Bone
Bone Functions:
Mechanical support
Determines size, proportions
Protect organs (viscera, neurological tissue)
Calcium metabolism
Hematopoiesis (red blood cell production)
Joints
Where two or more bones meet
Joint functions
Provide stability and mobility to the skeleton
Types of joints
Synarthrosis - immovable joint-- head
Amphiarthrosis - slightly movable joint- knee
Diarthrosis - freely movable joint- shoulder
Skeletal Muscle
Skeletal Muscle Functions:
Body movement
Muscle tone to maintain body position
Stabilize joints
Maintain body temperature
Patho concepts
Hypertrophy: high muscle size, from exercise
Hyperplasia: high number of muscle fibers, from injury
Atrophy: from disuse, limited mobility, nutritional deficiency, weak flaccid muslce
Patho Concepts
Strains
Trauma to muscle or tendon
Usually related to being stretched beyond its normal limits
May involve tissue tears or ruptures
Inflammation occurs with injury leading to pain and swelling of tissue
Healing may take several weeks
Sprain-
Stressing or
Patho concepts
Joint Dislocation:
Bone is displaced from its position in the joint
Subluxation: Partial dislocation of the joint
Cause
Trauma
Congenital
Clinical Manifestations
"Popping" noise heard at time of injury
Marked pain, swelling and loss of range of motion of
Fractures
It is a break in the continuity of a bone
Complete Fracture: the bone is broken all the way through
Incomplete Fracture: the bone is damage but still in one piece
Open Fracture: if skin is open
Closed fracture: skin is closed
Comminuted Fracture: a fractu
Osteoporosis
Density or mass of bone is reduced
Results in increased porosity of the skeleton
Bone that remains is normal but there is not enough of it to maintain skeletal integrity and mechanical support
Disease can be
Generalized
Regional
Affects 10-20 million Amer
Causes
Multifactorial
Inadequate dietary Ca intake
Inadequate dietary Mg intake
Lack of exercise
Lack of Vitamin D
Decreases levels of estrogen
Family history
Risk factors
Genetic
Family history
White race
Increased age
Female
Antropometric
Small stature
Fair or pale skinned
Thin build
Dietary
Low dietary Ca
Excess protein, Na
High caffeine
High Phosphorous
Hormonal
Early menopause
Late menarche
Nulliparity
Obesity
Low endo
Patho of osteoporosis
Remodeling cycle is disrupted leading to an imbalance in the coupling process
Normal takes 4 months to complete a remodeling cycle - with osteoporosis it can take 2 years
Bone mass is lost because of the imbalance between bone resorption and formation
Clinical Manifestations
Depends on bones involved
Pain
Bone deformity
Fractures
Lost of height
Kyphosis (forward bending of the spine)
Dowager's hump (abnormal outward curvature of the vertebrae of upper back)
Diagnosis
History and physical
Exclude other bone diseases
X-ray
Blood: Ca, Ph, alkaline phosphatase, parathyroid hormones.
o Alk may be elevated from seeping bone, Ca low and Phosphorous increased
Bone biopsy
Bone scans
Treatment
Goal to slow progress of disease
Weight bearing exercise
Estrogen-progesterone replacement therapy (testosterone in men)
Dietary changes
Ca supplements
Drug therapy
Biophosphonates - decrease bone resorption
Osteomyelitis
Infection of the bone
Caused primarily by bacteria but may also be due to fungi, parasites and viruses
Occurs most frequently between 3-12 years old
Exogenous:
Infection that enters from outside the body
Endogenous (Hematogenous):
Pathogens carried in the
Causes
Staphylococcus aureus
Group B streptococci
Haemophilus influenzae
Salmonella
Mycobacterial
Fungal infections
Primary sources of bacteria
-Cutaneous
-Sinus
-Ear
-Dental
Total joint replacements
Human, animal, insect bites
Blows to the mouth
Open bone fract
Pathophysiology
Organism lodges in bone, multiples and initiates inflammatory response
Pus accumulates, pressure within bone cavity increases and blood supply to the are decreases
Leads to necrosis and death of the area of infected bone producing sequestrum (an area of d
Clinical Manifestations
Vary with
Age of individual
Site of involvement
Initiating event
Infecting organism
Stage of infection
acute < 6 weeks
Chronic > 6 weeks
Fever
Chills
Pain
Reluctance to move limb
Fatigue
Malaise
History of infection
Evidence of injury and inflammation at