Copyright © 2011 Wolters Kluwer Health | Lippincott Williams & Wilkins
Chapter 43
Disorders of the Skeletal System:
Trauma, and Infections
(Through page 1112)
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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
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Common Joint Injuries (cont.)
• Rotator cuff injuries
– Clavicle fractures
– Dislocations
– Bursa damage
– Torn tendons
• Hip injuries
– Dislocation
– Fracture
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Knee Injuries
• Meniscus injury
• Patellar dislocation
• Chondromalacia
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Question
True or false.
Chondromalacia is the most common type of knee injury.
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Answer
False
The most common knee injuries are tear of the ACL (anterior cruciate ligament), caused by hyperextension, and damage to the meniscus.
Copyright © 2011 Wolters Kluwer Health | Lippincott Williams & Wilkins
Fractures
• Transverse
• Oblique
• Spiral
• Comminuted
• Segmental
• Butterfly
• Impacted
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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
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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
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Answer
a. Hematoma – cartilage – bone
Following a fracture, a hematoma forms; collagen and cartilage are deposited (soft callus); bone tissue is ossified (hard callus).
Copyright © 2011 Wolters Kluwer Health | Lippincott Williams & Wilkins
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
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Osteomyelitis
• Infection of bone
– Direct contamination
– Contamination through blood (hematogenous)
º Miliary tuberculosis
– Contamination from skin lesions
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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
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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
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Osteonecrosis
• Caused by ischemia to bone due to:
– Bone injury
– Thrombosis or embolism
– Vessel injury
– Compartment syndrome inside bone (increased intraosseous pressure)
– Corticosteroid associated
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Question
Which type of bone disorder is associated with thrombus formation or embolus?
a. Hematogenous osteomyelitis
b. Chronic osteomyelitis
c. Osteonecrosis
d. Osteoinfarction
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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).