CLOSURE OF RHOMBOID SKIN DEFECTS: THE FLAP~, OF
Transcription
CLOSURE OF RHOMBOID SKIN DEFECTS: THE FLAP~, OF
British ffournal of Plastic Surgery (197’0, zS, 3oo-3 ~4 CLOSURE OF RHOMBOIDSKIN DEFECTS: THE FLAP~, OF LIMBERG AND DUFOURMENTEL ByG. D. LISTER, M..B., F.R.C.S.(Ed.&Eng.) and T. GIBSON,D.Sc.,/VLB.,F.R.C.S.(Ed. &Glasg.) Westof ScotlandRegionalPlastic andOralSurgeryUnit, Canniesburn Hospital, Bears&n,Glasgow IN excising the majority of skin lesions, surgeonscreate an elliptical can be closed directly. As the lesions increase in size, however, there comes wheneither the long axis of the ellipse becomestoo long for the local cosmetic result, or the short axis too wide to permit direct suture. In instances the excisional outline maybe replanned and closure obtained with flap, until of course the defect becomesso large that cover can only be imported skin. Designingsuch local flaps, particularly whenthe secondarydefect is to directly, can tax the skill of the most experienced plastic surgeon. Only trial and error does he learn intuitively to judge the maximum tension under can suture the pardy devascularised flap and the absolute limits to which stretch the surroundingskin ; the art of designing such flaps takes long to is hard to teach. There are, however,2 exceptions to whichwewouldlike to draw the flaps designed by Limberg(I 946, 1966, and 1967) and by Dufourmentel to close rhomboiddefects. A rhombusis an equilateral parallelogram and regarded as an" ellipse with straight sides .". Rhomboid excision has so over elliptical excision particularly whenthe defect is to be closed with a For example,less normalskin needsto be excised in the long axis, the designand of a straight-sided flap is far simpler than that of the round flap and rhomboid lends itself to the technique recommended by Borghouts(1964) of histological lion of the specimen margins to check mmourclearance. The Limbergflap and the Dufourmentelflap are different in design and and will be described and discussed separately. THE !LIMBERG FLAP The flap 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 UVW.The design may regarded as a rhomboidflap XUVW of the same size and shape as the defect into it is to be rotated. The flap whenused singly is suitable for closure only of rhomboid angles of 60° and I2O° ; in this paper such a defect is called a 60° rhomboid. rhombusis thus composedof 2 equilateral triangles and the short axis is length as each side. In constructing the flap (Fig. I) the short diagonal is extendedin one direction by its ownlength to the point V. A further incision VWparallel to equal to each of the sides completes the design. It will be evident that the UW is also equal to the short diagonal[ of the defect and therefore to all other in the plan. All attractive aspect of this Limbergflap is that, oncethe len diagonal has been determined, the. remainder of the design maybe completedby calipers set to that length. 3oo Foran’. ~s shownin rotated thr.c areaP~=:,-x~ thesepoints in turn de~ ~onsideratie ¢xtensibilit) at right ang as at righta its ownlenl t~pthe skin ~houldif primary Fig.4, a). withthe po: ttowever,v &rthe rho: Lirnbe anglesand l.imberg’s : modelsprc ~aut,slight ~hornboid CLOSURE OF RHOMBOID SKIN FLAPS ~tical ,~erecomes ii local z. In ained with be DEFECTS 301 For any given 6o° rhomboiddefect there are theoretically 4 Limbergflaps available shownin FigUreo3.Oncethe most appropriate flap has been chosen and raised it is --~ ,hrou~h 6o and placed in the defect (Fig. 2). It will be seen that U and o totat~u " ~ a~proximatedin closing the secondary defect. If Nllowsthat the ease with which ~k~ts be apposed determ~esavailabfiky whether or and not ex[ensib~ity the design isof appropriate t~s mrn can dcpends on the relative the skin. A ;major ~nsiderafion. in planing should therefore be to seek out the d~ecfion of maxim~ ~tensibilit~ xn t~e skin ~r2und,~defect (gibso~ et ~l., z~69~. This line is usually right angmsto ~anger s ~mes~umsonet at., ~97~) ana on merace it maybe regarded ~ at right angles to the crease ~es. It maybe readily determ~edclinically by pic~g %ctis to Only on under ~ to which 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~ the skin between finger and thumb. Havingfi~und that line, the points U and W : design may .a~.~ ~p *h0uld if 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 Fig. 4, A). If the lesion is circular, the rhomboidcan be rotated giving ~ moreflaps omboid defe~~ "*’ith the points Uand Win the sameline of maxim,am extensibility (Figs. 4, B and4, c). ° 6o rhomboid. ttowever, when the shape of the lesion already determines the positioning of the rhom~ort axis is the Midthese remarksare not appropriate and one selects the most suitable flap available ’.’or the rT, omboid so positioned. ~ded in one or Limberg pointed out that movingany flap inwflves but 2 processes, opening wound gr parallel to ingles and closing woundangles. Closing a woundangle produces a dog-ear or, in !ent that the dii~ I.imberg’s more precise term, a standing cone. Openingan angle in Limberg’spaper : to all other modelsproduces a lying cone. This cannot forra in skin ; what usually occurs is a ~he length of th~ :aut, slightly depressed area around the angle. If for exampleone were to close the )e completed by.