CLOSURE OF RHOMBOID SKIN DEFECTS 301

British ffournal of Plastic Surgery (197’0, zS, 3oo-3~4 Foran’.
~s shownin
CLOSURE OF RHOMBOIDSKIN DEFECTS: THE FLAP~,
OF LIMBERG AND DUFOURMENTEL rotated thr.c

ByG. D. LISTER, M..B., F.R.C.S.(Ed.&Eng.) areaP~=:,-x~
and T. GIBSON,D.Sc.,/VLB.,F.R.C.S.(Ed.&Glasg.) thesepoints
Westof ScotlandRegionaPl lastic andOralSurgeryUnit, in turn de~
~onsideratie
CanniesburHn ospital, Bears&nG, lasgow ¢xtensibilit)
at right ang
IN excising the majorityof skin lesions, surgeonscreate an elliptical asat righta
can be closed directly. Asthe lesions increase in size, however,there comes
wheneither the long axis of the ellipse becomestoo long for the local its ownlenl
cosmetic result, or the short axis too wide to permit direct suture. In
instances the excisional outline maybe replanned and closure obtained with t~pthe skin
flap, until of course the defect becomesso large that cover can only be ~houldif
primary
imported skin. Fig.4, a).
Designingsuch local flaps, particularly whenthe secondarydefect is to withthepo:
ttowever,v
directly, can tax the skill of the mostexperiencedplastic surgeon. Only &rthe rho:
trial and error does he learn intuitively to judge the maximutmension under
can suture the pardy devascularised flap and the absolute limits to which Lirnbe
stretch the surroundingskin ; the art of designing such flaps takes long to anglesand
l.imberg’:s
is hard to teach. modelsprc
Thereare, however,2 exceptionsto whichwewouldlike to draw ~aut,slight
~hornboid
the flaps designedby Limberg(I 946, 1966, and 1967) and by Dufourmentel
to close rhomboiddefects. Arhombusis an equilateral parallelogram and
regarded as an" ellipse with straight sides .". Rhomboiedxcision has so
over elliptical excision particularly whenthe defect is to be closed with a
For example,less normalskin needsto be excisedin the long axis, the designand
of a straight-sided flap is far simplerthan that of the roundflap and rhomboid
lends itself to the technique recommendebdy Borghouts(1964) of histological

lion of the specimenmargins to check mmoucr learance.
TheLimbergflap and the Dufourmentefllap are different in design and

and will be described and discussed separately.

THE !LIMBERG FLAP

Theflap which Limbergdesigned for a rhomboiddefect is one extension
classical studies on transposed triangular flaps. Thusin Figures I and 2 the

dosed by interchanging the unequal flaps TLWand UVWT. he design may

regarded as a rhomboidflap XUVoWf the samesize and shape as the defect into

it is to be rotated.

angleTshoeffla6p0° wanhdenIu2sOe°d;siinngltyhisis suitable for closure only of arh6o0m° brhooidmboid.
paper such a defect is called

rhombusis thus composedof 2 equilateral triangles and the short axis is

length as eachside.
In constructing the flap (Fig. I) the short diagonal is extendedin one

direction by its ownlength to the point V. Afurther incision VWparallel to
equal to each of the sides completesthe design. It will be evident that the

UWis also equal to the short diagonal[of the defect and therefore to all other

in the plan. All attractive aspectof this Limbergflap is that, oncethe len
diagonal has been determined, the. remainder of the design maybe completedby

calipers set to that length.

