Chapter 45 quick study

osteochondroses

Avascular diseases of the bone are collectively referred to as osteochondroses and are caused by an insufficient blood supply to growing bones.

Child bone and muscle growth

By 1 year of age, 50% of the total growth of the spine has occurred, and most children have achieved 50% of their adult height by 2 years of age. The appendicular skeleton (extremities) grows faster during childhood than the axial skeleton. Muscle fibers reach their maximal size in females at 10 years of age and at 14 years of age in males.

Cartilage cells

Cartilage cells multiply and enlarge on the epiphyseal side, and they are destroyed and replaced with bone on the metaphyseal side

Corner metaphyseal fractures

Children who are not yet ambulatory and exhibit a long bone fracture have a greater than 75% chance that the fracture was caused by nonaccidental trauma. Corner metaphyseal fractures, caused by a twisting force, are nearly pathognomonic of abuse. The most common presentation is a transverse tibia fracture.

Developmental dysplasia of the hip (DDH)

Developmental dysplasia of the hip (DDH) is an abnormality in the development of the femoral head, acetabulum, or both. It is a serious and disabling condition in children if not diagnosed and treated early, preferably in infancy. DDH is more common in girls. Other risk factors for DDH are family history, metatarsus adductus, torticollis, oligohydramnios (deficient volume of amniotic fluid), first pregnancy, and breech presentation.

Syndactyly

The most common congenital defect of the upper extremities is syndactyly (webbing of the fingers).

rhabdomyosarcoma

The most common type of childhood soft tissue tumor Rhabdomyosarcoma originates from embryonal rhabdomyoblasts that normally differentiate into mature striated muscle. Clinical manifestations of rhabdomyosarcoma depend on the anatomic location; superficial tumors exhibit a painless palpable mass, whereas deep-seated tumors cause functional impairment. Rhabdomyosarcoma is treated with a combination of surgery, radiation, and chemotherapy.

Congenital muscle disorders (myopathies)

include the absence of muscles, hypoplasia, hyperplasia, and faulty intrinsic development.

Clubfoot (equinovarus)

is a common deformity in which the foot is twisted out of its normal shape or position. Clubfoot can be positional, idiopathic, or teratologic.

Rickets

is a condition caused by deficiencies in vitamin D, calcium, and usually phosphorus characterized by the failure of bones to become mineralized (ossified); it results in skeletal deformity.

Structural scoliosis

is a curvature of the spine associated with vertebral rotation.

perichondrium

is a dense connective tissue layer. Osteoblasts within the perichondrium develop into the periosteal collar around the cartilage model.

Metatarsus adductus

is a forefoot adduction deformity.

Juvenile idiopathic arthritis

is an inflammatory joint disorder characterized by pain and swelling. Large joints are most commonly affected. The large joints are affected, and pain is often less significant than in the adult type. Subluxation and ankylosis of the cervical spine are common if the disease progresses. Serologic tests rarely detect the rheumatoid factor.

Osgood-Schlatter disease

is characterized by inflammation or partial separation of the tibial tubercle caused by chronic irritation, usually as a result of overuse of the quadriceps muscles. The condition is seen primarily in muscular, athletic adolescent males. Osgood-Schlatter disease consists of tendinitis of the anterior patellar tendon, within which the patella (kneecap) is embedded, and osteochondrosis of the tubercle of the tibia is associated.

Cartilage anlage

is from mesenchymal tissue, which defines the shape of the bone

Genu valgum

is knock knee

Legg-Calvé-Perthes disease

is one of the most common osteochondroses. This disorder is characterized by epiphyseal necrosis or degeneration of the head of the femur followed by regeneration or recalcification. Legg-Calvé-Perthes disease is a self-limited disease of the hip and presumably produced by recurrent interruption of the blood supply to the femoral head.

Mesenchyme

is the fetal membrane from which the cranium, facial bones, clavicles, and parts of the jawbone arise.

Genu varum

is the term for bowed legs

Pes planus

is the term for flat foot.

