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Burns of bone: can these bones live?
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Burns, 1,356-372
Burns of bone: can these bones live? I I.
Results of 98 cases and discussion of treatment
Douglas Jackson Burns Unit, Birmingham Accident Hospital Summary
In the first paper the history of the management
of burns of bone has been described with reference to the principle papers. The aetiology and incidence of the injury has been recorded and illustrated from a series of cases treated in Birmingham over the last 25 years. In the second paper the results of treating these patients have been assessed using the criteria of operations required, healing time and mortality. Wound closure with free grafts after bone excision, and with skin flaps with or without excision have been described, and the factors favouring each method discussed. Finally, early cover with skin flaps over dead bone is encouraged. THE history of the treatment of burns of bone and the aetiology of the condition in Birmingham, have been described in a previous paper (pp. 342355). This article summarizes the results of treating a series during the 25 years, 1948-74. The series does not include cases involving digits only, and if several bones in one hand or foot were involved, this was counted as one hand or foot. Cases of early amputation of destroyed limbs have not been included because burned bone in these cases was not treated. Following a review of our results, present management of the condition is discussed in the light of our experience and illustrated by it.
NATURAL HISTORY OF THE LESION Rational treatment must be based on natural history. In our approach to treatment we should continually ask ourselves, what will happen if I do nothing? A burn which spares the periosteum of a bone is a soft-tissue injury only, similar to avulsion of the scalp. In the absence of further injury by infection or drying the periosteum will granulate and take a free graft.
Exposed bone, whether burned or not, is soon colonized by bacteria, but it is a good barrier against infection, and invasion will only occur when the outercortex has been eroded by granulation tissue at the edge of the exposed bone, or the foramen of an emissary vein has provided a portal of entry for infection. Exposed bone separates ‘silently’, with a low-grade osteitis and with none of the septicaemic illness of acute osteomyelitis. Diploic, extradural and cerebral abscess may arise by direct spread of infection from a burn of the skull associated with conservative treatment, but meningitis and encephalitis more often follow blood-stream spread from extensive soft-tissue burns. If more than a few millimetres of cortical bone are exposed by removal of periosteum and left uncovered, the bone will eventually sequestrate. This is not due to drying. Keeping the exposed bone wet with cream dressings does not prevent its death and sequestration. The outer surface of exposed cortical bone is too avascular to form granulation tissue even when the blood supply of the marrow is normal. If the cortex is killed by heat in addition to exposure, it neither looks different nor behaves differently; both show no signs of life and eventually sequestrate. Sequestration starts with erosion of bone at its junction with granulation tissue. In practice this is an infected process on the surface and at first the marrow is not infected. Eventually erosion of the outer cortex reaches the marrow and then sequestration spreads more rapidly as an infected osteitis of cancellous bone. The skull, with its 2 tables and intervening diplo@, is the commonest bone to be burned right through. If the dip106 is seriously burned, it becomes avascular with purple clotted blood filling the spaces of the cancellous bone and
Jackson:
Burns of Bone II
sometimes discolouring the cortical table. Like the outer table the full thickness of the inner table cannot survive if its superficial blood supply (in this case from the dip&) is destroyed. Both tables of the skull need a blood supply from both sides to survive. On several occasions, while removing dead diploe and inner table, we have noticed slight bleeding from the deepest layer of the inner table. This deep half of the inner table gets its blood supply from the dura. If a burn kills the diploe but not the inner table, much but not all of the inner table will sequestrate. The deepest part of the inner table will survive and this is important in treatment. These findings parallel those of Johnson (1927) on the blood supply of long bones. The time that burned bone takes to sequestrate spontaneously varies from 2 months to 3 years, and it seems to depend largely on the thickness of the compact bone which has to be eroded. There is also great variation in the amount and vascularity of the marrow. The deep osteogenic layer is sometimes left behind when burned bone sequestrates. The osteogenic layer of the dura or the periosteum on the deep surface of a burned long bone will granulate if it is alive and exposed, and if skin cover is provided by a free graft or a flap it may produce new bone. RESULTS OF 98 CASES Burns of bone in this series were sometimes isolated lesions, but more often part of extensive injuries. tn the latter event the soft-tissue burns took precedence and the area of the burn was reduced as early as possible. When the burn of bone was the main injury, a delay of a week or two was considered well spent to improve the patient’s condition if he had respiratory tract damage due to smoke, or suffered from heart failure. Nevertheless, in treating an isolated burn of bone we considered that nothing was to be gained by waiting for more than two or three weeks, and this may account for the absence of extradural and diploic abscesses in our series. The principle we usually followed was to remove exposed outer cortex as soon as possible and the defect was then closed with split-skin grafts or the dead inner table treated in a manner that will be described. One hundred and fifteen cases of exposed bone were treated with split-skin grafts in this way : 22 were treated with skin flaps and 12 submitted to amputation after setting out to cover the bone. The use of mean time intervals to describe treatment is of only moderate value, but they are
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given to permit comparison with other series. The site of bone injury was first attacked surgically on a mean day 21 (range O-104 days). This was usually the first or second operation on the patient (mean 1.4) and sometimes amounted to excision and grafting of soft tissues only. The removal of exposed bone was started on a mean day 35 (range l-104 days) and a mean 3.2 operations were required to get the site of burned bone healed. The first grafting of bone was always on the day of decortication. Equal numbers of cases had their first bone excisions before and after 30 days, the mean day of excision for these 2 groups being day 18 and 50 respectively. The mean healing time from injury was 4.6 months. Two cases were not included, treatment being withheld for age and psychiatric reasons. There were 9 deaths in our series, a case mortality of 9.2 per cent. Their ages ranged from 8 months to 86 years, Three patients over 70 died I, 19 and 27 days after operation; their causes of death were acute cardiac failure. clinical renal failure and prostatectomy with pneumonia. This raises the question, would they have been better treated conservatively? A fourth, aged 86, with half the skull exposed, was not operated on but died shortly after transfer to a geriatric hospital. The other causes of death were less controversial-burn of brain, coliform septicaemia in a 70 per cent burn, cardiac arrest during anaesthetic induction, acute cardiac failure when the burn was virtually healed, and acute cholecystitis with cholecystectomy. DISCUSSION OF TREATMENT There are 2 approaches to the surgical management of the burned skull. The first is to close the wound with split-skin grafts after excision of avascular bone, the second is to close the wound with a skin flap, with or without excision of exposed bone. After describing these techniques, factors influencing the choice of treatment will be discussed, and an attempt will be made to answer the question of whether exposed and burned bone can regularly be preserved. Wound closure with split-skin grafts after excising avascular bone The point has already been made that exposed cortical bone is avascular on its superficial surface, no matter whether it is simply denuded of periosteum or whether it is also burned. In either case, therefore, the wound can be closed by excising the cortex and grafting viable marrow. Burns of the skull will be considered first, then burns of other bones.
Burns
358 Case I
A trapped fireman received a burn of his skull as part of extensive injuries (Fig. I). On day 41 the outer table of the skull was divided into squares with a motor saw and the squares were removed with an osteotome and hammer. The diplo& was covered with split-skin grafts on 2 occasions and, in spite of developing some minor septic pustules for a few months, the wound healed soundly and has not broken down again over 20 years.
Surgical technique-outer
Vol. l/No. 4
Bleeding from the bone can easily be stopped with a little bone wax on a finger tip; this does not prevent the take of split-skin grafts. The depth of cancellous diploe is variable but only rarely is it difficult to find a plane of cleavage. Removal of the outer table over the venous sinuses presents no problem. Naturally one must exercise care in approaching the thin skull of the temporal region; if this is exposed or burned, the full thickness of the bone may be nibbled away.
table
Adherent scalp and periosteum should first be stripped off, using a rougine. The outer table can
then be cut into squares of about 1 cm2 with an oscillating motor saw and, if the diplo@ is alive, the cuts bleed slightly. A rotating saw blade is inclined to catch on gauze or towels and ‘run away’; it represents a special danger to the assistant’s hands which must never be in front of the blade. A high-speed drill with a cutting burr is an alternative instrument, but we have found it less suitable. The squares of outer cortex should then be removed with an osteotome and light hammer. Provided the osteotome is held tangentially to the skull surface and tapped with appropriate strength, there is no danger of penetration. (A chisel is likely to penetrate the skull and should not be used.) If the inner table is cracked, as at a suture line, there is at once a typical cracked resonance. Theosteotome should then be removed and the area approached from another angle.
a
b
Fig. 1.-Case 1. a, Outer table being cut into squares with an oscillating motor saw. b, All but one square of outer table has been removed, exposing diploe. c, The diploewas covered withsplit-skin soundly.
graftswhicheventually
healed
Jackson : Burns
of Bone II
The idea of cutting the skull into squares with a motor saw and removing them with an oseotome was first practised, to my knowledge, by Gissane and Ross at this unit in 1948. They waited for the diplo& to granulate before grafting it (Fig. 2). It was on the basis of their unpublished case that we began in 1950 to graft exposed diploi? immediately, judging that what would granulate should take a split-skin graft directly. Case 2 (Gissane and Ross’ case) An old man, aged 79, was dozing by an open fire and fell with his head on the coals. He suffered from high blood pressure and occasional blackouts. He received a circular charred burn of the back of his head (Fig. 2). On day 42 the outer table was criss-crossed with an electric saw and the bare bone was chipped away with an osteotome on three occasions. On day 61 split-skin grafts were applied to the granulating area which was healed in 3 months. Small spicules of bone discharged from pustules on the scalp for some time but apart from this he had no further trouble.
