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RESULTS The comparison of primary contraction values between
square‑ and circle‑shaped FTSG specimens was not
In the first part of the study, comparison was made statistically significant (P = 0.14). The circle‑shaped STSG
between the contractions of FTSGs and STSGs. The initial specimens demonstrated a primary contraction ranging
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surface area of the FTSG specimens was 12.56 cm . After from 12.6 cm (0% shrinkage) to 11.9 cm (5.0% shrinkage).
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excision and defatting, the area values of the contracted The mean area value of the circle‑shaped STSGs was 12.4
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skin grafts ranged from 12.6 cm (0% shrinkage) to 9.3 cm cm and the median was 12.6 cm . In the circle‑shaped
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(25.6% shrinkage). The mean area value of the FTSGs STSGs group, the mean percentage of graft shrinkage was
after primary contraction was 11.1 cm and the median 1.1% and the median was 0% [Table 2]. The square‑shaped
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was 11.0 cm . The mean percentage of graft shrinkage specimens showed primary contraction ranging from
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was 12.0% and the median was 12.2% [Table 1]. The initial 16.0 cm (0% shrinkage) to 15.8 cm (1.3% shrinkage). The
surface area of the STSG specimens was 16 cm . After mean and median area values of the square‑shaped STSGs
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harvesting with the dermatome, the area values of the were both 16.0 cm . In the square‑shaped STSGs group,
contracted skin grafts ranged from 16 cm (0% shrinkage, the mean percentage of graft shrinkage was 0.31% and
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1 specimen recorded) to 13.30 cm (17% shrinkage). The the median was 0% [Table 2]. The different shrinkage rates
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mean area value of the STSGs after primary contraction between square‑ and circle‑shaped STSG specimens were
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was 14.9 cm and the median was 15.2 cm . The mean not statistically significant (P = 0.33).
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percentage of graft shrinkage was 6.9% and the median
was 5.0% [Table 1]. FTSGs presented greater primary DISCUSSION
contraction than STSGs at a statistically significant level
(P = 0.0011) [Table 1]. Skin graft contraction is a common problem resulting
in significant morbidity with restriction of joint mobility
In the second part, the role of the skin graft shape on and cosmetic complications, often requiring multiple
primary skin contraction was investigated. The initial corrective operations. Secondary contraction has received
surface area of the circle‑shaped specimens of both the most research emphasis due to the fact that it is
FTSGs and STSGs was 12.6 cm and the initial surface clinically more important than primary contraction.
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area of the square‑shaped specimens was 16.0 cm . After Secondary contraction often results in severe effects
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excision and defatting, the circle‑shaped FTSGs had a on body function or patient appearance. Studies on
calculated surface range from 12.3 cm (2.0% shrinkage) the cellular activity underlying skin graft contraction
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to 11.3 cm (9.8% shrinkage). The mean area value of the support a most probable theory that the contraction
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circle‑shaped FTSGs was 11.8 cm and the median was occurs secondary to the differentiation of fibroblasts
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11.7 cm . In this group, the mean percentage of graft to myofibroblasts with expression of α‑actin filament
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shrinkage was 5.8% and the median was 6.9% [Table 2]. bundles which exert an inward pull on the wounds
On the other hand, the square‑shaped FTSGs ranged edges. [1,9,10] The myofibroblasts have contractile properties
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from 15.6 cm (2.5% shrinkage) to 14.8 cm (7.4% similar to smooth muscle cells and organize their actin
shrinkage). The mean area value of the square‑shaped cytoskeleton along the lines of greatest skin tension. [1,11]
FTSGs was 15.3 cm and the median was 15.4 cm . In the As the myofibroblasts are adherent both to one another
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square‑shaped FTSGs group, the mean percentage of graft and to the fibronectin‑rich wound bed, the entire mass
shrinkage was 4.2% and the median was 3.8% [Table 2]. of granulation tissue contracts. Keratinocytes may also
[1]
Table 1: First part of the study: comparison between contraction of FTSGs and STSGs
Skin Initial area Mean area value Mean percentage of Mean SD P
graft value (cm ) after primary area value of FTSG to percentage of t-test FTSG
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type contraction (cm ) the initial area value (%) shrinkage (%) versus STSG
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FTSG 12.56 11.5 87.96 12.04 0.069 0.0011
STSG 16 14.9 93.13 6.87 0.052
FTSG: Full thickness skin graft, STSG: Split thickness skin graft, SD: Standard deviation
Table 2: Second part of the study: evaluation of the role of shape of skin graft in primary skin contraction
Skin graft type Initial area Mean area value Mean percentage of Mean SD P
value after primary area value of FTSG to percentage of t-test circle
(cm ) contraction (cm ) the initial area value (%) shrinkage (%) versus square
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FTSG
Circle shaped FTSGs 12.56 11.5 87.96 12.04 0.069 0.0011
Square shaped FTSGs 16 14.9 93.13 6.87 0.052
STSG
Circle shaped STSGs 12.56 11.83 94.17 5.83 0.021 0.142
Square shaped STSGs 16 15.34 95.85 4.15 0.016
FTSG: Full‑thickness skin graft, STSG: Split‑thickness skin graft, SD: Standard deviation
24 Plast Aesthet Res || Vol 2 || Issue 1 || Jan 15, 2015