Bone Fractures

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Bone Fractures (Breaks)

• Bone fractures are classified by:

• The position of the bone ends after fracture

• Completeness of the break

• The orientation of the break to the long axis

• Whether or not the bones ends penetrate the skin

Typical Bone Fractures – General Classification

• Open Fracture – bone breaks through the skin, or at least causes a surface wound (bone may not break through skin)

• Closed Fracture – bone break occurs without causing damage to the skin

Typical Bone Fractures – General Classification

• Complete fracture: A fracture in which bone fragments separate completely.

• Incomplete fracture (greenstick): A fracture in which the bone fragments are still partially joined

Typical Bone Fractures - Specific Classification

Classified by direction of break / fracture line

• Linear fracture: A fracture that is parallel to the bone's long axis.

• Transverse fracture: A fracture that is at a right angle to the bone's long axis.

• Oblique fracture: A fracture that is diagonal to a bone's long axis.

• Spiral fracture: A fracture where at least one part of the bone has been twisted.

Typical Bone Fractures

• Linear fracture

• Transverse fracture

Classified by direction of break / fracture line

Typical Bone Fractures

• Oblique (diagonal) Fracture

• Spiral Fracture

Classified by direction of break / fracture line

More Bone Fractures• Simple fractures are

fractures that only occur along one line, splitting the bone into two pieces

•multi-fragmentary or comminuted fractures involve the bone splitting into multiple pieces

More Bone Fractures

• compression fracture usually occurs in the vertebrae, for example when the front portion of a vertebra in the spine collapses

More Bone Fractures

• An avulsion fracture is an injury to the bone in a place where a tendon or ligament attaches to the bone.

• When an avulsion fracture occurs, the tendon or ligament pulls off a piece of the bone.

More Bone Fractures• A stress fracture occurs

when the forces are much lower, but happen repetitively for a long period of time; these injuries are also known as "fatigue fractures."

• Stress fractures are commonly seen in athletes who run and jump on hard surfaces, such as distance runners, volleyball players, and ballet dancers.

Stages in the Healing of a Bone Fracture

• Hematoma formation

• Torn blood vessels hemorrhage

• A mass of clotted blood (hematoma) forms at the fracture site

• Site becomes swollen, painful, and inflamed

Figure 6.13.1

Stages in the Healing of a Bone Fracture

• Fibrocartilaginous callus forms

• Granulation tissue (soft callus) forms a few days after the fracture

• Capillaries grow into the tissue and phagocytic cells begin cleaning debris

Figure 6.13.2

Stages in the Healing of a Bone Fracture

• Bony callus formation

• New bone trabeculae appear in the fibrocartilaginous callus

• Fibrocartilaginous callus converts into a bony (hard) callus

• Bone callus begins 3-4 weeks after injury, and continues until firm union is formed 2-3 months later

Figure 6.13.3

Stages in the Healing of a Bone Fracture

• Bone remodeling

• Excess material on the bone shaft exterior and in the medullary canal is removed

• Compact bone is laid down to reconstruct shaft walls

Figure 6.13.4

Treatment of Bone Fracture

• In order for a fracture to heal as well as possible, a good reduction, or placement, of the bones must be attained.

• When doctors talk about reduction of a fracture, or reducing the broken bone, they are talking about improving the alignment of the broken ends of the bone.

Reduction of a Fracture

• In most cases reducing a fracture involves placing the broken bone in a cast, often after a little pulling and tugging to achieve improved alignment.

• If the reduction cannot be satisfactorily achieved surgery may be necessary (fixation of the bone with pins, plates, screws or rods).

Bone Diseases & Disorders

Homeostatic Imbalances

• Osteomalacia

• Bones are inadequately mineralized causing softened, weakened bones

• Main symptom is pain when weight is put on the affected bone

• Caused by insufficient calcium in the diet, or by vitamin D deficiency

Homeostatic Imbalances

• Rickets

• Bones of children are inadequately mineralized causing softened, weakened bones

• Bowed legs and deformities of the pelvis, skull, and rib cage are common

• Caused by insufficient calcium in the diet, or by vitamin D deficiency

Homeostatic Imbalances

• Osteoporosis

• Group of diseases in which bone reabsorption outpaces bone deposit

• Spongy bone of the spine is most vulnerable

• Occurs most often in postmenopausal women

• Prevented or delayed by sufficient calcium intake and weight-bearing exercise

Paget’s Disease

• Characterized by excessive bone formation and breakdown

• Pagetic bone with an excessively high ratio of cancellous to compact bone is formed

• Pagetic bone, along with reduced mineralization, causes spotty weakening of bone

• Osteoclast activity wanes, but osteoblast activity continues to work