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Necrosis of skull and long bones resulting from deep burns, with evidence of regeneration
Necrosis of Skull and Long Bones Resulting from Deep Burns, with Evidence of Regeneration DONALD M. GLOVER, M.D., Cleveland,
AJOR bone necrosis has occurred three times in approximately I ,500 hospitaIized burn cases, in the experience of the author at St. Luke’s Hospital, Cleveland, Ohio. The due to mechanism of production is ischemia
M
coaguIation of surrounding soft tissues and periosteum by the burning agent. Treatment is often compIicated by the fact that other severe injuries are present. The following three cases illustrate the problems involved and provide the basis for a discussion of methods of treatment. CASE
REPORTS
L. B., a Negro steel worker forty-eight years of age, was severely burned about the face and frontal region when he feI1 into a pit of moIten sIag. Subsequent information seemed to indicate that he was unconscious from an epiIeptiform seizure when he fell. Immediately a hard, dense eschar developed over the forehead and face, and there were minor burns about the chest, neck and hands. When first seen by the author approximateIy two months Iater, there was complete denudation of almost the entire fronta area and nasa1 bones. There were also deep burns of the tip of the nose, both cheeks, lips and chin, which were granmating. Since the margins of the exposed frontal bone had not yet demarcated, it was assumed that bone necrosis invoIved only the outer tabIe and that circulation was stir1 present in the diplo@ between inner and outer tabIes. Accordingly, the exposed bone was driIIed with many holes, about 3 mm. in diameter and IO mm. apart. Free bIeeding from the diplo& encouraged us to believe that most of the fronta bone might revascularize. This procedure was performed without anesthesia. A few days later large spIit-thickness skin grafts were applied to the granuIating areas of the cheeks and outlay grafts to the commissures of the mouth. One month later additiona free grafts were applied
Ohio
to the eyelids to overcome ectropion, and to the lips. Two months after the perforations had beer1 made in the frontai bone, a good layer of granuIation had pretty we11 covered the outer table of the frontal bone, and the nasal bones had likewise revascularized without assistance. Accordingly, split-thickness grafts were placed over both areas after First removing a few bone spicules and Ieveling the granulations. AIL grafts heaIed we11 enough to provide a satisfactory cover, and the patient was sent out from the hospital for a period of ambulatory rehabilitation prior to continuing extensive soft tissue reconstruction. About one year after injury a bilateral cervicothoracic ffap was prepared in stages and swung to the nose, and pedicIes were reversed to form fuII-thickness skin for the supraorbital ridges and lips. It took more than a year to compIete these procedures. The areas of origina denudation were now covered with stabIe skin, but the cosmetic effect was far from ideal. (Fig. I .) Additiona procedures were planned to improve his appearance two years later, but just prior to the time of the pIanned readmission to the hospita1 the patient died suddenly in another city from what was assumed to have been a cerebrovascular accident. V. S., a forty-two year old electrical lineman for a power company, was severely iniured when hr came in contact with a high tension line carrying 7,500 volts (resistance not known). He suffered deep burns about the scalp, forehead, right eye, hands and right foot. When first seen by the author six months later, the crown of his skull was compIeteIy exposed, with exudate around tht margins where sequestration was apparent. The exposed bone included the parieta1 bones, part of the occipita1, and the right side of the frontal bone down to and including the supraorbita1 ridge. The right eye had been enuclated. Two fingers of the right hand and one on the Ieft had been amputated;
Glover
FIG. I. Necrosis of the frontalfbone and extensive burns of the face from molten sIag, after partial reconstruction with fret and pcdiclcd grafts.