~ :homboiddefect shownin Figure I directly, dog-ears would form at points T and X 302 BRITISH JOURNAL OF PLASTIC SURGERY 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 deformations aroundthe other angles can bc placed in less obtrusive v FIG. 12. A, B C the flap designed in Figure I has been cut and transposed into the defect. post-operatively. C, z weeks post-operatively. LME PRACTICAL APPLICATIONS 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 Fro. 4. \V Fig. I) lie, ~a ~e so s CLOSURE OF RHOMBOID SKIN DEFECTS 303 losure [ue, ;lV~ FIG. 3. In theory a choice of 4 Limberg flaps is available for any 6o ° rhomboid defect. LME LME __ J__~ ~tefect. B, 6 _ vance a with local is wise to ;ition then bly long to t;I..~. 4. With roughly circular lesions the rhombus should rlg: I) lie on the line of maximumextensibility. There are ~n t~e so sited (A and B) and thus 4 flaps of this kind are applicable if the shape of the lesion dictates the be so positioned that points U and W ~ possible ways in which the rhombus available (C). This of course is position of the rhombus. 304 BRITISH JOURNAL OF PLASTIC SURGERY Fro. 5. A, Two alternative Limberg flaps have been designed. The 2 others theoretically available would encroach upon the ear. B, Direct closure ~va8 felt to involve suturing 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 may be found that U and W .~ :s. 6. Adefect in the formof a parallel:,r:am, havingacute angles of 60° and long ~,3~ twice that of the short, cart be closed ,.:.~., Limbergflaps. The5 possible designs are shown. A OSLlreJS ad a flap U and W B C ~" "- A parallelogram defect created by excision of a rodent ulcer closed by ~ Limbergflaps. distortion of the eyebrowor irregularity of the hairline wasavoided by the choice of flaps. Any 306 BRITISH JOURNAL OF PLAsTIc SURGERY approximated even after undermining. The flap must then be replaced alternative means of skin cover found. With a little experience, however, Occurs. The Simultaneous Use of 2 Limberg Flaps. Any defect which can be as a parallelogram the long side of which is twice as long as the short side, angles of which are 6o°, may be closed with 2 Limberg flaps. FiG. 8. A circular defect may be considered as a hexagon. Each side equals the radius of the original circle in length. measured a~ limbs pointi should 2 sh~ positio.n,,an is crc’:. :. ulcero’~ occurred. On oc~ undesirable Gillies fan f FIG. 9- All equilateral hexagons are made up of three 6o° rhomboids. 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 anatomically,° but the angle closed at A is 12o and will produce a dog-ear. FtG. 8 > FIG. 9 FIG. IO There are 5 possible constructions (Fig. 6) ; the choice will depend anatomy and the availability of skin. A clinical example is shown in Figure 7. The Simultaneous Use of 3 Limberg Flaps. A circular defect closely to the form of a hexagon, the length of the radius equalling the length of each sides (Fig. 8). All such equilateral hexagons are made up of three ° 3 Limberg flaps can therefore be designed to close the defect (Fig. 9). In this the calipers are invaluable ; set to the radius of the circular defect 18 teukoplakiao that no furtt which was n: a commonb Altho,u.~h it flap of~uc~ have -. a d/ i’:;;2erP, and free skir backs while becauseof tl: ts divided in and further replaced however, h can be rt side, andi ar defect S a the radius :le in length. CLOSURE OF RHOMBOID SKIN DEFECTS 3O 7 tneasured and markedand the design completed. The flaps should have the peripheral in the same direction as in Figure 9. Only in s pecial circumstances limbs19ointing ~hould~ share a common base (as at a in Figure IC.) since, whenthey are rotated into ~POScrition ~:zo° is closed and a pronounced probablypermanent , an theangle caseofillustrated in Figure ~, excisionand and a " dog-ear g raftin g of radlonecrotlc " ¯~ eared. . In . ulcer , .: backhad previously beenperformed,but the graft failed and further necrosis ~x-currcd. "fhe ulcer was again excised and successfhlly closed with 3 Limbergflaps. On occasion closure of a defect maybe quite feasible technically but mayhave undesirable results. In the case shownin Figure ~:z the patient had previously had a Gillies fan flap rotated at the left angle of his mouthand nowpresented with active ateral hexagons hree 60° rhom-~ 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~ 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 transposed and sutured with, later, (D) sound healing. A FIG. IO rill dependon wn in Figure 7. :ct closely -, length of each °aree 6o ~Fig. 9). In defect 18 l,’ukoplakia of the opposite commissure.WhileexcMonwas indicated, it was important :hat no further narrowing of the mouthshould result. Three Limbergflaps, one of ahich was mucosal, gave an acceptable solution. The 2 skin flaps were designed with ~ common base, however,and this resulted in the ,creation of a dog-ear as predicted. ¯ }tthoughit cannot be easily appreciatedin black and white photographs,the use of the :Up of buccal mucosaserved to reconstitute the vermilion in a mannerwhich would bare beendifficult to achieve by other means. 