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Burned hands in children
Burned Hands in Children JA~ES W. SMIT~, M.D., New York, New York
From the Department of Surgery (Plastic) and the Department of Anatomy, The New York tfospital-Cornell Medical Center, New York, New York.
the part elevated. When elevation can be achieved only by fixing the extremity in the desired position, it m a y result in the child's thrashing and struggling and thus increase the chances of further damage. The accumulation of edematous fluid and any compromise in circulation m a y be mitigated by careful application of elastic bandages to the extremities to effect a mild compression. Even late application of these dressings can sometimes produce improvem e n t sufficient to delay the necessity for emergency decompression. Such treatment, however, is not suggested as a substitute for adequate decompression when it is needed. Fingertips or some other portion of the exposed hand distal to the dressing should be regularly checked to assure t h a t the constricting effect of burned tissue is not continuing to exert an insidious and increasing effect on the local circulation. Decompression, if it proves necessary, cannot be relegated to the status of a bedside procedure. Young children will require general anesthesia in the operating room. When the eschar is incised through its length under sterile conditions, its margins will spread apart, relieving the tension. Because the deeper tissues are edematous they will often seem tense. However, if they have not been burned and are normally elastic, it will be unnecessary to incise them. As edematous fluid is released through the incisions, tension will diminish and a more norreal circulation of blood and l y m p h will be restored. When decompression is required, some or all of the burned tissue can be debrided from the extremity, the patient's condition permitting. (Fig. 1). If the tissues have been burned more or less uniformly and the line of demarcation is clear, excision of the eschar m a y be followed by immediate application of skin grafts. The use of a tourniquet will minimize loss of blood
medical a n d surgical t r e a t m e n t of burns, it is often quite difficult to restore good function to a badly burned hand. This is even truer of children than of adults because of : (1) the thinness of the protective skin which covers the area; (2) the smallness and mobility of the parts; (3) the inability of children to fight scar contracture as it overpowers useful m o v e m e n t ; and (4) the difficulty children have in understanding either the injury or the treatment. For these reasons certain more challenging problems arise more frequently in children t h a n in adults. Such problems are: (1) constricting circumferential burns; (2) burns which expose tendons and joints, especially those on the back of the hand; and (3) scar contracture resulting in late deformity.
D
ESPITE RECENT ADVANCES i n
CIRCUMFERENTIAL BURNS
A comparatively narrow flame can easily sear the entire circumference of a child's extremity because the projected two-dimensional surface area is so small. So little heat is required to destroy the relatively thin skin of the arm t h a t flame, flash, and even hot liquids often cause third degree burns. With burning there is an immediate loss of elasticity and a contracting of the burned tissue, while at t h e same time the vascular response encourages a rapidly accumulating edema. Major veins are often damaged or destroyed because they lie closer to the skin than arteries and also because they are concentrated in the back of the hand, a common site of burns. This further impairs venous return and increases the edema. Smaller children lack the ability to comprehend the problem of edema and the necessity for keeping 58
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B u r n e d H a n d s in C h i l d r e n and other fluids. Another distinct advantage of such early grafting is the reduction in the extent of the burns to the body b y as much as 9 per cent in the early postburn period, when the patient is still in relatively good condition. TREATMENT OF EXPOSED TENDONS AND NERVES
Some physicians advise t h a t grafting be delayed for twenty-four to forty-eight hours after excision of the eschar. Theoretically, this has two advantages: any remaining nonviable tissue can be identified and excised before the grafts are applied, and there is better local hemostasis. When grafting is carried out one or two days after debridement, additional areas of devitalized tissue are often found. Such findings m a y suggest t h a t either the surgeon failed to appreciate the extent of the injury at the time of the initial debridement or t h a t some injured but viable tissues failed to survive: these seem to fortify the belief t h a t it is best to delay grafting. Nevertheless, there is another possibility. Some tissues lie at a lower level to the vascular system than others. While their metabolism requires a smaller volume of blood, neither can they survive great variations in environment nor tolerate as much trauma. This is especially true of exposed tendon, nerve, and fat. In only
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the time it takes to perform a surgical procedure, the glistening sheen, the degree of transparency, and the other characteristics of health of these tissues can disappear with relatively little exposure to the air. Bathing t h e m in such "physiologic solutions" as normal saline solution does not prevent such changes. This t y p e of damage probably is magnified postoperatively b y the evaporation of water from the dressing of normal saline solution. Increased concentrations of salt exert an ever increasing osmotic effect upon the more dilute solutions lying in the intra- or extracellular spaces. If evaporation continues to the point where dressings become dry, the tissues are further damaged. These facts have been recorded m a n y times in the typical surgical note: " A t the time of debridement the tendons and nerves appeared glistening and viable, yet when inspected 48 hours later, necrosis of both was obvious." T h a t circulation was not sufficient for survival seems a natural conclusion. Studies on the blood supply of tendons and nerves nevertheless suggest t h a t these conclusions drawn from clinical studies are erroneous. (Fig. 2.) Tendons are nourished entirely through the mesotendon regardless of whether they serve the extensor or flexor mechanism [1 ]. Because the mesotendon almost invariably enters on the deep surface of a tendon, its blood