F;g. 2.-Case
2. The diplo& granulating.
The management of dead bone over the frontal sinuses and mastoid air cells requires special consideration. If outer table is removed down to a sinus, the osteotome is likely to perforate the sinus mucosa. There is no danger in removing the outer cortex itself as this will later be cast off spontaneously if it is dead ; but if mucosais opened by mistake, a flap will be needed to close it, and often a local flap is not available. Split-skin grafts take well on the bony wall of the frontal sinus
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after removal of the mucosa, but the fistula into the nose cannot be closed in this way. Nevertheless, split-skin grafts on the sinus wall may be useful in making the raw area small enough to be closed by a local flap. Case 3 An epileptic woman of 31 dressed to go out to work one morning and was found, shortly afterwards, lying across a paraffin heater with her face and hands destroyed. She lost both hands, her sight, and her nose and ears, but, even so, it was not a mortal wound. Parts of the outer table of the skull and the mandible which were exposed were excised and split-skin grafted (Fig. 3). The frontal sinus, which was laid open by removing the front wall with the rest of the outer table, was eventually closed with the abdominal pedicle which was used to provide a new nose.
Fig. 3.-Cuse 3. The frontal sinus is completely exposed following excision of the outer table of the frontal bones and the orbital ridges. All raw areas have been closed with split-skin grafts; the only wet areas are mucous membrane and conjunctiva. No local flap is available. Case 4 A woman, aged 71, fell on a fire in an epileptic fit and burned the right side of her face, eyelids and skull (Fig. 4). After 4 operations in 4 months the burn was healed apart from a persistent small opening into the right frontal sinus. The diplog had been grafted and a
360 lid adhesion was established on either side of the right pupil. Two months later excess skin from the left upper lid was used as a full-thickness graft to correct skin shortage of the right upper lid, and a If-inch local skin flap, based on the bridge of the nose, was successfully transposed to close the opening into the frontal sinus. Later, the lid adhesions were divided and she was fitted with a wig.
Fig. 4.-Case 4. The skull has had an excision of outer table which opened the right frontal sinus, followed by split-skin grafts. A local flap from above the nose was transposed to close the sinus.
Our practice now is to X-ray the sinuses before operation and to leave the dead outer table over the frontal sinuses unexcited-this is after excising the rest of the exposed skull and grafting the diploe. When the rest of the face and skull has healed one or two months later, a small patch of dead bone remains over the sinuses for a further few months, Then it separates spontaneously without opening the sinus, and a pedicle flap from a distance is avoided. We have had one deep burn of the mastoid process in an elderly lady which remained wet and scabbing after the separating cortex was eased off with an osteotome. Two split-skin grafts on the granulating air cells failed to epithelize the surface, and she refused the necessary skin flap.
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Low-grade osteitis sometimes follows split-skin grafting on the diplo&, no matter whether the grafts are applied immediately after excision of the outer table or put on the granulation tissue which develops later. Pustules form around little spicules of bone and then discharge and heal, only to be followed by others. This condition may take 6-18 months to clear up spontaneously. It does not occur under a flap, nor, in our experience, if a split-skin graft ‘takes’ well on really vascular marrow (e.g. the medulla of the tibia). Unsatisfactory free grafts can always be replaced with a flap. Surgical technique-diplog and inner table The surgeon will usually have removed the outer table before being faced with a choice about the inner. If the diploe has been damaged by heat, it will be purple or brown and will not bleed if drilled. If thrombosed marrow is exposed by decortication, it is still impossible to know by inspection whether the whole thickness of the inner table is dead. This can only be ascertained by making a burr hole through it, and perhaps taking a clean bite of inner table with bone nibbling forceps. If it does not bleed, of course, it is dead. Often, however, the deepest quarter of the inner table, which gets its blood supply from the dura, bleeds. If the inner table is completely avascular on making a burr hole, a flap may be indicated and this will be considered later. If a flap is not available, however, the avascular bone should be removed with nibbling forceps until bleeding bone is reached. The dura should then be covered with split-skin grafts which usually take well on it in our experience. We have avoided active removal of inner table over venous sinuses because, if bleeding became severe from a tear of the sinus, there would be no bony table to pack against. There is no point in drilling completely dead, avascular inner table. It is bound to sequestrate eventually after many months and it is quicker to remove it. If, however, the deepest quarter of the inner table is still vascular and bleeds when drilled, this is the type of case for multiple drill holes placed close together to let granulations come through, as illustrated by Artz and Reiss (1957). About 6 months later the superficial three-quarters of the inner table can be separated gently with an osteotome and hammer. This delay in wound closure is only acceptable as the price of preserving a thin bony vault to the skull. A bone defect in the skull of 1-2 inches diameter is usually symptomless and safe, and can be
Jackson : Bums of Bone II
covered with a pad and wig if necessary. If an old patient has a more extensive skull defect, he may be prepared to wear a protective metal plate in a cap, but younger patients should probably have an osteoplastic repair.
361 were grafted and 2 toes and their metatarsals were removed. On day 40 the full thickness of burned membrane bone of the skull, which was already separating, was removed leaving granulating dura matter. The defect was skin grafted, and by day 50 the head was
Case 5 A man of 52 suffered from traumatic epilepsy due to a shrapnel wound. He fell on a fire in a fit and received deep burns of his skull. On day 28 the outer table was removed and the marrow appeared dead. A trephine hole in the right frontal region showed the bone was completely avascular in this area. The dura appeared normal. Burr holes were made over therest of the inner table which bled from its deepest part. Granulations grew through these holes but they did not spread over the residual dead bone of the inner table. Six months post burn, the full thickness of the inner table in the right frontal region had to be removed where it was burned through. In other places the outer threequarters of the inner table was removed with an osteotome and hammer, leaving a thin layer of bleeding bone to take a free graft. The head was virtually healed IO months after burning.
The following full-thickness burn of the skull in a baby showed bone regeneration. Case
6
A baby girl, aged 4 months, was left in a cradle in front of an inadequately guarded fire. A coal fell from the fire and set light to the linoleum and cradle causing an I I per cent burn of the baby’s scalp, left arm and foot (Fig. 5). On days 14 and 41, granulating areas
b
Fig. 5.-C’use 6. a, The exposed skull in this photograph was loose and removed on day 40, leaving the bony defect seen in b, which was grafted. c, (overleaf) This picture was taken 18 months later. The previous extent of hone loss. marked out in ink, was all hard.
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healed. Over the next 18 months the obvious hole in the skull became hard, presumably with new bone. Five years later a narrow hair-bearing flap was raised in the right parietal region and transposed to the frontal region to restore the hair line.
4
Case 8 A moulder, aged 66, had his thumb trapped in a hot mould for 15 minutes before he could be freed (Fig. 7). After excision of the burn on the following day, the extensor tendon was covered with a split-skin graft but the tendon proved to be dead. By day 43 it was obvious that the backs of both phalanges of the thumb were dead and the interphalangeal joint was open, Dead cortical bone was removed from the back of both phalanges and cover with split-skin grafts was 90 per cent successful. The foundry man was healed and back at work 3 months after his injury with only a stiff interphalangeal joint. Case 9
A single woman of 58 had a severe personality disorder associated with addiction to chlorodyne. She had recently walked out of a psychiatric hospital without leave and could not be traced. Under the influence of chlorpromazine and carbital tablets she fell on a gas fire setting her clothes alight, and getting a 5 per cent whole skin-loss burn of the chest, loin and buttock (Fi,. 8). Only after 2 weeks did she attend her own doctor.’ The eleventh rib wasexposed and the bare crest of the ilium protruded through the skin. Both were simply excised and the whole burn grafted succescfully on day 18.
Case 7 When a man of 53 fell asleep in a chair after a drinking
Wound closure with skin flaps with or without excision of bone Skin cover with local flaps or with flaps from a distance is sometimes an alternative to excision of dead bone and free grafting. Its most striking advantage is that sequestration can sometimes be prevented in this way, even though the flap is placed on dead bone colonized with bacteria. With burns of the skull the benefit is greatest when the inner table can be saved and a fullthickness skull defect prevented. The dead bone is revascularized under the skin flap and gradually replaced like a bone graft; most or all of it is preserved and not extruded. A flap may be used directly on denuded outer table (Jackson, 1975). The following was a ‘friction burn’ which may have been mechanical, thermal or a combination of both.
bout, his cigarette set his trousers alight producing a deep 4 per cent burn of the right leg (Fig. 6). On day 28 the soft-tissue burns were excised and grafted successfully, leaving the lower two-thirds of the tibia and tibialis anterior tendon exposed. On day 48 the tibia1 cortex and thenecrotic part of tibialis anterior were removed, and on day 54 both were split-skin grafted successfully. He was healed,and discharged in just over 3 months. Although the graft on the tibia caused no further trouble, the free graft which was adherent to muscle and tendon broke down several times. The presence of exposed tendon in the graft bed may be a stronger reason for a flap (if available) than the presence of exposed bone.
In 1953 a 5-year-old boy fell off a wall and was dragged some distance by a car. He received multiple injuries including a friction burn of the temporal bone (Fig. 9). The burn was small enough to be covered with a local flap, and suitably placed for hair distribution to be improved by such a flap. Moreover, removal of outer table only at this site in a child would have been impossible. The bone, which was colonized withaprofuse growth of Staphylococcus aureus, was successfully covered with an occipital-based flap with the hair shafts in the right direction and the boy has worn an adhesive hair-piece to cover the bald area.
Other bones can often be treated in the same way by excision of burned cortex and split-skin grafting. This is particularly valuable if no easy flap is available, or if, for instance, the back of a phalanx is exposed in a burned and crushed hand where early wound closure and active movement are imperative.
