Unit 3 - Chapter 46 Alterations of musculoskeletal fx in children

Question 1

Beginning skeletal growth and development

Answer 1

1) delivery of bone cell precursors to sites of bone formation
2) aggregating of these cells at primary centers of ossification (7-8th week of embryonic development => middle to late twenties [peak bone mass]) where they mature to secrete osteoid (unmineralized bone tissue)

Question 2

Ossification takes place where?

Answer 2

1) primary center (or diaphysis - long, central portion of bone)
2) secondary center (or epiphysis - end portions of the bone)

Question 3

Growth at 1 year and 2 year old?

Answer 3

1) at 1 y/o, 50% of total growth of spine has occurred
2) most children reach 50% of their adult height by 2 years of age

Question 4

Appendicular skeleton vs axial skeleton growth

Answer 4

The appendicular (extremities) grow faster during childhood than axial skeleton

Question 5

Muscle fiber growth

Answer 5

• reach maximal size at 10 y/o for females
• 14 y/o for males

Question 6

Most common defect of upper extremities for children?

Answer 6

Syndactyly (webbing of the fingers)

Question 7

DDH or developmental dysplasia of hip

Answer 7

• abnormal development of femoral head (end bone that goes into the pocket of hip in following term), acetabulum, or both.
• dibilitating if not diagnosed and can be treated at infancy

Question 8

Clubfoot (equinovarus)

Answer 8

• common deformity when foot is twisted out of its normal shape or position

1) positional (otherwise normal foot is held in an incorrect position in womb)
2) idiopathic (occurs w/ no other medical problems)
3) teratologic (r/t neurological d/o, such as spina bifida)

Question 9

Congenital muscle d/o (myopathies)

Answer 9

• absence of muscles
• hypoplasia (poor development in which an organ or part remains below normal size or in an immature state)
• hyperplasia (excessive cell growth)
• faulty intrinsic development

Question 10

Osteogeneis imperfecta

Answer 10

• brittle bone disease
• genetic d/o of collagen (fiberlike structure used to make connective tissue, even bone) that affects mainly bones and results in fractures of many bones

Question 11

Rickets

Answer 11

• d/t deficiency in vitamin D, calcium, and usually phosphorous characterized by failure of bones to mineralize (ossified) and RESULTS in skeletal deformity
• Rickets is a condition that affects bone development in children. It causes bone pain, poor growth and soft, weak bones that can lead to bone deformities.
• eating calcium and vitamin D

Question 12

Scoliosis

Answer 12

• lateral curvature of spinal column
  d/t
  1) cogenital malformation of spine
  2) neuromuscular disease
  3) trauma
  4) extraspinal contractures
  5) bone infections
  6) metabolic bone disorders
  7) tumors

Question 13

Osteomyelitis

Answer 13

• local or generalized bacterial infection of bone and bone marrow
• d/t nearby infection, bloodstream or trauma
• septic arthritis (bacteria within joint) can be assocaited with osteomyelitis and is a surgical emergency

Question 14

Juvenile idiopathic arthritis

Answer 14

• inflammatory joint disorder
• pain and swelling
• large joints mostly affected
• hereditary and environmental?

Question 15

Avascular diseases of bone

Answer 15

• known as osteocondroses (collectively)
• insufficient blood supply to growing bones

Question 16

Legg-Calve-Perthes disease

Answer 16

• most common osteocondroses (avascular disease of bone)
• epiphyseal (growth plate, end of bone separating two regions; epiphysis and metaphysis) necrosis or degenration of head of femur (upper leg bone) followed by regeneration or recalcification
• if ball no longer round after it heals than can cause pain + stiffness
• several yr process

Question 17

Osgood-Schlatter disease

Answer 17

• inflammation or partial separtion of the tibial tubercle (upper end of lower leg bone; inside one, other side is fibula) d/t chronic irritation d/t usually overuse of quadricep muscles
• seen in mainly muscular, athletic adolescent males

Question 18

Muscular dystrophies

Answer 18

• genetically transmitted diseases (x-linked inheritance)
• progressive atrophy of symmetrical groups of skeletal msucles w/o evidence of involvement or degenration of neural tissue
• great loss of strength in all forms of the disorder w/ increasing disability and deformity