1 .,. IVebs. Moderatedegrees of finger webbingare usually treated by release ¯ nd flee skin graft or by Z-plasty. However,a free graft has certain inherent drawNcks while a Z-plasty maynot introduce sufficient tissue into the line of the web becauseof the limitation in length of the central limb. It was noted that, whena web ’-~ divided in the midline (Fig. ~3) and the fingers separated, the defect is rhomboid a~adfurther that there is frequently sufficient skin on the sides of the fingers adjacent the we favoris In o l~ave ,k-sign ar :rodthe f. ~upplyis .my of ,:k~cd ~’~ndar, readih hair =any di£ :F~nwitk The ~mcourag, FIG.12. A, Excisionof leukoplakiaof the .commissure is planned.Twoskin flaps and(B) mucosal flap designed.C, The2 skinflaps witha common baseas in FigureI I has resultedin a dog-ear.D, Furthernarrowing of the stomahas beenavoidedby reconstructingthe vermilion’ commissure withthe buccalmucosalflap. ~re a If co :~ults CLOSUREOF RHOMBOID SKIN 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. FIG. 13. A, Midline incision of a finger web burn contracture resulted in a rhomboid defect when the fingers were separated. B, A flap designed on the adjacent finger was cut, transposed and sutured into place (C). DISCUSSION ,s and (B) one esulted in the vermilion In our experience of over 5° cases in which the Limberg flap has been used, we have found it safe, reliable and versatile. One great merit of its geometrically precise design and the fact that only one measurement is 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, common to 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 more often possible to construct a flap of the right skin than with less versatile designs. The final 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 match and overall[ appearance, are excellent. 310 BRITISH JOURNAL OF PLASTIC THE DUFOURMENTEL SURGERY FLAP 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 unlike the Limberg construction, the short axis of the defect need not equal 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 defect. 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 some use 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 may be 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 when it 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. may prov dosed 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 Limberg flap, 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 which lies between 6o° o°, and 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° rhomboidwhich can bel with the simpler Limberg flap. Where, however, such additional excision is indicated, for example by the proximity of vital structures, then a One r be.ing60° ~ Dufourme: learn and Dufourme: l.imberg i CLOSURE OF RHOMBOID SKIN :homboid ", can, in osceles :d not equal 3n of two flap into a (Fig. 14) the angle so he defect. ~gain equals ing the flap lace the flap le defect. homboid nboid giving 8 fine :rg flap. This nsideration, e triangular te geometrical gle between ages by less DEFECTS 3I~ ~rovide a satisfactory solution. Such a procedure for a defect whichcould not be r directly withoutunduetensionis shownin Figurex7maYdo~ed ~ .... ¯ ~,~,~.,~ q F), I I : FIG. 14 O° . 9 ~ tO aaximumskin ds of the which the armentel flap b~ aed therefore preferred. becomes F the flap is only :ange that the FIG. 14. Design of a Dufourmentel flap. LMNKrepresents a rhomboid defect. LN and KN are extended and the angle thus formed bisected by a line NQequal to each of the sides of the rhomboid. QR is then drawn of equal length and parallel to the long axis of the defect MK. FIG. 15. In theory a choice of 4 Dufourmentel flaps is available for any defect approximating to a 6o° rhomboid. value where no advantage ~as a safer blood mt of the blood 7 and never on ~ 60° o°, and9 en created as oid whichcan be i onal excision is ,en a Dt FIG. 16. If the defect is square in shape a choice of 8 flaps is available. Fm. 16 DISCUSSION ~:~.e major merit of the Limbergflap is the simplicity of the design, all angles being 6o° or ~zo°, all sides being equal. This rnakes it easy to learn and apply. The Dufourmentelflap is by no meanscomplicated, but it is certainly more difficult to learn and to plan than the Limbergdesign. Indeed, at first sight it.seems that