Case 10
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Jackson : Burns of&Bone II
b Fig. 6.-C’use
7. a, Granulating tibialis anterior muscle and its tendon lie to the left of 4 in of tibia1 marrow which has just been exposed by decortication. (Pointer on tibia1 marrow.) b, The whole was successfully covered with split-skin grafts; but, whereas the graft on the marrow provided good permanent cover, the graft on the moving tendon tended to break down for several years.
Fig. 7.-Case 8. Burn of both phalanges and interphalangeal joint treated by excision of dead bone and split-skin grafts.
A flap may also be used if heat has thrombosed the diplo& and rendered the superficial half of the inner table avascular. We have already mentioned that this state of affairs is often obvious on inspection before decortication. The three cases reported by North (1948), Worthen (1971) and Freeman and Cudmore (1973) were all of this depth at least (if not completely through the inner table as well) and by using skin flaps they too succeeded in limiting the bone loss substantially. In our unit we have always removed discoloured outer cortex before applying a flap to dead marrow and inner table. In Cast I I the completely dead inner table was excised and a flap was successfully applied over damaged dura and the rim of partly dead inner table. In Curse 12 the flap was applied over brown, infected marrow and the wound healed except for 2 minute exposures of bone (l-2 mm) which the patient does not wish to have treated.
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Burns
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Fig. 8.-Case 9. Burn of the right ilium which was satisfactorily treated by cutting it (,ff just 1Jelow the surface when the wound was grafted.
a
b
Fig. 9.-Case 10. a, Friction burn due to being dragged along the road by a car. b, It was covered with a transposed flap based on the occipital region. Case 7 I In 1970, at the age of 73, a lady who had been fit all her life began to neglect herself and her home. She had complained of feeling weak, and was then found unconscious by the fire which had gone out and was quite cold. There was a deep burn 4 inches in diameter on one parietal region (Fig. 10). Four days later she was fit for surgery. A swab from the surface of the burn showed a profuse colonization with coliform bacilli. The dead scalp and outer table were removed
with an osteotome. The diplo& was clearly dead. The central dead inner table (14 x 2 inches) was removed down to the dura and the edge of the bone was nibbled away until there was bleeding from the deeper part. The dura was oedematous and had several thrombosed veins on its surface. It was not excised to minimize the risk of cerebral infection. The damaged dura and the remaining inner table were successfully covered with a transposed flap. When examined 24 years later in a geriatric hospital the wound had remained
Jackson : Burns of Bone II
365
b Fig. 10. --c‘use I 1. a. Dead dip& after removal of outer table. b, Some inner table removed, exposing oedematous dura with thrombosed viens. A rim of brown dinfoe was left, rather than increase the defect, c, Transposed flap-exposed periosteum was split-skin grafted. . soundly healed and the lady was having no symptoms from the bone defect. Dead bone had not been discharged and there was no sequestrum revealed on X-ray.
rest of the dead bone has stayed permanently covered for over 2%years. She now wears a full wig and does not wish to have any further treatment. X-rays show no sequestrum.
Case 12 In 1972, an epileptic woman of 40 fell on a coal fire and burned the frontoparietal region (Fig. 11). On day 7 the outer table was excised leaving a central area of dead inner table with a rim of bleeding diplot: around it. The central area consisted of dry, brown, thrombosed dip&! and inner table. For 2 months treatment was delayed for psychiatric reasons. On day 70 there was still 7 x 10 cm of brown dip&+ and inner table exposed. A small exploration showed healthy dura, and on day 77 (11 weeks) the dead bone and dura were covered with a local transposed skin hap. Two small areas of dead bone (l-2 mm in diameter) became exposed in the suture line but the
Covering contaminated dead bone with a flap when it has been exposed for weeks is a far cry from the principles of plastic and orthopaedic surgery. The surgery of burns is the surgery of necrosis and infection, and this generally means excising dead tissue. However, the following case shows that contaminated dead bone may be preserved long enough for replacement to begin--it may be that more prolonged protection (antibacterial and mechanical) would have allowed it to be completed.
Flaps on long bones
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Burns Vol. l/No. 4
a
b
Fig. 11.-Case 12. a, Burn of skull from coal fire, sustained in a fit. Day 7, half of outer table has been removed showing brown dead diploe. b, Seven weeks after a scalp flap was transposed over dead diploe and inner table. A small, dry exposure of bone remains at the suture line with no demonstrable sinus. The patient wears a full wig over this result. Case 13 In 1974, a moulder, aged 23, received severe burns when hot plastic was injected into his right forearm at work (Figs. 12, 13). The burn destroyed all the long tendons to the radial side of the hand, 3 inches of median nerve, the radial artery and radial nerve sensation in the hand. Separation of the slough took 6 weeks and left 4.5 cm of bare radius bridging a gap between granulating forearm and wrist. X-ray at this time showed a line of rarefaction at the proximal end of the exposed segment. Cultures grew Staphylococcus aureus and coliform bacilli. On day 50 the bone was covered with an axial groin flap, which was inset on day 78, with suction drainage for 2 days. Although there were no local or general signs of infection, aspiration down to bone on day 85 produced 1.5 ml of turbid fluid which grew Staph. aureus. Aspiration was repeated almost daily from day 87 to day 98 and the cavity washed out with cloxacillin. Fucidin (400 mg daily) was given systemically. On day 99 and 102 there was no growth on culture of the aspirate and aspirations were stopped. Fucidin systemically was continued for a further 6 weeks. The burned bone, which had been colonized by bacteria for over 3 months, was covered and the wound remained healed and symptom-free for 9 months. Serial X-rays confirmed that the previously exposed bone was dead, and the radius was protected with a plaster for 3 months to reduce the risk of fracture. Five months after wound closure cancellous bone appeared to be in continuity on X-ray although the living and dead
cortices had not united. In fact the cortex of the burned fragment gradually absorbed. The sequel is disappointing, but instructive. Nine months after healing there was a little swelling of the flap(which unfortunately was not aspirated and treated with antibiotics as it should have been) and a small sinus appeared at its edge. The result was a foregone conclusion: 5 months later the patient fractured the lower end of the dead fragment pushing himself out of a chair, and the rest of the dead bone was removed after another 3 months. By this time the sequestrum and its X-ray shadow measured 5 cm in length while the original dead segment had measured 6 cm. One cm of dead bone had been reconstituted proximally. Histology of the fragment subsequently confirmed ‘bone necrosis with pyogenic coccal infection, and very early revascularization and new bone formation at one end ‘. The patient has a useful ulnar nerve hand and can lift an electric kettle with it, but he has lost some supination with loss of the radial fragment.
Factors influencing the choice treatment for burned bone
of
The choice of management may be influenced by the following factors: the size and depth of the burn of bone, the availability of local skin flaps, the site of hair loss, the time between burning and treatment, the likelihood of further trauma, and the age and frailty of the patient.
Jackson
: Burns
The extent
of Bone II
of exposed
367
bone
It is not possible to cover a defect of more than
about athirdof thescalpwithalocal flap, so larger areas need a flap from a distance or must be treated by removal of the dead boneandfreegrafting. Free flaps may be possible in some plastic surgery centres. Sometimes excision and free grafting of part of the exposed bone will reduce the extent sufficiently to make a flap possible where it is really needed (e.g. over dead inner table).
a
the dura and brain might be walled off with adhesions in the 3-4 weeks that would pass while getting the soft tissues grafted and the outer table removed. It might be safe to apply homografts until such a wound granulated. Some surgeons have successfully excised dead dura and grafted the defect (Brown and Fryer, 1956; Gatewood and McCarthy, 1957; Stuckey, 1963) and some have excised burned brain and closed the wounds with grafts (Ranev and Shindarsky, 1969) but
b
Fifi. I2.--Cus~ 13. a, The exposed, dead segment of radius, denuded of periosteum and bridging the soft-tissue gap. b. The wound was healed and aspirations
The depth
of bone
stopped at 14 weeks after injury.
involved
If the diplo& is alive, there is often a choice between an early flap and free grafting after excision of the outer table. If the diplo& is dead, the choicelies between a flap over dead outer table or marrow on the one hand, and, on the other, drilling of exposed inner table and delayed excision of its superficial part and free grafting. If no local flap is immediately available, and excision has exposed a coagulated dura, a reasonable course of management is to keep the dura covered with homografts or pig skin until a flap from a distance can be made available to cover it. A necrotic lesion of
hemiplagic patients, who presumable have burns of the brain, have been known to survive and recover from their hemiplegia without brain exploration (Gatewood and McCarthy, 1957). Early skin flap cover without any bone excision is perhaps especially indicated for such cases. Local flaps and baldness A local flap may be indicated in preference to free grafting if it transfers a lateral or frontal bald area to the crown of the head. Some patients use considerable ingenuity in solving their own individual problems.
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a
b
c
d
Fig. 13.-Case 13. a, X-ray at 4 weeks, showing soft-tissue defect around bone. Small erosion of cortex visible at proximal end of dead segment (arrow). b, X-ray at 20 weeks. Limits of dead bone are now obvious by erosion of cortex. c, X-ray one year after b, showing replacement of sequestrum with new bone from both ends. This was 4 months after the sinus had developed. d, X-ray 6 weeks after c. Fracture at the distal end of the fragment 17 months after the injury.
