Presentation on theme: "Osteoporosis Stephanie Wetmore, PT PED 596: Adv. Cardiac Rehab Wayne State College."— Presentation transcript:
Osteoporosis Stephanie Wetmore, PT PED 596: Adv. Cardiac Rehab Wayne State College
Osteoporosis A disease characterized by irregularities in the quantity and architectural arrangement of bone tissue that lead to decreased skeletal strength and increased vulnerability to fractures.
Normal Physiology Functions Provides support to body Protects vital organs Assists in movement via leverage Hematopoiesis (blood cell production) Storage area for Ca++
Cell Types Osteoblasts Synthesize bone Remodeling and repair Osteoclasts Responsible for bone resorption Remodeling and repair Osteocytes Primary cells of mature bone Osteoblasts surrounded by matrix during bone formation Maintenance and resorption
Bone Formation & Growth Intermembranous ossification Bone forms directly in the embryonic connective tissue Endochondral ossification A “scale model” of hyaline cartilage is replaced by bone Process of formation for most bones
A Closer Look at Endochondral Ossification and Growth 1. Formation of cartilage skeleton in embryo (6-12 wks gestation) 2. Ossification and growth occur in subsequent months 3. When ossification completed, growth in length occurs at epiphyseal plates
4. Widen by multiplication of cartilage cells and cancellous bone replaces the dying cartilage 5. Growth in width occurs by depositing of compact bone beneath the periosteum (outer surface) and enlargement of the marrow cavity by bone resorption 6. Growth ceases when epiphyseal plate is replaced by bone.
Endochondral Ossification & Growth
Homeostasis Balance between bone formation & resorption Remodeling process Old bone destroyed by osteoclasts New bone constructed by osteoblasts Dependent upon Ca++, P, and vitamins (esp. vit. D) Controlled by hormones
Regulation of Bone Formation & Growth Vitamin D Increases rate of Ca++ absorption from intestine Growth Hormone Needed to stimulate proliferation of cartilage cells at growth plate Vitamin C Important in synthesis of collagen Thyroxin Increases rate of replacement of bone at growth plate and needed for synthesis of GH
Vitamin A Stimulates resorption of bone Estrogens & androgens Promote ossification and maintenance of matrix Parathyroid hormone & Calcitonin Regulate release of Ca++ from bone
Parathyroid hormone & calcitonin When blood Ca++ levels are low, PTH is released. Release of PTH increases rate of bone resorption, which increases the concentration of Ca++ in the blood. When blood Ca++ levels are high, calcitonin is released, which inhibits resorption.
Pathophysiology Osteoporosis can be either hormonally induced or mechanically induced. Mechanical Electrical changes created with weight bearing stimulate activity of osteoblasts, which lead to a build up of Ca++. This does not occur without weight bearing (when someone is on bed rest)
As we age normally Birth to age GH influences deposition of bone, which exceeds resorption rate Age ~50 to age 80 Resorption exceeds deposition due to decreased osteoblast activity and changes in Ca++ metabolism
Rates of Bone Loss with Normal Aging Female >30-35 Lose.5-1% of bone mass/year Postmenopausal Females Lose 2-3% bone mass/year until ~age 70 Women will lose ~45-50% in lifetime Men will lose ~20-30% in lifetime
Normal Bone vs. Osteoporosis
Normal vs. Ostoeporosis
Epidemiology of Primary Involutional Osteoporosis Most common fracture sites Wrist, vertebrae and hip
Risk of Fracture Caucasian Women Vertebral 15.6% Hip 17.5% Wrist 16% Overall 39.7% Caucasian Men Vertebral 5% Hip 6% Wrist 2.5% Overall 13.1%
Fracture Risk (cont.) Wrist & hip fractures are most commonly the result of a combination of bone loss and moderate trauma such as a fall Of all NH admissions, 21% are made following a hip fracture. Vertebral compression fractures can occur simply by coughing, bending forward or hugging.
Risk Factors Advancing age – 1.4 to 1.8 fold increase with each decade Gender – women > men Family or personal hx of fx as an adult Repeated fx’s, severe stooped posture
Risk factors (cont.) Race – Caucasian & Asian > African American or Hispanic Bone Structure and Body Weight – small-boned and thin women (<127#) are at greater risk Menopause/Menstrual history Normal, premature (<45 y/o) or surgical Late onset menarche (>15 y/o) or prolonged amenorrhea – anorexia nervosa, bulimia, excessively low body fat
Risk Factors (cont.) Lifestyle/Nutrition Cigarette smoking – inhibits estrogen Alcoholism Inadequate intake of Ca++ Sedentary lifestyle High caffeine consumption and phosphoric acid intake (cola drinks) Eating disorders
Are you getting enough Calcium?