FIG. 2. F&-thickness necrosis bone due to an eIcctrica1 burn sequestrum. When removed applied over exposed dura and
FIG. 3. Application of the sponge rubber method of fixation of free skin graft. The graft is sutured to the recipient area with many line sutures. The ends of the sutures are left long and are subsequently passed through and about a block of sponge rubber (about 1$ inch thick) which has been cut to fit the defect accurately. A singIe Iayer of xeroform@ gauze is interposed between the graft and the sponge rubber. When tied to each other the suture ends fix the sponge rubber securely to the graft and its bed, so that slipping is impossible.
of the skuI1 and frontal prior to removal of the :I split-skin graft was margins of inner table.
remaining fingers were contracted in fIexed position. There was an open uIcer in the healing scar on the plantar surface of the right foot. (Fig. 2.) After a few days of surgical hypochlorite dressings and systemic antibiotic it was possibIe to separate and lift off the entire mass of necrotic bone. About the margins the inner table was viabIe and granuIating, but the entire centra1 area, about 38 sq. cm. in diameter, was occupied by dura covered by a thin Iayer of granulations. A thick spIit graft was applied immediately over this surface and fixed in position by fine siIk sutures tied through and around a block of sponge rubber
cut to fit the defect. (Fig. 3.) The graft healed promptly and was comfortable from the first week. This was not, of course, ideal coverage for the dura and underIying brain, but the size of the defect precluded the use of scalp flaps and the patient refused to consider the tedious process of migrating an abdominal flap via the wrist to the scaIp. Without such a flap, insertion of bone grafts into the bone defect was out of the question.
680
Necrosis
of SkuII and Long Bones from Burns
After t\vtr years there had been suflicient regencraticrn of l)onc from the inner table of the skull so that the dura was stabilizrd, and visible pulsation of the Ijrain was no longer obvious. The patient had t1ecidc.d to \vear a baseball cap with metal intcrlincr tor protection of the brain rather than to ha\.< atlditional reparative procedures. Other incidental plastic procedures employed during the earlier- intc.rval of treatment had included: (I) al)plication ot’ a split-thickness graft to the sole and free of the, rright fclot; (2) multiple Z-plastics grafts to the contracted lingers aided by rubber band traction splinting; (3) a pedicled llap from the right arm IO the forehead and supraorbital region. C. T., a tlventy-eight year old power company lineman, made contact with a high tension conductor with his left forearm, grounding the current through both lower cxtrcmities. He suffered deep burns of the dorsal aspect of the Ieft forearm, the medial and lateral aspects of the left ankle and i;jot, the calf of the right leg and the medial aspect of the right ankle. \Vhen the dense eschar over the prosimal iralf of the dorsal aspect of the forearm scpar-atcd, it was obvious that the bellies of the c,stcnsor and supinator muscles, and the radial ncrvc supplying them had been destroyed, and about 8 cm. of the proximal radius was exposed and avascular. At this time split-thickness grafts lverc applied to the remaining soft tissues about the crposc~l radius, and the burns of the lower cxtrcmitics wcrc similarly grafted. The bone sequestrum separated slowly and was removed :rbout six weeks following the injury. At the same {Jperation an abdominai flap, which had been prcparcd at the pre\-ious operation, was appliccl to the remaining soft tissue defect in the forearm. Consideration was giv-en to the likely necessity of placing a bone graft to bridge the defect in the radius; but since a I cm. wide strip of medial periosteum had been preserved at the timr of the sequestrectomy, it was elected to await cvidcncc of bone regeneration. Serial roentgenograms so~ln showed such satisfactory restoration of tfrc radius that thoughts of bone graft were abandoned. (Figs. 1 and 5.) By the end of two years the upper end of the radius was completely reconstituted. After plastic procedures aimed at partially restoring the lnst extensor and supinator mechanisms of the wrist and fingers, the patient was able to return to his former employment, actually IIn a better job. During the period of early bone healing the wrist had been supported by a light aluminum splint, witfr rubljcr band traction to the fingers designed to suppnr-t wrist and hand and to supply resistance to the normal flexor muscles. This mechanism favored maintaining mobility of all joints. The patient actually returned to work first wearing