Jackson
: Burns
of Bone II
369
a
b
excised on day 8, there was a good vasculardiplti, but thiscase required three operations in 4 months to get the wound healed. b, Although the bald area was not too badly situated for a man, he managed to keep it hidden with a rather ingenious hair style. Fig. 14.-C~rsr
14. a, When
the outer table was
Case 74 A carpenter, aged 39, was found outside his burning house with a deep burn of his skull (Fig. 14). No explanation could be obtained. Eight days later the outer table was removed and the dipI& grafted in spite of profuse colonization with micrococci. Two further small grafting operations were required, and the burn was healed in 4 months. Subsequently, a flap was offered because small spicules of bone began to separate, but he chose to cover the scar with an original hair style. The time from burn to operation Progress in erosion and separation of dead bone depends on the time since injury. Once infection has invaded the marrow or extradural space, excision of overlying dead bone will be essential. Flaps on dead skull which has been exposed for several weeks usually, but not always, secure complete healing. No case of a primary (same day) flap on clean, burned bone has been found in burn literature, although flaps are regularly successfulover pieces of autoclaved bone in cranial surgery. There is no doubt this will now be practised where it is not contra-indicated for some special reason.
The likelihood of further trauma Involvement of a malleolus is almost always an indication for a cross-leg flap. Often a split-skin graft will be tried in the first instance when the rest of the foot and ankle is being grafted, but, if this fails, time should not be wasted on a second, third and fourth attempt at free grafting. This is a common mistake and a great waste of time. A local flap is usually not available. Case 15 A caster, aged 46, was burned when the bottom fell out of a pot of molten iron and it ran into his boot (Fig. 15). He lost his toes, but the pressure areas on the sole were spared. The burn healed in 3 months with split-skin grafts, except over the malleoli where bone was exposed. A cross-leg tlap was used to cover the medial malleolus, the worse of the two malleolar burns. The lateral malleolus took a year more to heal, and broke down again from year to year causing him many months off work. A second flap, without undue delay, would have saved him the months off work. The age and frailty of the patient Among the elderly there isa time for less than full curative treatment. If a patient has a large area
370
of skull exposed by burning, he may be too frail for major excisions and reconstructions with multiple stage pedicles. If all the soft-tissue burn has been grafted, such a person is often able to live his last months without pain, smell or discharge in spite of a large area of skull being exposed. He can live at home wearing a cap or scarf for cover, and the bone condition may well play no part in his death.
Burns
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4
Conservative treatment is not always indicated in the elderly, however, and, if the bone exposure is small, one quick operation may be sufficient to heal it.The two following cases show the benefit of early surgery and keeping the elderly mobile. Case 17 A rather unsteady man, aged 75, got out of bed and fell on to an unguarded gas fire. On day 12, the outer
Fig. 1~--CUE 15. A burn of the malleolus should usually be covered with a cross-leg flap without undue delay. This man should probably have been pressed more strongly to have a second cross-leg flap to the burned lateral malleolus: it would have saved him prolonged disability and financial loss. Case 76 An old man of 86 was very deaf and a little confused. On the night of his injury his leg ‘gave way’ and he fell on to an unguarded fire receiving a very deep burn of his face, scalp and neck amounting to 4 per cent (Fig. 16). The left ear was destroyed. On day 23 the dead outer table of the skull was removed and the marrow would have been grafted if living. However, it was completely avascular. On day 39 the face and neck were skin grafted. On day 56 he was discharged from hospital with his soft-tissue burns healed and 14 per cent of inner table exposed. At this stage he was losing his memory and major surgery was contraindicated. Two months later he was admitted to a geriatric unit where he died 6 months after his injury. At no time was there evidence of intradural complications, and we considered, in this case correctly, that he would die before the inner table sequestrated. In a younger man, a flap or tube pedicle would have been reasonable.
table was ‘squared’ with a motor saw,removedwithan osteotome,and the defect covered withsplit-skingrafts. The graft was a complete take and he was healed and discharged from hospital on day 25. His only complaint 6 months later (and it was made with great feeling) was that his legs had been weak and stiff ever since his stay in hospital. This experience influenced us in the next case. Case 18 An active old man of 78 was well looked after by his two daughters. Falling asleep one evening, he tumbled on to an unguarded coal fire. There was no history of epilepsy or blackouts. Theonlyabnormal physical sign was an extensor plantar reflex. He regularly walked 7 miles a day. Since he only had a 1 per cent burn on the back of his head, he was sent home to his daughters on day 3 for some partial skin loss to heal, and re-admitted on day 37. During these weeks he walked 3-5 miles every day. On the day after admission
Jackson : Burns
of Bone
II
b Fig. lb.-Cuse 16. a, A 4 per cent burn from a fall on to an unguarded fire. b, After removing the outer table and grafting the soft tissues, the inner table was clearly dead. No further surgery seemed indicated.
the outer table was removed and the diplog successfully grafted with the loss of half a litre of blood. A week later he had a short period of confusion, but on day 53 he was sent home virtually healed. Small spicules of bone were occasionally discharged for a further year, but 3 months after his operation he was wearing a wig and enjoying a touring holiday in Germany. Total hospitalization was 19 days.
Can these bones live? The fate of exposed bone which is dead -from
burning or ischaemia can be influenced by treatment, and this is now worth further experimental study. Exposed burned bone sequestrates unless it is so small in area that granulation tissue can ’mushroom’ over it; but we have seen that sequestration can be prevented by covering the bone with a skin flap and that this is in spite of bacterial colonization. How reliable is the method? It is not surprising that few surgeons have considered covering contaminated dead bone with a flap when excision was a practical alternative. However, this paper has attempted to collect all the cases and to assess the results. Six cases were reported by North (1948), Trapnell and Jackson (1965), Worthen
(1971), Freeman and Cudmore (1973-2 cases), and Lute and Hoopes (1974) and 4 further cases are reported in this paper (Cases 10-13). Nine of these 10 flaps were inset over contaminated, burned skull; one (the only failure) was over a long bone. (In a further case, not in this series, excision of the burned posterior cortex of both phalanges of a thumb showed the marrow to be dry and brown. This, too, was successfully covered with a skin flap.) On the skull the method seems reliable. Out ot 9 cases, 6 were completely and permanently healed. In 2 cases a sinus down to dead bone developed at the suture line, suggesting that flaps should be liberal in size so that the suture line is over living periosteum. It would seem that North’s case (1948) failed due to the flap being too small fop such a large and awkward defect. No failures were attributable to infection in any of these cases, but scalp flaps have an exceptional blood supply. Our usual practice in Birmingham has been to remove exposed or burned outer cortex and then to apply the flap over burned inner table. There is no positive benefit in keeping dead outer table. but it naturally adds to the operation to remove
372
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it, and this now seems unnecessary. This explains why we have only 4 cases of burned skull covered with flaps: we reserved the method for burns of diploe and inner table. No conclusions can be drawn from our one failure. The burn of radius (Case 13) behaved in many ways like Phemister’s (1926) experimental radium necrosis cases. Phemister showed that if a segment of a long bone in a dog was killed by radium, it was replaced by new bone if it remained free of infection and functioned in the support of the part. He described this replacement as ‘creeping substitution’. In the medulla necrotic debris was replaced by connective tissue and in turn by spongy new bone. The junction of dead and living cortex developed an irregular groove from absorption by granulation tissue in a case that went on to sequestration. However, in another which did not sequestrate, the dead cortex showed invasion and replacement by new bone. He also showed that the necrotic bone sequestrated from the living boneif secondary infection occurred, or if fracture occurred and the bone was not used. Human long bones killed by radium in the treatment of tumours were gradually replaced by new bone if they remained free of infection and functioned in the support of the part. Our failure cannot be taken to imply that flap cover for burned and contaminatedlong bonesiscontra-indicated;antibiotic therapy, mechanical protection and functional use are probably important factors for success. Infection was the cause of the failure. Obviously, the sooner a wound is closed the better, but even though the denuded radius was bathed in pus for 3 months, infection was supressed for 9 months after cover with a flap, and the medulla began to be replaced with new bone. Aspiration and antibiotics, as soon as a painless cold swelling appeared beneath the flap, might have prevented sinus formation, fracture and sequestration. We have concluded that flap cover sets the stage for burned bone to live again. There is a striking analogy between this phenomenon and tangential excision and grafting of burned skin. In the latter procedure a thin layer of dead or damaged dermis will ‘revive’ and be re-incorporatedinto the body beneath a split-skin graft, provided the rich subdermal plexus is intact. Both procedures involve closing the wound with a rich blood supply adjacent to the devitalized tissues. In both, one might say, new life is in the blood. Both procedures also have an infection risk : in tangential excision cases theskin graft and recipient area contain about lOORequesfs.for reprints should be addressed to: Mr Douglas Birmingham, B15 INA.
Jackson,
400 living organisms per gram (Lawrence and Lilley, 1972); and recent histological examination of a biopsy from a dry, ‘I-week-old burn of outer table of skull showed Gram-positive cocci and Gram-negative bacilli in the Haversain canals (Sevitt, 1975). It would be surprising if infection were not an occasional cause of morbidity in both procedures, and we know that it is. Both, however, now have a place in burn management. Acknowledgements I am deeply indebted to my colleagues for their co-operation-to Mr H. Proctor (Case lo), Mr J. E. M. Smith (Case 13), and especially Mr J. S. Cason who worked on most of these cases with me; also to Dr Mary Davies for collecting many of the cases, Mr N. R. Gill for the photographs and Miss S. Miles for her secretarial help. REFERENCES ARTZ C. P. and REISSE.
(1957) TheTreatmentof Burns. Philadelphia, W. B. Saunders, p. 140.
BROWN J. B. and FRYER M. P. (1956) Repair of industrial electrical burns. Plast. iieconstr. Surg. 18, 177. FREEMANN. V. and CUDMORER. E. (1973) . , Personal communication. GATEW~~D J. W. and MCCARTHY H. H. (1957) The treatment of electric burns of the skull. Am. J. Surg.
9, 93, 525. JACKSOND. M. (1975) Burns of bone: can these bones live? 1. Burns 1, 342. JOHNSONR. W. (1927) A physiological study of the blood supply of the diaphysis. J. Bone Joint Surg.
