PATHHO CH 51 - Alterations in Musculoskeletal Function

Trauma, Infection, & Disease

disorders of musculoskeletal system

• bone diseases

• diseases of skeletal muscle

• soft tissue injuries

osteomyelitis

• severe infection of bone & local tissue in which organisms reach bone

• needs urgent care

ways organisms reach bone in osteomyelitis

• bloodstream

• adjacent soft tissue

• direct introduction of organism

bloodstream / hematogenous osteomyelitis

• most common

• infectious agent introduced by blood from infection elsewhere in body

adjacent soft tissue / contiguous focus

• caused by burns, sinus disease, trauma, malignant tumor, necrosis, periodontal infection, infected pressure ulcer

• ex: bedsores (prolonged pressure on skin)

direct introduction of organism

direct infection causes open fracture, penetrating wounds, surgical contamination, or insertion of screws/metal plates

osteomyelitis usually occurs in

• children < 16 y/o (mean age 6 y/o) & elderly

• IV drug users

• indwelling intravascular catheters / central line

• diseases (sickle cell anemia; chronic granulomatous disease)

• long bones (metaphysis/rich in bone marrow 4 child)

diseases that can lead to osteomyelitis

• sickle cell anemia

• chronic granulomatous diseases

  • sarcoidosis

  • chron’s dx

  • TB

pathogens associated with osteomyelitis

• staph. aureus (most common)

• strept. pneumoniae

• H. influenzae (rare b/c vaccination)

clinical manifestations of osteomyelitis in children

• high fever & pain at site of bone involvement

• signs of inflammation (redness; swelling; heat)

• brodie abscess (subacute osteomyelitis)

brodie abscess / subacute osteomyelitis

localized infection enclosed by fibrotic tissue

clinical manifestations of osteomyelitis in adults

fever; malaise; anorexia; night sweats; weight loss

result of healing complications of osteomyelitis if not managed or treated sufficiently

• necrotic bone leads to dead segments in healthy bone

• abscess or chronic infection

• involucrum

involuvrum (result of healing complication of osteomyelitis)

prevents successful effects of antibiotics

treatment of osteomyelitis

• 4-6wks of antibiotic IV therapy

• abscess formation = debridement

• amputation

scoliosis

• lateral curvature of spine ≥ 10˚

• S or C shaped

• 2-4% of US population

• = for men & women

etiology & pathogenesis of scoliosis

• idiopathic (majority)

• consequence of:

  • congenital disorder (hemi-vertebrae)

  • connective tissue disorder (marfan’s sx)

  • neuromuscular disorder (cerebral palsy)

congenital disorder related to scoliosis

hemi-vertebrae

connective disorder related to scoliosis

marfan’s sx

neuromuscular disorder related to scoliosis

cerebral palsy

clinical manifestations of scoliosis

• present AFTER puberty

• asymmetry of shoulders, hips, chest wall

• possible respiratory problems

• GI dysfunctions

nonstructural scoliosis

• RESOLVES when patient bends to the affected side

• NO VERTEBRAL ROTATION / bony deformity of vertebrae

• related to postural problems, inflammation, or compensation due to leg discrepancy

• not progressive

structural scoliosis

• fails to correct itself on forced bending against the curvature

• VERTEBRAL ROTATION

• involves deformity of vertebrae & asymmetric changes in hip, shoulder, & rib cage positions

• progressive

treatment of scoliosis

• bracing

• exercises

• surgical interventions w/ spinal alignment if ≥ 40-50˚ curve

most common metabolic bone disease & cause of broken bone among elderly

osteoporosis

osteoporosis

• bone reabsorption greater than that of bone formation

• greater in female than male

• osteoClastic balance is DISRUPTED but NORMAL osteoBlastic activity

• mineral & protein matrix components are decreased

• cancellous bone lost faster than cortical bone

rate of bone loss is influenced by

age; genetics; estrogen level; family history (major risk factor)

risk factors of osteoporosis

family history (MAJOR); estrogen deficiency; white or asian race; menopause;

• small frame (less bone tissue & faster bone loss)

• disease (cushing dx; scurvy (vit. c def.))

clinical manifestations of osteoporosis

• muscle wasting; back muscle spasms; difficulty bending over

• fractures [fx] (colles fx of wrist; vertebral compression fx)

• kyphosis (thoracic spine: DOWAGER’S HUMP)

• shortened stature

how much height loss is normal

½ inch every 10 years after age 40

diagnosis of osteoporosis

• based on bone mineral density (BMD)

