CH 38: Degenerative Disorders of the Musculoskeletal System

Cortical bone

dense bone

Trabecular bone

spongy, cancellous (more susceptible to osteoporosis)

Low calcium in blood

parathyroid glands stimulate parathyroid hormone (PTH) stimulates osteoclasts to reabsorb bone → bone releases Ca++ into blood

High calcium in blood

signals thyroid to secrete calcitonin → calcitonin stimulates osteoblasts to make bone

process of bone remodeling

constant cycle to maintain normal calcium in blood

how degeneration of the bone occurs in osteoporosis

Osteoclasts greater than osteoblasts causing degeneration of the bone, and there is not enough osteoblasts for reconstruction

how degeneration of the joints occur in osteoarthritis

osteophytes shown in the presence of OA and inflammation causing decreased lubricin → arthritis formation

osteoarthritis (bones affected)

cervical and lumbosacral spine

hip

knee

1st metatarsal phalangeal joint (fingers)

relationship between hip fracture, osteoporosis, and death in older adults

Increased mortality risk w/ osteoporotic hip fractures

most common test used to diagnose osteoporosis

Dual energy x-ray absorptiometry (DEXA) scan: measures bone marrow density

lifestyle changes recommended for patients with osteoporosis

diet of 1000mg of calcium and 400IU vitamin D, UV light, appropriate weight-bearing exercise

risk factors for osteoarthritis

age (greater than 40yrs)

obesity

hx of team sports/trauma/overuse

heavy occupational work

presenting symptoms and exam findings for patients with osteoarthritis

deep aching pain

pain relieved w/ rest

joint pain during cold weather

stiffness in the morning

crepitus of joints