3oo

CLOSURE OF RHOMBOID SKIN DEFECTS 301

FLAPS For any given 6o° rhomboiddefect there are theoretically 4 Limbergflaps available

~tical shownin FigUreo3.Oncethe most appropriate flap has been chosen and raised it is
,~erecomeisi t~otaa-t~~-u~pr"o,hxriomuoa~tehd6ino and placed in the defect (Fig. 2). It will be seen that U and
local closing the secondary defect. If Nllowsthat the ease with which
z. In
ained with ~km~trsn cdacnpebnedsaopnpothseedrdeelatetirvme~easvwaihlaebthfeikryorannodtexth[eendsiebs~igitny iosf atphperospkriina.teA;mta~josr
be
~nsiderafion. in planing should therefore be to seek out the d~ecfion of maxim~
%ctis to
Only ~tensibilit~ xn t~e skin ~r2und,~defect (gibso~ et ~l., z~69~.This line is usually
right angmsto ~angers ~mes~umsonet at., ~97~)ana on merace it maybe regarded
on under
~to which ~ at right angles to the crease ~es. It maybe readily determ~edclinically by pic~g
long to

mentel
)gram and
as some

=l wit_ha local~i
~ design and
[rhomboid ex’~i~
.lstologlcal ex~

;ign and appli~~

V

Fro. i. Design of a Limberg flap. STUXrepresents a 60° rhomboid defect. SU is extended by

,ts ox :~ ;:ngth to V. "qWis then drawn parallel and equal to UX. Note that the distance between
any 2 adjacent points in the design is identical.
~ne extension
c and 2 the defee~jli~
~p the skin betweenfinger and thumb. Havingfi~und that line, the points Uand W
: design may .a~.~ *h0uldif possible be placedon it ; they lie on the sameline as oneof the sides of the
:he defect into primary defect and ~ flaps can be designed in this fashion for any one 6o° rhomboid

omboid defe~~ Fig. 4, A). If the lesion is circular, the rhomboidcan be rotated giving ~ moreflaps
6o° rhomboid.
~ort axis is the "*’ith the points Uand Win the sameline of maxim,aemxtensibility (Figs. 4, Band4, c).

ttowever, whenthe shapeof the lesion already determinesthe positioning of the rhom-
Midthese remarksare not appropriate and one selects the mostsuitable flap available

~ded in one or ’.’or the rT, omboisdo positioned.
gr parallel to Limbergpointed out that movingany flap inwflves but 2 processes, openingwound

!ent that the dii~ ingles and closing woundangles. Closing a woundangle produces a dog-ear or, in
: to all other I.imberg’s moreprecise term, a standing cone. Openingan angle in Limberg’spaper
~he length of th~ modelsproduces a lying cone. This cannot forra in skin ; what usually occurs is a
)e completed by.~ :aut, slightly depressed area around the angle. If for exampleone were to close the

:homboiddefect shownin Figure I directly, dog-ears wouldform at points T and X

302 BRITISH JOURNALOF PLASTICSURGERY

and depressed areas at S and U. By adding the rhomboid flap for closure
avoids any movementof angles T and S. This can bc of cosmetic value,
i~ the deformationsaroundthe other angles can bc placed in less obtrusive

v

BC LME
FIG. 12. A, the flap designed in Figure I has been cut and transposed into the defect.
Fro. 4. \V
post-operatively. C, z weeks post-operatively. Fig. I) lie,
~a ~e so s
PRACTICAALPPLICATIONS

Excisional Surgery. In most cases it is possible to decide in advance
skin lesion will require elliptical excMonand direct closure, excision with
closure or excision and distant skin cover.

Where doubt exists about the practicabilky of direct closure k is wise to
only the lesion with appropriate clearance as the initial step. If apposition then
that direct closure is feasible further excision to create an ellipse suitably long to

CLOSURE OF RHOMBOID SKIN DEFECTS 303

losure

[ue,

;lV~

FIG. 3. In theory a

choice of 4 Limberg
flaps is °avrahiloamblbeoifdor
any 6o

defect.

LME

LME __ J__~ _

~tefect. B, 6 t;I..~. 4. With roughly circular lesions the rhombus should be so positioned that points U and W
rlg: I) lie on the line of maximumextensibility. There are ~ possible ways in which the rhombus
vance ~n t~e so sited (A and B) and thus 4 flaps of this kind are available (C). This of course is
a with local
is wiseto applicable if the shape of the lesion dictates the position of the rhombus.
;ition then
bly long to

304 BRITISH JOURNAL OF PLASTIC SURGERY

Fro. 5. A, Two alterna-
tive Limberg flaps have
been designed. The 2
others theoretically avail-
able would encroach upon
the ear. B, Direct closure
~va8 felt to involve sutur-
ing under undue tension.
C, The more suitable flap
was chosen, cut, transposed
and sutured, (D and E)

with good result.

the formation of permanent dog-ears is performed. If direct closure is form
inapplicable no normal tissue has been discarded needlessly and a flap
designed can be cut and rotated into position (Fig. 5).