the aluminum splint tvithout linger attachments. During this period of activity the prc~xrmal stumps of the extensor muscles had rcco\ crud function and had hypertrnphicd. It was then possible to utrlrze remarnrng fascia and scar in the for-eat-m to bridge partially the gap betwcrn the strrmps of the extensors and their tendons proximal to the \vrist. \Vith additional hypcrtrophy of muscle stumps enough strength was nbtained to support the wrist in mid-dorsillexion and to cutend the* distal phalanges of all the fingers to tvithin 4s dcgrecs of the normal range. Abduction of the thumb was still weak. The additional strength was suflicient to make tfrc splint unnecessary. \I’(> \\crc at first somewhat doubtful if his forearm and hand would be strong enough to support him sal’cly: in pole climbing, but he soon convinced us of 1~1sability to do so. After a year back at work and a fishing trip to Canada he concluded that pulling in heavy fish all day was harder on his injured arm than his regular occupation. He returned to \\ork happily to rest up for his next lishing trip. COMMENTS
has little Prirnar?treatment of the burn influence on the incidence of bone necrosis. Factors which are more important are the causative agent of the burn, duration of the heat and the anatomic region affected. By- far the most common accidental cause is the passage of eIectric current of high potential, the nest in order of frequency being exposure to molten metal or super-heated liquids. In the
681
GIover
9-A
SB
5c:
SD
FIG. 5. Necrosis of a full-thickness section of radius. Serial roentgenograms showing compIete regeneration: A, dead bone separating prior to removal. B, periostea1 bone beginning to form two months after removal of sequestrum. C, regeneration of bone at two years. D, practicalIy complete reconstitution of the radius :It thirty months foIIowing injury.
Iatter category might be cited the case of a young bakery worker who had a grand ma1 epileptic seizure, faIIing unconscious with his arm suspended in a vat of hot grease. The resuhing burn caused compIete ischemic necrosis of the entire forearm. The unconscious person is not protected by norma reflexes which might Iimit his exposure to the burning agent, and is therefore more IikeIy to receive deep burns. Bones which Iie cIose to the cutaneous surface are particuIarIy IikeIy to be damaged by burning agents, which expIains the preponderance of cases of necrosis of skuI1 among reported instances of injury of this type. Immediate excision of smaI1, deep eIectrica1 burns is an effective method of treatment, but not in regions where bone is subcutaneous, since in the Iatter instance excision of soft tissue may expose bone, Ieading to necrosis which might not otherwise occur. Other methods of treatment have IittIe influence upon the fate of bone. Of some interest is the difference in behavior of bone which has been damaged by other burning agents from that which has been injured by radium or x-ray radiation. Burns due to heat or passage of eIectrica1 current cause aImost immediate coaguIation thrombosis of nutrient vesseIs of the periosteum; the resuIting
destruction is sharply limited and efforts at repair begin aImost immediateIy. With burn effects of this type, some degree of bone regeneration may be expected. In contradistinction, radiation produces diffuse perivascuIar infiltration and thrombosis which is progressive with the passage of time [I]. As a resuIt radiation necrosis is progressive and proceeds reIentIessIy to an extent of destruction which initiaIIy seemed unIikeIy. These differences naturaIIy inAuence treatment. In burns of the first category, reconstructive procedures may be instituted as soon as the dead bone is removed, including bone grafts when indicated, With radiation bone necrosis, on the other hand, bone grafts are not empIoyed with confidence until two or three years have eIapsed after sequestration seems compIete. The cases described herein are iIIustrative of the capacity of bone to regenerate foIIowing acute burns. The third case (patient C. T.) demonstrated a degree of regeneration of a Iong bone from a narrow strip of periosteum that is rarely seen. It is obviousIy an advantage to cover bone defects with fuII-thickness skin of good quaIity, for which purpose adjacent scalp flaps provide the best source of skin for covering skuIl defects [2,3]. In some instances, however, when 682
Necrosis
of Skull and Long Bones from Burns CONCLUSIOKS
local scalp flaps are not practical (as in the second cast cited), or when other defects have prior claim on donor areas (as in the first case),
Major bone necrosis due to deep burns occurs infrequentIy but poses special problems in management when it does. Some of these are discussed and illustrated. In such necrosis due to fire or electrical burns some degree of bone regeneration may be expected, in contradistinction to radiation necrosis where progressive destruction is aImost the rule. An unusual case of compIete regeneration of a section of the radius, folIowing fuli-thickness bone loss due to an electrical burn, is described. Free skin grafts may- provide a satisfactory cover for fuII-thickness or outer table bone loss of the skuI1, but pedicIed scalp flaps are preferred when practical.
