SKIN TRANSFER TO AMPUTATION STUMPS By J. R. ASCOTT, M.B., B.S., D.O.M.S. From the Department of Plastic Surgery, Queen Mary's Hospital, Roehampton THE ideal amputation stump should have an ample covering of skin with normal sensation, the scar should be mobile, narrow, and flat, and so placed that it escapes undue pressure from the socket of the prosthesis. In war such ideals are not always attained, since conditions dictate the use of open flap and guillotine amputations, while civil trauma may result in amputation stumps deficient in skin cover. Open flap amputations heal to form a puckered adherent scar ; guillotine amputations and amputations through compound fractures with skin loss may take many months to heal. Infection of the cut bone end is the rule, and if the stump is too short to be reamputated it may well be nine to twelve months before it is in a fit condition to wear a prosthesis. Even then the broad terminal adherent scar will require very skilful limb fitting and graduated limb wearing, as it will tend to break down if not carefully protected. The records of such patients show that it may indeed be eighteen months or longer from the time of amputation until they can wear a limb all day. Their future is somewhat precarious because at any time additional stress may cause a breakdown of the stump. This long period of rehabilitation can be very materially shortened by transferring suitable skin to make good the defect in the covering of the stump, and at the same time the requirements of the ideal stump are more closely attained. FREE SKIN GRAFTS If, following an amputation, a stump is short of skin covering, treatment should be directed towards securing epithelialisation as soon as possible since an infected granulating surface not only delays rehabilitation but leads to fibrosis and retarded healing. The usual procedure of skin traction reduces the area of apparent skin loss but should not be used as a substitute for skin replacement. As soon as the granulating surface is suitable for grafting, judged by clinical appearance and bacteriological findings, it should be covered by free skin grafts either as pinch grafts or as small squares of split-skin graft. Such a graft may fail to take over the cut end of the bone owing to infection in the bone end, but if the remainder of the graft has taken, the bone end usually heals over without much delay (Figs. I and 2). In the case of amputations through joints there is no cut bone to cover and a good take can be expected. If grafting has been delayed for two or three months dense fibrosis will have occurred with the formation of unhealthy granulation tissue and the chances of a successful skin graft are considerably reduced (O'Connor and Kessler, 1945). When healed, the stump is reviewed by orthopmdic and limb-fitting surgeons with a view to finalisation. Procedures to be considered are :-- I. Fitting a Prosthesis to the Stump as it is.--a stump healed by free skin grafts 115
116 BRITISH JOURNAL OF PLASTIC SURGERY is unlikely to stand up to limb-wearing unless the area of graft is comparatively small, and by virtue of being placed over soft tissue is reasonably mobile. 2. Revision of Stump without shortening the Bone.--This usually involves the readjustment of available skin, the object being to replace adherent or depressed scars or grafted areas with mobile skin, leaving flat, non-adherent scar lines. 3. Reamp utation.mlf the limb-fitting surgeon is agreeable to the stump being shortened, reamputation will produce a relative increase in the skin available to cover the end of the stump. Factors such as the blood supply of the stump and the age and general condition of the patient will influence the decision whether to preserve a joint or reamputate above it. FIG. IA FIG. I B FIG. 2 Figs. IA and IB.--A short below-knee amputation stump with a large skin defect and sequestrum, later healed by free skin grafts. Fig. 2.--A below-knee amputation stump three months after amputation showing the skin defect covered with unhealthy granulations. 4. Skin Replacement.--If further shortening is contraindicated, replacement of unstable skin graft or scar by a suitable skin flap should be considered. LOCAL FLAPS Generally speaking, there is not sufficient skin on an amputation stump for use as a local flap in making good any but the smallest defects. It may be that an excess of skin has been left in one area at the time of amputation and it may be possible to advance this skin to close the defect or cover the most unstable part of it. Each case is a problem on its own and must be worked out individually, and it should be borne in mind that all scar lines and secondary defects must not be adherent and must be so placed that they do not interfere with comfortable limb-wearing. TUBED PEDICLE FLAPS When the problem of flap transfer was first considered early in the last war the cross-leg flap procedure was adversely criticised as making unnecessary inroads