9, 153. LAWRENCEJ. C. and LILLEY H. A. (1972) A quantitative method for investigating the bacteriology of skin: its application to burns. Br. J Exp. Pathol. 53,
5.50. LUCE E. A. and H~~PES J. E. (1974) Electrical burn of the scalp and skull. Plast. Reconstr. Surg. 54, 359. NORTH J. P. (1948) Electric burns of head and arms with residual damage to eyes and brain. Am. J. Surg.
76, 631. PHEMISTER D. B. (1926) Radium necrosis of bone. Am.
J. RoentPenol Radium Ther. Nucl. Med.
N.S.
16. 340.
RANEV D.and SHINDARSKYB. (1969) Operative treatment of deep burns of the scalp. Br. J. Plast. Surg. 22,
309. SEVITTS. (1975) Personal communication. STUCKEY J. G. (1963) The surgical management of massive electrical burns of the scalp. Plast. Reconstr.
Surg. 32,538. TRAPNELL D. H. and JACK~XIND. (1965) Bone and joint changes following burns. Clin. Radiol. 16, 180. WORTHENE. F. (1971) Regeneration of the skull following a deep electrical burn. Plast. Reconstr. Surg.
48, 1. FRCS,
Burns
Unit, Birmingham
Accident
Hospital,
Bath Row,
Burns, 1,356-372
Burns of bone: can these bones live? I I.
Results of 98 cases and discussion of treatment
Douglas Jackson Burns Unit, Birmingham Accident Hospital Summary
In the first paper the history of the management
of burns of bone has been described with reference to the principle papers. The aetiology and incidence of the injury has been recorded and illustrated from a series of cases treated in Birmingham over the last 25 years. In the second paper the results of treating these patients have been assessed using the criteria of operations required, healing time and mortality. Wound closure with free grafts after bone excision, and with skin flaps with or without excision have been described, and the factors favouring each method discussed. Finally, early cover with skin flaps over dead bone is encouraged. THE history of the treatment of burns of bone and the aetiology of the condition in Birmingham, have been described in a previous paper (pp. 342355). This article summarizes the results of treating a series during the 25 years, 1948-74. The series does not include cases involving digits only, and if several bones in one hand or foot were involved, this was counted as one hand or foot. Cases of early amputation of destroyed limbs have not been included because burned bone in these cases was not treated. Following a review of our results, present management of the condition is discussed in the light of our experience and illustrated by it.
NATURAL HISTORY OF THE LESION Rational treatment must be based on natural history. In our approach to treatment we should continually ask ourselves, what will happen if I do nothing? A burn which spares the periosteum of a bone is a soft-tissue injury only, similar to avulsion of the scalp. In the absence of further injury by infection or drying the periosteum will granulate and take a free graft.
Exposed bone, whether burned or not, is soon colonized by bacteria, but it is a good barrier against infection, and invasion will only occur when the outercortex has been eroded by granulation tissue at the edge of the exposed bone, or the foramen of an emissary vein has provided a portal of entry for infection. Exposed bone separates ‘silently’, with a low-grade osteitis and with none of the septicaemic illness of acute osteomyelitis. Diploic, extradural and cerebral abscess may arise by direct spread of infection from a burn of the skull associated with conservative treatment, but meningitis and encephalitis more often follow blood-stream spread from extensive soft-tissue burns. If more than a few millimetres of cortical bone are exposed by removal of periosteum and left uncovered, the bone will eventually sequestrate. This is not due to drying. Keeping the exposed bone wet with cream dressings does not prevent its death and sequestration. The outer surface of exposed cortical bone is too avascular to form granulation tissue even when the blood supply of the marrow is normal. If the cortex is killed by heat in addition to exposure, it neither looks different nor behaves differently; both show no signs of life and eventually sequestrate. Sequestration starts with erosion of bone at its junction with granulation tissue. In practice this is an infected process on the surface and at first the marrow is not infected. Eventually erosion of the outer cortex reaches the marrow and then sequestration spreads more rapidly as an infected osteitis of cancellous bone. The skull, with its 2 tables and intervening diplo@, is the commonest bone to be burned right through. If the dip106 is seriously burned, it becomes avascular with purple clotted blood filling the spaces of the cancellous bone and
Jackson:
Burns of Bone II
sometimes discolouring the cortical table. Like the outer table the full thickness of the inner table cannot survive if its superficial blood supply (in this case from the dip&) is destroyed. Both tables of the skull need a blood supply from both sides to survive. On several occasions, while removing dead diploe and inner table, we have noticed slight bleeding from the deepest layer of the inner table. This deep half of the inner table gets its blood supply from the dura. If a burn kills the diploe but not the inner table, much but not all of the inner table will sequestrate. The deepest part of the inner table will survive and this is important in treatment. These findings parallel those of Johnson (1927) on the blood supply of long bones. The time that burned bone takes to sequestrate spontaneously varies from 2 months to 3 years, and it seems to depend largely on the thickness of the compact bone which has to be eroded. There is also great variation in the amount and vascularity of the marrow. The deep osteogenic layer is sometimes left behind when burned bone sequestrates. The osteogenic layer of the dura or the periosteum on the deep surface of a burned long bone will granulate if it is alive and exposed, and if skin cover is provided by a free graft or a flap it may produce new bone. RESULTS OF 98 CASES Burns of bone in this series were sometimes isolated lesions, but more often part of extensive injuries. tn the latter event the soft-tissue burns took precedence and the area of the burn was reduced as early as possible. When the burn of bone was the main injury, a delay of a week or two was considered well spent to improve the patient’s condition if he had respiratory tract damage due to smoke, or suffered from heart failure. Nevertheless, in treating an isolated burn of bone we considered that nothing was to be gained by waiting for more than two or three weeks, and this may account for the absence of extradural and diploic abscesses in our series. The principle we usually followed was to remove exposed outer cortex as soon as possible and the defect was then closed with split-skin grafts or the dead inner table treated in a manner that will be described. One hundred and fifteen cases of exposed bone were treated with split-skin grafts in this way : 22 were treated with skin flaps and 12 submitted to amputation after setting out to cover the bone. The use of mean time intervals to describe treatment is of only moderate value, but they are
357
given to permit comparison with other series. The site of bone injury was first attacked surgically on a mean day 21 (range O-104 days). This was usually the first or second operation on the patient (mean 1.4) and sometimes amounted to excision and grafting of soft tissues only. The removal of exposed bone was started on a mean day 35 (range l-104 days) and a mean 3.2 operations were required to get the site of burned bone healed. The first grafting of bone was always on the day of decortication. Equal numbers of cases had their first bone excisions before and after 30 days, the mean day of excision for these 2 groups being day 18 and 50 respectively. The mean healing time from injury was 4.6 months. Two cases were not included, treatment being withheld for age and psychiatric reasons. There were 9 deaths in our series, a case mortality of 9.2 per cent. Their ages ranged from 8 months to 86 years, Three patients over 70 died I, 19 and 27 days after operation; their causes of death were acute cardiac failure. clinical renal failure and prostatectomy with pneumonia. This raises the question, would they have been better treated conservatively? A fourth, aged 86, with half the skull exposed, was not operated on but died shortly after transfer to a geriatric hospital. The other causes of death were less controversial-burn of brain, coliform septicaemia in a 70 per cent burn, cardiac arrest during anaesthetic induction, acute cardiac failure when the burn was virtually healed, and acute cholecystitis with cholecystectomy. DISCUSSION OF TREATMENT There are 2 approaches to the surgical management of the burned skull. The first is to close the wound with split-skin grafts after excision of avascular bone, the second is to close the wound with a skin flap, with or without excision of exposed bone. After describing these techniques, factors influencing the choice of treatment will be discussed, and an attempt will be made to answer the question of whether exposed and burned bone can regularly be preserved. Wound closure with split-skin grafts after excising avascular bone The point has already been made that exposed cortical bone is avascular on its superficial surface, no matter whether it is simply denuded of periosteum or whether it is also burned. In either case, therefore, the wound can be closed by excising the cortex and grafting viable marrow. Burns of the skull will be considered first, then burns of other bones.
Burns
358 Case I
A trapped fireman received a burn of his skull as part of extensive injuries (Fig. I). On day 41 the outer table of the skull was divided into squares with a motor saw and the squares were removed with an osteotome and hammer. The diplo& was covered with split-skin grafts on 2 occasions and, in spite of developing some minor septic pustules for a few months, the wound healed soundly and has not broken down again over 20 years.
Surgical technique-outer
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Bleeding from the bone can easily be stopped with a little bone wax on a finger tip; this does not prevent the take of split-skin grafts. The depth of cancellous diploe is variable but only rarely is it difficult to find a plane of cleavage. Removal of the outer table over the venous sinuses presents no problem. Naturally one must exercise care in approaching the thin skull of the temporal region; if this is exposed or burned, the full thickness of the bone may be nibbled away.
table
Adherent scalp and periosteum should first be stripped off, using a rougine. The outer table can
then be cut into squares of about 1 cm2 with an oscillating motor saw and, if the diplo@ is alive, the cuts bleed slightly. A rotating saw blade is inclined to catch on gauze or towels and ‘run away’; it represents a special danger to the assistant’s hands which must never be in front of the blade. A high-speed drill with a cutting burr is an alternative instrument, but we have found it less suitable. The squares of outer cortex should then be removed with an osteotome and light hammer. Provided the osteotome is held tangentially to the skull surface and tapped with appropriate strength, there is no danger of penetration. (A chisel is likely to penetrate the skull and should not be used.) If the inner table is cracked, as at a suture line, there is at once a typical cracked resonance. Theosteotome should then be removed and the area approached from another angle.
a
b
Fig. 1.-Case 1. a, Outer table being cut into squares with an oscillating motor saw. b, All but one square of outer table has been removed, exposing diploe. c, The diploewas covered withsplit-skin soundly.
graftswhicheventually
healed
Jackson : Burns
of Bone II
The idea of cutting the skull into squares with a motor saw and removing them with an oseotome was first practised, to my knowledge, by Gissane and Ross at this unit in 1948. They waited for the diplo& to granulate before grafting it (Fig. 2). It was on the basis of their unpublished case that we began in 1950 to graft exposed diploi? immediately, judging that what would granulate should take a split-skin graft directly. Case 2 (Gissane and Ross’ case) An old man, aged 79, was dozing by an open fire and fell with his head on the coals. He suffered from high blood pressure and occasional blackouts. He received a circular charred burn of the back of his head (Fig. 2). On day 42 the outer table was criss-crossed with an electric saw and the bare bone was chipped away with an osteotome on three occasions. On day 61 split-skin grafts were applied to the granulating area which was healed in 3 months. Small spicules of bone discharged from pustules on the scalp for some time but apart from this he had no further trouble.