• measured by dual energy x-ray absorptiometry (DEXA)

• T score: ≤ -2.5

T score that indicates osteopenia ranges between

-1.0 & -2.5

treatment for osteoporosis

• calcium & vit. D supplements

• exercise

• bisphosphonates = antiresorptive agent (not for long term use/5 years)

• recombinant human parathyroid hormone (2 years ONLY)

exercise best for increasing bone density

weight bearing exercise

rickets/osteomalacia (same disorder just called different based on age)

both involve vit. D deficiency that leasts to soft osteopenic bone

• in children = rickets

• in adults = osteomalacia

clinical manifestations of rickets/osteomalacia

• kyphosis

• genu valgum (knock knee)

• genu varum (bowleg)

• pain in adults

rickets

deficits in mineralization of newly formed bone matrix in GROWING skeleton (children)

osteomalacia

deficits in mineralization of newly formed bone matrix in MATURE skeleton (adults)

etiology of rickets/osteomalacia

inadequate concentration of:

• vit. D

• calcium or phosphorus

• poor vit. D metabolism

• renal disease

treatment for rickets/osteomalacia

• vit. D

• calcium

• phosphorus supplementation

most common primary tumor of bone

multiple myeloma or sarcoma

multiple myeloma

slow growing bone marrow malignancy

etiology & pathogenesis of multiple myeloma

• neoplastic proliferation of a single clone of plasma cells

• usually in elderly

• affects kidneys; immune system; circulatory system

clinical manifestations of multiple myeloma

• BONE PAIN in predominant symptom

• pathologic fractures & HYPERCALCEMIA

• kidney dysfunction

• neurologic symptoms

• UNEXPLAINED ANEMIA

• fatigue; weakness

diagnosis of multiple myeloma

• homogenous immunoglobulin present in urine & serum (bence hones proteins)

• BONE MARROW ASPIRATION & biopsy

• imaging tests

• bone destruction = lytic bone lesions

treatment of multiple myeloma

• aggressive combination chemotherapy

• local radiation

• survival > 2-3 years (< 10%)

muscular dystrophy

• group of GENETICALLY determined myopathies characterized by progressive muscle weakness & degeneration

• muscle tissue is replaced by fat & fibrous connective tissue

muscular dystrophy is classified by the pattern of

• inheritance

• age of onset

• distribution of muscular weakness

duchenne muscular dystrophy

• most common & most severe form

• inherited as X-linked trait (AFFECTS ONLY MEN)

• muscle cells deficient in the protein dystrophin

• muscle necrosis & degeneration

• rod-shaped cytoplasmic protein

clinical manifestations of duchenne muscular dystropphy

• disease begins at brith & is usually apparent by age 3

• calf muscles enlarged

• distal muscle involvement

• dies by 20

calf muscles enlarged in duchenne muscular dystrophy due to

• infiltration of fat cells

• degeneration of muscle fibers

distal muscle involvement in duchenne muscular dystrophy leads to

• frequent falling by age of 5 or 6

• by age 12-14 yrs most children are confined to a wheelchair

treatment of duchenne muscular dystrophy

• appropriate education of patient & family

• corticosteroid therapy & preservation of function

myasthenia gravis

• chronic autoimmune disease

• affects neuromuscular function of voluntary muscles

• acetylcholine receptor antibodies destroy/block receptors = profound muscle weakness & fatigability

myasthenia gravis risk factors

• women > men

• peak onset 20-30 y/o

rapid diagnostic of myasthenia gravis

ice bag test or edrophonium test

clinical manifestations of myasthenia gravis

• ptosis (drooping or falling of upper eyelid)

• painless muscle weakness

  • improves by rest & exacerbated by repetitive use

treatment of myasthenia gravis

• antiacetycholinesterase / acetylcholinesterase inhibitors

• coricosteroids

• IV immune globin

• plasmapheresis

• immunosuppressive agents

• thymectomy if not responsive to meds

[faulty treatment of myasthenia gravis] myasthenia crisis results from

INSUFFICIENT medication; emotional stress; trauma; infection; surgery; sudden increase in BP & pulse

[faulty treatment of myasthenia gravis] cholinergic crisis / SLUDGE syndrome results from

excessive medication; fasciculations (especially around mouth)

SLUDGE syndrome

• salivation

• lacrimation

• urination

• defecation/diarrhea

• gastrointestinal distress

• emesis