Split Thickness Skin Graft 
Richard Davis, Vallery Logedi 
OPEN MANUAL OF SURGERY IN RESOURCE-LIMITED SETTINGS 
www.vumc.org/global-surgical-atlas 
This work is licensed under a Creative Commons Attribution-ShareAlike 3.0 Unported License  
 
Introduction:  
Split thickness skin graft is a useful way to 
cover wounds that have no living epidermal cells, 
such as deep abrasions, burns, venous stasis ulcers, 
and sites of tumor excision. It is a good option for 
covering even large wounds, as split thickness skin 
can be expanded to cover more space than the area it 
came from, through the process of “meshing” which 
is described further below. Skin grafts, either split or 
full thickness, are not useful for pressure ulcers; an 
option that is more tolerant of pressure must be used 
in this situation. 
Split thickness grafts can be harvested in 
various thicknesses, as discussed further below. 
Every split thickness graft will contract after being 
placed; the thinner a graft is, the more it will contract. 
Conversely, the thicker a graft is, the less it will 
contract, and the stronger and more resistant it is to 
trauma. The strength of increased thickness comes at 
the price of a slightly higher chance that the graft will 
not “take,” or successfully implant at the graft site.  
It is acceptable to use split thickness grafts on 
the face in certain situations, although in general they 
should be avoided because of their tendency to 
contract. When used on the face, they should be thick 
and not “meshed” because of the cosmetic effects of 
doing so. 
 
Typical appearance of a meshed skin graft after healing. Peter 
M 
Nthumba, 
CC 
BY-SA 
2.0 
<https://creativecommons.org/licenses/by-sa/2.0>, 
via 
Wikimedia Commons 
 
A skin graft can be thought of as 
transplantation of living epidermal cells from one 
location to another. Therefore, the surgeon must 
assure that there are sufficient epidermal cells 
remaining at the donor site after harvest, and that the 
recipient site will support these newly arrived cells 
after their transplantation.  
 
To assure that living cells remain at the donor 
site after harvest, the graft must be taken at a depth 
that is less than the hair follicles. The donor site will 
re-epithelialize by migration of these cells, from the 
hair follicles, into the rest of the wound. Hair 
follicles’ depth is variable depending on the part of 
the body, but in general they are located at about 2-
3mm of depth. So the dermatome, whether manual or 
mechanical, must be set to a depth to leave a good 
deal of the hair follicle behind. Most skin grafts 
harvest skin around 0.3-0.5mm deep. It is the 
surgeon’s responsibility to make sure that the 
dermatome is set properly and remains so, harvesting 
neither to little nor too much skin. A dermatome that 
cuts too deep will result in a non-healing wound at 
the donor site, as there will be no viable epidermal 
cells remaining there.  
 
Anatomy of the epidermis and hair follicle. The dermis is 
represented here by wavy lines. The epidermal cells, near the 
surface, are also located all along the hair follicle (Red arrow) 
which extends to a depth of 2-4mm. A skin graft harvested 
through a depth of 0.5mm, represented by the Red line, takes 
viable epidermal cells above the red line, and leaves behind 
viable epidermal cells around the hair follicle. 
 
Split Thickness Skin Graft 
Richard Davis, Vallery Logedi 
OPEN MANUAL OF SURGERY IN RESOURCE-LIMITED SETTINGS 
www.vumc.org/global-surgical-atlas 
This work is licensed under a Creative Commons Attribution-ShareAlike 3.0 Unported License  
 
 
A healing donor site. Epidermal cells are migrating from the 
hair follicles to fill the wound and cover the dermis. 
Melanocytes have migrated with them, giving a dark color. 
When the migration is complete, the wound will be a uniform 
color and the previously exposed dermis will be completely  
covered.  
 
 
To assure that the transplanted epidermal 
cells survive where they are grafted, the graft site 
must be clean and well perfused. Generally the 
presence of healthy granulation tissue indicates good 
perfusion and absence of infection. 
For venous stasis ulcers, the edema must be 
controlled and the patient must be properly 
counseled on prevention of edema in the future 
through compression stockings. It is possible for skin 
grafts to fail years later when the patient stops taking 
measures to prevent edema, so proper counseling on 
the nature and chronicity of venous stasis disease is 
very important.  
 