SKIN TRANSFER TO AMPUTATION STUMPS 117 on the skin of the patient's only remaining leg. In view of this it was decided at first to use abdominal skin brought down via the wrist as a tubed pedicle flap (Fig. 3)- FIG. 3 Case 4 showing stages of skin transfer. Case i.--the rear gunner of a crashed Sunderland who had a right below-knee amputation through a compound fracture, leaving a 4½ in. stump with an anterior skin defect which had been epithelialised by pinch grafts and a rather papery scar adherent to the tibia 2½ by 2 in. Opinion was unanimous that this thin scar would not stand up to limb-wearing, and Professor Kilner proceeded to replace it by an abdominal tubed pedicle flap brought down on the right wrist. A good result was obtained, and after being fitted with a prosthesis the airman returned to operational duty and served a further two and a half years as a rear gunner. The stump has since given no trouble. Two other cases were then considered for the same procedure. Case 2.--A guillotine amputation sixteen months previously had a left below-knee stump 4 in. long, with a terminal adherent scar 2½ in. in diameter, in the centre of which was a small ulcer. The prospects of such a stump healing soundly after such a time seemed remote. Case 3"--Sepsis followed the primary amputation, and had flared up on reamputation a year previously, resulting in delayed healing due to infection in the bone end. This below-knee stump was 5½ in. long--long enough for reamputation--but it was thought that the bone infection would be better controlled by excising the terminal scar and ulcer and covering the bone with a skin flap rather than sawing through potentially infected
I18 BRITISH JOURNAL OF PLASTIC SURGERY bone and covering it with local flaps with a terminal suture line as had been done previously. In Cases 2 and 3 abdominal tubed pedicle flaps were prepared, and both gave trouble, keeping the patients in bed about four weeks. During this time both stumps healed and limb-wearing was subsequently tried. Both stumps behaved so well that further skin transfer was postponed, and these two patients have now been wearing limbs for nine years with very little trouble in spite of adherent terminal scars. After this experience, flap transfer to stumps in any form was advised only when very definite indications existed. Case 4.JA guillotine below-knee amputation stump 4 in. long. A limb had been fitted but the terminal adherent scar was continually breaking down and reamputation above the knee was advised as an alternative to supplying skin cover. The scar was replaced by an abdominal tubed pedicle flap, brought down on the wrist, giving an excellent stump with linear non-adherent scar lines. The patient has since worn a prosthesis without having any further trouble. CROSS-LEG FLAPS The cross-leg flap provides a much simpler method of supplying skin to below-knee stumps, halving the stages and the time taken for the transfer of abdominal skin, while the position is much easier for the patient. Experience with this procedure in non-amputation cases suggested that the secondary defect on the donor leg was unlikely to give trouble provided that it was sited in the upper half of the leg and not directly over bone. It could then be discounted as a contraindication to carrying out this procedure on leg amputees (Jayes, 195o). Example.--A case has been seen in which a cross-leg flap was taken from the lower half of the leg over the subcutaneous surface of the tibia, leaving a secondary defect covered by a free graft adherent to the bone. The recipient leg was subsequently amputated on account of persistent bone sepsis and the donor area proved quite unstable, so much so that an abdominal tubed pedicle flap had to be brought down on a wrist to provide adequate skin cover. Technique.--This is based on the use of a prefabricated plaster splint developed in conjunction with the plaster technicians at this hospital (Fig. 4)- The flap should be of generous size and should be planned so that :-- I. The line on which the flap hinges corresponds as far as possible with a long edge of the defect. 2. At least 8o per cent. of the flap is implanted at the first stage. 3. The length is not greater than the width of the base, thus avoiding the need for delaying procedures. 4. The stump rests against the donor leg at the base of the flap so that there is practically no bridge of flap between the stump and the leg. Fixation.--After deciding on the relative positions of the leg and the stump, posterior piaster casts of both limbs are made and fixed to a triangular wooden frame which forms a base, so that the limbs may be lowered into the splints from above. By this means each limb is supported in the required position from a common base which rests on the bed. Sections may be cut away to give access to the posterior part of the leg where required (Fig. 5). The flap is now planned in detail with the leg and stump in the splint. A