expediency dictates the use of free grafts. Not infrequently they are permanently satisfactory from a functional standpoint, if not from that of appearance. If a bone graft is required, a well vascularized skin flap is mandatory to aid in providing bIood suppIy to the graft. Most skull defects should be hIled in by bone grafts for protection of the brain and for better contour. In some instances, as in the cases described hrrein, bone regeneration may be sufficient to render them unnecessary. Damage to the brain is not infrequent in deep burns with loss of’skull, but none existed in these cases. The sponge rubber method of fixation of free grafts (Fig. 3) is particuIarIy usefu1 in difficult areas, as in the scaIp, face, neck and axiIIa. The Iong ends of the sutures carried through and around the bIock of sponge rubber when tied, ensure holding the graft flat and in contact with all parts of the recipient area. It is thus virtually unnecessary to appIy cumbersome covering dressings which are frequentty employed with other methods. Having used this type of fixation for the past twenty years and taught it to a generation of residents, we regard it as nearly foolproof. This method was described in a previous communication [4j.
REFERENCES
I. KIEHN, C. L. and GLOVER, D. M. Functional repair of the mandible, folIowing bone loss from injury, irradiation necrosis or tumor. Am. J. Surp., 80: 753-761, 1950. 2. BROWN, J. B. and FRYER, M. P. Reconstruction of eIectrica1 injuries, including cranial losses. Ann. h-g., 146: 342-356, 1957. 3. GATEWOOD,J. W. and MCCARTHY, tl. H. Treatment of electrical burns of the skull. Am. .I. Surg., 93: 525-532, 1957. 4. GLOVER, D. M. SurgicaI treatment of irradiation dermatitis and carcinoma. Am. J. S’urp., ~4: 735.746, ‘947.
683
AJOR bone necrosis has occurred three times in approximately I ,500 hospitaIized burn cases, in the experience of the author at St. Luke’s Hospital, Cleveland, Ohio. The due to mechanism of production is ischemia
M
coaguIation of surrounding soft tissues and periosteum by the burning agent. Treatment is often compIicated by the fact that other severe injuries are present. The following three cases illustrate the problems involved and provide the basis for a discussion of methods of treatment. CASE
REPORTS
L. B., a Negro steel worker forty-eight years of age, was severely burned about the face and frontal region when he feI1 into a pit of moIten sIag. Subsequent information seemed to indicate that he was unconscious from an epiIeptiform seizure when he fell. Immediately a hard, dense eschar developed over the forehead and face, and there were minor burns about the chest, neck and hands. When first seen by the author approximateIy two months Iater, there was complete denudation of almost the entire fronta area and nasa1 bones. There were also deep burns of the tip of the nose, both cheeks, lips and chin, which were granmating. Since the margins of the exposed frontal bone had not yet demarcated, it was assumed that bone necrosis invoIved only the outer tabIe and that circulation was stir1 present in the diplo@ between inner and outer tabIes. Accordingly, the exposed bone was driIIed with many holes, about 3 mm. in diameter and IO mm. apart. Free bIeeding from the diplo& encouraged us to believe that most of the fronta bone might revascularize. This procedure was performed without anesthesia. A few days later large spIit-thickness skin grafts were applied to the granuIating areas of the cheeks and outlay grafts to the commissures of the mouth. One month later additiona free grafts were applied
Ohio