In general, skin grafts will not take on 
exposed bone unless periosteum is present (which is 
almost never the case.) They will be very unlikely to 
take on exposed tendon unless granulation tissue has 
covered the tendon. The common situation is an 
ankle or lower leg wound with exposed bone and 
tendon after trauma, infection, or venous stasis 
disease. Small tendons can be resected if they are not 
functional (the ankle is frozen) though the Achilles 
tendon should not be completely resected. Careful 
consideration of an alternate method of wound 
closure (flap coverage of tendon or exposed bone, or 
amputation) should be considered. Sometimes a 
vacuum-assisted dressing can encourage granulation 
tissue to cover exposed tendons or even small 
segments of exposed bone.  
 
In general, split thickness skin grafts proceed 
in the following general steps: 
● Debridement of the recipient site 
● Setup and adjustment of the dermatome 
● Harvest of the skin  
● Preparation of the skin by expansion through 
“meshing” if indicated 
● Placement of the graft on the recipient site and 
securing the graft in place 
● Application of a dressing that will protect and 
secure the skin graft 
● Application of a dressing that will protect the 
donor site 
 
Steps: 
1. While counselling the patient on the planned 
operation, it is important to emphasize the 
cosmetic implications of a meshed graft, and to 
counsel the patient on the risk of graft failure. 
2. The wound is cleaned before the grafting is done. 
Change gloves after debridement and prior to 
harvesting the graft.  
 
A wound that is ready for debridement and grafting. There is 
no foul smell, no discharge of pus, and the eschar is thin and 
easily debrided. Care should be taken when debriding over 
bone or tendon, to preserve some clean granulation tissue to 
support the graft.  
 
Split Thickness Skin Graft 
Richard Davis, Vallery Logedi 
OPEN MANUAL OF SURGERY IN RESOURCE-LIMITED SETTINGS 
www.vumc.org/global-surgical-atlas 
This work is licensed under a Creative Commons Attribution-ShareAlike 3.0 Unported License  
 
 
Healthy granulation tissue of uniform thickness after 
debridement shows that the wound is ready to accept a graft.. 
It is acceptable to have a small amount of slough on the wound, 
as in the picture above, but if there is excessive purulent or 
necrotic tissue, it should be debrided and followed with serial 
dressing changes until clean.  
 
3. 
Mineral oil, also known as liquid paraffin, is 
applied to the donor site to make it easier for the 
blade to move over the skin. Tension is applied to the 
skin. 
 
Tension is held on the skin at the donor site using sponges, with 
help from an assistant. The skin has been lubricated with 
Mineral Oil. 
 
4. 
 The manual dermatome is held at a 45-
degree angle on the skin. The dermatome is then 
moved back and forth in a sawing motion while 
slowly advancing down the limb. For a mechanical 
dermatome, the machine is held at a 45-degree angle 
above the skin, turned on, and then lowered to 
contact the skin and gently advanced. In both cases, 
the main driver of dermatome advancement is the 
kinfe cutting the skin; the operator gives gentle 
pressure to allow the dermatome to continue in a 
smooth forward motion. 
The back and forth motion of the knife harvests the skin at the 
appropriate depth. The surgeon should avoid “forcing” the 
blade to advance, but rather apply gentle pressure allowing the 
blade to advance as it cuts the layer of skin.  
 
As the blade advances it the harvested skin will collect within 
the dermatome. An assistant can gently pull the skin upwards 
but this is usually not necessary.  
 