F;g. 2.-Case
2. The diplo& granulating.
The management of dead bone over the frontal sinuses and mastoid air cells requires special consideration. If outer table is removed down to a sinus, the osteotome is likely to perforate the sinus mucosa. There is no danger in removing the outer cortex itself as this will later be cast off spontaneously if it is dead ; but if mucosais opened by mistake, a flap will be needed to close it, and often a local flap is not available. Split-skin grafts take well on the bony wall of the frontal sinus
359
after removal of the mucosa, but the fistula into the nose cannot be closed in this way. Nevertheless, split-skin grafts on the sinus wall may be useful in making the raw area small enough to be closed by a local flap. Case 3 An epileptic woman of 31 dressed to go out to work one morning and was found, shortly afterwards, lying across a paraffin heater with her face and hands destroyed. She lost both hands, her sight, and her nose and ears, but, even so, it was not a mortal wound. Parts of the outer table of the skull and the mandible which were exposed were excised and split-skin grafted (Fig. 3). The frontal sinus, which was laid open by removing the front wall with the rest of the outer table, was eventually closed with the abdominal pedicle which was used to provide a new nose.
Fig. 3.-Cuse 3. The frontal sinus is completely exposed following excision of the outer table of the frontal bones and the orbital ridges. All raw areas have been closed with split-skin grafts; the only wet areas are mucous membrane and conjunctiva. No local flap is available. Case 4 A woman, aged 71, fell on a fire in an epileptic fit and burned the right side of her face, eyelids and skull (Fig. 4). After 4 operations in 4 months the burn was healed apart from a persistent small opening into the right frontal sinus. The diplog had been grafted and a
360 lid adhesion was established on either side of the right pupil. Two months later excess skin from the left upper lid was used as a full-thickness graft to correct skin shortage of the right upper lid, and a If-inch local skin flap, based on the bridge of the nose, was successfully transposed to close the opening into the frontal sinus. Later, the lid adhesions were divided and she was fitted with a wig.
Fig. 4.-Case 4. The skull has had an excision of outer table which opened the right frontal sinus, followed by split-skin grafts. A local flap from above the nose was transposed to close the sinus.
Our practice now is to X-ray the sinuses before operation and to leave the dead outer table over the frontal sinuses unexcited-this is after excising the rest of the exposed skull and grafting the diploe. When the rest of the face and skull has healed one or two months later, a small patch of dead bone remains over the sinuses for a further few months, Then it separates spontaneously without opening the sinus, and a pedicle flap from a distance is avoided. We have had one deep burn of the mastoid process in an elderly lady which remained wet and scabbing after the separating cortex was eased off with an osteotome. Two split-skin grafts on the granulating air cells failed to epithelize the surface, and she refused the necessary skin flap.
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Low-grade osteitis sometimes follows split-skin grafting on the diplo&, no matter whether the grafts are applied immediately after excision of the outer table or put on the granulation tissue which develops later. Pustules form around little spicules of bone and then discharge and heal, only to be followed by others. This condition may take 6-18 months to clear up spontaneously. It does not occur under a flap, nor, in our experience, if a split-skin graft ‘takes’ well on really vascular marrow (e.g. the medulla of the tibia). Unsatisfactory free grafts can always be replaced with a flap. Surgical technique-diplog and inner table The surgeon will usually have removed the outer table before being faced with a choice about the inner. If the diploe has been damaged by heat, it will be purple or brown and will not bleed if drilled. If thrombosed marrow is exposed by decortication, it is still impossible to know by inspection whether the whole thickness of the inner table is dead. This can only be ascertained by making a burr hole through it, and perhaps taking a clean bite of inner table with bone nibbling forceps. If it does not bleed, of course, it is dead. Often, however, the deepest quarter of the inner table, which gets its blood supply from the dura, bleeds. If the inner table is completely avascular on making a burr hole, a flap may be indicated and this will be considered later. If a flap is not available, however, the avascular bone should be removed with nibbling forceps until bleeding bone is reached. The dura should then be covered with split-skin grafts which usually take well on it in our experience. We have avoided active removal of inner table over venous sinuses because, if bleeding became severe from a tear of the sinus, there would be no bony table to pack against. There is no point in drilling completely dead, avascular inner table. It is bound to sequestrate eventually after many months and it is quicker to remove it. If, however, the deepest quarter of the inner table is still vascular and bleeds when drilled, this is the type of case for multiple drill holes placed close together to let granulations come through, as illustrated by Artz and Reiss (1957). About 6 months later the superficial three-quarters of the inner table can be separated gently with an osteotome and hammer. This delay in wound closure is only acceptable as the price of preserving a thin bony vault to the skull. A bone defect in the skull of 1-2 inches diameter is usually symptomless and safe, and can be
Jackson : Bums of Bone II
covered with a pad and wig if necessary. If an old patient has a more extensive skull defect, he may be prepared to wear a protective metal plate in a cap, but younger patients should probably have an osteoplastic repair.
361 were grafted and 2 toes and their metatarsals were removed. On day 40 the full thickness of burned membrane bone of the skull, which was already separating, was removed leaving granulating dura matter. The defect was skin grafted, and by day 50 the head was
Case 5 A man of 52 suffered from traumatic epilepsy due to a shrapnel wound. He fell on a fire in a fit and received deep burns of his skull. On day 28 the outer table was removed and the marrow appeared dead. A trephine hole in the right frontal region showed the bone was completely avascular in this area. The dura appeared normal. Burr holes were made over therest of the inner table which bled from its deepest part. Granulations grew through these holes but they did not spread over the residual dead bone of the inner table. Six months post burn, the full thickness of the inner table in the right frontal region had to be removed where it was burned through. In other places the outer threequarters of the inner table was removed with an osteotome and hammer, leaving a thin layer of bleeding bone to take a free graft. The head was virtually healed IO months after burning.
The following full-thickness burn of the skull in a baby showed bone regeneration. Case
6
A baby girl, aged 4 months, was left in a cradle in front of an inadequately guarded fire. A coal fell from the fire and set light to the linoleum and cradle causing an I I per cent burn of the baby’s scalp, left arm and foot (Fig. 5). On days 14 and 41, granulating areas
b
Fig. 5.-C’use 6. a, The exposed skull in this photograph was loose and removed on day 40, leaving the bony defect seen in b, which was grafted. c, (overleaf) This picture was taken 18 months later. The previous extent of hone loss. marked out in ink, was all hard.
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healed. Over the next 18 months the obvious hole in the skull became hard, presumably with new bone. Five years later a narrow hair-bearing flap was raised in the right parietal region and transposed to the frontal region to restore the hair line.
4
Case 8 A moulder, aged 66, had his thumb trapped in a hot mould for 15 minutes before he could be freed (Fig. 7). After excision of the burn on the following day, the extensor tendon was covered with a split-skin graft but the tendon proved to be dead. By day 43 it was obvious that the backs of both phalanges of the thumb were dead and the interphalangeal joint was open, Dead cortical bone was removed from the back of both phalanges and cover with split-skin grafts was 90 per cent successful. The foundry man was healed and back at work 3 months after his injury with only a stiff interphalangeal joint. Case 9
A single woman of 58 had a severe personality disorder associated with addiction to chlorodyne. She had recently walked out of a psychiatric hospital without leave and could not be traced. Under the influence of chlorpromazine and carbital tablets she fell on a gas fire setting her clothes alight, and getting a 5 per cent whole skin-loss burn of the chest, loin and buttock (Fi,. 8). Only after 2 weeks did she attend her own doctor.’ The eleventh rib wasexposed and the bare crest of the ilium protruded through the skin. Both were simply excised and the whole burn grafted succescfully on day 18.
Case 7 When a man of 53 fell asleep in a chair after a drinking
Wound closure with skin flaps with or without excision of bone Skin cover with local flaps or with flaps from a distance is sometimes an alternative to excision of dead bone and free grafting. Its most striking advantage is that sequestration can sometimes be prevented in this way, even though the flap is placed on dead bone colonized with bacteria. With burns of the skull the benefit is greatest when the inner table can be saved and a fullthickness skull defect prevented. The dead bone is revascularized under the skin flap and gradually replaced like a bone graft; most or all of it is preserved and not extruded. A flap may be used directly on denuded outer table (Jackson, 1975). The following was a ‘friction burn’ which may have been mechanical, thermal or a combination of both.
bout, his cigarette set his trousers alight producing a deep 4 per cent burn of the right leg (Fig. 6). On day 28 the soft-tissue burns were excised and grafted successfully, leaving the lower two-thirds of the tibia and tibialis anterior tendon exposed. On day 48 the tibia1 cortex and thenecrotic part of tibialis anterior were removed, and on day 54 both were split-skin grafted successfully. He was healed,and discharged in just over 3 months. Although the graft on the tibia caused no further trouble, the free graft which was adherent to muscle and tendon broke down several times. The presence of exposed tendon in the graft bed may be a stronger reason for a flap (if available) than the presence of exposed bone.
