week 8 - skeletal part 2

What is osteopenia?

• generalized breakdown of bones

• bone loss that is greater than normal but not severe enough to be classified as osteoporosis.

• results from an imbalance between bone formation and bone breakdown

• characterized by decreased mineralization of bone

What is the normal purpose of the balance between bone formation and bone breakdown?

The balance between bone formation and bone breakdown helps replace damaged bone and maintain the amount and density of bone.

How does osteopenia contribute to disease?

contribute to the pathology of all metabolic bone diseases and predisposes individuals to fractures, particularly of the hip and vertebrae.

how to see osteopenia

special x-ray called DEXA scan

• measures how much x-ray is absorbed by the bone

blood test for osteopneia

• serum for

  • elevated alkaline phosphatase = abnormal bone turnover (increased bone turnover)

  • abnormal Ca+/P- levels also

predisposition of osteopenia

• fractures (#) of hip and vertebra

Define osteoporosis.

• chronic, progressive metabolic bone disease

  • low bone mass

  • structural deterioration of bone tissue

  • lead to increased bone fragility, increase risk of # (fractures - hip/wrist/spine)

• characterized by porous bone and decreased bone mass

• result = increased fracture risk.

Why is osteoporosis described as "porous bone"?

causes loss of bone density and deterioration of bone structure, creating porous and fragile bones that are more susceptible to fractures.

why is osteoporosis more common in women?

• low Ca+ intake

• less bone mass (smaller frame)

• bone reabsorption at an earlier age in women accelerated in menopause

• breastfeeding = use skeletal reserve endless Ca+ intake adequate

• longevity (women live longer than men)

What is trabecular bone tissue? - osteoporosis

spongy and porous bone material composed of hard and soft tissue components.

• long bones + vertebrae (shock absorbers)

• RBCs

• quick bone remodelling

• highly sensitive to hormonal changes (women and loss of estrogen in menopause)

  • see perforation in women (loss of connectivity and complete trabeculae)

• men = thinning

  • hormonal decline more gradual

Where is trabecular bone located?

epiphyses and metaphyses of long bones and within vertebral bodies.

osteoporosis screening

• predispositions

  • rheumatoid arthritis

  • steroid use (3+mths past year)

  • age

• DEXA scan

What screening test is used to diagnose osteoporosis?

Dual-energy X-ray absorptiometry (DEXA scan).

What does a DEXA scan measure?

A DEXA scan measures bone density using a T-score.

Why are DEXA scans repeated over time?

evaluate changes in bone density over time and assess the effectiveness of treatments such as osteoporosis therapy.

What happens to bone absorption in osteoporosis?

Bone absorption (resorption) increases, resulting in progressive loss of bone mass.

• risk factors

• this leads to complications of SPINE and HIP

risk factors for osteoporosis

• age

• post-menopause women

• physical inactivity (need regular weight bearing activity)

• inadequate Ca+ and Vit D

• CKD/endo disorders (hyperparathyroid)

What spinal complications can occur with osteoporosis?

• vertebral compression fractures

  • bending, lifting, minor fall, minimal trauma

  • no pain, fracture unnoticed = experience repeated vertebral fractures = loss of height and kyphosis

• Vertebral fractures

• kyphosis

• scoliosis - further worsens if already have

What hip complication commonly occurs with osteoporosis?

Hip fractures.

• pain

• reduced mobility

• loss of independence

• prolonged hospitalization

• increase risk of mortality (older adults/comorbidities)

What is osteomalacia?

softening of bones due to inadequate mineralization of bone tissue.

• osteomalacia = adults

• rickets = children

• inadeuate Ca+/P- into bone matrix = soft/decreae bone growth

What is osteoid in osteomalacia?

Osteoid refers to soft, inadequately mineralized bone.

What is the major cause of osteomalacia?

Conditions that result in vitamin D deficiency.