Split Thickness Skin Graft 
Richard Davis, Vallery Logedi 
OPEN MANUAL OF SURGERY IN RESOURCE-LIMITED SETTINGS 
www.vumc.org/global-surgical-atlas 
This work is licensed under a Creative Commons Attribution-ShareAlike 3.0 Unported License  
 
For the mechanical dermatome, hold the machine above the 
skin at a 45 degree angle, engage the throttle, and lower your 
hand until the blade touches the skin. Tension and lubrication 
are applied as described above. In this case, the surgeon is 
applying tension with a sterile tongue depressor. Source: 
Hoffman HT (ed) Iowa Head and Neck Protocols “Case 
Example Split Thickness Skin Graft STSG Zimmer Dermatome 
settings” 
https://medicine.uiowa.edu/iowaprotocols/case-
example-split-thickness-skin-graft-stsg-zimmer-dermatome-
settings Accessed 5 May 2022 
 
5. 
One the desired amount of skin is harvested, 
raise the dermatome away from the skin. For a 
mechanical dermatome, keep the machine running 
while you raise it away from the skin, then turn it off. 
Use scissors to divide the remaining skin where it is 
still attached.  
Once the desired amount of skin is harvested, raise the 
dermatome away from the skin and cut the graft flush with the 
unharvested skin.  
 
 
Once harvesting is completed, raise the dermatome away from 
the skin and then turn off the throttle. Cut the graft flush with 
the skin exactly as in the example above. Source: Hoffman HT 
(ed) Iowa Head and Neck Protocols “Case Example Split 
Thickness Skin Graft STSG Zimmer Dermatome settings” 
https://medicine.uiowa.edu/iowaprotocols/case-example-split-
thickness-skin-graft-stsg-zimmer-dermatome-settings Accessed 
5 May 2022 
 
6. 
Harvested skin is immediately placed in a 
bowl with wet gauze to keep it moist. 
 
The skin is removed carefully from the dermatome with gentle 
tracton and placed in saline.  
 
7. 
If the graft needs to be meshed to cover a 
large defect, then it can be passed through a mesher 
as shown below. 
Split Thickness Skin Graft 
Richard Davis, Vallery Logedi 
OPEN MANUAL OF SURGERY IN RESOURCE-LIMITED SETTINGS 
www.vumc.org/global-surgical-atlas 
This work is licensed under a Creative Commons Attribution-ShareAlike 3.0 Unported License  
 
 
The mesher places even cuts on the graft to allow it to expand. 
Some types of meshers require the graft to be placed on a plastic 
insert (called a “Carrier”) that controls the number of cuts 
made. This one does not.  
 
 
The skin must lie flat as it enters the mesher.  
 
 
As the graft exits from the mesher, make sure that it does not 
become entrapped in the blades.  
 
8. 
The graft is then applied on the wound and 
secured 
with 
either 
staples 
or 
absorbable 
monofilament suture such as chromic gut. It is 
crucial to orient the dermis side of the graft 
downwards. In light skin it can be difficult to tell 
which way the skin should be oriented. Close 
examination of the graft shows that the dermis 
(inward-facing) side is smooth, while the epidermis 
(outward-facing) side retains the tiny wrinkles of the 
skin.  
Split Thickness Skin Graft 
Richard Davis, Vallery Logedi 
OPEN MANUAL OF SURGERY IN RESOURCE-LIMITED SETTINGS 
www.vumc.org/global-surgical-atlas 
This work is licensed under a Creative Commons Attribution-ShareAlike 3.0 Unported License  
 
The pieces of graft are placed on the wound bed and positioned. 
A non-tooth forceps, or sometimes the blunt side of an 
instrument, can be used to slide the graft into position. It is then 
secured with staples or interrupted chromic gut.  
 
9. 
We apply silver sulfadiazine cream directly 
to both sites before applying petroleum jelly gauze: 
other antibiotic ointment or petroleum jelly alone is 
also acceptable. Both graft and donor site are dressed 
with Petroleum jelly-soaked gauze followed by wet,  
then  dry dressing. The graft must be kept moist 
under the dressing for the duration of the 4-5 days 
that the dressing is in place. For large wounds, avoid 
topical antibiotic ointment (such as neomycin) 
because there is a theoretical risk of systemic 
absorption of the antibiotic.  
Following application of silver sulfadiazine or petroleum jelly, 
a petroleum jelly-soaked gauze is applied to the graft.  
 
