– Incidence
• Young males and older adults
• Tibia, clavicle, lower humerus (young persons)
• Hands, feet -- workplace accidents
• Upper femur, upper humerus, vertebrae, pelvis (elderly)
– Osteoporosis
– Diff types (complete/incomplete, open/closed)
• Incomplete -- bones of children
– Flexible
– Growing
• Stress w/ repeated stress (ex athletics)
– Fatigue
– Insufficiency (weight bearing bones)

• Healing similar to soft-tissue injuries stages
– No scar tissue
• Periosteum, blood vessels disrupted
• Bleeding  clot form
= n (hematoma)
• Stages
– Hematoma
– Procallus form = n
» Intense inflammatory response
» Fibroblasts, collagen, growth factors, osteoblasts impt
– Callus
» Hardened membr (woven bone)
– Remodeling
» Osteoclasts;  original shape
» Resorption unneeded callus

– Clinical
• Signs/symptoms
– Impaired function
– Unnatural alignment; possible rotation, angulation
– Swelling
– Tenderness
– Severe pain (trauma, muscle spasm)
• Stress fractures -- pain with accelerated remodeling
– Relieved by rest
– Treatment
• Realign to normal position (manipulation, traction)
• Surgery
– Prosthesis, screw, plate, etc., possible
• Splints, casts

– remodeling imbalance favors bone resorption
– Incidence
• Common disorder of bone metabolism
• Heredity evidence in women
– Fracture due to bone weakness
• Common -- vertebrae, distal radius, proximal femur
• Fractures after trauma
• Compression fractures (esp vertebral)
– Non-symptomatic until indicated by fracture

– Pathophysiology
• Age 
– Bone resorption exceeding bone growth
– 
Net bone mass loss
– More rapid in women
» Exaggerated at menopause
» Type I (Postmenopausal)
– Type II C both sexes over age 70
» Neck, hip, humerus, tibia
• May involve postaglandins, interleukins, various growth factors that affect osteoclasts
• Estrogen decr w/ menopause  incr
= d risk
– Estrogen inhibits bone resorption
– Also in young, female athletes
» Training  decr
= d estrogen
» Found decr = d bone mass, incr’d fractures

– Clinical
• Pain
• Bone deformity
• Fractures
• Vertebral collapse  hunchback, decr
= d height
– Treatment C slow rate of Ca, bone loss
• Incr dietary Ca
• Vit D  incr intestinal abs
= n Ca
• Regular, moderate exercise
• Hormone treatment (estrogen, progesterone)
• Reduce risk of falls

– Common secondary tumor site
• Primary often prostate, breast, thyroid, lung, kidney
• Access through blood
• Often axial skeleton (not skull), proximal femur, humerus
• May induce bone breakdown or bone growth

– Primary tumors less common
• Actively growing bone
• Pain early indication
• May  bone weakening
• Pressure  adjacent bone deformed by abnormal remodeling
• Metastasis often to lung
• Most more in males than females
– About 1/3 primary tumors benign
• Ex: osteoma of skull and osteoid osteoma of long bone
• Ex: chondroblastoma
– Arises in cartilage of epiphyses of arm, leg bones
– Rare

– Malignant bone tumors
• Osteogenic sarcoma (=osteosarcoma) most common
– Usually age 10-20 years
– Knee often
– Common metastasis  lung
– Previous metastasis by time of diagnosis  poor prognosis
– Now better chemotherapy (80% 5 yr recovery rate)
– Surgery often
• Chondrosarcoma
– Usually age 30-50 yrs
– Slow-growing
– May break through bone surface
– Interior of pelvis, ribs, prox femur, humerus
– Surgical excision

– Incidence
• Most common joint disease in US
• Incr = s w/ age
– Age 60 -- most affected
– > 75 yrs -- 85% affected
– Pathophysiology
• Articular cartilage becomes thin, irregular, frayed
– Probably enz breakdown of cartilage
• 
Cracks, fissures in articular cartilage
– Fill w/ synovial fluid

– Pathophys (cont’d)
• Penetrates to underlying bone w/ progression
– May  fluid-filled cysts
– Bone forms around cysts
– May  microfractures
• Fibrocartilage plugs form for repair
– Activyt  plugs stripped away, then reformed, then restripped
–  Smooth bone surface
• Fibrocartilage fragments may react at synovial membr surface
–  inflamm response
–  decr
= d movement
C
> repair
• Cells in synovial membr may dev into osteoblasts
–  form
= n bone spurs at joint
–  pain, decr
= d movement