Idiopathic scoliosis

is when the cause is not known. Infantile, juvenile, and adolescent are the classifications for idiopathic scoliosis.

Scoliosis

lateral curvature of the spinal column that can be caused by congenital malformations of the spine, neuromuscular disease, trauma, extraspinal contractures, bone infections, metabolic bone disorders, joint disease, and tumors.

Ewing sarcoma

originates from cells within the bone marrow space and is located most often in the midshaft of long bones, in ribs, or in flat bones. Ewing sarcoma is more common in males and is usually diagnosed between the ages of 5 and 15 years. The primary treatment for Ewing sarcoma is a combination of chemotherapy, radiation, and surgery.

Osteosarcoma,

the most common malignant childhood bone tumor, originates in bone-producing mesenchymal cells and is most often located in the distal end of the femur or proximal end of the tibia. Most childhood osteosarcoma tumors occur between the ages of 10 and 18 years. The primary treatments for osteosarcoma are surgery and chemotherapy.

Childhood benign tumors

-nonossifying fibroma -osteochondroma. Other benign bone tumors include simple bone cysts, aneurysmal bone cysts, osteoid osteoma, and fibrous dysplasia.

Non-accidental trauma

1. Nonaccidental trauma must be considered with any long bone injury in a preambulatory child. 2. Evidence of soft tissue injury, corner fractures, and fractures at different stages of healing are extremely helpful in making a diagnosis of nonaccidental trauma. 3. When nonaccidental trauma is suspected, a child must be evaluated radiographically for other fractures, head trauma, and retinal hemorrhage. 4. Children from all social strata are at risk. 5. The health care provider is legally responsible to report suspected nonaccidental trauma.

vestigial tab

A vestigial tab is an extra digit.

physeal plate

Growth in the length of bone occurs here

Rickets

Insufficient vitamin D, insensitivity to vitamin D, wasting of vitamin D, or inability to absorb vitamin D or calcium in the gut causes rickets.

Becker muscular dystrophy

The Becker form of muscular dystrophy is similar to Duchenne, but this form has a more benign course. Incidences of heart failure rarely occur, resulting in premature death, and the onset is between 5 and 15 years.

Sinding-Larsen-Johansson syndrome

affects the distal patellar pole, whereas Kohler disease is associated with the navicular bone of the foot.

Non-structural scoliosis

Nonstructural scoliosis results from causes that do not involve the spine. Causes include leg-length discrepancies, pain, and posture.

Ossification locations

Ossification takes place in two centers in long bones: (1) the primary center, or the diaphysis (the long, central portion of the bone); (2) the secondary center, or the epiphysis (the end portions of the bone).

Osteogenesis imperfecta

Osteogenesis imperfecta (brittle bone disease) is a genetic disorder of collagen that affects primarily bones and results in fractures of many bones. A genetic disorder of collagen that affects primarily bones and results in fractures of many bones is the only cause of osteogenesis imperfecta (brittle bone disease).

Peak bone mass

Peak bone mass is achieved by the middle to late twenties.

facioscapulohumeral muscular dystrophy.

Scapuloperoneal is a variant of facioscapulohumeral muscular dystrophy but the distal muscles are involved early instead of the facial and shoulder muscle weakness that is the early sign in facioscapulohumeral muscular dystrophy.

Skeletal growth phases

Skeletal growth and development consists of two phases: (1) delivery of bone cell precursors to sites of bone formation (2) the aggregation of these cells at primary centers of ossification, where they mature to secrete osteoid.

malignant childhood bone tumor

The two main types of malignant childhood bone tumors are osteosarcoma and Ewing sarcoma. Pain is the usual presenting symptom for osteosarcoma or Ewing sarcoma.

Types of clubfoot

Three types of equinovarus (clubfoot) exist: - The positional type lends itself to rapid correction with the application of serial casts. -The idiopathic variety is treated with casts, and surgery is used if deformities are refractory. -Teratologic equinovarus almost always requires surgery.