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FIG. 1. A, rline y e a r old child s u s t a i n e d 30 per c e n t deep b u r n s of t h e face, neck, t r u n k , a n d r i g h t u p p e r e x t r e m i t y . T h e a r m was b u r n e d e i r c u m f e r e n t i a l l y a n d t h e c o n s t r i c t i n g effect of t h e e s c h a r p r o d u c e d progressive e d e m a a n d ischemia of t h e h a n d . E d e m a as well as a n u n s p l i n t e d h a n d w h i c h l:Las fallen o u t of t h e " p o s i t i o n of f u n c t i o n " are seen. T h e e d e m a a c c u m u l a t e s r a p i d l y in t h e h a n d f r o m t h e t o u r n i q u e t effect of t h e e s c h a r above. O n l y p o r t i o n s of t h e p a l m suffered t h i r d degree b u r n s . On t h e d o r s u m of t h e h a n d where t h e skin is m u c h t h i n n e r t h e b u r n s were nearly all t h i r d degree. B, t h e e s c h a r w a s incised in this case to p e r m i t d e c o m p r e s s i o n of t h e distal p a r t of t h e extremity. B e c a u s e t h e p a t i e n t ' s condition r e m a i n e d satisfactory, it was possible to proceed f u r t h e r a t t h e t i m e of surgery. T h e b u r n e s c h a r was excised a n d t h e e x t r e m i t y resurfaced with skin grafting. T h e e d e m a d i s a p p e a r e d rapidly after decompression, a n d w h e n this p h o t o g r a p h was t a k e n a t t h e e n d of t h e operation, t h e h a n d fell into t h e position of f u n c t i o n ; this position should be m a i n t a i n e d d u r i n g t h e period of healing b y proper splinting. Vol. 112, July 1966
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Fla. 2. Magnified view of an extensor tendon (T). It has been injceted with a compound of silicone and rubber and cleared With glycerol to demonstrate the m a n n e r in which extensor tendons gain their supply of blood. A mesotendon ( M T ) lying deep to the tendon serves as a m e c h a n i s m through which blood is carried from the fixed vascular bed (B) beneath to the tendon. Vessels pass from it through the mesotendon to enter the under surface of the tendon. T h e upper or superficial surface (S~ of the tendon is nearly avascular. No vessels enter it from the overlying skin or subcutaneous tissues, which in this specimen h a v e been removed. In clinical cases the circulation to a tendon is not altered by the debriding of tissues superficial to its surface. Yet, it will undergo necrosis if not protected from this exposure by a skin graft or some other biologic dressing.
supply is not damaged directly by exposure. Thus, the effect of an altered environment itself must deliver the fatal blow which causes necrosis. The same situation occurs in the case of nerves [2]. The fact t h a t the blood supply to the exposed tendon or nerve has not been destroyed and remains intact can be demonstrated b y covering these i m p o r t a n t structures with a skin graft, even if temporarily, to prevent damage from the effects of exposure. T h e graft employed for such a dressing can be p a r t of the permanent autograft applied to adjacent areas. I t m a y be an autograft used to cover only the tendon, when adjacent tissues are not ready for grafting, or can even be a homograft. H o m o grafts seem to serve just as well as autografts when only a t e m p o r a r y biologic dressing is necessary. Just how the skin graft preserves the surface of the tendon from external damage has not
been demonstrated. This clinical observation probably can best be explained through knowledge of the histologie mechanism whereby skin grafts are vascularized [3]. Soon after a skin graft has been applied to a raw wound, it doubles in weight. By absorbing nutrient fluids from the underlying bed in a spongelike manner, the graft survives the forty-eight to seventy-two hour period until capillary buds can grow in and establish a more permanent circulation. Skin grafts, applied as a covering for tendons or nerves, absorb local fluids in the same manner. This apparently serves as a medium through which the surface of the tendon is bathed in fluids, even though the skin graft m a y not become vascularized. Skin grafts, employed as t e m p o r a r y biologic dressings in clinical cases m a y need replacement at the end of two or three days b y a similar dressing or the more permanent covering of a pediele flap. In several instances, covering the nerve or tendon with skin grafts eventually resulted in success. One autograft was used as a physiologic dressing for three weeks without replacement. Although the portion of the skin graft covering the bared tendon was not revaseularized and showed progressive signs of deterioration, the underlying tendon was found to be viable and appeared healthy at the end of this period. In several instances, nerves or tendons repeatedly dressed with autografts of skin survived. T h e problem of the exposed tendon becomes compounded when the underlying joints are also exposed or injured. T h e backs of children's fingers are especially vulnerable to this type of injury because the skin and subcutaneous tissues are so thin. This is especially true over the joints of the fingers, where evolution has thinned both the soft tissues and the skin to increase their degree of mobility. I m m e d i a t e l y beneath each extensor tendon complex lies the synovium of the finger joint. Damage to this area often is followed b y stiffness, bacterial contamination of the joint space, pyoarthrosis, and destruction of the joint. A great number of problems are encountered in treating third degree burns on the back of fingers, especiMly in younger children. The parts are small and the child is active. The fingers, though damaged, m a y never seem to stop moving. This makes it much more difficult to apply an effective dressing and to keep it in place. When infection, exposure, and drying American Journal of Surgery
