J Plast Reconstr Aesthet Surg. 2008;61( 5):529-34.
The final appearance of a scar may be influenced by tension or mechanical factors
[Borges AF. Scar prognosis of wounds. Br J Plast Surg 1960;13:47-54; Arem AJ, Madden
JW. Effects of stress on healing wounds. J Surg Res 1976;20:93-102; Burgess LP, Morin
GV, Rand M, et al. Wound healing. Relationship of wound closing tension to scar width
in rats. Arch Otolaryngol Head Neck Surg 1990;116:798-802; Meyer M, McGrouther DA.
A study relating wound tension to scar morphology in the pre-sternal scar using Langer's
technique. Br J Plast Surg 1991;44:291-4] Karl Langer suggested that information could
be gained about the tension inherent in skin, in all directions, by observing the
wound edge retraction that occurred after making circular skin incisions [Langer K.
On the anatomy and physiology of the skin II. Skin tension. Br J Plast Surg 1978;31:93-106].
Circular wounds may be used to demonstrate the orientation of the dominant axis of
'tension' in the skin but is this always a tensile stress as opposed to a compressive
stress? This is the second article in a series documenting the mechanical properties
of circular punch biopsy wounds. The aim of this study was to make detailed observations
of the dimensional distortions of circular wounds on the face and neck, from which
deductions could be made with regard to mechanical stress. One hundred and seventy-five
benign head and neck lesions were excised from 72 volunteers using circular dermal
punch biopsies. The distortions of the resulting wounds were observed to be elliptical
in most cases. Measurements were taken of the maximum and minimum diameters of the
wound and expressed as ratios of the size of the punch biopsy used for excision. The
change in area from the area of the punch biopsy to that of the wound was also calculated.
The maximum diameter of the wound was smaller than the diameter of the punch biopsy
in 40.6% of cases, the minimum diameter of the wound was smaller in 97.7% of cases
and the area of the wound was smaller than that of the punch biopsy in 90.3%. These
dimensional changes varied between sites (P=0.0005, P=0.0001 and P<0.0001, respectively).
We conclude that the reported rhomboidal or lattice structure [Ridge MD, Wright V.
The directional effects of skin. A bioengineering study of skin with particular reference
to Langer's Lines. J Invest Dermatol 1966;46:341-6] of skin has individual components
which are under tensional force due to elastic retraction. Wounds smaller than the
rhomboidal unit will reduce in area, due to the intact tensional forces in the individual
dermal components, giving an appearance of the skin overall being under compression.
Larger wounds, disrupting more of the lattice structure, will gape.