CH 12--DISEASES OF BONES--Bone 3/Infection and Fractures

Question 1

BONE INFECTIONS—Osteomyelitis—1

A—Etiology:
Pyogenic organisms, mainly— staphyloccocus aureus

B—Route of INFECTION:
- _____________ spread (most common)
- Direct penetration (less frequent) e.g. wounds,
fractures

Answer 1

Hematogenous

Question 2

BONE INFECTIONS—Osteomyelitis—2

1. Initial suppurative lesion at metaphysis (most
   vascular part)
2. Spread of infection into:
   - epiphysis
   - medullary cavity
3. Ischemic bone necrosis:
   - increased pressure
   - stretching & compression of periosteal vessels
   - isolating more bone from its blood supply
4. Separation of necrotic bone into ___________
5. Subperiosteal new bone formation around zone of
   inflammation (____________)

Answer 2

sequestrum
*****A sequestrum (plural: sequestra) is a piece of dead bone that has become separated during the process of necrosis from normal or sound bone.

involucrum
**An involucrum is a complication of osteomyelitis and represents a thick sheath of periosteal new bone surrounding a sequestrum.

so….The drainage tract in the subperiosteal shell of viable NEW bone (involucrum) reveals the inner native NECROTIC
cortex (sequestrum)

Question 3

BONE INFECTIONS—Osteomyelitis—3

Clinical:

1. Malaise, fever, chills and ____________
2. Bone pain (throbbing pain) usually intense

Diagnosis:
1. X-ray: lytic zone of bone destruction surrounded by a 
zone of sclerosis
2. Blood culture
3. Biopsy and bone culture
4. Bone scan
5. MRI

Answer 3

leukocytosis

Question 4

BONE INFECTIONS—Osteomyelitis—4

Treatment:

1. ________________ (vigorous & prolonged)
2. Surgical wound cleaning
3. ___________Oxygen therapy

Answer 4

Antibiotics

Hyperbaric

Question 5

BONE INFECTIONS—Osteomyelitis—5

Complications:

1. chronic osteomyelitis (5-25% of cases)
2. pathological fracture
3. direct spread of infection = ___________
4. blood spread (_____________)
5. secondary amyloidosis
   * ***Amyloidosis is a group of diseases in which one or more organ systems in the body accumulate deposits of abnormal proteins.

Answer 5

arthritis

septicemia

***Septicemia is also known as bacteremia or blood poisoning. Septicemia occurs when a bacterial infection enters the bloodstream. Untreated septicemia can quickly progress to sepsis, which is a serious complication of an infection characterized by inflammation throughout the body. This inflammation can cause blood clots and block oxygen from reaching vital organs, resulting in organ failure and death in some cases.

Question 6

BONE FRACTURES X 7 SEE SLIDE 14

Types of fractures:
1— ________ (closed): intact overlying skin
2— Compound (opened): _________ skin
3— Complete: extends through entire bone thickness
4— Incomplete: does NOT extend from one side to another (______________ fracture)
5— Comminuted: bone breaks into 3 or more parts
6— Traumatic: due to mechanical injury of normal bone
7— Spontaneous (pathological): in structurally abnormal bone (e.g. tumors)

Answer 6

Simple

disrupted

greenstick

Question 7

Healing of fractures:

1. ____________– rupture of blood vessel at site of
   fracture
2. Organization of hematoma = ___________
3. Differentiation of local mesenchymal cells into
   chondroblasts = ___________ callus
4. Removal of internal and external callus by osteoclasts = leaving intermediate = (___________ callus)
5. Remodeling of permanent callus along lines of
   weight bearing

Answer 7

Hematoma:

procallus

fibrocartilagenous

permanent

Question 8

Healing of fractures:

1–Fractures of upper limbs heal in 6 weeks
2–Fractures of lower limbs heal in 3 months
3–A bone that doesn’t heal is called a ____-_____ fracture
that may create a false joint or ________________

Answer 8

non-union

Pseudoarthrosis