B u r n e d H a n d s in C h i l d r e n begin to work synergistically with fingers that are allowed to move constantly, the effect m a y be disastrous. Motion of the joint encourages cracking of the overlying eschar, thus inviting bacterial infections. Adequate debridement will eliminate the eschar and temporarily remove the exudate, but tendons and nerves, even if they appear viable after debridement, soon succumb to the effects of exposure, drying, and bacterial contamination. As the process continues, further destruction results. Stiffness, fusion, subluxation, dislocation, and distortion often are among the more common sequelae. The extensor tendon mechanism is spread rather diffusely over the dorsum of the fingers as well as over the joints. Because of this, burns often damage or destroy only portions of the system. Unfortunately, some of the most important parts of the system either lie on the mid-dorsum of the finger or pass quite superfically over bony prominences. An example of this is the course of each extensor tendon into its hood area at the metaearpophalangeal joint. The thickened portion of the tendon passes directly over the metacarpal head and lies so superfically that its movements can clearly be seen even in the adult as the fist is clenched. The middle slip of the extensor tendon is another important portion of this complex which is so frequently injured. I t is especially vulnerable at the site where it passes across the head of the proximal phalanx and over the proximal interphalangeal joint to insert onto the middle phalanx. If the middle slip of the extensor tendon complex were to be cut by a knife rather than injured by a burn, the possibility of a boutonniSre deformity would naturally be considered. Tendon repair and splinting might be employed as aids for repairing the damage and minimizing the possibility of late deformity. Yet, when the central slip is destroyed directly by flame or indirectly by exposure, too seldom is thought directed to preventing the same type of later deformity. With continuing movement the defect in the tendon, centered over the joint, increases in size. The lateral bands slip more and more in a volar direction until they function as flexors of the proximal interphalangeal joint rather than as extensors. Such factors as lack of skin cover, absence of functioning extensor tendons, and prolonged exposure of the joint to infection have dictated a gloomy prognosis in these cases. Vol. 112, J u l y 1966
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The need for arthrodesis, either immediate or delayed, has been considered almost certain with damage to the extensor mechanism, the joint capsule, or the joint. This is not necessarily true when the injured joint is properly immobilized and adequately covered. In children it may be extremely difficult to treat wounds caused by burning and at the same t i m e keep the small parts immobilized. A small Kirschner pin can be of great value. Placed obliquely across an exposed joint, such internal fixation aids immobilization and at the same time facilitates change of dressings, if they are required. Progressive herniation of the head of a metacarpal or phalanx through the damaged central portion of any of the extensor tendon expansions is prevented. Once the joint has been fixed in the desired position, the exposed tendons can be biologically dressed with the skin graft. This minimizes further damage until the condition of the local tissues and the general condition of the patient are conducive to the performance of a more definitive procedure. SCAR C O N T R A C T U R E R E S U L T I N G I N LATE DEFORMITY
As it heals, the burned hand of a child may become contracted and deformed despite the excellence of both medical and surgical care. This is because these tissues so frequently respond to injury and infection by forming hypertrophic scars, keloids, and contractures. Results of treatment seem best when the time required for healing is short and suppuration is kept to a minimmu. However, linear scars which do not Parallel skin creases do tend to thicken and contract. Plaqnelike areas of thickened scar which result from a burn can even further magnify this effect. As they contract, the supple joints of the child's fingers easily become distorted. Any physiotherapeutic att e m p t to improve function by stretching out the contracture may accentuate its rate of hypertrophy and increase the degree of deformity. Correction of the problem may require revision of scars or excision and skin grafting. A recurrence of contracture can sometimes be prevented by performing the excisional surgery in such a way that subsequent scars will parallel lines of skin tension. Either split or full thickness skin grafts can be used. Because the former have a greater tendency to contribute to
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A
B
C
D
Fie. 3. A, the hands of a five year old child six months after only a brief contact with scalding water had resulted in third degree burns on both of her hands. The wounds were first treated with moist dressings and later were grafted. Failure to splint them in the proper position both initially and after grafting probably aided the production of the severe deformity. Fixed byperextension at the metacarpophalangeal joints and loss of the transverse and longitudinal arches of the palm prevented the child from doing much more than flexing his fingers to the distal palm; function was poor. B, severity of joint distortion is demonstrated on roentgenogram. To restore normal architecture, it is necessary to excise the scar tissue which produced it, reposition the hand in the position of function, and the employ some means for maintaining it during the period of healing. C, in children, the smallness of the parts and the lack of cooperation sometimes make it advantageous to employ internal fixation as a means of splinting. Small Kirschner wires were used here to hold the hand in the position of function during the time the skin grafts were applied and postoperatively until healing was completed. D, when all wounds were healed, the pins were removed. Clefts were re-established between the fingers of both hands. Flexion eontraetures in the fingers were eliminated by placing suture lines either transversely or in the mid-lateral line on the side of the finger. Nearly normal function was restored to the badly crippled hand by employing these principles. Children have the advantage of being able to regain good joint motion even after prolonged periods of time. This fact often makes attempts at reconstruction worthwhile in spite of long-standing deformities.
