Chapter 38 Degenerative Disorders of the Musculoskeletal System Patho

Osteoarthritis (OA)

* Degeneration of joints caused by aging
* Affects individuals older than age 40 years
* Associated with trauma to joints over course of life
* Slowly progressive, degenerative, and inflammatory condition
* Changes in cartilage lead to inflammation and changes in
* joint surfaces & loss of joint space
* Osteophytes (hallmark of OA) - impinge on nerves & obstruct blood supply
* synovial membrane often becomes inflamed

risk factors of osteoarthritis

aging, obesity, participation in sports, trauma or overuse of a joint, heavy occupational work, misalignment of the pelvis, hip, knee, ankle, or foot

clinical manifestations of osteoarthritis

* Deep, aching joint pain
* Pain relieved with rest
* Joint pain during cold weather
* Stiffness when arising in the morning •
* Crepitus of the joint during motion
* Joint swelling
* Altered gait
* Limited range of motion
* Burning sensations or muscle spasms

Physical Examination of osteoarthritis

* Joint deformity
* Joint tenderness
* Decreased range of motion
* Fingers are often involved in OA Swellings
* Heberden’s nodes
* Distal interphalangeal joint ( DIP)
* Bouchard’s nodes
* Proximal interphalangeal joint (PIP)

Articular Cartilage Deterioration

* Cartilage loss & breakdown occurs with aging, obesity, and with continued excessive force / repetitive injuries or use
* Subchondral bone deterioration
* Osteophytes
* Form at margin of cartilage loss
* Hallmark of OA

Osteoporosis

* Most common degenerative disease of bone
* Occurs with aging
* Osteoclast activity greater than osteoblast activity


* “Porous bone”
* Low bone density
* Structural deterioration of bone
* Bone fragility & increased risk of bone fracture (hips, vertebrae & wrists more common)
* Osteopenia• Thinning of trabecular matrix (occurs before osteoporosis)
* cause: Reduction in bone density due to imbalance in osteoclasts & osteoblasts

Risk Factors of Osteoporosis

* Female gender
* Lack of estrogen in female
* Lack of testosterone in male
* Thin and small-framed women
* Lack of recommended daily intake of calcium and vitamin D
* Lack of weight-bearing exercise


* Excess alcohol consumption
* Excess caffeine consumption
* Smoking
* Excess carbonated soft drink consumption

Osteoporosis modifiable and no modifiable factors

Primary- modifiable

* Prolonged negative calcium balance 


* Poor dietary habits, lack of weight-bearing exercise, lack of daily exposure to sunlight

Secondary- non-modifiable

* Disorders that affect bone tissue
* Hormonal disorders, hyperparathyroidism, corticosteroids

clinical manifestations of osteoporosis

* "Silent disease"
* Vertebral compression fractures
* Reduced vertebral mass
* Back pain that radiates to trunk - Increasing deformities
* Kyphosis
* Loss of height

Osteomalacia

Bone softening in adults usually due to prolonged deficiency of vitamin D.

Vitamin D deficiency is not necessarily caused by malnutrition

Common causes:

Lack of sufficient exposure to sunlight

Cancer

Renal disorders

Gastrointestinal malabsorption

signs and symptoms of osteomalacia

Lumbar back pain, difficulty walking upstairs, proximal muscle weakness, difficulty rising from squatting position, diffuse bone pain

Rickets

Softening & weakening of bones in children usually due to extreme and prolonged vitamin D deficiency.

* Children (infants 4 to 12 months of age)
* Lack of vitamin D & calcium
* Food supplementation with vitamin D has reduced
* development of rickets
* Reduced vitamin D decreases calcium absorption
* If serum calcium levels fall, PTH secreted, stimulating bone breakdown

risk factors of rickets

Diets low in calcium or vitamin D, dark skin, cultural full body clothing, impoverished areas, breastfed infants of mothers with Vitamin D & calcium deficiencies, excessive sunscreen use in children, children who play indoors all the time, Lactose intolerance, malabsorption, malnutrition

physical assessment of rickets

* Malformation of bones develops
* Stunted growth & short stature, low weight
* Bone pain & muscle cramps: arms, legs, pelvis, spine
* Protrusion of sternum
* Varus deformity (bowing) of the legs
* Delayed gross motor skills
* Wrist spasms, tetany, seizures
* teeth deformities and delays