Podiatry Boards Part 2
In wound healing when do neutrophils first appear at wound site?
Within 24 hours
What happens from 24-48 hours at the wound site?
The cut edges thicken from mitotic activity of basal cells, epithelial cells and the dermis depositing basement membrane.
What day are neutrophils replaced by macrophages?
Day 3 but do not bridge the gap.
What time period do collagen fibers bridge gap?
What is the plasmatic stage of skin graft healing?
Occurs 24-48 hours after graft application.
A fibrin layer is formed between the graft and host which anchors it and allows for diffusion of nutrients to the graft.
What are the stages of graft healing?
What is the inoscultation stage?
Begins at 48 hours
Revascularization of the graft tissue.
Lymphatics by 4-5 days
What is the reorganization stage?
Process of reorganization for months.
Connective tissue reogranizes and regulates vascular and lymphatic flow.
What is the reinnervation stage?
Occurs simultaneously with the reogranization stage.
May require 1-2 years to complete
What does tension do to a scar?
What age group may hypertrophy scars?
How can you tell you are in the RSTL?
Pinch the skin tightly together and look for a deep well formed furrow.
RSTL run what directions to muscle and tendon?
Perpendicular to long axis of muscle and tendons
Parallel to joints
What is the order of importance in healing a wound and covering it?
Direct closure then Grafts then Local Flaps then Distant Flaps
What is an isograft?
Graft from an identical twin
What is another name for allograft?
What thickness of graft contracts the most?
Thin grafts, but encorporate well to host.
What thickness of graft less contraction but harded to incorporate to host?
Why mesh grafts?
Use any thickness
Wider surface area
Decrease hematoma and seroma complications
A full thickness graft has some sub q tissue on it which needs to be removed before application. When do you use these grafts?
For weightbearing areas or flexion points
What is the down side about grafts?
High failure rate over tendons and bone
What should the size of the graft be?
Slightly larger than the wound.
How long can a graft be kept if not used?
21 days in a refridgerator
How long should the dressing remain after sx?
What is the MC cause of skin graft failure?
Seroma- because it places something between the graft and the host and it can't get its blood supply. Tissue will die in these areas
What organisms cause fibrinolysis and disrupt/destroy a graft quickly?
Streptococcus pyogenes and pseudomonas pyocyane
Apligraft has a well-differentiated stratum corneum and dermal layer of type 1 collagen. But it does not have what?
Langerhan cells, melanocytes, macrophages, lymphocytes, blood vessels or hair.
What are some requirments for apligraft?
Noninfected partial or full thickness ulcers
Venous insufficiency >1 month of other tx
What is the media for apligraft?
A random pattern (cutaneous flap) must be what?
They have no axial arteries
Pedicle base must be as wide as flap is long.
What is the axial pattern (aerterial flap)?
Direct blood supplu from citaneous artery.
: DP flap or lateral calcaneal arterial flap
: no skin bridge
: Transferred from distant site. More common in Podiatry.
What are the local flaps?
Rotational flap: pivot about pedicle. (Half circle- moved in a lateral direction. )
What is a Burow's triangle?
Excision of the triangle adjacent to the pivot point.
What is a transpositional flap?
Rectangular or square. Movement is an arc.
: Bi-lobed flap, limberg glap (Rhomboid)
What are advancement flaps?
Moved directly forward to cover defect.
: V-Y flap and a Y-V flap
What is a muscle mycocutaneous flap?
bulk and vascularity.
What muscles could be used in what areas?
: Abductor hallucis
: Abductor digiti minimi
Distal 1/3 of leg?
Gastroc/Soleus and Peroneals
What is the Zplasty?
Essentially a transposition of 2 triangular flaps.
Angle of the flaps 60 degrees
Where should the apex be on a V-Y plasty?
Wide and apex should be proximal
V-Y does what
and a Y-V does what?
V-Y will lengthen in 1 plane
Y-V will lengthen in the other plane or perpendicular.
You do a sx and you have too much skin or redudant skin plasty what should you do?
When do you use a double S incision?
Very large incision
When do you use syndactylization?
When one is flail and adjacent is stable.
You get a dog ear while suturing up the incision, what do you do?
Large ones you can extend incision along the dog ear and allow flap to rotate.
Cutting wedges out
How long should a plantar incision sutures stay in?
How to manage Keliods?
Use z plasties to reduce tension
Use nonabsorable suture and remove in 7 days
Corticosteriods to inhibit collagen
Pressure on scar of 25mmHg for 4-12 months
Podiatry Boards Part 2