At the other extreme of applicability, it maybe found that U and W

.~ :s. 6. Adefect in athneglfeosrmofof6a0°paanradllloenl-g
:,r:am, havingacute
~,3~twice that of the short, cart be closed
,.:.~., Limbergflaps. The5 possible designs
are shown.

A

OSLlreJS BC
ad a flap ~" "- Aparallelogram defect created by excision of a rodent ulcer closed by ~ Limbergflaps. Any

U and W distortion of the eyebrowor irregularity of the hairline wasavoidedby the choiceof flaps.

306 BRITISH JOURNAL OF PLAsTIc SURGERY measureda~

approximated even after undermining. The flap must then be replaced limbs pointi
alternative means of skin cover found. With a little experience, however, should 2 sh~

Occurs. positio.n,,an

The Simultaneous Use of 2 Limberg Flaps. Any defect which can be is crc’:. :.
as a parallelogram the long side of whichis twice as long as the short side,
angles of which are 6o°, maybe closed with 2 Limberg flaps. ulcero’~
occurred.
FiG. 8. A circular defect may
be considered as a hexagon. On oc~
Each side equals the radius of
undesirable
the original circle in length. Gillies fan f

FIG. 9- All equilateral 6oh°exrahgoomn-s
are made up of three

boids. Three Limberg flaps can

be constructed to close a hexagonal

defect. Preferably the peripheral
limbs should point in the same

direction.

FIG. IO. Construction where 2

of the flaps have peripheral limbs
pointing towards one another.

This may be necessary anatomic-

a1l2lyo°, but the angle closed at A is
and will produce a dog-ear.

FtG. 8

> teukoplakiao
that no furtt
FIG. 9 FIG. IO whichwas n:
a commonb
There are 5 possible constructions (Fig. 6) ; the choice will depend
Altho,u.~iht
anatomy and the availability of skin. A clinical example is shownin Figure 7. flap of~uc~
have -. a d/
The Simultaneous Use of 3 Limberg Flaps. A circular defect closely
i’:;;2erP,
to the form of a hexagon, the length of the radius equalling the length of each and free skir
sides (Fig. 8). All such equilateral hexagons are madeup of three ° backs while
becauseof tl:
3 Limberg flaps can therefore be designed to close the defect (Fig. 9). In this ts dividedin
and further
the calipers are invaluable ; set to the radius of the circular defect 18

7CLOSUROEF RHOMBOISDKIN DEFECTS 3O

replaced tneasured and markedand the design completed. Theflaps should have the peripheral
however, limbs1- 9ointing in the samedirection as in Figure 9. Onlyin special circumstances
~hould~ share a commobnase (as at a in Figure IC.) since, whenthey are rotated into
h can be
rt side, andi ~¯~POeaSrcerdi.t.ioI,nnatnheancgaleseofil.~lu:zsot°ratiesdcloisnedFaignudrae p~r,oneoxucniscieodnanadgnpdrorabfatgbinlypoerfmraaadn"leonndteocrgo-tel"acr
ulcer , .: backhad previously beenperformed,but the graft failed and further necrosis
ar defect ~x-currcd."fhe ulcer wasagain excised and successfhlly closed with 3 Limbergflaps.

Sa Onoccasion closure of a defect maybe quite feasible technically but mayhave

the radius undesirable results. In the case shownin Figure ~:z the patient had previously had a
:le in length.
Gillies fan flap rotated at the left angle of his mouthand nowpresented with active

ateral 60h°exrahgoomn-s~
hree

nberg flaps can:

:lose a hexagonal

y the peripheral

int in the same

ion.