a recurrence or eontracture, their use requires greater accuracy of placement in relation to lines of skin tension. Healing also must be accomplished without complication. Important in achieving this end is deciding whether the hand can be properly immobilized in the ideal position for the desired period of time with external splinting and dressings or whether internal splinting is more advantageous. In younger children the parts are so small and the joints so close together, relatively, t h a t fixation of the joints with small Kirschner pins may be the only way the parts can be immobilized. (Fig. g.) The same m a y be true for joints that have been distorted and will no longer stay in the desired position even though the scar tissue responsible for the deformity has been removed. Finally, in patients in whom frequent changes
of dressing are required and for whom a general anesthetic cannot be given each time, these pins will serve well to maintain the necessary degree of immobilization in the desired position. For best results after the resurfacing of the dorsum of the hand or its volar surface, a neutral position (the position of function) must be maintained during the time the skin grafts are being sutured into place and during the time they are gaining their vascularity. Such positioning is advantageous to the ultimate range of function simply because it represents a position midway between flexion and extension. When skin grafts are applied to a hand in this midposition, they ultimately should have enough elasticity to permit the additional stretching required as fingers flex in the making of a fist. Extension from the mid-position' can likewise American Journal of Surgery
B u r n e d H a n d s in C h i l d r e n be accomplished without excessive wrinkling and redundancy of skin as cutaneous tensions become more relaxed. The hand immobilized in the position of function will have less postoperative joint stiffness, regardless of age. In this position the collateral ligaments of the joints are stretched, a fact which anatomically aids later in mobilization. The period of postoperative immobilization required will depend largely upon the rapidity with which skin grafts are vascularized. Thus, factors aiding vaseularization will also diminish the length of postoperative immobilization. These factors include: (1) Use of a pneumatic tourniquet for surgery. This permits easier identification of proper planes for dissection. Exacting dissection will result in a more complete excision of scar and create a better vascular bed for the graft. (2) When sufficient scar has been excised, distorted parts can be restored to more normal sites. If they do not remain in the reduced position, small Kirschner pins placed across the joints may aid in maintaining reduction and eliminate the possibility of immediate recurrence of the deformity. This technic of pin fixation also aids in preventing such problems as adduetion contractures of the thumb. (3) The application of skin grafts promptly after they have been cut. The defect created by excision of the scar should be outlined with the hand in the position desired during the period of immobilization. Prepared from a piece of transparent plastic, this pattern also aids in verifying the fact that sufficient skin has been removed from the donor site to cover the defect. (4) Before attempting to gain hemostasis, the hand should be elevated, the tourniquet deflated, and a moderate amount of pressure over the incision maintained for a minimum of ten minutes. This period generally is required for a reflex hyperemia, which follows release of the tourniquet, to subside. Clamping and tying of bleeding vessels sooner than this eauses unnecessary tissue damage and places more foreign bodies (suture material) in the bed of the wound. (5) "Adequate" rather than "absolute" hemostasis should be effeeted. Venous oozing of a minor degree can be controlled as easily with the slight pressure of a postoperative dressing as it can when slight manual pressure is applied to the area after release of the tourniquet. (6) After adequate hemostasis has been gained, the extremity should be elevated for at least a minute to Vol. 112, J u l y 1966
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permit drainage of venous blood, and then the tourniquet should be reinflated. Some surgeons prefer to reapply the Esmareh rubber bandage before inflating the tourniquet, while others do not feel it necessary; there appears to be no difference in the result. Maintaining the tourniquet inflated during the period when grafts are sutured into place prevents the accumulation of blood in any form between the graft and the bed. (7) All dressings over grafted areas should be applied prior to release of the tourniquet. One type of dressing technic employs Owens ®gauze* [4] over the graft to prevent adherence. Several thicknesses of gauze sponge cut to the outline of the grafted area are applied over the Owens gauze to insure more even pressure on the graft. Cotton waste or opened gauze applied as fluffs can next be applied to give the dressing a little "springiness." An elastic bandage of cotton base is applied to produce slight compression. If plaster of Paris is to be used for either immobilization or compression, "sheet wadding" or Webril®t should be applied first to prevent the elastic bandage from adhering to it. When possible, the plaster of Paris should be applied to the side of the extremity away from the graft. This permits the surgeon to elevate the extremity and maintain slight manual pressure over the grafted area from five to ten minutes without compressing the plaster as it dries. It also allows him to examine the grafted area later without necessarily removing the splint. (8) When these steps are completed and the tourniquet is released, an assistant should remove it promptly from the extremity. This prevents any circumferential compression of the extremity from elevating venous pressure distal to the area where the tourniquet was applied. Confidence in the effectiveness of this technic for insuring the successful take of a skin graft eliminates the necessity for an early change of dressing in clean cases. When there are no complaints on the part of the child or his parents, and no foul odors about the dressing, it can be left undisturbed for two or three weeks. By this time, grafts are well vaseularized and can withstand the type of trauma so often imposed upon them by children. When wounds have reached the point in their maturation when use does * Manufactured b y Davis & Geck, Danbury, Connecticut. Manufactured by the Kendall Company, Chicago, Illinois.
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not result in pain, the pins can be removed. In such circumstances the child will immediately begin to use his hand again. This discourages stiffness and encourages the early restoration of good function. If the pins are removed before healing is complete and pain remains a prominent factor, the child may hold the hand in a stiff, abnormal position, guarding it against additional injury and pain. Rather than risk a series of events terminating in recurrence of deformity, it is better to postpone removal of the Kirschner pins until healing is more complete. In children, joints usually can be immobilized with small Kirschner pins for as long as five or six weeks without risk of any permanent stiffness. SUMMARY
Children's hands are extremely vulnerable to injury by burning. Among the more difficult problems facing surgeons as they deal with the burned hand are (1) constricting circumferential burns; (2) exposed tendons and joints, especially with burns on the back of the hand; and (3) scar contractures resulting in later deformity. Circumferential constricting burns must be incised throughout their length if they are causing any significant degree of circulatory
impairment. Incision of the tissues deep to the eschar is unnecessary if they are comparatively normal and adjust to mobility. Problems associated with exposed tendons and joints are especially common in the fingers because the tissues covering the extensor tendon mechanism and joints are so thin. Regardless of the circumstances, when fatty tissues, tendons, and nerves are exposed, they do not respond well to such alterations in their environment. The use of a skin graft for either a temporary or permanent biologic dressing for these areas minimizes their exposure and significantly enhances their chances of survival. Denudation or damage of tendons in fingers may be compounded by an exposed or injured joint. Such injuries can be treated more effectively by immobilizing them with internal fixation and applying the biologic dressing of a skin graft. REFERENCES 1. SMITH, ]. W. Blood supply of tendons. Am. J. Surg., 109 : 272, 1985. 2. SMITH, J. W. Factors influencing nerve repair. I. Blood supply of peripheral nerves. Arch. Surg., in press. 3. SMITH, J. W., RINGLAND. J., and WILSON, R. Vascularization of skin grafts. S. Forum, 15: 473, 1964. 4. OWENS, N. Rayon, an ideal surgical dressing for surface wounds. Surgery, 19 : 482, 1946.