to the eyelids to overcome ectropion, and to the lips. Two months after the perforations had beer1 made in the frontai bone, a good layer of granuIation had pretty we11 covered the outer table of the frontal bone, and the nasal bones had likewise revascularized without assistance. Accordingly, split-thickness grafts were placed over both areas after First removing a few bone spicules and Ieveling the granulations. AIL grafts heaIed we11 enough to provide a satisfactory cover, and the patient was sent out from the hospital for a period of ambulatory rehabilitation prior to continuing extensive soft tissue reconstruction. About one year after injury a bilateral cervicothoracic ffap was prepared in stages and swung to the nose, and pedicIes were reversed to form fuII-thickness skin for the supraorbital ridges and lips. It took more than a year to compIete these procedures. The areas of origina denudation were now covered with stabIe skin, but the cosmetic effect was far from ideal. (Fig. I .) Additiona procedures were planned to improve his appearance two years later, but just prior to the time of the pIanned readmission to the hospita1 the patient died suddenly in another city from what was assumed to have been a cerebrovascular accident. V. S., a forty-two year old electrical lineman for a power company, was severely iniured when hr came in contact with a high tension line carrying 7,500 volts (resistance not known). He suffered deep burns about the scalp, forehead, right eye, hands and right foot. When first seen by the author six months later, the crown of his skull was compIeteIy exposed, with exudate around tht margins where sequestration was apparent. The exposed bone included the parieta1 bones, part of the occipita1, and the right side of the frontal bone down to and including the supraorbita1 ridge. The right eye had been enuclated. Two fingers of the right hand and one on the Ieft had been amputated;
Glover
FIG. I. Necrosis of the frontalfbone and extensive burns of the face from molten sIag, after partial reconstruction with fret and pcdiclcd grafts.
FIG. 2. F&-thickness necrosis bone due to an eIcctrica1 burn sequestrum. When removed applied over exposed dura and
FIG. 3. Application of the sponge rubber method of fixation of free skin graft. The graft is sutured to the recipient area with many line sutures. The ends of the sutures are left long and are subsequently passed through and about a block of sponge rubber (about 1$ inch thick) which has been cut to fit the defect accurately. A singIe Iayer of xeroform@ gauze is interposed between the graft and the sponge rubber. When tied to each other the suture ends fix the sponge rubber securely to the graft and its bed, so that slipping is impossible.
of the skuI1 and frontal prior to removal of the :I split-skin graft was margins of inner table.
remaining fingers were contracted in fIexed position. There was an open uIcer in the healing scar on the plantar surface of the right foot. (Fig. 2.) After a few days of surgical hypochlorite dressings and systemic antibiotic it was possibIe to separate and lift off the entire mass of necrotic bone. About the margins the inner table was viabIe and granuIating, but the entire centra1 area, about 38 sq. cm. in diameter, was occupied by dura covered by a thin Iayer of granulations. A thick spIit graft was applied immediately over this surface and fixed in position by fine siIk sutures tied through and around a block of sponge rubber
cut to fit the defect. (Fig. 3.) The graft healed promptly and was comfortable from the first week. This was not, of course, ideal coverage for the dura and underIying brain, but the size of the defect precluded the use of scalp flaps and the patient refused to consider the tedious process of migrating an abdominal flap via the wrist to the scaIp. Without such a flap, insertion of bone grafts into the bone defect was out of the question.