~ction where

s one another.
essary anatomic-
;e closed at A is’
~duce a dog-ear.i~

A Flc,. z t. A, A circular radionecrotic ulcer of the back was excised as an equilateral hexagon and 3
I.i:. flaps designed as in Figure xo. B, The defect excised and the flaps cut. C, Flaps tran-
FIG. IO
sposed and sutured with, later, (D) sound healing.
rill dependon
wnin Figure 7. l,’ukoplakia of the opposite commissure.WhileexcMonwasindicated, it wasimportant
:ct closely :hat no further narrowingof the mouthshould result. Three Limbergflaps, one of
-, lengthof each ahich wasmucosal, gave an acceptable solution. The2 skin flaps were designedwith
a°ree 6o ~ commobnase, however,and this resulted in the ,creation of a dog-ear as predicted.
~Fig. 9). In ¯ }tthoughit cannotbe easily appreciatedin black and whitephotographs,the use of the
defect 18 :Up of buccal mucosaserved to reconstitute the vermilion in a mannerwhich would
bare beendifficult to achievebyother means.

1 .,. IVebs. Moderatedegrees of finger webbingare usually treated by release
¯ nd flee skin graft or by Z-plasty. Howevera, free graft has certain inherent draw-
Nckswhile a Z-plasty maynot introduce sufficient tissue into the line of the web
becauseof the limitation in length of the central limb. It wasnoted that, whena web
’-~ divided in the midline (Fig. ~3) and the fingers separated, the defect is rhomboid
a~adfurther that there is frequentlysufficient skin onthe sides of the fingers adjacent

the we
favoris

In o
l~ave
,k-signar
:rodthe f.
~upplyis
.my of

,:k~cd
~’~ndar,

readih
hair
=any di£
:F~nwitk

The

FIG.12. A, Excisionof leukoplakiaof the .commissurise planned.Twoskin flaps and(B) ~mcourag,
mucosaflap designedC. , The2 skinflapswitha commboanseas in FigureI I hasresultedin a
dog-ear.D, Furthernarrowinogf the stomahas beenavoidedbyreconstructingthe vermilion’ ~re a
If co
commissuwreiththe buccalmucosafllap.
:~ults

CLOSUREOF RHOMBOISDKIN DEFECTS 309

Wthe web to supply a Limbcrg flap large enough to give good correction. The limiting
factor is again the amountof skin available, but this is easily assessed in advance.

,s and (B) one FIG. 13. A, Midline in-
esulted in cision of a finger webburn
contracture resulted in a
the vermilion rhomboid defect when the
fingers were separated. B,
A flap designed on the
adjacent finger was cut,
transposed and sutured

into place (C).

DISCUSSION

In our experience of over 5° cases in which the Limberg flap has been used, we
have found it safe, reliable and versatile. Onegreat merit of its geometrically precise
design and the fact that only one measurementis needed to construct both the defect
and the flap, is that it is so easily taught. The trainee has the assurance that the blood
~upply is adequate and that the edges to be apposed will fit together precisely without
any of the adjustment so often required in placing other flaps ; in other words, the
ttap vi!! " work".

¯ ,, :.major limitation of the Limberg flap is that the secondary defect must be
closed directly and flap placement cannot be eased by the use of free grafts on the
~condary defect ; the size depends directly on the awdlability of skin in the area. A
further limitation, commotno all local flaps, is that the correct quality of skin maynot
be readily available, for exampleafter excision of lesion’,; of or near the eyelids and close
to hair margins. At the same time because the Limberg flap can be designed in so
raany different directions, it is moreoften possible to construct a flap of the right skin
than with less versatile designs.

Thefinal scar follows a slightly bizarre line whichcannot all be lost in crease lines,
but ;., ~aost cases the quality of the scar has been good without spreading or hyper-
:ropl:. ad the result has certainly been better than that obtainable by the simplest
~hernadve, a full thickness graft. Theoretically the shape of the Limberg flap should
encourage the formation of a raised " trap-door " scar. Whether the increased tension
~mposedon the flap prevents this is not known,but we have only seen it on one occasion,
:~here a rather small flap was used.

