musculoskeletal

• mechanisms of abnormal skeletal muscle contraction (usually ATP, electrolyte, or neurotransmitter)
• mechanisms of abnormal skeletal muscle contraction- common problems

  • weakness due to:
  • disuse (atrophy)
  • systemic wasting disorders
  • fatigue:
  • intracellular acidosis
  • lack of energy production
  • disruption in calcium flux
  • cramps: involuntary muscle spasm due to dehydration or electrolyte depletion
  • direct injury
  • hematoma
  • muscle tears
  • myoglobin released in urine
  • myoglobinuria (rhabdomyolysis: life threaten)
  • increased CPK
  • risk for renal failure
• Pathological muscle disorders

  • muscular dystrophies: genetically transmitted through recessive gene on the X chromosome, produces progressive muscle wasting
• Pathological muscle disorders

  • muscular dystrophies
  • classification
  • rapidly progressing: Duchenne's muscular dystrophy
  • slower progressing: Becker's (5 yo), limb girdle (10 yo)
  • pathophysiology
  • dystrophin: protein thought to affect muscle contraction
  • defect in gene that produces dystrophin
  • muscles cells die -> phagocytosis
  • replaced with fatty tissue
  • respiratory and cardiac failure
  • clinical mani
  • difficulties with early motor development
  • Gower's manuever
  • progression (falls a lot)
• Pathological muscle disorders

  • Inflammatory myopathies
  • polymyositis
  • autoimmune or viral (reacted B and T cells)
  • patchy muscle necrosis
  • may involve the joints
  • progression of weakness
  • dermatomyositis: autoimmune response following infection
  • rash and puffiness
  • sluffing of skin, calcifications
  • fibromyalgia
  • chronic musculoskeletal pain with no evidence of arthritis
  • stiffness, fatigue
  • inappropriate levels of neurotransmitters
  • decreased ATP and CrP levels in area of tenderness
• Pathological muscle disorders

  • Cancer of muscle
  • rhabdomyosarcoma
  • head, neck, abdomen, extremities
• fractures and associated injuries

  • classification of fractures
  • simple (crack)
  • compound (open/through skin)
  • complete (through whole bone)
  • comminuted (three fragments)
  • depressed (skull)
  • compression (spine)
• fractures and associated injuries

  • dislocation
  • separation of bone from the joint, partial dislocation is called subluxation)
• fractures and associated injuries

  • signs and symptoms of fractures
  • swelling (bruising or soft tissue injury)
  • loss of function
  • deformity
  • pain
• fractures and associated injuries

  • fracture healing: formation of new bone (osteoblasts) through sequential process
• fractures and associated injuries

  • fracture healing
  • immobilization problems
  • compromised blood supply
  • infection (osteomyelitis)
  • bloodstream or extension of infection
  • direct surgical or traumatic introduction
  • organism adheres to bone -> inflammatory response
  • exudate forms
  • nonunion (infection, movement)
  • compartment syndrome: muscle and nerve damage due to excessive swelling
  • enclosed area: pressure builds up in compartment
  • fascia permits no outward enlargement
  • compression of blood vessels and nerves leads to necrosis and gangrene if no intervention
• fractures and associated injuries

  • soft tissue traumas
  • tendon/ligament damage
  • avulsion: pulling apart of piece of bone attached to tendon
  • tendon laceration: loss of ability to flex or extend
  • physical tear in ligament
  • healing tendon or ligament
  • visceral damage
  • organs (liver, lung, spleen)
  • sprains: ligament or joint capsule
  • strains: stretching or partial tear in muscle or muscle-tendon unit (abnormal stretch of contracted muscle)
• bone disease

  • osteoporosis
  • reduction in bone matrix and mineralization
  • numerous risk factors
  • osteopenia
  • bone loss exceeds bone formation leading to thinning of the cortex
  • classifications
  • type I
  • type II
  • clinical mani
  • fracture
  • loss of height
  • kyphosis (dowager hump)
  • osteonecrosis
• bone disease

  • osteomalacia: softening of bone (adult form of rickets)
  • etiology
  • calcium, vitamin D, or phosphate deficiency
  • medications, lack of sunlight
  • pathophysiology
  • inadequate mineralization -> weakening of bone
  • clinical mani
  • pain, fractures, bowing of legs
• bone disease

  • Paget Disease (osteitis deformans)
  • etiology: genetic and environmental influences; greater incidence in men
  • pathophysiology
  • excessive bone resorption
  • disorganized bone repair with newly formed bone of poor quality
  • mosaic like pattern
  • adjacent bone marrow replaced by loose connective tissue and blood vessels
  • clinical mani
  • skeletal expansion and distortion
  • headache, dizziness
  • kyphosis
  • bowing of leg bones
  • increased risk for osteogenic sarcomas
• bone disease

  • bone cancer
  • benign
  • fibrous origin: common in growing bones
  • cartilaginous origin: chondromas or osteochondromas
  • malignant: primary or secondary
  • rapid growth
  • symptoms: pain, unexplained swelling, feeling of warmth
  • pathophys: uncontrolled proliferation of cancer cells
  • increased production of abnormal bone, cartilage, or surrounding tissue
  • malignant = destructive to adjacent normal cells
  • weakens bone
  • hypercalcemia possible
  • hormones secreted by tumor increase reabsorption of calcium or increased parathyroid related peptides
  • osteosarcoma: circular ball-like mass in bone tissue
• bone disease

  • disorders of bone growth
  • scoliosis: curvature of the spine
  • osteogenesis imperfecta (brittle bone disease): genetic mutation
  • disorder of synthesis of collagen
  • prone to fractures, osteoporosis, deformed limbs
• alterations in joints

  • osteoarthritis (degenerative joint disease: DJD): progressive breakdown of cartilage
• alterations in joints

  • osteoarthritis
  • pathophys: depletion of matrix in articular cartilage
  • collagen fibers exposed
  • synovial fluid enters the cracks: formation of cysts
  • synovial capsule decreases in size -> exposing bone
  • clinical mani: due to enlargement of joints
  • pain, stiffness
  • difficulty with movement
• alterations in joints

  • rheumatoid arthritis: systemic autoimmune disease
  • IgG/rheumatoid factor (RF) interaction
  • activation of a T cell mediated response to an immunologic trigger
  • inflammation in joints -> thickening and destruction of cartilage
  • synovial membrane thickens -> pannus development -> scar tissue
  • clinical mani:
  • systemic: fever, weakness, weight loss, stiffness
  • joint pain, tenderness (part. in AM)
  • warmth, bogginess
  • loss of mobility
  • rheumatoid nodules in skin, heart, lungs, and spleen
• alterations in joints

  • Ankylosing Spondylitis
  • inflammation of skeletal joints
  • stiffening and fusion of spine and sacroiliac joints
• alterations in joints

  • bursitis
  • inflammation of a bursa
  • excess fluid
  • pressure on sensory nerve endings
  • trauma, infection, rheumatoid arthritis
  • knee, elbow, feet
• alterations in joints

  • Osteochondroses
  • Legg-Calve-Perthes Disease: affects femoral head
  • Osgood-Schlatter disease
• alterations in joints

  • Gout: metabolic disorder
  • increased level of uric acid
  • uric acid crystals may precipitate into joints