What is adequate Ca++ intake? Age 1-3 years500 mg/day Age 4-8 years800 mg/day Age 9-18 years1300 mg/day Age years1000 mg/day Age >50 years1200 mg/day
Risk Factors…Medications Glucocorticoids Corticosteroids Excessive thyroid hormones Anticonvulsants Gonadotropin releasing hormones Methotrexate Cyclophosamide Dexamethasone Lithium Cyclosporine A Heparin or Coumadin Cholestyramine No ERT or HRT Low testosterone levels Chemotherapeutics Antacids Isoniazid Immunosuppressants Diuretics
Risk Factors…Chronic Diseases Arthritis Glycocorticoid excess Lung disease (COPD) Organ transplants SCI Hyperthyroidism Hyperparathyroidism Chronic kidney/liver disease RA RSD Malabsorption problems Turner syndrome CVA MS Lupus IDDM Chronic inflammation Chron’s disease CA Burns Asthma Mental illness (depression)
Bone Mineral Density Testing Painless, non-invasive test, which identifies osteoporosis, determines fx risk and monitors response to treatment.
WHO Definitions Normal +/- 1 SD of the young adult mean Low Bone Mass (osteopenia) -1 to –2.5 SD of the young adult mean Osteoporosis >-2.5 SD of the young adult mean Severe (established) osteoporosis >-2.5 SD of the young adult mean & one or more osteoporotic fractures
DEXA Images & Reports
Pharmacology Estrogen Replacement Therapy/Hormone Replacement Therapy Reduces bone loss, increases bone density, reduces risk of fx in postmenopausal women Increase risk of uterine and breast CA, increased risk of thromboembolism
Biphosphonates Alendronate Sodium (Fosamax) Reduces bone loss, increases bone density, reduces risk of spine and hip fractures Side effects include bone, muscle and/or joint pain and headache Risedronate Sodium (Actonel) Slows bone loss, increases bone density and decreases spine and hip fractures Also approved for men & women to prevent and/or treat steroid-induced osteoporosis
SERMs family Selective estrogen receptor modulators Raloxifene (Evista) Prevent bone loss, increase bone mass and decrease risk of vertebrae fracture Side effects: DVT, leg cramps, syncope, arthralgia, tendon disorder and vertigo – chest pain, myalgia and arthritis possibly (
Calcitonin (Miacalcin) Naturally occurring hormone involved in Ca++ regulation and bone metabolism Slows bone loss, increases bone density and relieves pain associated with vertebral fractures
Exercise Testing Modification/ Exercise Limitations/Capacity Weight-bearing exercise and resistance training recommended with precautions
Weight-bearing Exercise Brisk walking is ideal Alternatives: hiking, stair climbing, dancing and racquet sports Contraindicated = stair steppers, bicycling (including stationary), rowing machines, running and high-impact aerobics Stair steppers – combination of unilateral WB and force to depress step Bicycle – increased flexion Rowing machines – deep forward bending (flexion)
Testing Contraindications Sub maximal cycle ergometer Step-tests
Resistance Training Light weights recommended Major muscle groups emphasized Slow progression over several months Fatigue after reps Increases do not exceed 10% per week Proper technique Every third day If joint swelling, limping or pain after, decrease weight by 25-50%.
Resistance Training Contraindications Weight carrying tests Repetitive lifting tests
Flexibility Exercises Flexion exercises contraindicated if vertebral bone density decreased or risk of compression fx Avoid knee to chest Forward bending Touching the toes Partial sit-up Okay if thoracic spine stabilized and do not lift head and chest above T-6 level.
Flexibility Exercises Contraindications Sit-and-reach test Curl-up muscular endurance test
Other exercise HR, BP, ECG, ventilation frequency, tidal volume, oxygen saturation and expired oxygen and carbon dioxide should not be affected by osteoporosis medications. Increasing kyphosis of the thoracic spine will make it more difficult to expand the lungs fully during inspiration
Sample Exercise Prescription Brisk walking minutes 3-4x/wk Begin with 5-minute walks and increase by one minute every other session Flexibility program – body extender, shoulder pinches, chin tucks, elbow backs, arm reaches and back arches daily Sinaki & Mikkelsen study Flexion programs – 86% fx rate Extension programs – 16% fx rate Control group – 67% fx rate Flex/Ext programs – 57% fx rate
Sample Exercise (cont.) Resistance Training Every third day Major muscle groups especially those integral to fall prevention Hip extensors, flexors, adductors, abductors, quadriceps, ankle dorsiflexors & plantar flexors and trunk extensors & stabilizers One set reps Increase no greater than 10% per week for amount of weight
Resources National Osteoporosis Foundation American Academy of Orthopedic Surgeons Lewis, C.B. (1990), Aging: The Healthcare Challenge (2 nd ed.) Sinaki & Mikkelsen (1988) Katz & Sherman (1998)