If correctly executed and if good primary healing occurs, the Limbergflap produces
:esults which, for colour and texture matchand overall[ appearance, are excellent.

310 BRITISH JOURNAL OF PLASTIC SURGERY may prov
dosed
THE DUFOURMENTEL FLAP
be.inOgn6e0° r
Whereas the Limberg flap can only be constructed for a 6o° rhomboid ~
Dufourmentel flap, " ’ le lambeau en L pour losange ’ dit ’ LLL’", can, in
used for any rhomboid. The rhombus is thus composed of two isosceles Dufourme:
unlike the Limberg construction, the short axis of the defect need not equal learn and
its sides. The procedure may be regarded again as transposition of two
flaps or more obviously the rotation of an irregular quadrilateral flap into a Dufourme:
defect.
l.imberg i
In planning the Dufourmentel flap, the short diagonal LN(Fig. 14)
other of the adjacent sides of the defect KNare extended and the angle so!
bisected by a line (NQ)equal in length to each of the sides of the defect.
line (QR)is then drawn parallel to the long axis of the defect and again equals
each side of the defect. Calipers are: of someuse in constructing the flap
incisions are of equal length, l:.ut a protractor is necessary to place the
accurately. Once raised, the flap KNQRis transposed into the defect.
in Figure 15, 4 Dufourmentel flaps can be planned for any rhomboid
the 4 angles of the defect come to equal one another, as the rhomboid
shape of a square, flaps maybe designed at each of the 4 angles giving 8
(Fig. 16).

The merit of placing the equivalent points N and R in the line of
extensibility has already been discussed in considering the Limbergflap.
complicated with the Dufourmentel design ; indeed, on initial consideration,
to be quite impractical, since the relationship of the baseline of the trian
defect varies as the shape of the rhomboid varies. However,as the geometrical
of the design given as an appendix to this paper shows, the angle between
axis of the flap (NR) and the short axis of the defect (LN) changes by
degrees from 15o° as the acute angle of the defect varies from 6o° to 9o°. Thisi
may be ignored and, in practice, having determined the line of maximumskin
bility, points N and R may be placed upon it and the short axis of the
angle of I5o° to that line. Tiffs applies only to those cases in which the
the rhombusis not dictated by the shape of the lesion.

As the acute angle of the defect falls below 6o°, the Dufourmentel flap
progressively wider than the primary defect. Little is to be gained therefore
use of the flap in these circumstances and direct closure is to be preferred.

As the acute angle of the defect increases from 6o°, the defect becomes
wider than the flap and whenit reaches a square the short axis of the flap is
quarters the length of the short axis of the defect. It is in this range that the
clinical value.

PRACTICAL APPLICATIONS

As shown above, the Dufourmentel flap has no practical value where
angle is less than 6o°. In closing a 6o° rhomboid defect, it has no advantage
Limbergflap, although it has been argued in its favour that it has a safer blood
than the Limberg flap because its base is wider. Embarrassment of the blood
of a Limberg flap, however, is rarely seen anywhere on the body and never on

It is in closing defects the acute angle of whichlies between6o° oan°,d 9
that the Dufourmentel flap is of use. Such defects are not often created as
excision is usually possible to convert the defect to a 6o° rhomboidwhichcan bel
with the simpler Limberg flap. Where, however, such additional excision is
indicated, for example by the proximity of vital structures, then a

CLOSURE OF RHOMBOID SKIN DEFECTS 3I~

:homboid ~rovidea satisfactory solution. Sucha procedurefor a defect whichcould not be
", can, in maYdo~r eddirectly withoutunduetensionis shownin Figurex7-
osceles
:d not equal ~
3n of two
flap into a ....¯ ~,~~,.,~

(Fig. 14) q :
the angle so F), I
he defect.
~gain equals I
ing the flap
lace the flap FIG. 14
le defect.
homboid FIG. 14. Design of a Dufour-
nboid mentel flap. LMNKrepresents
giving 8
a rhomboid defect. LN and
fine KNare extended and the angle
:rg flap. This thus formed bisected by a line
nsideration,
e triangular NQequal to each of the sides of
te geometrical the rhomboid. QR is then drawn
gle between of equal length and parallel to
ages by less the long axis of the defect MK.

