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Disorders of the Skeletal System, Metabolic and Rheumatic Disorders

Terms in this set (93)

Bone healing occurs in a manner similar to soft tissue healing, however, it is a more complex process and takes longer.
1. Hematoma formation occurs during the first 1-2 days after fracture. Disruption of blood vessels also leads to death of bone cells at the fracture site. In 2-5 days, the hemorrhage forms a large blood clot. Hematoma formation is thought to be necessary for the initiation of the cellular events essential to bone healing.
2. The next event in fracture healing is formation of granulation tissue or soft tissue callus. During this stage of bone heling, fibroblasts and osteoblasts migrate into the fracture site from the nearby periosteal and endosteal membranes and begin reconstruction of bone. Osteoblast begin depositing bone into the matrix.
3. Ossification represents the depositing of mineral salts into the callus. This stage usually begins during the third to fourth week of fracture healing. During this stage, mature bone gradually replaces the fibrocartilaginous callus, and the excess callus is gradually reabsorbed by the osteoclasts.
4. Remodeling involves resorption of the excess bony callus that develops in the marrow space and encircles the external aspect of the fracture site

¬ Malunion is healing with deformity, angulation or rotation that is visible on x-ray films.
¬ Delayed union is the failure of a fracture to unite with the normal period.
¬ Nonunion is failure to produce union and cessation of the processes of bone repair.
¬ Diet is very important for bone healing
o Rich in protein and V-C to absorb the protein - green veg, oranges, supplements
Hematogenous Osteomyelitis: originates with infectious organisms that reach the bone via the bloodstream.
o Acute hematogenous osteomyelitis occurs predominantly in children.
o In adults, it is seen more commonly in debilitated persons and in those with a history of chronic skin infections, chronic urinary tract infections, and intravenous drug use in those who are immunologically suppressed.
o The pathogenesis of hematogenous osteomyelitis differs in children and adults.
♣ In children, the infection usually affects long bones of the appendicular skeleton. With advancement of the infection, purulent exudate collects in the rigidly enclosed bony tissue.
♣ In adults, the long bone microvasculature no longer favors seeding, and hematogenous infection rarely affects the appendicular skeleton. Instead, vertebrae, sternoclavicular and sacroiliac joints, and symphysis pubis are involved. Infection usually first involves subchondral bone, then spreads to the joint space.

♣ Signs of bacteremia
♣ Fever, chills
♣ Pain on movement
♣ Tenderness
♣ Erythema
♣ Edema
♣ Malaise

- Chronic osteomyelitis: usually occurs in adults. Generally, these infections occur secondary to an open wound, most often to the bone or surrounding tissue. It may be the result of delayed or inadequate treatment of acute hematogenous osteomyelitis caused by direct contamination of bone or exogenous organisms. The hallmark feature of chronic osteomyelitis is the presence of infected dead bone., a sequestrum, that has separated from the living bone. The treatment for bone infections begins with wound cultures to identify microorganisms and its sensitivity to antibiotic therapy. Initial antibiotic therapy is often followed by surgery to remove foreign bodies or sequestra and by long-term antibiotic therapy.
o Usually adults
o Usually secondary to open wound
o Sequestrum - Infected dead bone , separated by sheath
o Difficult to detect when near a joint prosthesis (an artificial body part, such as a leg, a heart, or a breast implant)
Osteonecrosis is an aseptic destruction of a segment of bone that is due to an interruption ion blood flow rather than an infection. It is a relatively common disorder and can occur in the medullary cavity of the metaphysis and the subchondral region of the epiphysis, especially in the proximal femur, and proximal humerus. Destruction of bone frequently is severe enough to require joint replacement surgery.
o Bone destruction d/t interruption in blood flow
♣ Idiopathic - relating to or denoting any disease or condition that arises spontaneously or for which the cause is unknown.
♣ Bone injury - fractures
♣ Thrombosis/embolism - Sycle cell disease - deep sea diving
♣ Vessel injury - radiation therapy
♣ Increased intraosseous pressure
♣ Corticosteriod associated (unclear)

- Chronic pain, unrelated to movement

- Although bone necrosis results from ischemia, the mechanisms producing the ischemia are varied and include mechanical interruption such as occurs with fracture; thrombosis and embolism, vessel injury, and increased intraosseous pressure with vascular compression.
- Other than vessel injury and obstruction, the most common causes of bone necrosis are idiopathic (those of unknown causes), and prior steroid therapy.
- The pathological features of bone necrosis are the same, regardless of cause. The site of the lesion is related to the vessels involved. There is necrosis of cancellous bone and marrow. The cortex usually is not involved because of the collateral blood flow.
- The symptoms associated with osteonecrosis are varied dependent on the site and extent of infarction. Typically, subchondral infarcts cause chronic pain that is initially associated with activity, but gradually becomes more progressive until it is experienced at rest. Subchondrial infarcts often collapse are predispose the patient to severe secondary osteoarthritis.
Matrix is weakened and mineralization is decreased