American Journal of Surgery
From the Department of Surgery (Plastic) and the Department of Anatomy, The New York tfospital-Cornell Medical Center, New York, New York.
the part elevated. When elevation can be achieved only by fixing the extremity in the desired position, it m a y result in the child's thrashing and struggling and thus increase the chances of further damage. The accumulation of edematous fluid and any compromise in circulation m a y be mitigated by careful application of elastic bandages to the extremities to effect a mild compression. Even late application of these dressings can sometimes produce improvem e n t sufficient to delay the necessity for emergency decompression. Such treatment, however, is not suggested as a substitute for adequate decompression when it is needed. Fingertips or some other portion of the exposed hand distal to the dressing should be regularly checked to assure t h a t the constricting effect of burned tissue is not continuing to exert an insidious and increasing effect on the local circulation. Decompression, if it proves necessary, cannot be relegated to the status of a bedside procedure. Young children will require general anesthesia in the operating room. When the eschar is incised through its length under sterile conditions, its margins will spread apart, relieving the tension. Because the deeper tissues are edematous they will often seem tense. However, if they have not been burned and are normally elastic, it will be unnecessary to incise them. As edematous fluid is released through the incisions, tension will diminish and a more norreal circulation of blood and l y m p h will be restored. When decompression is required, some or all of the burned tissue can be debrided from the extremity, the patient's condition permitting. (Fig. 1). If the tissues have been burned more or less uniformly and the line of demarcation is clear, excision of the eschar m a y be followed by immediate application of skin grafts. The use of a tourniquet will minimize loss of blood
medical a n d surgical t r e a t m e n t of burns, it is often quite difficult to restore good function to a badly burned hand. This is even truer of children than of adults because of : (1) the thinness of the protective skin which covers the area; (2) the smallness and mobility of the parts; (3) the inability of children to fight scar contracture as it overpowers useful m o v e m e n t ; and (4) the difficulty children have in understanding either the injury or the treatment. For these reasons certain more challenging problems arise more frequently in children t h a n in adults. Such problems are: (1) constricting circumferential burns; (2) burns which expose tendons and joints, especially those on the back of the hand; and (3) scar contracture resulting in late deformity.
D
ESPITE RECENT ADVANCES i n
CIRCUMFERENTIAL BURNS
A comparatively narrow flame can easily sear the entire circumference of a child's extremity because the projected two-dimensional surface area is so small. So little heat is required to destroy the relatively thin skin of the arm t h a t flame, flash, and even hot liquids often cause third degree burns. With burning there is an immediate loss of elasticity and a contracting of the burned tissue, while at t h e same time the vascular response encourages a rapidly accumulating edema. Major veins are often damaged or destroyed because they lie closer to the skin than arteries and also because they are concentrated in the back of the hand, a common site of burns. This further impairs venous return and increases the edema. Smaller children lack the ability to comprehend the problem of edema and the necessity for keeping 58
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B u r n e d H a n d s in C h i l d r e n and other fluids. Another distinct advantage of such early grafting is the reduction in the extent of the burns to the body b y as much as 9 per cent in the early postburn period, when the patient is still in relatively good condition. TREATMENT OF EXPOSED TENDONS AND NERVES
Some physicians advise t h a t grafting be delayed for twenty-four to forty-eight hours after excision of the eschar. Theoretically, this has two advantages: any remaining nonviable tissue can be identified and excised before the grafts are applied, and there is better local hemostasis. When grafting is carried out one or two days after debridement, additional areas of devitalized tissue are often found. Such findings m a y suggest t h a t either the surgeon failed to appreciate the extent of the injury at the time of the initial debridement or t h a t some injured but viable tissues failed to survive: these seem to fortify the belief t h a t it is best to delay grafting. Nevertheless, there is another possibility. Some tissues lie at a lower level to the vascular system than others. While their metabolism requires a smaller volume of blood, neither can they survive great variations in environment nor tolerate as much trauma. This is especially true of exposed tendon, nerve, and fat. In only
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the time it takes to perform a surgical procedure, the glistening sheen, the degree of transparency, and the other characteristics of health of these tissues can disappear with relatively little exposure to the air. Bathing t h e m in such "physiologic solutions" as normal saline solution does not prevent such changes. This t y p e of damage probably is magnified postoperatively b y the evaporation of water from the dressing of normal saline solution. Increased concentrations of salt exert an ever increasing osmotic effect upon the more dilute solutions lying in the intra- or extracellular spaces. If evaporation continues to the point where dressings become dry, the tissues are further damaged. These facts have been recorded m a n y times in the typical surgical note: " A t the time of debridement the tendons and nerves appeared glistening and viable, yet when inspected 48 hours later, necrosis of both was obvious." T h a t circulation was not sufficient for survival seems a natural conclusion. Studies on the blood supply of tendons and nerves nevertheless suggest t h a t these conclusions drawn from clinical studies are erroneous. (Fig. 2.) Tendons are nourished entirely through the mesotendon regardless of whether they serve the extensor or flexor mechanism [1 ]. Because the mesotendon almost invariably enters on the deep surface of a tendon, its blood
