Fracture & Fracture Repair Flashcards
What is the most common lesion in bone?
Fracture
What is a pathological fracture?
Fracture through diseased bone
Are all fractures pathologies?
Yes
Are all fractures pathologic fractures?
No
What are the three phases of fracture repair?
- Inflammation phase
- Repair phase
- Remodeling phase
When does the inflammatory phase occur?
Onset to approximately 10 days
When does the reparative phase occur?
Approximately one week to a few months
When does the remodeling phase occur?
Several weeks on
inflammatory phase
What events occur between onset and two days post fracture?
- Rupture of blood vessels (in both soft tissue and bone)
- Hematoma
- Tearing of periosteum
- Necrosis of bone and soft tissue
What is the function of hematoma during the inflammatory phase?
Fills gaps, surrounds injury, seals off fracture
inflammatory phase
What events occur 2-5 days post fracture?
- Fibrin mesh develops
- Fibroblasts migrate into area
- Begins to form and lay down cartilage between bone ends
- Necrosis and macrophage activity continues
inflammatory phase
Which cells are involved in necrosis post fracture?
Macrophages and PMNs (neutrophils)
inflammatory phase
What events occur 5-10 days post fracture?
- Soft tissue callus (procallus) begins to form
- Macrophage activity is ongoing
The early part of the reparative phase occurs simultaneously with the ___
later part of the inflammatory phase
What events occur during the reparative phase?
- Osteoclasts and mononuclear cells clean up debris
- Extensive neovascularization/angiogenesis
- Callus formation begins
- Significant osteoblastic activity occurs
reparative phase
How might a fracture appear on X ray ten days to two weeks post fracture?
Fracture appears wider
reparative phase
How might a fracture appear on X ray four weeks post fracture?
A hazy cloud is seen as callus formation begins
What events occur during the remodeling phase?
- Occurs as callus seals the bone
- Bone adjusts its strength and shape (Wolff’s Law)
remodeling phase
What is the state of the fracture as the callus seals the bone?
Fracture is stable depending on age, general health, and fracture location
What cells are involved in the inflammation phase?
- PMNs
- Macrophages
- Osteoclasts (may be present)
What cells are involved in the reparative phase?
- Chondrocytes
- Osteoblasts
- PMNs
- Macrophages
What cells are involved in the remodeling phase?
- Osteoblasts
- Osteoclasts
- Osteocytes
What is clinical union?
Point when cast is removed; implies fracture is stable
What is malunion?
Healing with residual deformity
What is delayed union?
Failure to heal up to 6 months post fracture
What is non-union?
Failure to heal after 6 months
What is pseudoarthrosis?
Non-union fracture healing with pseudojoint
How common is a transverse fracture?
Uncommon
What is a transverse fracture?
- About 90 degrees to long axis
- High velocity injury
- Often pathologic
- Referred to as Paget’s “banana” fracture
How common is an oblique fracture?
Very common
What is an oblique fracture?
- Shaft of tubular bone
- About 45 degrees to long axis
What causes a spiral fracture?
Torsion and axial compression
What is a spiral fracture?
Angulated fracture; has pointed ends
What is a bone bruise?
Hemorrhage, edema, trabecular microfracture of bone
How is a bone bruise visualized?
Not seen on radiographs; best visualized on MRI
Incomplete vs. complete fracture refers to ___
discontinuities in the cortex of the bone
What is a Greenstick fracture?
Incomplete fracture in skeletally immature individuals where bending fractures bone on one side
Often caused by falling on outstretched arm
What specific fracture is shown here?
Greenstick fracture
skeletally immature
What is a Torus fracture?
Incomplete fracture in skeletally immature individuals where buckling fractures bone on one side
Often caused by falling on hand
What specific fracture is shown here?
Torus fracture
skeletally immature
What is a closed fracture?
Fracture that does not break the skin
What is an open fracture?
Fracture that breaks the skin
What is a comminuted fracture?
Three or more fragments that have separated from the bone:
- Crushed or pulverized bone
- “Butterfly fragment”
What is a noncomminuted fracture?
- One break
- Two fragments
Compression and impaction fractures are frequently due to ___
axial compression
Compression almost exclusively refers to ___ fractures
vertebral
Impaction refers to ___ fractures
extremity
What is a Salter-Harris fracture?
Fractures involving the growth plate (physis) classified by location to or damage to the physeal region
What are the subcategories of stress fracture?
- Fatigue
- Insufficiency
stress fracture
What causes fatigue fracture?
Abnormal repetitive stress on normal bone causing gradual formation of microfracture
What is a March fracture?
Stress fracture from fatigue of 2nd or 3rd metatarsal
stress fracture
What causes insufficiency fracture?
Normal stress through diseased bone; a form of pathologic fracture
What is an avulsion fracture?
Forcible ripping or tearing of tissue:
- Tearing away of bone fragment
- Pull from ligament, tendon, or muscle
What is a Clay Shoveler’s fracture?
Avulsion fracture of a lower cervical segment spinous process
What specific fracture is shown here?
Clay shoveler’s fracture
avulsion fracture
What is an occult fracture?
A radiographically invisible fracture; most common in scaphoid, also ribs
What is secreted by osteoblasts when depositing bone?
Alkaline phosphatase
In what situations or conditions would you expect to see an increase in alkaline phosphatase in the blood?
- Fast/aggressive bone building pathologies
- Pathologies that involve a large portion of the skeleton
What is erythrocyte sedimentation rate?
Indicates inflammatory process by how quickly red blood cells settle to the bottom of a test tube
What may cause an elevated erythrocyte sedimentation rate?
- Bone conditions
- Infection
- Autoimmune diseases ie rheumatic fever, tuberculosis
What is radionuclide imaging?
Bone scan with a Gamma camera specific for areas of increased metabolic activity
Overall, very sensitive, not specific
