Disorders of Skeletal Function:Trauma, Infections, and Neoplasms

Causes of Musculoskeletal Injuries
Blunt tissue trauma
Disruption of tendons and ligaments
Fractures of bony structures
Athletic Injuries
Acute injuries
Caused by sudden trauma
Include injuries to soft tissues (contusion, strains, and sprains) and to bone (fractures)
Overuse injuries
Chronic injuries
Include stress fractures that result from constant high levels of physiological stress without sufficient recovery time
Types of Soft Tissue Injuries
Contusion
An injury to soft tissue that results from direct trauma and is usually caused by striking a body part against a hard object
Hematoma
A large area of local hemorrhage
Laceration
An injury in which the skin is torn or its continuity is disrupted
Types of Joint Injuries
Strain
A stretching injury to a muscle or a musculotendinous unit caused by mechanical overloading
Sprain
Involves the ligamentous structures surrounding the joint, pain and swelling subside more slowly than in a strain
Caused by abnormal or excessive movement of the joint
Types of Joint Injuries (cont.)
Dislocation
Displacement or separation of the bone ends of a joint with loss of articulation
Loose bodies
Small pieces of bone or cartilage within a joint space

Locations of Joint Injuries
Shoulder and Rotator Cuff Injuries
Knee Injuries
Meniscus injuries
Patellar subluxation and dislocations
Chondromalacia
Classifications of Fractures
Location
Types
Pattern of fracture line
Signs and Symptoms of a Fracture
Pain
Tenderness at the site of bone disruption
Swelling
Loss of function
Deformity of the affected part
Abnormal mobility
Five Stages of Bone Healing
Hematoma formation
Cellular proliferation
Callus formation
Ossification
Remodeling
Layers of Bone Structure Involved in Bone Healing
Periosteum
Outer covering of the bone
Endosteum
Inner covering
Medullary canal
Contains the bone marrow
Factors Delaying Bone Healing
Patient’s age
Current medications
Debilitating diseases
Local stress around the fracture site
Circulatory problems
Coagulation disorders
Poor nutrition

Immobilization of a Body Part
External devices
Splints, casts, traction, or external fixation devices
Internal fixation devices
Inserted during surgical reduction of the fracture

Complications of Fractures
Loss of skeletal continuity
Injury from bone fragments
Pressure from swelling and hemorrhage
Fracture blisters, compartment syndrome
Involvement of nerve fibers
Reflex sympathetic dystrophy and causalgia
Development of fat emboli

Origin of Bone Infections
Microorganisms introduced during injury
Microorganisms introduced during operative procedures
Microorganisms from the blood stream
Actions of Microorganisms Localized in Bone
Proliferate
Produce cell death
Spread within the bone shaft
Incite a chronic inflammatory response with further destruction of bone
Prevention of Bone Infection
Careful cleaning and debridement of skeletal injuries
Strict operating room protocols
Types of Osteomyelitis
Hematogenous Osteomyelitis
Originates with infectious organisms that reach the bone through the blood stream
Contiguous Spread Osteomyelitis
Secondary to a contiguous focus of infection
Direct inoculation from an exogenous source or from an adjacent extraskeletal site
Chronic Osteomyelitis
Occur secondary to an open wound
Spread of Tuberculosis
Tuberculosis can spread from one part of the body to the bones and joints
When this happens, it is called extrapulmonary or miliary tuberculosis
It is caused by Mycobacterium tuberculosis
The disease is localized and progressively destructive but not as contagious as primary pulmonary tuberculosis
Causes of Osteonecrosis
Mechanical disruption of blood vessels
Thrombosis and embolism
Vessel injury
Increased intraosseous pressure
Symptoms of Bone Tumors
Pain
Presence of a mass
Impairment of function
Characteristics of Benign Tumors
Limited to the confines of the bone
Well-demarcated edges
Surrounded by a thin rim of sclerotic bone
Types of Benign Bone Tumors
Osteoma
Chondroma
Osteochondroma
Giant cell tumor

Characteristics of Malignant Bone Tumors
Tend to be ill defined
Lack sharp borders
Extend beyond the confines of the bone
Types of Malignant Bone Tumors
Osteosarcoma
Ewing’s Sarcoma
Chondrosarcoma

Treatment Goals for Metastatic Bone Disease
Preventing pathologic fractures
Promoting survival with maximum functioning
Allowing the person to maintain as much mobility and pain control as possible
Treatment Methods for Metastatic Bone Disease
Chemotherapy
Irradiation
Surgical stabilization