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FIG. 1. A, rline y e a r old child s u s t a i n e d 30 per c e n t deep b u r n s of t h e face, neck, t r u n k , a n d r i g h t u p p e r e x t r e m i t y . T h e a r m was b u r n e d e i r c u m f e r e n t i a l l y a n d t h e c o n s t r i c t i n g effect of t h e e s c h a r p r o d u c e d progressive e d e m a a n d ischemia of t h e h a n d . E d e m a as well as a n u n s p l i n t e d h a n d w h i c h l:Las fallen o u t of t h e " p o s i t i o n of f u n c t i o n " are seen. T h e e d e m a a c c u m u l a t e s r a p i d l y in t h e h a n d f r o m t h e t o u r n i q u e t effect of t h e e s c h a r above. O n l y p o r t i o n s of t h e p a l m suffered t h i r d degree b u r n s . On t h e d o r s u m of t h e h a n d where t h e skin is m u c h t h i n n e r t h e b u r n s were nearly all t h i r d degree. B, t h e e s c h a r w a s incised in this case to p e r m i t d e c o m p r e s s i o n of t h e distal p a r t of t h e extremity. B e c a u s e t h e p a t i e n t ' s condition r e m a i n e d satisfactory, it was possible to proceed f u r t h e r a t t h e t i m e of surgery. T h e b u r n e s c h a r was excised a n d t h e e x t r e m i t y resurfaced with skin grafting. T h e e d e m a d i s a p p e a r e d rapidly after decompression, a n d w h e n this p h o t o g r a p h was t a k e n a t t h e e n d of t h e operation, t h e h a n d fell into t h e position of f u n c t i o n ; this position should be m a i n t a i n e d d u r i n g t h e period of healing b y proper splinting. Vol. 112, July 1966
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Fla. 2. Magnified view of an extensor tendon (T). It has been injceted with a compound of silicone and rubber and cleared With glycerol to demonstrate the m a n n e r in which extensor tendons gain their supply of blood. A mesotendon ( M T ) lying deep to the tendon serves as a m e c h a n i s m through which blood is carried from the fixed vascular bed (B) beneath to the tendon. Vessels pass from it through the mesotendon to enter the under surface of the tendon. T h e upper or superficial surface (S~ of the tendon is nearly avascular. No vessels enter it from the overlying skin or subcutaneous tissues, which in this specimen h a v e been removed. In clinical cases the circulation to a tendon is not altered by the debriding of tissues superficial to its surface. Yet, it will undergo necrosis if not protected from this exposure by a skin graft or some other biologic dressing.
supply is not damaged directly by exposure. Thus, the effect of an altered environment itself must deliver the fatal blow which causes necrosis. The same situation occurs in the case of nerves [2]. The fact t h a t the blood supply to the exposed tendon or nerve has not been destroyed and remains intact can be demonstrated b y covering these i m p o r t a n t structures with a skin graft, even if temporarily, to prevent damage from the effects of exposure. T h e graft employed for such a dressing can be p a r t of the permanent autograft applied to adjacent areas. I t m a y be an autograft used to cover only the tendon, when adjacent tissues are not ready for grafting, or can even be a homograft. H o m o grafts seem to serve just as well as autografts when only a t e m p o r a r y biologic dressing is necessary. Just how the skin graft preserves the surface of the tendon from external damage has not
been demonstrated. This clinical observation probably can best be explained through knowledge of the histologie mechanism whereby skin grafts are vascularized [3]. Soon after a skin graft has been applied to a raw wound, it doubles in weight. By absorbing nutrient fluids from the underlying bed in a spongelike manner, the graft survives the forty-eight to seventy-two hour period until capillary buds can grow in and establish a more permanent circulation. Skin grafts, applied as a covering for tendons or nerves, absorb local fluids in the same manner. This apparently serves as a medium through which the surface of the tendon is bathed in fluids, even though the skin graft m a y not become vascularized. Skin grafts, employed as t e m p o r a r y biologic dressings in clinical cases m a y need replacement at the end of two or three days b y a similar dressing or the more permanent covering of a pediele flap. In several instances, covering the nerve or tendon with skin grafts eventually resulted in success. One autograft was used as a physiologic dressing for three weeks without replacement. Although the portion of the skin graft covering the bared tendon was not revaseularized and showed progressive signs of deterioration, the underlying tendon was found to be viable and appeared healthy at the end of this period. In several instances, nerves or tendons repeatedly dressed with autografts of skin survived. T h e problem of the exposed tendon becomes compounded when the underlying joints are also exposed or injured. T h e backs of children's fingers are especially vulnerable to this type of injury because the skin and subcutaneous tissues are so thin. This is especially true over the joints of the fingers, where evolution has thinned both the soft tissues and the skin to increase their degree of mobility. I m m e d i a t e l y beneath each extensor tendon complex lies the synovium of the finger joint. Damage to this area often is followed b y stiffness, bacterial contamination of the joint space, pyoarthrosis, and destruction of the joint. A great number of problems are encountered in treating third degree burns on the back of fingers, especiMly in younger children. The parts are small and the child is active. The fingers, though damaged, m a y never seem to stop moving. This makes it much more difficult to apply an effective dressing and to keep it in place. When infection, exposure, and drying American Journal of Surgery
