Osteoporosis

Anna Mae Smith, MPAS, PA-C

Lock Haven University Physician Assistant

Program

Osteoporosis

• Affects 25 million Americans • Causes more than 1 million fractures every

year in this country — usually in the spine, hip or wrist.

• 1/2 of all Caucasian women age 50 and older can expect to have a bone fracture due to osteoporosis

• 1/3 of men have some osteoporosis by age 75

Definition

• A multifactorial skeletal disease characterized by severe bone loss and disruption of skeletal micro-architecture sufficient to predispose to atraumatic fractures of the…

• vertebral column

• upper femur

• distal radius

• proximal humerus

• pubic rami and ribs

Types of Osteoporosis

• Type I - Postmenopausal

• Type II - Involutional - occurs in both sexes over 75 y/o…A mixture of Type I & II is common

• Idiopathic - rare form of primary osteo. Cause unknown, occurs in premenopausal women & men( prior to age 75)

Types of Osteoporosis

• Juvenile - A rare form of variable severity occurring in prepubertal children. Self-limited with cessation of fractures at puberty. Cause unknown.

Types of Osteoporosis

• Secondary - due to extrinsic factors such as• eating disorders

• steroid excess

• RA

• chronic liver/kidney disease

• malabsorption syndromes

• hyperparathyroidism

• hyperthyroidism

• hypogonadal states

• idiopathic hypercalciuria

Genetics

• Familial predisposition

• More common in Caucasians and Orientals than in black and Latino ethnic groups

Incidence

– Elderly– Females > Males

• 30-40% cumulatively in women

• 5-15% in men

– Prevalence of idiopathic and juvenile types unknown

– Secondary osteoporosis cumulatively 5-10%, both sexes

Signs & Symptoms

– Back ache/pain; acute/chronic – Kyphosis/scoliosis which leads to ‘pot’ belly– Atraumatic fractures – No peripheral bone deformities – Sclerae not blue/green/grey – Loss of height

Etiology

– Postmenopausal (Type I): Hypoestrogenemia – Involutional (Type II): Unknown – Idiopathic: Unknown – Juvenile: Unknown – Secondary - see slide 5

Etiology

• Bone loss occurs with aging

• Osteoporosis occurs most frequently in individuals who fail to achieve optimal skeletal mass during development or lose bone rapidly thereafter

Risk Factors

– Dietary -• inadequate calcium

• excessive phosphate/protein

• inadequate vitamin D intake in the elderly

– Physical - immobilization, sedentary lifestyle– Social - alcohol, cigarettes, caffeine – Medical - chronic diseases, malabsorption,

endocrinopathies

Risk Factors

– Iatrogenic - corticosteroids, excess thyroid hormone replacement, chronic heparin, chemotherapy, loop diuretics, anticonvulsants, radiation therapy, depro-provera, methotrexate, GnRH agonists

– Genetic/familial - suboptimal bone mass at maturity, "familial fast bone losers"

Differential Diagnosis

– Multiple myeloma – Other neoplasia – Osteomalacia – Osteogenesis imperfecta tarda (Type I) – Skeletal hyperparathyroidism (primary and

secondary) – Hyperthyroidism – Mastocytosis (rare)

Labs

• CBC - usually normal

• Alk Phosphatase - may be transiently increased after a fracture

• Serum &/or urine protein

• TFT’s & urinary cortisol - normal in primary types

• Serum osteocalcin - if high, indicates high turnover type

• Urine calcium level

Pathological findings

– Reduced skeletal mass, trabecular bone more so than cortical bone. Loss of trabecular connections.

– Osteoclast and osteoblast number variable – No evidence of other metabolic bone diseases

and no increase in unmineralized osteoid – Marrow normal or atrophic

Imaging

• X-ray

• Bone scan

• Bone mineral density (BMD)– most common is a DEXA scan - lumbar spine,

forearm & upper femur

33 y/o

55 y/o

72 y/o

Treatment

• Pain - if a fracture occurs, Physical therapy

• May need to consider joint replacement

• Decrease falls

• Keep moving

Diet

• Weight - reduce if overweight

• Calcium 1500 mg/day

• 600-1000 IU of Vitamin D a day

• Avoid excess phosphate or protein intake… certain beverages with phosphoric acid

Drugs

• HRT• Calcitonin (miacalcin nasal spray) or

injections• Fosamax – Alendronate

– Actonel

• Didronel - inhibit bone resorption• Evista/Raloxifene• Miacalcin nasal spray

Prognosis

– 70% of patients stabilize skeletal manifestations; increase bone mass, increase mobility, and have reduced pain

– 20-30% of upper femoral fractures lead to chronic care and/or premature death

• http://courses.washington.edu/bonephys/opmovies.html