• bone deformity as well

• inadequate diet

• malabsorption issues

• disorders affected Vit D metabolism (poor intestinal/renal tubular disease)

osteomalacia patho

• decrease Vit D = no mineralization of bone + decrease intestinal uptake of Ca+

• decrease serum Ca+ = increase PTH

• increase PTH secretion = …

  • increase osteoclast = increase serum Ca+ (from bone to blood)

  • increased Ca+ reabsorption by kidney

  • decrease PO4 = decrease mineralization

What is rickets?

disease of childhood characterized by weak and soft bones.

What causes rickets?

• Extreme and prolonged vitamin D deficiency

• genetic abnormalities

  • X-linked hypophosphatemic rickets

  • genetic causes Vit D deficiency

What complications can result from rickets?

• Pain

• poor growth

• skeletal deformities.

What is Paget's disease of bone?

increased bone remodeling with excessive bone resorption and formation.

• single or several bones

• INITIALLY = NO S/S

• rare = develop into a lesion (osteosarcoma)

What happens to bones in Paget's disease?

Bones enlarge, more porous and become softer, and structurally abnormal.

• disorganized manner

• bone deformity + patho fractures

Which bones are commonly affected by Paget's disease?

• Skull

• vertebrae

• sacrum

• sternum

• pelvis

• femur.

What medication is commonly used to treat Paget's disease?

Bisphosphonates.

What is the "cotton wool patch" seen in Paget's disease?

A radiographic finding representing thickened, disorganized trabeculae.

How can Paget's disease affect the brain?

Brain compression can cause altered cognitive function and dementia.

How can Paget's disease affect cranial nerves?

Compression of cranial nerves can cause sensory and motor changes.

What is osteomyelitis?

bacterial infection of bone.

What organism most commonly causes osteomyelitis?

Staphylococcus aureus.

What is endogenous osteomyelitis?

develops when infection spreads to bone through the bloodstream.

• skin or dental infection to the bone

What is exogenous osteomyelitis?

direct contamination of bone from trauma, surgery, or adjacent infection.

Describe the pathophysiology of osteomyelitis.

• Infection causes inflammation

• blood vessel thrombosis

• exudate accumulation within canaliculi (bone canals increase amount of pressure = disrupts blood supply = necrosis + sequestrum (hallmark of chronic infection)

• Haversian canals

• Volkmann canals.

How does exudate damage bone in osteomyelitis?

causes periosteal separation, disrupts blood supply, and leads to necrosis of underlying bone.

What is a sequestrum? - osteomyelitis

devascularized fragment of dead bone formed during osteomyelitis.

osteomyelitis complciations

• weakens bone

• spreads to joints

• delayed wound healing

• delayed healing of fractures

  • nonunion bone

• bone destruction/infection

  • septicemia

  • chronic osteomyelitis

How does osteomyelitis affect bone strength?

It weakens bone and increases fracture risk.

• inflammation and necrosis is the cause

What joint complication can result from osteomyelitis?

Spread of infection to joints.

• lead to septic arthritis

How does osteomyelitis affect wound healing?

impaired blood flow of infected bone…

• delayed wound healing

• delayed fracture healing = nonunion

  • Failure of a fractured bone to heal properly

What severe systemic complication can occur with osteomyelitis?

Septicemia.

What chronic complication can develop after osteomyelitis?

Chronic osteomyelitis.

What is the primary treatment for osteomyelitis?

Intravenous antibiotics.

• prolonged IV abx

• start abx in hospital

• get peripheral central access device or PIC line to continue abx IV at home for wsk

• long b/c need to fully eradicate bacteria in poorly vascularized bone tissue

What is osteonecrosis?

bone death caused by ischemia due to inadequate blood supply.

• avascular necrosis

• needs constant Oz/nutrients from blood

• no blood = bone cells die = weakne + collapse of bone

What are causes of osteonecrosis?