~O°.tO 9 FIG. 15. In theory a choice of

aaximumskin
ds of the
which the

armentelflap b~
aed therefore
preferred.
becomes
F the flap is only
:ange that the

4 Dufourmentel flaps is available

for any ade6feoc°t approximating to
rhomboid.

value where FIG. 16. If the defect is square
no advantage in shape a choice of 8 flaps is
~as a safer blood
mt of the blood available.

Fm. 16

DISCUSSION

7 a6n0°d oann°e,dv9er on bein~g:~6.oe° omraj~ozrom°,erailtl of the Limbergflap is the simplicity of the design, all angles
~ sides being equal. This rnakes it easy to learn and apply. The

en created as Dufourmentelflap is by no meanscomplicated, but it is certainly moredifficult to

oid whichcan be i learn and to plan than the Limbergdesign. Indeed, at first sight it.seems that the

onal excision is Dufourmenteflap with its angles rarely matchingthose of the defect is inferior to the

,en a Dt Limbergdesign, but this is too superficial a view. In both instances a defect is

312 BRITISH JOURNAL OF PLASTIC SURGERY

AB closedan,
t,znsion;
D bythe en,

C In its
flap!"
FIG. 17. A, A Dufour-
more
mentel flap has been de-
signed for a planned the defect
obtuse an:
rhomboid excision 7h5a°v.inBg, the obtus~
an acute angle of become
cited byt
Direct closure would have ~mto h’,

involved suturing under The:

considerable tension. corn[" ~i ~cr

Fro. 17. C, The flap was The ]
cut, transposed and sut- dderation
ured (D) with good result knowledge
fortunate
(E). age group
far-closed
cosmetical

As th~
trend has
from Figm

Varial
angleof a:

byo::c
l "arial

tcadity see
With each
equal whet

Since
I44, the a1
l~.vplotting
~zcs which

l"l,~,p,.,..

In oth,
~hisis negli

CLOSURE OF RHOMBOID SKIN DEFECTS 313

dosedandin closinigt thesurroundisnkginis stretcheadndputunderincreased

t~sio;ntheanglescarefullpylanneadndmeasuremdayhavechangecdonsiderably
bytheendoftheprocedure.
" In i,s range of usefulness between60° and 9o°,the acute angle of the Dufourmentel

lta-; -ws moreacute than that of the defect, while the obtuse angle of the flap is
moreobtuse than that of the defect. But imaginepoint L being pulled to point Nas
the defect is closed ; the acute angle of the flap wouldtend to becomeless acute, the
obtuse angle less obtuse, while the acute angle of the defect becomesmoreacute and
~he obtuse angle moreobtuse. In other words the angles of the flap and the defect
becomemuchmore congruous. Unfortunately this variation in angle size is compli-
cated by the closure of the secondarydefect ; app,’oximatingpoint Nto point Rwould
.~rn to havethe oppositeeffects on the angles than bringing L to N.

The matter is obviously very complex;even if we had simple reliable methods

of rnc:~,.wingextensibility of skin at any onesite and the effect of varyingtensions on
~, th, , ..".y, sis and prediction of the exact behaviourof either flap wouldrequire a
,-omputerrather than a plastic surgeon.

TheDufourmenteflap is probablythe better design in so far as it takes into con-

sideration the effects of increased tension onthe skin, but until wehavemoreprecise
knowledgeof the latter both designsare still to someextent empirical. It is perhaps
fortunate that the majority of cases in whichthe tlaps havebeen usedare in the older

age groupand old skin absorbs unequalangles, unequalsides, too-far-openedand too-
far-closed angles in a waywhichmakessuch flaps, with their various shortcomings,
~smeticallyso successful.

APPENDIX

MATHEMATICAL CONSIDERATIONS IN THE DuFOURMENTEL FLAP

Astheangleosfthedefecvtarysodo themeasuremeonfttsheflap.Thegeneral

t~¢nhdasbeengiveinn thetext,butthemathemativcaarliatioanrscreadildyerived
fromFigure18, A.

