Week 4 Powerpoint Chapter 43

Copyright © 2011 Wolters Kluwer Health | Lippincott Williams & Wilkins

Chapter 43

Disorders of the Skeletal System:

Trauma, and Infections

(Through page 1112)


Common Joint Injuries

• Injuries to muscles: strains

• Injuries to ligaments: sprains, ruptures

• Injuries to tendons: rotator cuff injuries

• Injuries to bone surfaces

– Joint dislocations

– Patellar dislocation

– Loose bodies

– Meniscus injuries

– Chondromalacia


Common Joint Injuries (cont.)

• Rotator cuff injuries

– Clavicle fractures

– Dislocations

– Bursa damage

– Torn tendons

• Hip injuries

– Dislocation

– Fracture


Knee Injuries

• Meniscus injury

• Patellar dislocation

• Chondromalacia


Question

True or false.

Chondromalacia is the most common type of knee injury.


Answer

False

The most common knee injuries are tear of the ACL (anterior cruciate ligament), caused by hyperextension, and damage to the meniscus.


Fractures

• Transverse

• Oblique

• Spiral

• Comminuted

• Segmental

• Butterfly

• Impacted


Bone Healing

• Hematoma forms and fibrin network fills it

• Cells grow along fibrin meshwork to form new tissue

• Calcium salts deposited in new tissue

• New tissue remodeled into normal shape


Question

Which of the following represents the correct sequence of bone healing?

a. Hematoma – cartilage – bone

b. Hematome – elastin – fibrocartilage

c. Cartilage – spongy bone – compact bone

d. Hemangioma – spongy bone – compact bone


Answer

a. Hematoma – cartilage – bone

Following a fracture, a hematoma forms; collagen and cartilage are deposited (soft callus); bone tissue is ossified (hard callus).


Complications Resulting from Soft Tissue Injury

• Skin injury: fracture blisters

• Muscle injury and swelling: compartment syndrome

• Nerve injury: reflex sympathetic dystrophy

• Adipose tissue or bone marrow: fat emboli


Osteomyelitis

• Infection of bone

– Direct contamination

– Contamination through blood (hematogenous)

º Miliary tuberculosis

– Contamination from skin lesions


Hematogenous Osteomyelitis

• In children:

– Affects long bones

– Purulent exudate inside bone

– Damages arteries to bone

– May penetrate skin or involve joints

• In adults:

– In vertebrae, sternoclavicular and sacroiliac joints, or pubic symphysis

– Tends to affect joint space


Chronic Osteomyelitis

• Areas of dead bone develop

– Sequestrum = infected dead bone

• Are surrounded by new bone

– Involcrum bone forms around the dead bone

• Identified by x-ray, bone scans


Osteonecrosis

• Caused by ischemia to bone due to:

– Bone injury

– Thrombosis or embolism

– Vessel injury

– Compartment syndrome inside bone (increased intraosseous pressure)

– Corticosteroid associated


Question

Which type of bone disorder is associated with thrombus formation or embolus?

a. Hematogenous osteomyelitis

b. Chronic osteomyelitis

c. Osteonecrosis

d. Osteoinfarction


Answer

c. Osteonecrosis

Bone has an extensive blood supply (remember, it can’t rely on diffusion of nutrients and gases like cartilage can). When blood flow to an area of osseous tissue is disrupted because of a clot/thrombus or an embolus (a clot that has broken off and traveled), the tissue dies (necrosis).

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Week 4 Powerpoint Chapter 43