 
A wet sponge is wrapped over the petroleum jelly gauze. This is 
covered by dry gauze and then wrapped gently but firmly with 
an elastic bandage.  
 
Split Thickness Skin Graft 
Richard Davis, Vallery Logedi 
OPEN MANUAL OF SURGERY IN RESOURCE-LIMITED SETTINGS 
www.vumc.org/global-surgical-atlas 
This work is licensed under a Creative Commons Attribution-ShareAlike 3.0 Unported License  
 
 
Continuous gentle pressure over a newly placed skin graft is 
crucial. On the extremities or the torso, this can be 
accomplished with an elastic bandage. In other areas such as 
the scalp or perineum, this is better accomplished by a “Tie 
over Bolster” dressing. Monofilament nylon is sutured to the 
skin circumferentially around the graft, the dressing is applied 
in the same way as described above, and then the sutures are 
tied to each other over the dressing.  
 
Pitfalls 
● An incorrectly set dermatome may cause the 
surgeon to harvest a graft that is either too thick 
or too thin. As mentioned earlier, harvesting too 
much skin at the donor site might result in a non-
healing wound that will also need grafting! 
● It is important that adequate tension is applied at 
the donor site during harvesting as this is key to 
how the dermatome works. Failure to do this will 
cause the dermatome to “bog down” and not 
advance. 
● Keep in mind the size of the defect to be covered 
while preparing and draping the patient. If the 
skin from one thigh might not be enough, it may 
be prudent to prepare both lower limbs and the 
abdomen just in case, rather than to run out of 
space to harvest skin. 
● Failure to correct the factors that led to the wound 
will lead to graft failure. Examples include poor 
glycemic control, lower extremity edema, 
infection, or even undiagnosed malignancy.  
Infections that may not be suspected include 
osteomyelitis deep to the ulcer, eumycetoma, 
mycobacteria, or atypical infections in the 
presence of immunosuppression.  
 
Guide- Setup and adjustment of the dermatome 
All dermatomes, whether mechanical or 
manual, have in common the blade, the guard, and 
the ability to adjust the distance between the two. The 
blade moves side to side to cut the skin, while the 
guard keeps the blade at the proper depth. The blade 
is removable from the device and intended for single 
patient use. If many grafts are being taken with the 
same blade, it may become dull as the operation 
proceeds.  
It is the surgeon’s responsibility to assure that 
the dermatome, whether mechanical or manual, is in 
perfect functioning order. If a graft is too thin, it may 
give a poor cosmetic or functional result, or may not 
take at all. If a graft is too thick, it may leave a full-
thickness defect at the donor site. The margin for 
error is between 0.25 and 0.5mm. The thickness of a 
standard #10 or #15 scalpel blade is 0.4mm. The 
thickness of your hospital's blades may vary, attempt 
to contact the supplier if you are starting to perform 
skin grafts for the first time in a new setting. 
Alternatively, for more precise measurements, a 
Feeler gauge can be used. This machine is used to 
measure the gap space in automotive spark plugs and 
may be available from a mechanic or auto supply 
store.  
 
Split Thickness Skin Graft 
Richard Davis, Vallery Logedi 
OPEN MANUAL OF SURGERY IN RESOURCE-LIMITED SETTINGS 
www.vumc.org/global-surgical-atlas 
This work is licensed under a Creative Commons Attribution-ShareAlike 3.0 Unported License  
 
A feeler gauge, with measurements in inches and mm. This can 
be used as is or disassembled and only the sizes used for skin 
grafts kept and used. By © Raimond Spekking / CC BY-SA 4.0 
(via 
Wikimedia 
Commons) 
https://commons.wikimedia.org/w/index.php?curid=71791974 
 
Manual dermatomes 
1. Place the blade in the space provided and secure 
it in place. 
 
The blade is slid into place between the guard and the base of 
the knife. 
 
 
Once in place, the blade is gently slid until its grooves are 
engaged by the tabs on the base of the knife.  
 
 
The cover is slid over the blade and secured by sliding it in the 
direction shown by the Red arrow.  
 
