Surgical Principles Flashcards
The three Phases of wound healing and the time periods
Inflammatory phase 2-5 days
Proliferative phase 2-3 weeks
Maturation phase 3 weeks - indefinitely.
What are the major cell types in the wound healing phases?
Inflammatory: Neutrophils
Proliferative: Macrophages and Fibropblasts
Maturation: Fibroblasts
When do wounds reach the tensile strength of suture. How does this strength compare to the original strength of the skin?
The wound will reach tensile strength during the proliferative phase at about 14 days.
This skin strength is only 35% of the original strength.
Scars carry only 80% of the original skin strength.
What is the most important cell involved in wound healing?
Macrophages!
Only inflammatory cell able to participate in the low oxygen levels of the wound edges.
Ingests debris, bacteria, forms capillarys, process antigens.
Which two vitamins effect wound healing?
Vitamin A
Vitamin C (Collagen production)
What’s the difference between primary and secondary bone healing?
Primary is seen with stable fixation and works via cutting cone fusion. (Haversian remodeling)
Secondary is seen with unstable fractures/casting and involves the formation of a bony callous.
What are the phases of secondary bone healing?
Hematoma formation Days 1-3
Fibrocartilagenous callus: Osteoclastic phagocytosis of necrotic bone with osteoblastic differentiation into cartilage. (10d - 6 wks)
Primary bone callous forms 6-10 weeks
Primary bone callus is absorbed and forms the secondary bone callus at 2.5 - 4 months.
Remodeling occurs secondary to wolf’s law (form follows function)
What law describes final bony maturation in secondary bone healing?
Wolf’s law
Form will follow function.
What is the name of the classification for non union
Weber and Check after 8-9 months of no healing.
Breaks it down into hypertrophic and atrophic.
What are the hypertrophic non-unions?
Elephants foot
Horse Hoof
Oligotrophic
What are the atrophic non-unions?
Atrophic
Defect
Torsion wedge
Cominuted
What is a Papineau grafting technqiue?
Described for osteomyelitis
Excise necrotic bone, use cancellous bone grafting with overlying skin coverage.
It is designed for rapid revascularization.
Hyaline vs Fibrocartilage
Hyaline: Has type II cartilage and glycosaminoglyxan matrix to maintain compressive forces.
Fibrocartilage is type I and is mostly responsible for tensile forces.
What cell type can differentiate into hyaline cartilage?
Mesenchymal stem cells!
Typically form into fibrocartilage as hyaline cartilage rarely ever reforms.
Whats the name of the classification that covers the extent of damage done directly to a nerve?
Seddons!
Neuropraxia
Axonotmesis
Neurotmesis
What is the name of the classification that covers the type of nerve deficit a patient might be experiencing?
Sunderlands!
Breaks it into 1st degree to 6th degree.
Which nerve degeneration involves wallerian degeneration?
Axonotmesis!
The axon is damaged but the structural framework is intact allowing for internal reconstruction.
Neurotmesis has wallerian degeneration as well distal to the transection resulting in a stump neuroma.
Autolytic debridement
The bodies own enzym removal and moisture.
It is selective in that only necrotic tissue is removed.
Facilitated with hydrocolloid, hydrogels, and transparent films.
Advantages: Safe, body removes and effective.
Disadvantages: Not as rapid as surgical, may promote anaerobic growth with occlusives.
What is mechanical debridement?
Typical Wet to dry, non selective debridement that poses a risk to healthy tissue.
Name the 5 types of debridement
Autolytic Manual Enzymatic Surgical Biological (Maggots)
“SAME B”
Pros vs cons of thin/split thickness skin grafts.
Pros: Take very quickly, require less nourishment.
Cons: Graft is fragile and shrinks up to 75%
Which has better survivability
FTSG or STSG?
Split thickness skin grafts have better survivability but are burdened by being weaker and shrinkage.
What are the ideal angles for Z-plasty skin grafts?
60 degree angles to gain up to 75% in additional length.
What are the three phases of skin graft healing?
Plasmitic 1-2 days (Fibrin anchor layer, nutrition is through diffusion.
Inosculation 2-4 days Capillary budding and lymphatic drainage begins.
Reorganization >5 days
Capillaries invade and the graft begins to reinervate. Will not be normal for a few years.