680
Necrosis
of SkuII and Long Bones from Burns
After t\vtr years there had been suflicient regencraticrn of l)onc from the inner table of the skull so that the dura was stabilizrd, and visible pulsation of the Ijrain was no longer obvious. The patient had t1ecidc.d to \vear a baseball cap with metal intcrlincr tor protection of the brain rather than to ha\.< atlditional reparative procedures. Other incidental plastic procedures employed during the earlier- intc.rval of treatment had included: (I) al)plication ot’ a split-thickness graft to the sole and free of the, rright fclot; (2) multiple Z-plastics grafts to the contracted lingers aided by rubber band traction splinting; (3) a pedicled llap from the right arm IO the forehead and supraorbital region. C. T., a tlventy-eight year old power company lineman, made contact with a high tension conductor with his left forearm, grounding the current through both lower cxtrcmities. He suffered deep burns of the dorsal aspect of the Ieft forearm, the medial and lateral aspects of the left ankle and i;jot, the calf of the right leg and the medial aspect of the right ankle. \Vhen the dense eschar over the prosimal iralf of the dorsal aspect of the forearm scpar-atcd, it was obvious that the bellies of the c,stcnsor and supinator muscles, and the radial ncrvc supplying them had been destroyed, and about 8 cm. of the proximal radius was exposed and avascular. At this time split-thickness grafts lverc applied to the remaining soft tissues about the crposc~l radius, and the burns of the lower cxtrcmitics wcrc similarly grafted. The bone sequestrum separated slowly and was removed :rbout six weeks following the injury. At the same {Jperation an abdominai flap, which had been prcparcd at the pre\-ious operation, was appliccl to the remaining soft tissue defect in the forearm. Consideration was giv-en to the likely necessity of placing a bone graft to bridge the defect in the radius; but since a I cm. wide strip of medial periosteum had been preserved at the timr of the sequestrectomy, it was elected to await cvidcncc of bone regeneration. Serial roentgenograms so~ln showed such satisfactory restoration of tfrc radius that thoughts of bone graft were abandoned. (Figs. 1 and 5.) By the end of two years the upper end of the radius was completely reconstituted. After plastic procedures aimed at partially restoring the lnst extensor and supinator mechanisms of the wrist and fingers, the patient was able to return to his former employment, actually IIn a better job. During the period of early bone healing the wrist had been supported by a light aluminum splint, witfr rubljcr band traction to the fingers designed to suppnr-t wrist and hand and to supply resistance to the normal flexor muscles. This mechanism favored maintaining mobility of all joints. The patient actually returned to work first wearing
the aluminum splint tvithout linger attachments. During this period of activity the prc~xrmal stumps of the extensor muscles had rcco\ crud function and had hypertrnphicd. It was then possible to utrlrze remarnrng fascia and scar in the for-eat-m to bridge partially the gap betwcrn the strrmps of the extensors and their tendons proximal to the \vrist. \Vith additional hypcrtrophy of muscle stumps enough strength was nbtained to support the wrist in mid-dorsillexion and to cutend the* distal phalanges of all the fingers to tvithin 4s dcgrecs of the normal range. Abduction of the thumb was still weak. The additional strength was suflicient to make tfrc splint unnecessary. \I’(> \\crc at first somewhat doubtful if his forearm and hand would be strong enough to support him sal’cly: in pole climbing, but he soon convinced us of 1~1sability to do so. After a year back at work and a fishing trip to Canada he concluded that pulling in heavy fish all day was harder on his injured arm than his regular occupation. He returned to \\ork happily to rest up for his next lishing trip. COMMENTS
has little Prirnar?treatment of the burn influence on the incidence of bone necrosis. Factors which are more important are the causative agent of the burn, duration of the heat and the anatomic region affected. By- far the most common accidental cause is the passage of eIectric current of high potential, the nest in order of frequency being exposure to molten metal or super-heated liquids. In the
681
GIover
9-A
SB
5c:
SD
FIG. 5. Necrosis of a full-thickness section of radius. Serial roentgenograms showing compIete regeneration: A, dead bone separating prior to removal. B, periostea1 bone beginning to form two months after removal of sequestrum. C, regeneration of bone at two years. D, practicalIy complete reconstitution of the radius :It thirty months foIIowing injury.