• Bone fractures

• thrombosis

• embolism

• vessel injury

• increased intraosseous pressure causing compartment syndrome

  • pressure builds in bone = vessels + nerve + tissues compromise, accelerate ischemia

• steroid therapy

  • alters lipid metabolism = fat accumulation in bone marrow blood vessels

• ALL = decrease BF to bone

What are bone tumors?

Abnormal growths of tissue within bone that may be benign or malignant.

bone tumours

• precursors from mesoderm

• type of cells = determine type of tumour

• fibroblast

  • osteoblast = bone-forming cells

    • osteogenic tumours x 3

  • chondroblast = cartilage precursor

  • fibroblast = collagen-producing cell

    • fibro

• reticulum

  • various blood cells precursors in bone marrow

    • myelogenous tumor

      • giant cell tumour

      • ewing sarcoma - malignant tumour in children/adolescent

benign bone tumours

• condroma

• osteochondroma/exostosis

• giant cell tumours/osteoclastoma

What is a chondroma? - benign bone tumours

A benign bone tumor composed of cartilage.

• small bones of HANDS + FEET

• location = class

  • endo = medullary of bone

  • surface

Where are chondromas most commonly found?

Small bones of the hands and feet.

What is an osteochondroma (exostosis)?

The most common primary benign bone tumor caused by overgrowth of cartilage near a growth plate (ends of bone)

• popcorn appearance (cartilage calcifies irregular way)

Where are osteochondromas commonly found?

Long bones of the leg, pelvis, and scapula.

What are the clinical manifestations of osteochondroma?

A painless, hard, immobile mass.

What is a giant cell tumor (osteoclastoma)?

A bone tumour composed of mononuclear cells and osteoclast-type giant cells.

• behaves like malignant tumour but is usually benign

• grey zone tumours (benign but can progress in aggressive clinical behaviour)

Where are giant cell tumors commonly found?

Near joints at the ends of bones, especially the distal femur, proximal tibia, and distal radius.

What percentage of giant cell tumors are benign?

Approximately 90%.

What symptoms occur with giant cell tumors?

Localized swelling, pain, and altered joint function.

malignant bone tumours

• osteosarcoma

• chondrosarcoma

• Ewing sarcoma

What are common signs and symptoms of malignant bone tumors?

Localized pain and swelling.

What is osteosarcoma? - malignant bone tumour

An aggressive malignant bone tumor arising from bone-forming osteoblasts.

What is the most common primary malignant bone tumor?

Osteosarcoma.

• terry fox

• children and adolescents

  • period of rapid growth (puberty)

Where is osteosarcoma commonly found? - malignant bone tumour

Metaphyses of long bones

• distal femur

• proximal tibia

• pelvis

presentation of osteosarcoma - malignant bone tumour

• localized pain + swelling

• sometime palpable mass

• 1st sign = patho fracture since growing tumour weakened bone

danger of osteosarcoma - malignant bone tumour

• highly aggressive

• mestatize to the lungs

• treatment = pre- surgery chemo (shrink tumour) followed by surgical recession of tumour

What is chondrosarcoma? - malignant bone tumour

A malignant tumor originating from cartilage.

• most common in MIDDLE age + OLDER adult

• pelvis, ribs, shoulder, prox femur

What is Ewing sarcoma? - malignant bone tumour

A malignant tumour that develops in the medullary cavity of long bones.

• PEAD cancer (adolescents/YA) - rapid growth period

Where is Ewing sarcoma commonly found? - malignant bone tumour

Femur, humerus, pelvis, and chest wall.

• long bones

Ewing sarcoma presentation - malignant bone tumour

• initially resembles infection + local pain/swelling

• warmth over the affected area

• occupational visible mass

• SYSTEMIC

What distinguishes Ewing sarcoma from many other bone tumors? - malignant bone tumour

It often produces systemic symptoms in advanced disease.

• fever

• fatigue

• weight loss

• blood = leukocytosis anemia (advanced disease progression)

variations in growth/development of bones

• as children grow, bones remodel

What are angular and torsional deformities?