1) Duchenne muscular dystrophy (DMD)
* deleted one or more exon of DMD gene on X chromosome or d/t nonsense mutation (rarer); dystrophin [large membrane stabilizing protein]
* this protein absent here in this condition (milder verson with residual is called Becker muscular dystrophy)
* Lack of dystrophin => fibers tear easily d/t contraction
* elevated CK (free Ca++ enters cells and kill them)
* 3-4 years old; 1st sx – toe walking, difficulty getting up from ground, frequent falls l/t waddling gait; hypertrophy of calves (80%)
* 3-5 shoulder girdle become involved
* 12-15 loss of ambulation l/t respiratory insufficiency, cardiomyopathy (diseased heart), orthropedic issues (scoliosis)

2) spinal muscular atrophy
* common, autosomal recessive d/o
* degeneration of motor neurons in spinal cord l/t progressive muscle atrophy
* tongue fasiculations (tremors in tongue), bell shaped chest as infants and tremor + quadricep atrophy in OA
* SMN1 gene mutation [profound weakness in initial months]
* rarely survive 2nd year and cannot sit and have resp compromise (type 1)
* type 2 SMA can sit but never walk; can survive into adulthood
* type 3 SMA more variable; some children can walk up to 10 meters
* Tx supportive like DMD; drug nusinersen (spinraza) recently approved

3) Facioscapulohumeral muscular dystrophy (FSHD)
* mild form of progressive, autosomal dominant muscular dystrophy
* varies from early childhood to adulthood and affects both genders equally
* weakness and atrophy of facial and shoulder girdle (scapulohumeral)
* eyes cannot close in early childhood
* face expressionless and pouting of lips
* drooping of shoulder and difficulty raising arms
* onset of weakness of lower limbs 20-30 years
* contractures and skeletal deformities less than DMD
* plastic ankle foot orthoses or figure of eight bracing

Question 19

Benign bone tumors

Answer 19

1) nonossifying fibroma - benign (non-cancerous), non-aggressive tumor that consists mainly of fibrous tissue. It usually occurs in the thighbone or shinbone but may also occur in the upper extremities. A non-ossifying fibroma usually produces no symptoms. It usually resolves by itself. It never spreads.

2) osteochondroma - a benign (noncancerous) tumor that develops during childhood or adolescence. It is an abnormal growth that forms on the surface of a bone near the growth plate. Growth plates are areas of developing cartilage tissue near the ends of long bones in children.

3) simple bone cysts - common, benign (noncancerous) bone tumor that primarily occurs in children and adolescents. Unicameral bone cysts (UBC) are cavities within bone that are filled with fluid.

4) anerysmal bone cysts - highly destructive, blood-filled benign (non-cancerous) bone tumor. ABCs can cause pain, swelling and fractures.

5) osteoid osteoma - a benign (non-cancerous), small tumor that usually grows in the long bones of a person’s lower extremities.

6) fibrous dysplasia - abnormal fibrous (scar-like) tissue replaces healthy bone. The fibrous tissue weakens the bone over time, which can lead to fractures (breaks) and misshapen bones. Some people with fibrous dysplasia have no symptoms, or only a few symptoms, usually in one bone (monostotic)

Question 20

Malignant childhood bone tumors

Answer 20

1) osteosarcoma - most common childhood bone tumor, originates in bone-producing mesenchymal cells => distal end of femur (towards foot; bottom) or proximal end of tibia (middle of knee; below femur)
* happen from 10-18
* primary tx: surgery + chemotherapy

2) Ewing sarcoma - originates from cells within bone marrow and located most often in midshaft of long bones, ribs, or flat bones (skull, rib, hip)
* more common in male; diagnosed 5-15
* chemotherapy, radiation, surgery (combination)

pain is usual presenting sx

Question 21

Rhabdomyosarcoma

Answer 21

• most common child soft tissue tumor
• originate from embryonal rhabdomyoblasts that normally differentiate ito mature straited muscle
• superficial tumors exhibit a painless palpable mass, while deep-seated tumors cause functional impairment
• combination of chemo, rad, surgery

Question 22

Nonaccidental trauma

Answer 22

• must be considered with any long bone injury in a preambulatory child
• child abuse
• soft tissue injury, corner fractures (injury to metaphysis or growing plate at each end of long bone), varying healing fractures