Associated (risk factors):
- Postmenopausal osteoporosis is when estrogen deficiency manifested by a loss of cancellous bone and predisposition to fractures of the vertebrae and distal radius
- Male hormone declination
-Genetics, Race
-Activity level
-Body size (Smaller > chance than larger)
-Age-related changes because of decreased osteoblast activity (Decreased physical activity levelsPostmenopausal - Estro, gen lack - for bone formation ,Nutrition, Caffeine, smoking)

Female Athlete Triad
- Emphasis of leanness and low body weight: Eating disorders (i.e. dietary restrictions) combined with excess exercise result in weight (fluctuations effects gonadotropic hormones)
Decreased LH, FSH
Decreased estrogen
Amenorrhea - the absence of a menstrual period in a woman of reproductive age

-Fractures d/t
-Loss of trabeculae from cancellous bone
-Thinning of cortex
-Postmenopausal Osteoporosis
-Increased osteoclastic activity results in loss of trabeculae
-Microfractures occur, bone compresses
-Senile/age-related osteoporosis
-Haversian system widens d/t loss of trabeculae
-Silent disorder
-Sudden onset fracture
-Hip, pelvis, humerous, etc
-Wedging/collapse of vertebrae (loss of height and syphosis/dowager)
-No bone pain unless fracture

Secondary osteoporosis (factors) - have a direct defect on bone tissue
- Endocrine Disorders
• Hyper/hypothyroidism (high of low levels of thyroid hormone which regulate the body's metabolic rate as well as heart and digestive function, muscle control, brain development and bone maintenance. Its correct functioning depends on having a good supply of iodine from the diet)
• Hyperparathyroidism (Effects calcium balance)
• Cushing syndrome (when your body is exposed to high levels of the hormone cortisol for a long time. Cortisol, which is produced in the adrenal glands, plays a variety of roles in your body. For example, cortisol helps regulate your blood pressure and keeps your cardiovascular system functioning normally.)
• Diabetes Mellitus (Malabsorption Issues)
• Celiac disease - GI absorption (Malignancies)
• Multiple myeloma (a malignant tumor in the bone marrow)
- Alcoholism (Alcohol is a direct inhibitor of osteoblasts and may also inhibit calcium absorption)
- Medications
• Corticosteroids
• Antacids with aluminum
• Anticonvulsants
• Antiretroviral therapy
- Premature Infants (Issues that will pre-dispose)
- Cystic Fibrosis (Imbalance between bone reabsorption and formation such that bone resorption exceeds bone formation)

Diagnosis and treatment:
- Daul-energy x-ray absorptiometry (DEXA) of the spine and hip
- Prevention and early detection of osteoporosis are essential to the prevention of associated deformities and fractures
- Regular exercise
- Adequate Calcium and V-D intake
- Weight bearing exercises

• Bisphosphonates - inhibitor of bone reabsorption = most effective
• Recombinant parathyroid hormone
• Selective estrogen receptor modulators - raloxifene - specific estrogen receptor PM women
• Calcitonin - inhibits osteoclastic activity
Articular manifestations:
-Polyarticular - arthritis that affects five or more joints within the first six months of having JIA. It is the second most common type of JIA in children and teenagers. There are two types of polyarticular arthritis: The first type has a positive rheumatoid factor (RF) result on a blood test, and the second type has a negative RF result. RF is an antibody that is present in the blood in certain types of JIA.
-Diarthrodial/synovial a form of articulation that permits maximal motion, as the knee joint. Joins bones with a fibrous joint capsule that is continuous with the periosteum of the joined bones, constitutes the outer boundary of a synovial cavity, and surrounds the bones' articulating surfaces
-Joint pain
-Joint swelling
-Limited joint movement
-Wrists, finger joints common (Pain when turning doorknob, opening jars, buttoning shifts, etc. )
-Feet (Pain on ball of feet when rising in morning and Widening of forefoot d/t inflammation)
-Ankles, knees, elbows, shoulders, spine
-Subluxation (a partial dislocation)
-Joint instability
-Swelling and thickening of synovium stretches joint capsule and ligaments ( results in Deformities, Muscle imbalances, Swan neck deformities of hand)

Extra- Articular manifestations:
-Fatigue, weakness, anorexia, weight loss
-Elevated ESR & C-reactive protein (CRP)
-Rheumatoid nodules (Granulomatous lesions with central necrotic core. They are either tender, or not; Moveable, or immovable; Small or large; Numerous other but they are more rare)
-Arthralgias/arthritis common early symptom
Most often hands, wrists, knees
Ligaments, tendons, joint capsules also
-No articular destruction like other arthritis'
-Avascular necrosis (usually in femoral head) a condition that results when bones do not get enough blood
-Contractures, tendon rupture, subluxation

