[HNF 129] - Chapter 6

• Musculoskeletal Disorders


  • Severely limit mobility and performance of the activities of daily life
  • Can cause considerable pain and disability
  • Potential to deform the body affecting its functions
• Components of the musculoskeletal system


  • Bones and cartilage of the skeleton
  • Muscles, tendons and ligaments attached to the bones

  
• Functions of the musculoskeletal system


  • Makes movement in the external environment possible
  • Gives shape and stability to the body
  • Protects and maintains the position of soft tissues
  • Bones reservoir of calcium
• Divisions of the skeletal system

  • Axial skeleton
  • Appendicular skeleton

  
• Musculoskeletal disorders are a major cause of disability
• Osteoporosis


  • Most common bone disease in humans
  • Compromised bone strength
  • Increased susceptibility to fracture and painful morbidity - fragility fracture

  
• 1 in 4 women may develop osteoporosis
• Osteoporosis


  • Bone loss/ decrease bone density
  • Deterioration of bone microarchitecture
  • Bone loss in females accelerates after age 40 and after menopause
  • Loss of both organic and bone mineral content

  
• More than 95% of osteoporosis in women and about 80% in men is primary
• Suspect osteoporosis in patients who have fractures caused by unexpectedly little force (fragility fractures) of the spine, distal radius, femoral neck, or greater trochanter

  
• Risk factors for osteoporosis


  • Immobilization or extended sedentary periods
  • Low body mass index
  • Certain ethnicities including whites and Asians
  • Insufficient dietary intake of calcium, phosphorus, magnesium, and vitamin D
  • Tobacco and alcohol
  • Family history of osteoporosis, particularly a parental history of hip fracture
  • Previous fragility fracture

  
• DEXA scan


  Dual-Energy X-ray Absorptiometry used to measure bone density

  
• 1. score


  The number of standard deviations that the patient's bone density differs from the peak bone mass of a healthy, young person of the same sex and ethnicity

  
• Indications for DEXA scan


  • Women ≥ 65 yr
  • Women between menopause and age 65 who have risk factors
  • Men and women of any age who have fragility fractures
  • Evidence on imaging studies of decreased bone density or asymptomatic vertebral compression fractures
  • Patients at risk of secondary osteoporosis

  
• Treatments and prevention for osteoporosis


  • Adequate intake of calcium and vitamin D, using supplements when necessary
  • Weight-bearing exercise
  • Minimizing use of caffeine, alcohol, and tobacco
  • Antiresorptive drugs like bisphosphonates, selective estrogen receptor modulators or anabolic drugs (PTH)
• Populations for osteoporosis prevention


  • Postmenopausal women
  • Older men
  • Patients who have osteopenia
  • Patients taking high-dose and/or long-term systemic glucocorticoids
  • Patients with osteoporosis
  • Patients with secondary causes for bone loss

  
• Paget's disease of bone


  • Chronic disorder of the adult skeleton in which bone turnover is accelerated in localized areas
  • Normal matrix is replaced with softened and enlarged bone
  • Bones most commonly affected are the pelvis, femur, and skull

  
• Paget's disease of bone


  • Pagetic lesions are metabolically active and highly vascular
  • Bone resorption and bone formation are hyperactive, causing coarsely woven, thickened lamellae and trabeculae
  • Abnormal structure weakens the bone, despite bone enlargement and areas of bone sclerosis

  
• Symptoms of Paget's disease


  • Pain, stiffness, fatigue, and bone deformity
  • Bone pain that is aching, deep, and occasionally severe, sometimes worse at night
  • Pain from compression neuropathy or osteoarthritis
  • Skull enlargement bitemporally and frontally (frontal bossing)
  • Dilated scalp veins
  • Nerve deafness in one or both ears or vertigo
  • Headaches
  • Deformities from bowing of the long bones or osteoarthritis
  • Pathologic fractures

  
• Complications of Paget's disease


  • Osteoarthritis
  • Fractures
  • Neural compression
  • Osteosarcoma
  • Hypercalcemia

  
• Diagnosis of Paget's disease


  • Unexplained bone pain or deformity
  • Suggestive findings on x-ray
  • Unexplained elevation of serum alkaline phosphatase
  • Bone scan to establish the extent and location of disease
  • Characteristic x-ray findings

  
• Treatment of Paget's disease


  • Supportive care for symptoms and complications
  • Bisphosphonates if disease is symptomatic or active in bones at risk of complications
  • Analgesics or NSAIDs for pain
  • Orthotics to help correct abnormal gait
  • Orthopedic surgery in some cases
  • Encourage weight bearing, avoid bed rest
• Rickets


  Insufficient mineralization of the organic matrix of bones due to Vitamin D deficiency

  
• Risk factors for rickets


  • Maternal Vitamin D deficiency
  • Prolonged breastfeeding without Vitamin D supplementation
  • Temperate climate
  • Lack of sunlight exposure
  • Calcium deficiency
  • Intake of high-phytate diet
• Treatment of rickets


  • Balanced diet appropriate for age
  • Adequate Vitamin D, Ca and P intake
  • Good posture, body positioning, bracing to prevent deformities
• Osteomalacia


  • Muscular weakness
  • Bone pain
  • Deformation of ribs, pelvis and bones of the legs

  
• Causes of osteomalacia


  • Vitamin D deficiency: sun exposure, low intake or malabsorption
  • Impaired Vitamin D action
  • Calcium deficiency
  • Hypophosphatemia
• Treatment of osteomalacia


  • Vitamin D supplement (20mg)
  • Calcium intake (1-2g)
  • Avoid drugs that accelerate hepatic breakdown of Vit D (phenytoin, phenobarbital, rifampin)
• Arthritis


  • Swelling and tenderness of one or more joints
  • Main symptoms are joint pain and stiffness, which typically worsen with age
• Arthritis can cause permanent joint changes, which may be visible or only seen on X-ray

  
• Types of arthritis that can affect other organs


  • Heart
  • Eyes
  • Lungs
  • Kidneys
  • Skin
• Risk factors for arthritis


  • Modifiable: Overweight, Joint injuries, Infections
  • Non-modifiable: Female sex, Family history
• Osteoarthritis

  • Most common arthritic condition
  • Leading cause of physical disability, increased health care cost and impaired quality of life
  • Joint pain, stiffness and limited movement, joint instability and deformity
  • Joints of fingers, feet, lumbar and cervical vertebra, hips and knees
  • Osteophytes or bone spurs
  • Cracked and eroded cartilage exposes bone
  • Bone cysts form when synovial fluid contacts bone

  
• Osteoarthritis treatment

  • Reduce joint inflammation
  • Reduce pain
  • Maintain mobility
  • Minimize disability
  • Non-pharmacologic: Body posture, Proper footwear, Weight reduction, Periodic rest, Heat application
  • Drug therapy: Pain relief, Adjunct to non-pharmacologic treatment
• Medications used to treat osteoarthritis include non-steroidal anti-inflammatory drugs, glucosamine and chondroitin
• Musculoskeletal Disorders


  • Severely limit mobility and performance of the activities of daily life
  • Can cause considerable pain and disability
  • Potential to deform the body affecting its functions
• Components of the musculoskeletal system


  • Bones and cartilage of the skeleton
  • Muscles, tendons and ligaments attached to the bones

  
• Functions of the musculoskeletal system


  • Makes movement in the external environment possible
  • Gives shape and stability to the body
  • Protects and maintains the position of soft tissues
  • Bones reservoir of calcium
• Divisions of the skeletal system


  • Axial skeleton
  • Appendicular skeleton

  
• Musculoskeletal disorders are a major cause of disability