B u r n e d H a n d s in C h i l d r e n begin to work synergistically with fingers that are allowed to move constantly, the effect m a y be disastrous. Motion of the joint encourages cracking of the overlying eschar, thus inviting bacterial infections. Adequate debridement will eliminate the eschar and temporarily remove the exudate, but tendons and nerves, even if they appear viable after debridement, soon succumb to the effects of exposure, drying, and bacterial contamination. As the process continues, further destruction results. Stiffness, fusion, subluxation, dislocation, and distortion often are among the more common sequelae. The extensor tendon mechanism is spread rather diffusely over the dorsum of the fingers as well as over the joints. Because of this, burns often damage or destroy only portions of the system. Unfortunately, some of the most important parts of the system either lie on the mid-dorsum of the finger or pass quite superfically over bony prominences. An example of this is the course of each extensor tendon into its hood area at the metaearpophalangeal joint. The thickened portion of the tendon passes directly over the metacarpal head and lies so superfically that its movements can clearly be seen even in the adult as the fist is clenched. The middle slip of the extensor tendon is another important portion of this complex which is so frequently injured. I t is especially vulnerable at the site where it passes across the head of the proximal phalanx and over the proximal interphalangeal joint to insert onto the middle phalanx. If the middle slip of the extensor tendon complex were to be cut by a knife rather than injured by a burn, the possibility of a boutonniSre deformity would naturally be considered. Tendon repair and splinting might be employed as aids for repairing the damage and minimizing the possibility of late deformity. Yet, when the central slip is destroyed directly by flame or indirectly by exposure, too seldom is thought directed to preventing the same type of later deformity. With continuing movement the defect in the tendon, centered over the joint, increases in size. The lateral bands slip more and more in a volar direction until they function as flexors of the proximal interphalangeal joint rather than as extensors. Such factors as lack of skin cover, absence of functioning extensor tendons, and prolonged exposure of the joint to infection have dictated a gloomy prognosis in these cases. Vol. 112, J u l y 1966
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The need for arthrodesis, either immediate or delayed, has been considered almost certain with damage to the extensor mechanism, the joint capsule, or the joint. This is not necessarily true when the injured joint is properly immobilized and adequately covered. In children it may be extremely difficult to treat wounds caused by burning and at the same t i m e keep the small parts immobilized. A small Kirschner pin can be of great value. Placed obliquely across an exposed joint, such internal fixation aids immobilization and at the same time facilitates change of dressings, if they are required. Progressive herniation of the head of a metacarpal or phalanx through the damaged central portion of any of the extensor tendon expansions is prevented. Once the joint has been fixed in the desired position, the exposed tendons can be biologically dressed with the skin graft. This minimizes further damage until the condition of the local tissues and the general condition of the patient are conducive to the performance of a more definitive procedure. SCAR C O N T R A C T U R E R E S U L T I N G I N LATE DEFORMITY
As it heals, the burned hand of a child may become contracted and deformed despite the excellence of both medical and surgical care. This is because these tissues so frequently respond to injury and infection by forming hypertrophic scars, keloids, and contractures. Results of treatment seem best when the time required for healing is short and suppuration is kept to a minimmu. However, linear scars which do not Parallel skin creases do tend to thicken and contract. Plaqnelike areas of thickened scar which result from a burn can even further magnify this effect. As they contract, the supple joints of the child's fingers easily become distorted. Any physiotherapeutic att e m p t to improve function by stretching out the contracture may accentuate its rate of hypertrophy and increase the degree of deformity. Correction of the problem may require revision of scars or excision and skin grafting. A recurrence of contracture can sometimes be prevented by performing the excisional surgery in such a way that subsequent scars will parallel lines of skin tension. Either split or full thickness skin grafts can be used. Because the former have a greater tendency to contribute to
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A
B
C
D
Fie. 3. A, the hands of a five year old child six months after only a brief contact with scalding water had resulted in third degree burns on both of her hands. The wounds were first treated with moist dressings and later were grafted. Failure to splint them in the proper position both initially and after grafting probably aided the production of the severe deformity. Fixed byperextension at the metacarpophalangeal joints and loss of the transverse and longitudinal arches of the palm prevented the child from doing much more than flexing his fingers to the distal palm; function was poor. B, severity of joint distortion is demonstrated on roentgenogram. To restore normal architecture, it is necessary to excise the scar tissue which produced it, reposition the hand in the position of function, and the employ some means for maintaining it during the period of healing. C, in children, the smallness of the parts and the lack of cooperation sometimes make it advantageous to employ internal fixation as a means of splinting. Small Kirschner wires were used here to hold the hand in the position of function during the time the skin grafts were applied and postoperatively until healing was completed. D, when all wounds were healed, the pins were removed. Clefts were re-established between the fingers of both hands. Flexion eontraetures in the fingers were eliminated by placing suture lines either transversely or in the mid-lateral line on the side of the finger. Nearly normal function was restored to the badly crippled hand by employing these principles. Children have the advantage of being able to regain good joint motion even after prolonged periods of time. This fact often makes attempts at reconstruction worthwhile in spite of long-standing deformities.