FIG. 4 A prefabricated plaster splint for the cross-leg flap procedure. FIG. 5 The limbs in position in the splint. I19
120 BRITISH JOURNAL OF PLASTIC SURGERY pattern is cut to the shape of the estimated defect on the stump and extended on to the donor leg. This leg is now removed from the splint with the pattern in position, and this is spread on the leg so that the outline of the proposed flap can be marked out. The position is checked by replacing the leg in the splint and spreading the pattern on the stump, holding it on the leg at the line of hinge of the flap. At the first stage operation it is advisable to prepare the defect on the stump J first, as there is usually considerable oozing which can be controlled by applying an iced pack and leaving it for a few minutes, during which time the flap can be prepared and the secondary defect covered with a graft. With the leg and stump held up in towels the splint is introduced underneath and the limbs are lowered in position. The flap now lies over the defect on the stump and can be sutured in position with the two limbs held in their final position. Extra padding may be required to hold the tip of the stump in the exact position necessary, and the splint is secured with bandages. If the patient complains of undue pressure at any point, both limbs can be lifted out of the splint and their relative positions maintained while the splint is adjusted. The second stage operation is carried out seventeen to twenty-one days after the first. The flap is divided across its base, the splint is removed, and the edge of the flap is "let in," while the donor leg is trimmed and sutured. It is advisable to give the appropriate antibiotic at this stage, because some infection of the narrow bridge of flap between the limbs is unavoidable. When healed, the suture lines are given deep freeing massage to prevent them from becoming adherent, and the usual stump exercises and firm bandaging are made a routine procedure. The flap should be very well established before limb-wearing is begun, a period in the region of eight weeks being necessary. Limb-wearing should be graduated until it is certain that the flap is not being adversely affected, as the return of sensation in the flap is very slow (Figs. 6 and 7). Five cases have had cross-leg flaps to below-knee stumps ; four have proved quite satisfactory over periods of two to five years, though there is a tendency for the suture line to break down if limb-wearing is begun too soon or without adequate supervision. The fifth case lost a small but vital part of the flap over the tip of the stump, and although he wore a limb for two years, an above-knee reamputation was eventually carried out at another hospital owing to the terminal scar repeatedly breaking down. In a young leg amputee a knee joint with 4 in. of tibia is well worth preserving by supplying the necessary skin cover, because a below-knee stump gives a functional result far superior to that of an above-knee one. The cross-leg flap procedure provides a relatively simple method of carrying this out in a single leg amputee. In double leg amputees function depends even more on the preservation of the knee joint but the problem of transferring suitable skin is more difficult. Abdominal skill brought down on a wrist as a tubed pedicle flap provides the necessary cover, but the procedure is not lightly undertaken on a patient who has recently had the misfortune to lose both legs. In such cases attempts to arrange the available skin so as to provide a stable covering are amply justified. If the stump does not stand up to limb-wearing, additional skin can be supplied at a later date.
FIG. 6 A cross-leg flap ready for detachment. 2D FIG. 7 A guillotine amputation stump treated by the cross-leg flap procedure. Same case as Fig. 6. i2i
122 BRITISH JOURNAL OF PLASTIC SURGERY In arm amputations skin may be transferred as a direct flap from the trunk (Dupertuis and Henderson, I946), but adherent scars seldom prove to be unstable and skin transfer is reserved for the elongation of a short below-elbow stump or a reconstructive procedure on a partially amputated hand. SUMMARY The need for making good skin defects on amputation stumps is discussed and suitable finalising procedures are indicated. The experience of skin flap transfer to below-knee stumps at Roehampton is given, with a detailed account of the cross-leg flap method. I wish to thank the Director-General of Medical Services of the Ministry of Pensions, also Professor Kilner and Mr Battle, under whose direction this work has been carried out. REFERENCES DrUPERTUIS, S. M., and HENDERSON, J. A. (1946). U.S. Naval med. Bull. (Supp.), 46, 65. JAYES, P. H. (195o). Brit. J. plast. Surg., 3, I. O'CoNNoR, G. B., and KESSLER, H. H. (1945). U.S. Naval reed. Bull., 44, 1167.