the Dufourmentel flap with its angles rarely matchingthose of the defect is inferior to the Limbergdesign, but this is too superficial a view. In both instances a defect is 312 BRITISH JOURNAL OF PLASTIC SURGERY closed an, t,znsion; by the en, In its flap!" more the defect obtuse an: the obtus~ become cited by t ~mto h’, The: corn[" ~i ~cr A B The ] dderation knowledge fortunate age group far-closed cosmetical As th~ trend has from Figm Varial angle of a: D C FIG. 17. A, A Dufourmentel flap has been designed for a planned rhomboid excision having an acute angle of 75° . B, Direct closure would have involved suturing under considerable tension. by o::c l "arial tcadity see With each equal whet Since I44 , the a1 l~.v plotting ~zcs which l"l,~p ,,.,.. Fro. 17. C, The flap was cut, transposed and sutured (D) with good result (E). In oth, ~hisis negli CLOSURE OF RHOMBOID SKIN DEFECTS 313 dosedandin closing it thesurrounding skinis stretched andputunder increased t~sion carefully planned andmeasured mayhavechanged considerably ; theangles bytheendoftheprocedure. " In i,s range of usefulness between60° and 9o°,the acute angle of the Dufourmentel lta-; -ws more acute than that of the defect, while the obtuse angle of the flap is moreobtuse than that of the defect. But imagine point L being pulled to point N as 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 becomesmore acute and ~he obtuse angle more obtuse. In other words the angles of the flap and the defect becomemuchmore congruous. Unfortunately this variation in angle size is complicated by the closure of the secondarydefect ; app,’oximatingpoint Nto point R would .~rn to havethe opposite effects 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. TheDufourmentel flap is probablythe better design in so far as it takes into consideration the effects of increased tension on the skin, but until wehavemoreprecise knowledgeof the latter both designs are still to someextent empirical. It is perhaps fortunate that the majority of cases in whichthe tlaps havebeen used are in the older age group and old skin absorbs unequalangles, unequalsides, too-far-opened and toofar-closed angles in a way whichmakessuch flaps, with their various shortcomings, ~smeticallyso successful. APPENDIX MATHEMATICAL CONSIDERATIONS IN THE DuFOURMENTEL FLAP Astheangles ofthedefect varysodo themeasurements oftheflap. Thegeneral t~¢nd hasbeengiven in thetext, butthemathematical variations arcreadily derived fromFigure18, A. Variationof the Acute Angleof 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 :~as been plotted on Figure ~8, B. For each degree of changein v., ~ changes °. by one quarter of a degree. Theyare only equal whenboth are 6o Variationof the ObtuseAngleof the Flap (8) ~with that 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 degree changeof y, 8 varies by one quarter of a degree and the angles are °. rqual whenboth are ~44 Since fi fits = precisely only whenboth are 6o° and 8 fits y only whenboth are ~44, the angles of the flap cannot both equal their respective angles in oneconstruction. };y plotting ~.//3 against y/8 in Figure I8, c it is possible to determinethat the angle ~es .,.vhich give the closest approximation to perfect fit are ~ 5o°, y ~3o° ; /3 58°, 8 ~48°. ~ :~ion of the Angle (0) betweenthe Short Axis of the Defect (a) and that of ~.:!ap ,i,5. °-/3/2. 0 can 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). EVER sin for grafti donorsit the skin a&ieved, skin is ri ~ually o not alwa} ~st-auri, :~r dora,’ ~ 0.sTs o.~ ~.o ~.s FIG. I8. A, See appendix. B, By plotting the acute angles of the flap and the defect, ~ and fl against one another a direct relationship is shown. A similar relationship is obtained plotting the obtuse angles 7 and 8 against one another. C, If the ratio of the acute angles one to the other, oqfl is plotted against the ratio of the obtuse angles y/8 the value at which these ratios are equal, and therefore at which the angles are most congruent, can be obtained. :-’.’-:..7 c REFERENCES BORGHOUTS, J. M. H. M. (x964)- Surgical treatment of basal-cell carcinoma and cell carcinoma of the skin. Archivum Chirurgicum Neerlandicum, x6, I9-3o. DUFOURMENTEL, C. (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. DUFOURMENTEL, C. (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, ~, 2oi-2o 4. GIBSON,T., STARK, H. and KENEDI, R. M. (~97~)- The significance of Langer’s Transactions of the Fifth International Congress of Plastic and Reconstructive p. ~2~3. Melbourne : Butterworths. LIMBERG, A. A. (~946). Mathematical principles of local plastic procedures on the of the human body. Leningrad : Medgis. LIMBERG,A. A. (~966). Design of local flaps. In " Modern Trends in Plastic Surgery Second Edition, ed. by Gibson, T. London : Butterworths. LIMBERG, A. A. (~967). Planimetrie und Stereometrie der Hautplastik. Jena Fischer Verlag. ~::G. I. ~ post. :--4 inade