Variationof the AcuteAngleof the Flap(/3) with that of the Defect (~.). /3 is one
angle of a right-angled triangle the other angle of whichis equal to Y/4. Since

y = ~8o-~ .’. /3 = 45+~/4

°b.y :~as been plotted on Figure ~8, B. For eachdegree of changein v., ~ changes
quarter of a degree. Theyare only equal whenboth are 6o
one

Variationof the ObtuseAngleof the Flap (8) ~withthat of the Defect (y). It can
readily seen that 8 = i8o-7’/4 and this relationship is also plotted on Figure ~8, B.
\rith each degreechangeof y, 8 varies by one quarter of a degree and the angles are
r°q. ual whenboth are ~44

Since fi fits = precisely only whenboth are 6o° and 8 fits y only whenboth are

~44, the angles of the flap cannotbothequal their respective anglesin oneconstruction.

};y plotting ~.//3 against y/8 in Figure I8, c it is possible to determinethat the angle
~es.,.vhich givethe closest approximatioton perfect fit are ~ 5o°, y ~3o° ; /3 58°, 8 ~48°.

~ :~ion of the Angle (0) betweenthe Short Axis of the Defect (a) andthat of
~.:!a,ip,5.

°0-c/3a/n2.be readily shownto be equal to ~ 8o
Substituting/~ -- 45° + e/4 and symplifying
0 = I57½°- ~/8.

In other words0 changesat a rate 8 times slower than ~ and in the clinical range
:his is negligible.

314 BRITISH JOURNAL OF PLASTIC SURGERY

Variation in Lengths of Short Axes’ of Flaps and Defect. Since the con:
madeup of isosceles triangles the same relationship exists betweena and b and!
ft. In other words a and b are equal whena is 6o°. As 0~ increases towards t
short axis of the defect (a) increases at a rate 4 times as rapid as (b).

~ 0.sTs FIG. I8. A, See appendix. B, EVERsin
By plotting the acute angles of for grafti
o.~ ~.o ~.s the flap and the defect, ~ and fl donorsit
against one another a direct re- the skin
lationship is shown. A similar a&ieved,
relationship is obtained plotting skin is ri
the obtuse angles 7 and 8 against ~ually o
one another. C, If the ratio of not alwa}
the acute angles one to the other,
oqfl is plotted against the ratio of ~st-auri,
the obtuse angles y/8 the value :~r dora,’
at which these ratios are equal,
and therefore at which the angles :-’.’-:..7
are most congruent, can be
~::G.I.
obtained. ~ post.
:--4 inade
c

REFERENCES

BORGHOUTJ.S, M. H. M. (x964)- Surgical treatment of basal-cell carcinoma and

cell carcinoma of the skin. Archivum Chirurgicum Neerlandicum, x6, I9-3o.

DUFOURMENTECL. ,(I962). Le fermeture des pertes de substance cutan6e limit&s

lambeau de rotation en L pour losange " dit " LLL". Annales de Chirut

7, 6~-66.
DUFOURMENTCE.L,(t963). An L-shaped flap for lozenge-shaped defects. Transactions

the Third International Congress of Plastic Surgery, p. 772. Amsterdam:

Medical Foundation.

GIBSON, T., STARK, H. and EVANS,J. H. (~969). Directional variations

of humanskin in vivo. ffournal of Biomechanics, ~T,he42o.sii-g2noificance of Langer’s
GIBSON,T., STARK,H. and KENEDI, R. M. (~97~)-

Transactions of the Fifth International Congress of Plastic and Reconstructive

p. ~2~3. Melbourne : Butterworths.

LIMBERGA,. A. (~946). Mathematical principles of local plastic procedures on the

of the human body. Leningrad : Medgis.

LIMBERGA, . A. (~966). Design of local flaps. In " Modern Trends in Plastic Surgery

Second Edition, ed. by Gibson, T. London : Butterworths.

LIMBERGA, . A. (~967). Planimetrie und Stereometrie der Hautplastik. Jena

Fischer Verlag.