2. Measure the gap between the blade and the 
guard using a #10 scalpel blade. 
 
The space between the guard and the blade is measured with a 
#10 scalpel blade, which should just barely fit in the space all 
along the length of the blade.  
 
3. Adjust the thickness of the gap. Verify with the 
scalpel blade, as it should fit with no room to 
spare all along the gap. In some knives, there is 
a separate thickness adjustment on each side of 
the knife.  
 
Adjustments to the thickness of the blade are made by turning 
the dial. On some models of the Humby knife, there is another 
dial that secures the thickness once the adjustment has been 
made.  
 
Mechanical Dermatomes 
1. Put the throttle on “Safe” mode. Alternatively, 
assure that the dermatome is not connected to 
power during setup. 
Split Thickness Skin Graft 
Richard Davis, Vallery Logedi 
OPEN MANUAL OF SURGERY IN RESOURCE-LIMITED SETTINGS 
www.vumc.org/global-surgical-atlas 
This work is licensed under a Creative Commons Attribution-ShareAlike 3.0 Unported License  
 
 
On this air-powered dermatome, the throttle (Green arrow) is 
squeezed to activate the machine. Currently it is in safety mode. 
When the throttle is raised away from the handle and the black 
switch on the throttle is moved downward, the button (shown by 
the Red arrow) can be depressed when the throttle is squeezed. 
Note also that the dermatome is not connected to its air hose, 
an extra measure of safety for installation and setup. 
 
2. Place the blade in the space provided, assuring 
that the hole in the blade is aligned with the 
drive pin. 
3. Place a plate of the desired thickness in place 
and tighten the screws. Do not tighten 
excessively. 
 
The disposable blade (Green dot) is made of metal and white 
plastic fused together. It is placed with the correct side facing 
up so that the drive pin (Blue arrow) passes through the hole in 
the plastic. The plate (Red dot) is then placed above the blade 
and the screws tightened. The blade must lie freely in the space, 
as it will vibrate when the machine is engaged 
 
 
Plates of different sizes can be fixed over the blade to assure 
harvest of a perfectly uniform width of split thickness skin. 
 
 
The dermatome completely assembled and ready to be 
calibrated and used. Source: Hoffman HT (ed) Iowa Head and 
Neck Protocols “Case Example Split Thickness Skin Graft 
STSG 
Zimmer 
Dermatome 
settings” 
https://medicine.uiowa.edu/iowaprotocols/case-example-split-
thickness-skin-graft-stsg-zimmer-dermatome-settings Accessed 
5 May 2022 
 
4. Set the desired skin graft thickness by turning 
the control lever adjustment knob.  
Split Thickness Skin Graft 
Richard Davis, Vallery Logedi 
OPEN MANUAL OF SURGERY IN RESOURCE-LIMITED SETTINGS 
www.vumc.org/global-surgical-atlas 
This work is licensed under a Creative Commons Attribution-ShareAlike 3.0 Unported License  
 
 
The control lever adjustment knob can be set to the desired 
thickness of the graft, in mm or inches.  
 
5. Measure the thickness with a feeler gauge or #10 
scalpel blade. (Note that the Owner’s Manual of 
some dermatomes say to omit this step, but our 
practice is to never assume that the machine is 
properly calibrated.)  
 
 
The space between the blade and the guard (Blue arrow) should 
be gently probed with a #10 scalpel blade or feeler gauge along 
the entire length of the space. Careless or aggressive insertion 
of the gauge will chip or dull the blade. Source: Hoffman HT 
(ed) Iowa Head and Neck Protocols “Case Example Split 
Thickness Skin Graft STSG Zimmer Dermatome settings” 
https://medicine.uiowa.edu/iowaprotocols/case-example-split-
thickness-skin-graft-stsg-zimmer-dermatome-settings Accessed 
5 May 2022 
 
 
 
Richard Davis, MD FACS FCS(ECSA) 
AIC Kijabe Hospital  
Kenya 
 
Vallery Logedi, MBBS 
AIC Kijabe Hospital 
Kenya 
 
April 2022 
 