-Butterfly rash on nose/cheeks
-Fingertip lesions
-Hair loss - quite common
-Muscous membrane lesions - usually only happens during exacerbations
-Sunlight sensitivity

-Glomerulonephritis is an Infection in the kidneys also called nephritis, is a disease of the kidneys in which the glomeruli, the tiny filters in the kidneys that help to clean the blood, become inflamed or damaged. This allows protein and red blood cells that normally circulate in the bloodstream to pass into the urine. If glomerulonephritis does not respond to treatment, the glomeruli may slowly be destroyed. The kidneys will then lose their ability to clean your blood and this will lead to kidney failure.
-Interstitial nephritis is a kidney disorder in which the spaces between the kidney tubules become swollen (inflamed)

-Pleural effusion is excess fluid builds around the lung
-Pleuritis is an inflammation of the pleura, or the lining of the lungs

-Pericarditis is an inflammation of the pericardium (the fibrous sac surrounding the heart). A characteristic chest pain is often present
-Heart block is a disease or inherited condition that causes a fault within the heart's natural pacemaker due to some kind of obstruction (or "block") in the electrical conduction system of the heart
- Hypertension
- Ischemic heart disease is reduced blood supply to the heart. It is the most common cause of death

-Photosensitivity: Headache (migraine)
-Hemorrhage is an escape of blood from a ruptured blood vessel, especially when profuse
-Thrombus is a blood clot formed in situ within the vascular system of the body and impeding blood flow
-Seizures are more frequent with renal disease
-Psychotic symptoms such as depression, euphoria, confusion, etc.
Rheumatoid arthritis
-T-cell mediated response to trigger and Inflammatory mediators released. Antibodies form against autoantigens
-Rheumatoid factor (RF) High RF titer is associated with severe and unremitting disease, mainly systemic complications. Synovial inflammation and joint destruction result and also Fluid accumulates.
-Neovascularization (is the formation of functional microvascular networks with red blood cell perfusion) in synovial membrane
-Pannus: vascular granulation
Destructive - extends from the synovium to involve the bare area a region of unprotected bone at the junction between cartilage and subchondral bone
tissue is formed that is destructive to joint
Inflammatory erosion of cartilage/bone

-Joint pain
-Joint swelling
-Limited joint movement
-Wrists, finger joints common
-Ankles, knees, elbows, shoulders, spine
-Joint instability
-Swelling and thickening of synovium stretches joint capsule and ligaments which cause deformities, muscle imbalances and swan neck deformities of hand

Osteoarthritis (OA)
-Degenerative changes to articular cartilage of joints. it is One of the 10th most disabling conditions. It involves the loss of cartilage, thickening of subchondral bone, osteophyte bone outgrowths at joint margins and mild synovial inflammation.
It can happen to any synovial joint in the body

-Insidious - proceeded in a gradual, subtle way but with harmful effects
-Joint pain, stiffness, motion limitations
-Crepitus, grinding
-Instability and deformity can occur - increased inflammation in the joint

Aggressive and highly malignant
Osteosarcoma (osteogenic sarcoma) is the most common primary bone tumour.
Osteosarcoma starts in bone cells.
---It develops most often in the bones of the arms, legs and pelvis.
---About half of these tumours develop in or around the knee.

--It occurs most often between the ages of 10 and 30 years.
---75% <20 years old
Osteosarcoma occasionally develops in people in their 60s and 70s.
It is rare in middle-aged people.
It occurs more often in males than in females.
Osteosarcoma is seen more often in people with a history of Paget's disease of the bone, retinoblastoma and previous radiation therapy.


Chondrosarcoma is the second most common primary bone tumour.
--Chondrosarcoma starts in cartilage cells.
--It develops most often in the bones of the:
arms or
---It occurs most often in people over the age of 20 (one-half of all cases occur in people older than 40 years of age).
It occurs equally in males and females.
In very rare cases, benign tumours, such as enchondromas and osteochondromas, turn into chondrosarcoma.
Most chondrosarcomas are low or intermediate grade.
Some chondrosarcomas have different features under the microscope.
These tumours start out as typical chondrosarcomas, but some tumour cells change to look like those of an osteosarcoma or fibrosarcoma.
They usually occur in older people and are more aggressive than usual chondrosarcomas.

Ewing sarcoma

Ewing sarcoma is the third most common primary bone tumour in adults, but it occurs more often in children and teenagers.

--Most Ewing sarcomas develop in bones, but they can start in other organs or tissues.
--Ewing sarcoma of the bone occurs most often in the
---pelvis, bones of the chest wall (such as the ribs and shoulder blades) and in the long bones of the arms and legs.
--It develops most often in people under the age of 20 years, but can occur in adults over the age of 30.
It occurs more often in males than females.
Ewing sarcoma is an aggressive type of bone sarcoma that responds well to treatment.
All people with Ewing sarcoma will be given chemotherapy.