Iatter category might be cited the case of a young bakery worker who had a grand ma1 epileptic seizure, faIIing unconscious with his arm suspended in a vat of hot grease. The resuhing burn caused compIete ischemic necrosis of the entire forearm. The unconscious person is not protected by norma reflexes which might Iimit his exposure to the burning agent, and is therefore more IikeIy to receive deep burns. Bones which Iie cIose to the cutaneous surface are particuIarIy IikeIy to be damaged by burning agents, which expIains the preponderance of cases of necrosis of skuI1 among reported instances of injury of this type. Immediate excision of smaI1, deep eIectrica1 burns is an effective method of treatment, but not in regions where bone is subcutaneous, since in the Iatter instance excision of soft tissue may expose bone, Ieading to necrosis which might not otherwise occur. Other methods of treatment have IittIe influence upon the fate of bone. Of some interest is the difference in behavior of bone which has been damaged by other burning agents from that which has been injured by radium or x-ray radiation. Burns due to heat or passage of eIectrica1 current cause aImost immediate coaguIation thrombosis of nutrient vesseIs of the periosteum; the resuIting
destruction is sharply limited and efforts at repair begin aImost immediateIy. With burn effects of this type, some degree of bone regeneration may be expected. In contradistinction, radiation produces diffuse perivascuIar infiltration and thrombosis which is progressive with the passage of time [I]. As a resuIt radiation necrosis is progressive and proceeds reIentIessIy to an extent of destruction which initiaIIy seemed unIikeIy. These differences naturaIIy inAuence treatment. In burns of the first category, reconstructive procedures may be instituted as soon as the dead bone is removed, including bone grafts when indicated, With radiation bone necrosis, on the other hand, bone grafts are not empIoyed with confidence until two or three years have eIapsed after sequestration seems compIete. The cases described herein are iIIustrative of the capacity of bone to regenerate foIIowing acute burns. The third case (patient C. T.) demonstrated a degree of regeneration of a Iong bone from a narrow strip of periosteum that is rarely seen. It is obviousIy an advantage to cover bone defects with fuII-thickness skin of good quaIity, for which purpose adjacent scalp flaps provide the best source of skin for covering skuIl defects [2,3]. In some instances, however, when 682
Necrosis
of Skull and Long Bones from Burns CONCLUSIOKS
local scalp flaps are not practical (as in the second cast cited), or when other defects have prior claim on donor areas (as in the first case),
Major bone necrosis due to deep burns occurs infrequentIy but poses special problems in management when it does. Some of these are discussed and illustrated. In such necrosis due to fire or electrical burns some degree of bone regeneration may be expected, in contradistinction to radiation necrosis where progressive destruction is aImost the rule. An unusual case of compIete regeneration of a section of the radius, folIowing fuli-thickness bone loss due to an electrical burn, is described. Free skin grafts may- provide a satisfactory cover for fuII-thickness or outer table bone loss of the skuI1, but pedicIed scalp flaps are preferred when practical.
expediency dictates the use of free grafts. Not infrequently they are permanently satisfactory from a functional standpoint, if not from that of appearance. If a bone graft is required, a well vascularized skin flap is mandatory to aid in providing bIood suppIy to the graft. Most skull defects should be hIled in by bone grafts for protection of the brain and for better contour. In some instances, as in the cases described hrrein, bone regeneration may be sufficient to render them unnecessary. Damage to the brain is not infrequent in deep burns with loss of’skull, but none existed in these cases. The sponge rubber method of fixation of free grafts (Fig. 3) is particuIarIy usefu1 in difficult areas, as in the scaIp, face, neck and axiIIa. The Iong ends of the sutures carried through and around the bIock of sponge rubber when tied, ensure holding the graft flat and in contact with all parts of the recipient area. It is thus virtually unnecessary to appIy cumbersome covering dressings which are frequentty employed with other methods. Having used this type of fixation for the past twenty years and taught it to a generation of residents, we regard it as nearly foolproof. This method was described in a previous communication [4j.
REFERENCES
I. KIEHN, C. L. and GLOVER, D. M. Functional repair of the mandible, folIowing bone loss from injury, irradiation necrosis or tumor. Am. J. Surp., 80: 753-761, 1950. 2. BROWN, J. B. and FRYER, M. P. Reconstruction of eIectrica1 injuries, including cranial losses. Ann. h-g., 146: 342-356, 1957. 3. GATEWOOD,J. W. and MCCARTHY, tl. H. Treatment of electrical burns of the skull. Am. .I. Surg., 93: 525-532, 1957. 4. GLOVER, D. M. SurgicaI treatment of irradiation dermatitis and carcinoma. Am. J. S’urp., ~4: 735.746, ‘947.
683