Lecture 15 Short Notes Flashcards
What is the goal of fracture fixation?
to restore structure and function to the skeleton and return the animal to full function
What factors influence fracture healing?
-animal’s age
-location and type of fracture
-stability of the fragments
-extent of soft tissue and vascular compromise
-presence of necrotic and/or infected tissues
What is the importance of mechanical stability in fracture healing?
determines the nature, time course, and efficiency of the fracture healing response
What are the two types of bone healing?
-primary (direct) bone healing
-secondary (indirect) bone healing
What characterizes primary bone healing?
new bone forms a direct bridge across the fracture plane without significant callus formation
What is a soft tissue callus?
a structure that forms under less stable conditions before being mineralized in secondary bone healing
What is interfragmentary strain?
a measure of fragment instability, defined as the displacement of the fragments divided by the original gap size
What is ‘absolute stability’ in bone healing?
condition where bones are anatomically reconstructed and maintained under rigid internal fixation, allowing primary bone healing
What is contact healing?
healing that occurs in areas of intimate contact between fragments through direct osteonal proliferation
What is gap healing?
healing that occurs in gaps between fragments where osteonal remodeling cannot occur, filled with blood vessels and granulation tissue
What is ‘relative stability’ in bone healing?
condition where main bone fragments are stabilized but a small amount of instability remains
What characterizes secondary bone healing?
formation of abundant callus that unites the bone fragments through various tissue stages
What factors influence the control of interfragmentary strain?
-weight of the animal
-activity
-fixation method
-implant size
-implant material
-implant application
-fracture type
How does fracture configuration affect stability?
simple fractures are poorly tolerant to instability, while comminuted fractures are more tolerant
What is the effect of choosing a compliant fixation for simple fractures?
it could lead to excessive strain at the fracture site, causing delayed healing, non-union, and implant failure
What types of implants control strain effectively?
-bone plates
-type 3 external fixators
What is a common reason for non-union in fractures?
mechanical instability
What factors can lead to delayed or non-union after a fracture?
-vascular compromise
-premature or excessive weight-bearing
-infection
-radiation therapy
-systemic illness