– Degeneration
• Mostly at larger weight-bearing joints (also fingers)
• Related to
– Wear-and-tear OR
– Biochem defect in joint cartilage OR
– Excessive loading (malformed joint, postural defect, obesity) OR
– Genetic
– Clinical
• Joint aches, stiffness
– Incr w/ activity; diminish w/ rest
• Progression w/ age
• Loss of mobility if hip, knee affected
– Therapy limited
• Analgesics for pain
• Reduce obvious stresses
• Surgical removal of bone spurs or artificial joint replacement

C
– Incidence
• About 1% adult pop = n affected
• 3 female: 1 male
• Age of onset usually 20-30 (but also infancy 
90's)
• May be due to
– Infection
– Autoimmune disorder
– Genetic predisposition

– Get immune-mediated destruction of joints
• Environmental stimulus  immune response to Ag
• If predisposed
, Ab
= s transform to
A rheumatoid factors
@
(Rfs)
• Rfs complex in blood, synovial fluid  inflamm response at joint
• Inflamm mediators breakdown joint tissue  joint tissue destroyed

– Get pattern of chronic inflamm = n
• Incr = d number of cells in synovium
• 
Thickening of synovium (maybe after cartilage destroyed by inflamm
= n process)
• Thickened synovium covers adjacent joint surfaces
– Over time may enlarge, fill joint space
– In late stage = ankylosis = fused joint
• Causes swelling; stiffness; pain
• Swelling also due to incr = d exudate in synovial membr
– Joint deformities
• 
Loss of joint motion
• 
Muscular atrophy

– Sytemic effects variable
• Generalized weakness, malaise
• Rheumatoid nodules form
– Focal subcu swelling
– Elbow, heel, dorsal surface of head; also internal
– Made of macrophages, lymphocytes, collagen, cell debris
– Typically painless
• Rheumatoid vasculitis common
– Systemic inflamm = n of blood vessels
– May involve pericardium, pleural effusion
– Therapy C no cure; can’t reverse destruction of structures
• Relieve pain, reduce swelling (antiinflammatories)
• Reduce stress
• Strengthen assoc = d muscles
• Replace severely effected joints

– Pathologic reduction in size of muscle fibers
• Follows prolonged bed rest, trauma, nerve damage
– Muscle strength decr = s from baseline
• About 3% per day
– To prevent
• Frequent isometric muscle contractions
• Passive lengthening exercise
– If no reuse in 1 year, regen = n muscle fibers impaired

– Chronic musculoskel syndrome
– Get diffuse chronic pain, tenderness w/ no inflamm
= n, fatigue
• Tenderness @ 9 common points in body (neck, shoulders, hips, knees)
• Profound fatigue
• May  depression
• Also migraine, irritable bowel disease common
– Incidence
• Mostly women
• Peak age = 30-50 yrs
• Increases w/ age

– Probably several causes
• virus,
• Phys/emotional trauma, emotional trauma,
• medication
– Found metab alterations in muscle
• May  pain, fatigue
– Also found diff blood flow to thalamus
• May C
> chronic stress response
– Treatment
• Antiinflammatories (not very effective)
• CNS active agents somewhat helpful

– Gen’l term for muscle damage
– Seen after traumatic, sports injuries
• Sudden, forced motion
• Muscle becomes stretched beyond normal length
• May include wounds
– Often involves tendon also
– May include hemorrhage, inflamm = n
– Muscle cells usually regenerate in up to 6 weeks
– Treatment
• Ice relieves swelling
• Analgesics
• Alternating heat/cold if more severe form
• Surgery, immobilization if tearing, bleeding

– Needed to support bones, joints
– May be due to major trauma
– Also spontaneous w/ corticosteroid admin, rheumatoid arthritis, lupus

– Common sites
• Tendons of hands, feet
• Knee
• Upper arm - w/ lifting excess wt
• Thigh
• Ankle
• Heel - w/ forced flexion
– Common sites
• Wrist
• Ankle
• Elbow
• Knee

– Avulsion = total sep = n tendon/ligament from bone
• Due to abnormal stress
• Young athletes (sprinters, hurdlers, runners)
– Pathophysiology
• Tearing  inflamm response
• Exudate forms @ torn ends
• Macrophages, fibroblasts
• Repair
– Collagen form = n random, then organized
– Vascular fibrous tissue fuses new, old tissues
– Healing tendon separates from surrounding soft tissue
– Can = t support strong pull for 4-5 weeks

– Pain C sharp, localized
– Soft-tissue swelling
– Joint swelling
– Flexion deformities
– If in extremities, motion affected
– Suture tendon/ligament
– Tendon/ligament grafting