In 1953 a 5-year-old boy fell off a wall and was dragged some distance by a car. He received multiple injuries including a friction burn of the temporal bone (Fig. 9). The burn was small enough to be covered with a local flap, and suitably placed for hair distribution to be improved by such a flap. Moreover, removal of outer table only at this site in a child would have been impossible. The bone, which was colonized withaprofuse growth of Staphylococcus aureus, was successfully covered with an occipital-based flap with the hair shafts in the right direction and the boy has worn an adhesive hair-piece to cover the bald area.
Other bones can often be treated in the same way by excision of burned cortex and split-skin grafting. This is particularly valuable if no easy flap is available, or if, for instance, the back of a phalanx is exposed in a burned and crushed hand where early wound closure and active movement are imperative.
Case 10
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b Fig. 6.-C’use
7. a, Granulating tibialis anterior muscle and its tendon lie to the left of 4 in of tibia1 marrow which has just been exposed by decortication. (Pointer on tibia1 marrow.) b, The whole was successfully covered with split-skin grafts; but, whereas the graft on the marrow provided good permanent cover, the graft on the moving tendon tended to break down for several years.
Fig. 7.-Case 8. Burn of both phalanges and interphalangeal joint treated by excision of dead bone and split-skin grafts.
A flap may also be used if heat has thrombosed the diplo& and rendered the superficial half of the inner table avascular. We have already mentioned that this state of affairs is often obvious on inspection before decortication. The three cases reported by North (1948), Worthen (1971) and Freeman and Cudmore (1973) were all of this depth at least (if not completely through the inner table as well) and by using skin flaps they too succeeded in limiting the bone loss substantially. In our unit we have always removed discoloured outer cortex before applying a flap to dead marrow and inner table. In Cast I I the completely dead inner table was excised and a flap was successfully applied over damaged dura and the rim of partly dead inner table. In Curse 12 the flap was applied over brown, infected marrow and the wound healed except for 2 minute exposures of bone (l-2 mm) which the patient does not wish to have treated.
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Fig. 8.-Case 9. Burn of the right ilium which was satisfactorily treated by cutting it (,ff just 1Jelow the surface when the wound was grafted.
a
b
Fig. 9.-Case 10. a, Friction burn due to being dragged along the road by a car. b, It was covered with a transposed flap based on the occipital region. Case 7 I In 1970, at the age of 73, a lady who had been fit all her life began to neglect herself and her home. She had complained of feeling weak, and was then found unconscious by the fire which had gone out and was quite cold. There was a deep burn 4 inches in diameter on one parietal region (Fig. 10). Four days later she was fit for surgery. A swab from the surface of the burn showed a profuse colonization with coliform bacilli. The dead scalp and outer table were removed
with an osteotome. The diplo& was clearly dead. The central dead inner table (14 x 2 inches) was removed down to the dura and the edge of the bone was nibbled away until there was bleeding from the deeper part. The dura was oedematous and had several thrombosed veins on its surface. It was not excised to minimize the risk of cerebral infection. The damaged dura and the remaining inner table were successfully covered with a transposed flap. When examined 24 years later in a geriatric hospital the wound had remained
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b Fig. 10. --c‘use I 1. a. Dead dip& after removal of outer table. b, Some inner table removed, exposing oedematous dura with thrombosed viens. A rim of brown dinfoe was left, rather than increase the defect, c, Transposed flap-exposed periosteum was split-skin grafted. . soundly healed and the lady was having no symptoms from the bone defect. Dead bone had not been discharged and there was no sequestrum revealed on X-ray.
rest of the dead bone has stayed permanently covered for over 2%years. She now wears a full wig and does not wish to have any further treatment. X-rays show no sequestrum.
Case 12 In 1972, an epileptic woman of 40 fell on a coal fire and burned the frontoparietal region (Fig. 11). On day 7 the outer table was excised leaving a central area of dead inner table with a rim of bleeding diplot: around it. The central area consisted of dry, brown, thrombosed dip&! and inner table. For 2 months treatment was delayed for psychiatric reasons. On day 70 there was still 7 x 10 cm of brown dip&+ and inner table exposed. A small exploration showed healthy dura, and on day 77 (11 weeks) the dead bone and dura were covered with a local transposed skin hap. Two small areas of dead bone (l-2 mm in diameter) became exposed in the suture line but the
Covering contaminated dead bone with a flap when it has been exposed for weeks is a far cry from the principles of plastic and orthopaedic surgery. The surgery of burns is the surgery of necrosis and infection, and this generally means excising dead tissue. However, the following case shows that contaminated dead bone may be preserved long enough for replacement to begin--it may be that more prolonged protection (antibacterial and mechanical) would have allowed it to be completed.
Flaps on long bones
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a
b
Fig. 11.-Case 12. a, Burn of skull from coal fire, sustained in a fit. Day 7, half of outer table has been removed showing brown dead diploe. b, Seven weeks after a scalp flap was transposed over dead diploe and inner table. A small, dry exposure of bone remains at the suture line with no demonstrable sinus. The patient wears a full wig over this result. Case 13 In 1974, a moulder, aged 23, received severe burns when hot plastic was injected into his right forearm at work (Figs. 12, 13). The burn destroyed all the long tendons to the radial side of the hand, 3 inches of median nerve, the radial artery and radial nerve sensation in the hand. Separation of the slough took 6 weeks and left 4.5 cm of bare radius bridging a gap between granulating forearm and wrist. X-ray at this time showed a line of rarefaction at the proximal end of the exposed segment. Cultures grew Staphylococcus aureus and coliform bacilli. On day 50 the bone was covered with an axial groin flap, which was inset on day 78, with suction drainage for 2 days. Although there were no local or general signs of infection, aspiration down to bone on day 85 produced 1.5 ml of turbid fluid which grew Staph. aureus. Aspiration was repeated almost daily from day 87 to day 98 and the cavity washed out with cloxacillin. Fucidin (400 mg daily) was given systemically. On day 99 and 102 there was no growth on culture of the aspirate and aspirations were stopped. Fucidin systemically was continued for a further 6 weeks. The burned bone, which had been colonized by bacteria for over 3 months, was covered and the wound remained healed and symptom-free for 9 months. Serial X-rays confirmed that the previously exposed bone was dead, and the radius was protected with a plaster for 3 months to reduce the risk of fracture. Five months after wound closure cancellous bone appeared to be in continuity on X-ray although the living and dead
cortices had not united. In fact the cortex of the burned fragment gradually absorbed. The sequel is disappointing, but instructive. Nine months after healing there was a little swelling of the flap(which unfortunately was not aspirated and treated with antibiotics as it should have been) and a small sinus appeared at its edge. The result was a foregone conclusion: 5 months later the patient fractured the lower end of the dead fragment pushing himself out of a chair, and the rest of the dead bone was removed after another 3 months. By this time the sequestrum and its X-ray shadow measured 5 cm in length while the original dead segment had measured 6 cm. One cm of dead bone had been reconstituted proximally. Histology of the fragment subsequently confirmed ‘bone necrosis with pyogenic coccal infection, and very early revascularization and new bone formation at one end ‘. The patient has a useful ulnar nerve hand and can lift an electric kettle with it, but he has lost some supination with loss of the radial fragment.
Factors influencing the choice treatment for burned bone
of
The choice of management may be influenced by the following factors: the size and depth of the burn of bone, the availability of local skin flaps, the site of hair loss, the time between burning and treatment, the likelihood of further trauma, and the age and frailty of the patient.
Jackson
: Burns
The extent
of Bone II
of exposed
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bone
It is not possible to cover a defect of more than
about athirdof thescalpwithalocal flap, so larger areas need a flap from a distance or must be treated by removal of the dead boneandfreegrafting. Free flaps may be possible in some plastic surgery centres. Sometimes excision and free grafting of part of the exposed bone will reduce the extent sufficiently to make a flap possible where it is really needed (e.g. over dead inner table).
a
the dura and brain might be walled off with adhesions in the 3-4 weeks that would pass while getting the soft tissues grafted and the outer table removed. It might be safe to apply homografts until such a wound granulated. Some surgeons have successfully excised dead dura and grafted the defect (Brown and Fryer, 1956; Gatewood and McCarthy, 1957; Stuckey, 1963) and some have excised burned brain and closed the wounds with grafts (Ranev and Shindarsky, 1969) but
b
Fifi. I2.--Cus~ 13. a, The exposed, dead segment of radius, denuded of periosteum and bridging the soft-tissue gap. b. The wound was healed and aspirations
The depth
of bone
stopped at 14 weeks after injury.
involved
If the diplo& is alive, there is often a choice between an early flap and free grafting after excision of the outer table. If the diplo& is dead, the choicelies between a flap over dead outer table or marrow on the one hand, and, on the other, drilling of exposed inner table and delayed excision of its superficial part and free grafting. If no local flap is immediately available, and excision has exposed a coagulated dura, a reasonable course of management is to keep the dura covered with homografts or pig skin until a flap from a distance can be made available to cover it. A necrotic lesion of
hemiplagic patients, who presumable have burns of the brain, have been known to survive and recover from their hemiplegia without brain exploration (Gatewood and McCarthy, 1957). Early skin flap cover without any bone excision is perhaps especially indicated for such cases. Local flaps and baldness A local flap may be indicated in preference to free grafting if it transfers a lateral or frontal bald area to the crown of the head. Some patients use considerable ingenuity in solving their own individual problems.
