*Plastics

Question 1

CREEP

Answer 1

INCREASE IN STRAIN seen when skin is under CONSTANT STRESS

occurs in a matter of minutes and is due to extrusion of fluid from the dermis and a breakdown of the dermal framework

Question 2

Stress

Answer 2

force applied per cross-sectional area

F/A

Question 3

Strain

Answer 3

CHANGE IN LENGTH divided by the ORIGINAL LENGTH of a given tissue when a force is applied

Question 4

Stress Relaxation

Answer 4

the decrease in stress when skin is held in tension at a constant strain for a given time;

this occurs over a matter of days to weeks and is due to an increase in skin cellularity and the permanent stretching of skin components

Question 5

what is good “take” of a graft?

Answer 5

• absence of infection
• perfect hemostasis
• good dressing
• absence of motion

Question 6

how does thickness of graft affect “take” and function?

Answer 6

• thinner the graft, the better the “take”
• the thicker the graft, the better the function

Question 7

which part of amniotic tissue allografts are known to contain maternal antigens?

Answer 7

Chorion layer: on the maternal side of the placenta; contains maternal antigens

Theory is that by removing chorion layer, less likely to have host rxn

(other side is Amnion)

Question 8

which side is against the wound in amniotic tissue allografts?

Answer 8

STROMAL side down against wound (Sticky and gelatinous side)

as compared to smooth/shiny epithelial surface

Question 9

amniotic membrane components

Answer 9

• structural collagen: type I, 3, 4, 5, 7
• ECM proteins: Fibronectin, proteoglycans, glycosaminoglycans
• Growth factors: EGF, TGF, FGF, PDGF, VEGF
• Regulating proteins: MMPs, TIMPs, IL-K

Question 10

Amniotic Membrane Allografts:

benefits

Answer 10

Question 11

examples of Amniotic Membrane Allografts

Answer 11

affinity, amniofix, biofix, epifix, grafix, neox, nucel, nushield, revitalon, xwrap

Question 12

compare FTSGs and STSGs

Answer 12

Question 13

reasons for skin graft failure

Answer 13

Question 14

Answer 14

Transpositional Flap

Question 15

Answer 15

Rotational Flap

Question 16

Answer 16

Bilobed Flap

Question 17

Answer 17

Rhomboid (Limberg) Flap

Longitudinal axis is parallel to the line of minimal skin tension

Question 18

Answer 18

Kutler-Type Biaxial V-Y

(Advancement Flap)

Question 19

Answer 19

Atasoy-Type Plantar V-Y

(Advancement Flap)

Question 20

Answer 20

Z-Plasty

good for linear scar contractures

Question 21

Z-Plasty Angles

Answer 21

Angles that are permissible for a Z-plasty are between 45° and 60°.

Angles less than 45° result in impaired blood flow to the flaps, and angles greater than 60° result in severe tension.

60° result in the greatest lengthening.

A Z-plasty with a 60° angle results in a 75% increase in skin length. Z-Plasties are particularly useful in treating linear scar contractures.

Question 22

Answer 22

V-YPlasty

Unidirectional skin-lengthening technique. The apex of the “V” is placed at the point of maximal skin tension

Question 23

Answer 23

Derotational Skin Plasty for Fifth Digits

Performed in conjunction with an arthroplasty. Acts to correct for the varus (frontal) and hammering (sagittal) of the digit. The incision is made from distal-medial to proximal-lateral.

Question 24

Direction of incision for Derotational Skin Plasty for 5th digits

Answer 24

distal-medial to proximal-lateral

Question 25

Answer 25

Desyndactyly Procedure Place needles from dorsal to plantar to line up apices.

Question 26

Answer 26

**Tsuge “Inchworm” Plastic Reduction Procedure** Fishmouth incision is made around the toe just dorsal to phalange. The dorsal skin is retracted, allowing the proximal skin to buckle. The tip of the toe is excised, and the nail may be reduced in width, if desired. Six to eight weeks after initial procedure, the dorsal redundant skin is excised.

Question 27

Answer 27

Ollier Incision ## Footnote Indications: - [triple arthrodesis](https://www.wheelessonline.com/orthopaedics/triple-arthrodesis/) and resection of a [calcaneonavicular bar](https://www.wheelessonline.com/orthopaedics/calcaneonavicular-coalition/); - incision may be extended to expose the subtalar, calcaneocuboid, and talonavicular joints; - wound usually heals well because the proximal flap is dissected full thickness and the skin edges are protected during retraction; * *- Cautions:** - preserve dorsal cutaneous branches of superficial peroneal nerve which cross the incision; * *- Incision:** - begins over dorsolateral aspect of the talonavicular joint, - continue incision obliquely & inferoposteriorly to end about 1 inch inferior to lateral malleolus

Question 28

Answer 28

DuVries Incision * Medial longitudinal incision * Limited exposure Indicates w/ classic heel spur operation; however, may sever branches of medial calcaneal nerve → produces nerve entrapments

Question 29

Answer 29

Cincinnati Incision * Transverse incision that involves extensive dissection of the posterior, medial, and lateral aspects of the foot and ankle * Do not perform in greater than 4-year-olds * Classic soft tissue release for **clubfoot**

Question 30

Answer 30

Lateral Extensile Incision * This is a full-thickness incision down to bone. * aka “sinus tarsi apprach” * Indications * displaced intraarticular calcaneal fractures * Designed to outline the distribution of the peroneal artery, also protects the sural nerve, and peroneal tendons.