Variations in growth and development that affect alignment and rotational positioning of bones.

What is in-toeing?

Inward turning of the feet during walking.

What is out-toeing?

Outward turning of the feet during walking.

What is femoral torsion and tibial torsion?

Abnormal twisting of the femur that may be internal or external.

Abnormal twisting of the tibia that may be internal or external.

• causes in and out toeing

sitting and torsion

• preferred sitting position

  • w sitting kneeling = frequent = enforce femoral torsion + intoeing

  • cross-legged position = enhance external torsion (outioesing gait)

• encourage balance of positions (muscle develop)

outlook on femoral torsion and tibial torsion?

• resolve naturally as kid more active + grows

angular changes of legs

• can be normal infant/young toddler

• preschool age - can be normal, resolve no treatment

  • bowlegs (varum)

  • knock-knees (valgum)

• need to know when normal and not to refer to a specialist

  • persistent

  • severe

  • asymmetrical

  • progressive deformity

What is genu varum?

Bowlegs, where the knees remain apart when standing with feet together.

What is genu valgum?

Knock-knees, where the knees touch while the ankles remain apart.

congenital disorders

• osteogenesis imperfecta

• developmental dysplasia of the hip

• clug footing

What is osteogenesis imperfecta?

ongenital disorder also known as brittle bone disease that results from a mutation in the collagen gene.

How does osteogenesis imperfecta affect bones?

The collagen gene mutation causes fragile bones that fracture easily and can lead to skeletal deformities.

What are the major consequences of osteogenesis imperfecta? - congenital disorders

Bone deformities and recurrent fractures due to bone fragility.

• children presents with multiple fractures after minimal trauma

• family hx of OI (osteogenesis imperfecta)

What is developmental dysplasia of the hip (DDH)?

A congenital disorder in which the hip joint develops abnormally, resulting in instability or dislocation of the hip.

What physical assessment finding may indicate developmental dysplasia of the hip?

Asymmetrical thigh folds or gluteal folds.

What are the Barlow and Ortolani tests used for?

Screening newborns and infants for developmental dysplasia of the hip.

• also ultrasound

What does a positive Barlow test suggest?

Hip instability where the femoral head can be dislocated from the acetabulum.

What does a positive Ortolani test suggest?

A dislocated hip that can be reduced back into the acetabulum.

What is the primary treatment for developmental dysplasia of the hip?

Pavlik harness.

• 1st line treatment

• wears harness 20+ hrs per day

• hold hips in flex/abduction position = stable femur head sitting in acetabulum

• let caregiver know routine follow-up + advise not to change straps

• monitor for complications = femoral nerve pulse

  • decrease leg movement

  • reduce profusion to toes

How does a Pavlik harness treat developmental dysplasia of the hip?

It maintains the hips in flexion and abduction to promote proper alignment and development of the hip joint.

What is congenital clubfoot?

A congenital deformity in which one or both feet are abnormally positioned at birth.

• one or both feed

• common

• dx before born sometimes or during NB assessment

What are common treatments for congenital clubfoot?

Serial casting and bracing.

• stretching cast → bracing

• akele tendon release surgery before bracing stage

What is scoliosis?

abnormal curvature of the spine in the coronal plane that is typically S-shaped or C-shaped and occurs in three dimensions.

• rotation of vertebrae

• 3Dm

• symmetry of trunk and shoulder

How is the spinal curve typically described in scoliosis?

An S-shaped or C-shaped curve.

What are possible causes of scoliosis?

• idiopathic

  • periods of rapid growth

• hereditary disorders

• dystonia.

  • affect muscle control

• from degenerative in older adults - alt spine alignment + stability

  • Degeneration of spinal discs

  • arthritis

  • osteoporosis

visual findings of scoliosis

• elevated shoulder

• rib hump with opposite side lumbar hump

• prominent hip