a recurrence or eontracture, their use requires greater accuracy of placement in relation to lines of skin tension. Healing also must be accomplished without complication. Important in achieving this end is deciding whether the hand can be properly immobilized in the ideal position for the desired period of time with external splinting and dressings or whether internal splinting is more advantageous. In younger children the parts are so small and the joints so close together, relatively, t h a t fixation of the joints with small Kirschner pins may be the only way the parts can be immobilized. (Fig. g.) The same m a y be true for joints that have been distorted and will no longer stay in the desired position even though the scar tissue responsible for the deformity has been removed. Finally, in patients in whom frequent changes
of dressing are required and for whom a general anesthetic cannot be given each time, these pins will serve well to maintain the necessary degree of immobilization in the desired position. For best results after the resurfacing of the dorsum of the hand or its volar surface, a neutral position (the position of function) must be maintained during the time the skin grafts are being sutured into place and during the time they are gaining their vascularity. Such positioning is advantageous to the ultimate range of function simply because it represents a position midway between flexion and extension. When skin grafts are applied to a hand in this midposition, they ultimately should have enough elasticity to permit the additional stretching required as fingers flex in the making of a fist. Extension from the mid-position' can likewise American Journal of Surgery
B u r n e d H a n d s in C h i l d r e n be accomplished without excessive wrinkling and redundancy of skin as cutaneous tensions become more relaxed. The hand immobilized in the position of function will have less postoperative joint stiffness, regardless of age. In this position the collateral ligaments of the joints are stretched, a fact which anatomically aids later in mobilization. The period of postoperative immobilization required will depend largely upon the rapidity with which skin grafts are vascularized. Thus, factors aiding vaseularization will also diminish the length of postoperative immobilization. These factors include: (1) Use of a pneumatic tourniquet for surgery. This permits easier identification of proper planes for dissection. Exacting dissection will result in a more complete excision of scar and create a better vascular bed for the graft. (2) When sufficient scar has been excised, distorted parts can be restored to more normal sites. If they do not remain in the reduced position, small Kirschner pins placed across the joints may aid in maintaining reduction and eliminate the possibility of immediate recurrence of the deformity. This technic of pin fixation also aids in preventing such problems as adduetion contractures of the thumb. (3) The application of skin grafts promptly after they have been cut. The defect created by excision of the scar should be outlined with the hand in the position desired during the period of immobilization. Prepared from a piece of transparent plastic, this pattern also aids in verifying the fact that sufficient skin has been removed from the donor site to cover the defect. (4) Before attempting to gain hemostasis, the hand should be elevated, the tourniquet deflated, and a moderate amount of pressure over the incision maintained for a minimum of ten minutes. This period generally is required for a reflex hyperemia, which follows release of the tourniquet, to subside. Clamping and tying of bleeding vessels sooner than this eauses unnecessary tissue damage and places more foreign bodies (suture material) in the bed of the wound. (5) "Adequate" rather than "absolute" hemostasis should be effeeted. Venous oozing of a minor degree can be controlled as easily with the slight pressure of a postoperative dressing as it can when slight manual pressure is applied to the area after release of the tourniquet. (6) After adequate hemostasis has been gained, the extremity should be elevated for at least a minute to Vol. 112, J u l y 1966
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permit drainage of venous blood, and then the tourniquet should be reinflated. Some surgeons prefer to reapply the Esmareh rubber bandage before inflating the tourniquet, while others do not feel it necessary; there appears to be no difference in the result. Maintaining the tourniquet inflated during the period when grafts are sutured into place prevents the accumulation of blood in any form between the graft and the bed. (7) All dressings over grafted areas should be applied prior to release of the tourniquet. One type of dressing technic employs Owens ®gauze* [4] over the graft to prevent adherence. Several thicknesses of gauze sponge cut to the outline of the grafted area are applied over the Owens gauze to insure more even pressure on the graft. Cotton waste or opened gauze applied as fluffs can next be applied to give the dressing a little "springiness." An elastic bandage of cotton base is applied to produce slight compression. If plaster of Paris is to be used for either immobilization or compression, "sheet wadding" or Webril®t should be applied first to prevent the elastic bandage from adhering to it. When possible, the plaster of Paris should be applied to the side of the extremity away from the graft. This permits the surgeon to elevate the extremity and maintain slight manual pressure over the grafted area from five to ten minutes without compressing the plaster as it dries. It also allows him to examine the grafted area later without necessarily removing the splint. (8) When these steps are completed and the tourniquet is released, an assistant should remove it promptly from the extremity. This prevents any circumferential compression of the extremity from elevating venous pressure distal to the area where the tourniquet was applied. Confidence in the effectiveness of this technic for insuring the successful take of a skin graft eliminates the necessity for an early change of dressing in clean cases. When there are no complaints on the part of the child or his parents, and no foul odors about the dressing, it can be left undisturbed for two or three weeks. By this time, grafts are well vaseularized and can withstand the type of trauma so often imposed upon them by children. When wounds have reached the point in their maturation when use does * Manufactured b y Davis & Geck, Danbury, Connecticut. Manufactured by the Kendall Company, Chicago, Illinois.
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not result in pain, the pins can be removed. In such circumstances the child will immediately begin to use his hand again. This discourages stiffness and encourages the early restoration of good function. If the pins are removed before healing is complete and pain remains a prominent factor, the child may hold the hand in a stiff, abnormal position, guarding it against additional injury and pain. Rather than risk a series of events terminating in recurrence of deformity, it is better to postpone removal of the Kirschner pins until healing is more complete. In children, joints usually can be immobilized with small Kirschner pins for as long as five or six weeks without risk of any permanent stiffness. SUMMARY
Children's hands are extremely vulnerable to injury by burning. Among the more difficult problems facing surgeons as they deal with the burned hand are (1) constricting circumferential burns; (2) exposed tendons and joints, especially with burns on the back of the hand; and (3) scar contractures resulting in later deformity. Circumferential constricting burns must be incised throughout their length if they are causing any significant degree of circulatory
impairment. Incision of the tissues deep to the eschar is unnecessary if they are comparatively normal and adjust to mobility. Problems associated with exposed tendons and joints are especially common in the fingers because the tissues covering the extensor tendon mechanism and joints are so thin. Regardless of the circumstances, when fatty tissues, tendons, and nerves are exposed, they do not respond well to such alterations in their environment. The use of a skin graft for either a temporary or permanent biologic dressing for these areas minimizes their exposure and significantly enhances their chances of survival. Denudation or damage of tendons in fingers may be compounded by an exposed or injured joint. Such injuries can be treated more effectively by immobilizing them with internal fixation and applying the biologic dressing of a skin graft. REFERENCES 1. SMITH, ]. W. Blood supply of tendons. Am. J. Surg., 109 : 272, 1985. 2. SMITH, J. W. Factors influencing nerve repair. I. Blood supply of peripheral nerves. Arch. Surg., in press. 3. SMITH, J. W., RINGLAND. J., and WILSON, R. Vascularization of skin grafts. S. Forum, 15: 473, 1964. 4. OWENS, N. Rayon, an ideal surgical dressing for surface wounds. Surgery, 19 : 482, 1946.
American Journal of Surgery