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a
b
c
d
Fig. 13.-Case 13. a, X-ray at 4 weeks, showing soft-tissue defect around bone. Small erosion of cortex visible at proximal end of dead segment (arrow). b, X-ray at 20 weeks. Limits of dead bone are now obvious by erosion of cortex. c, X-ray one year after b, showing replacement of sequestrum with new bone from both ends. This was 4 months after the sinus had developed. d, X-ray 6 weeks after c. Fracture at the distal end of the fragment 17 months after the injury.
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: Burns
of Bone II
369
a
b
excised on day 8, there was a good vasculardiplti, but thiscase required three operations in 4 months to get the wound healed. b, Although the bald area was not too badly situated for a man, he managed to keep it hidden with a rather ingenious hair style. Fig. 14.-C~rsr
14. a, When
the outer table was
Case 74 A carpenter, aged 39, was found outside his burning house with a deep burn of his skull (Fig. 14). No explanation could be obtained. Eight days later the outer table was removed and the dipI& grafted in spite of profuse colonization with micrococci. Two further small grafting operations were required, and the burn was healed in 4 months. Subsequently, a flap was offered because small spicules of bone began to separate, but he chose to cover the scar with an original hair style. The time from burn to operation Progress in erosion and separation of dead bone depends on the time since injury. Once infection has invaded the marrow or extradural space, excision of overlying dead bone will be essential. Flaps on dead skull which has been exposed for several weeks usually, but not always, secure complete healing. No case of a primary (same day) flap on clean, burned bone has been found in burn literature, although flaps are regularly successfulover pieces of autoclaved bone in cranial surgery. There is no doubt this will now be practised where it is not contra-indicated for some special reason.
The likelihood of further trauma Involvement of a malleolus is almost always an indication for a cross-leg flap. Often a split-skin graft will be tried in the first instance when the rest of the foot and ankle is being grafted, but, if this fails, time should not be wasted on a second, third and fourth attempt at free grafting. This is a common mistake and a great waste of time. A local flap is usually not available. Case 15 A caster, aged 46, was burned when the bottom fell out of a pot of molten iron and it ran into his boot (Fig. 15). He lost his toes, but the pressure areas on the sole were spared. The burn healed in 3 months with split-skin grafts, except over the malleoli where bone was exposed. A cross-leg tlap was used to cover the medial malleolus, the worse of the two malleolar burns. The lateral malleolus took a year more to heal, and broke down again from year to year causing him many months off work. A second flap, without undue delay, would have saved him the months off work. The age and frailty of the patient Among the elderly there isa time for less than full curative treatment. If a patient has a large area
370
of skull exposed by burning, he may be too frail for major excisions and reconstructions with multiple stage pedicles. If all the soft-tissue burn has been grafted, such a person is often able to live his last months without pain, smell or discharge in spite of a large area of skull being exposed. He can live at home wearing a cap or scarf for cover, and the bone condition may well play no part in his death.
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Conservative treatment is not always indicated in the elderly, however, and, if the bone exposure is small, one quick operation may be sufficient to heal it.The two following cases show the benefit of early surgery and keeping the elderly mobile. Case 17 A rather unsteady man, aged 75, got out of bed and fell on to an unguarded gas fire. On day 12, the outer
Fig. 1~--CUE 15. A burn of the malleolus should usually be covered with a cross-leg flap without undue delay. This man should probably have been pressed more strongly to have a second cross-leg flap to the burned lateral malleolus: it would have saved him prolonged disability and financial loss. Case 76 An old man of 86 was very deaf and a little confused. On the night of his injury his leg ‘gave way’ and he fell on to an unguarded fire receiving a very deep burn of his face, scalp and neck amounting to 4 per cent (Fig. 16). The left ear was destroyed. On day 23 the dead outer table of the skull was removed and the marrow would have been grafted if living. However, it was completely avascular. On day 39 the face and neck were skin grafted. On day 56 he was discharged from hospital with his soft-tissue burns healed and 14 per cent of inner table exposed. At this stage he was losing his memory and major surgery was contraindicated. Two months later he was admitted to a geriatric unit where he died 6 months after his injury. At no time was there evidence of intradural complications, and we considered, in this case correctly, that he would die before the inner table sequestrated. In a younger man, a flap or tube pedicle would have been reasonable.
table was ‘squared’ with a motor saw,removedwithan osteotome,and the defect covered withsplit-skingrafts. The graft was a complete take and he was healed and discharged from hospital on day 25. His only complaint 6 months later (and it was made with great feeling) was that his legs had been weak and stiff ever since his stay in hospital. This experience influenced us in the next case. Case 18 An active old man of 78 was well looked after by his two daughters. Falling asleep one evening, he tumbled on to an unguarded coal fire. There was no history of epilepsy or blackouts. Theonlyabnormal physical sign was an extensor plantar reflex. He regularly walked 7 miles a day. Since he only had a 1 per cent burn on the back of his head, he was sent home to his daughters on day 3 for some partial skin loss to heal, and re-admitted on day 37. During these weeks he walked 3-5 miles every day. On the day after admission
Jackson : Burns
of Bone
II
b Fig. lb.-Cuse 16. a, A 4 per cent burn from a fall on to an unguarded fire. b, After removing the outer table and grafting the soft tissues, the inner table was clearly dead. No further surgery seemed indicated.
the outer table was removed and the diplog successfully grafted with the loss of half a litre of blood. A week later he had a short period of confusion, but on day 53 he was sent home virtually healed. Small spicules of bone were occasionally discharged for a further year, but 3 months after his operation he was wearing a wig and enjoying a touring holiday in Germany. Total hospitalization was 19 days.
Can these bones live? The fate of exposed bone which is dead -from
burning or ischaemia can be influenced by treatment, and this is now worth further experimental study. Exposed burned bone sequestrates unless it is so small in area that granulation tissue can ’mushroom’ over it; but we have seen that sequestration can be prevented by covering the bone with a skin flap and that this is in spite of bacterial colonization. How reliable is the method? It is not surprising that few surgeons have considered covering contaminated dead bone with a flap when excision was a practical alternative. However, this paper has attempted to collect all the cases and to assess the results. Six cases were reported by North (1948), Trapnell and Jackson (1965), Worthen
(1971), Freeman and Cudmore (1973-2 cases), and Lute and Hoopes (1974) and 4 further cases are reported in this paper (Cases 10-13). Nine of these 10 flaps were inset over contaminated, burned skull; one (the only failure) was over a long bone. (In a further case, not in this series, excision of the burned posterior cortex of both phalanges of a thumb showed the marrow to be dry and brown. This, too, was successfully covered with a skin flap.) On the skull the method seems reliable. Out ot 9 cases, 6 were completely and permanently healed. In 2 cases a sinus down to dead bone developed at the suture line, suggesting that flaps should be liberal in size so that the suture line is over living periosteum. It would seem that North’s case (1948) failed due to the flap being too small fop such a large and awkward defect. No failures were attributable to infection in any of these cases, but scalp flaps have an exceptional blood supply. Our usual practice in Birmingham has been to remove exposed or burned outer cortex and then to apply the flap over burned inner table. There is no positive benefit in keeping dead outer table. but it naturally adds to the operation to remove
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it, and this now seems unnecessary. This explains why we have only 4 cases of burned skull covered with flaps: we reserved the method for burns of diploe and inner table. No conclusions can be drawn from our one failure. The burn of radius (Case 13) behaved in many ways like Phemister’s (1926) experimental radium necrosis cases. Phemister showed that if a segment of a long bone in a dog was killed by radium, it was replaced by new bone if it remained free of infection and functioned in the support of the part. He described this replacement as ‘creeping substitution’. In the medulla necrotic debris was replaced by connective tissue and in turn by spongy new bone. The junction of dead and living cortex developed an irregular groove from absorption by granulation tissue in a case that went on to sequestration. However, in another which did not sequestrate, the dead cortex showed invasion and replacement by new bone. He also showed that the necrotic bone sequestrated from the living boneif secondary infection occurred, or if fracture occurred and the bone was not used. Human long bones killed by radium in the treatment of tumours were gradually replaced by new bone if they remained free of infection and functioned in the support of the part. Our failure cannot be taken to imply that flap cover for burned and contaminatedlong bonesiscontra-indicated;antibiotic therapy, mechanical protection and functional use are probably important factors for success. Infection was the cause of the failure. Obviously, the sooner a wound is closed the better, but even though the denuded radius was bathed in pus for 3 months, infection was supressed for 9 months after cover with a flap, and the medulla began to be replaced with new bone. Aspiration and antibiotics, as soon as a painless cold swelling appeared beneath the flap, might have prevented sinus formation, fracture and sequestration. We have concluded that flap cover sets the stage for burned bone to live again. There is a striking analogy between this phenomenon and tangential excision and grafting of burned skin. In the latter procedure a thin layer of dead or damaged dermis will ‘revive’ and be re-incorporatedinto the body beneath a split-skin graft, provided the rich subdermal plexus is intact. Both procedures involve closing the wound with a rich blood supply adjacent to the devitalized tissues. In both, one might say, new life is in the blood. Both procedures also have an infection risk : in tangential excision cases theskin graft and recipient area contain about lOORequesfs.for reprints should be addressed to: Mr Douglas Birmingham, B15 INA.
Jackson,
400 living organisms per gram (Lawrence and Lilley, 1972); and recent histological examination of a biopsy from a dry, ‘I-week-old burn of outer table of skull showed Gram-positive cocci and Gram-negative bacilli in the Haversain canals (Sevitt, 1975). It would be surprising if infection were not an occasional cause of morbidity in both procedures, and we know that it is. Both, however, now have a place in burn management. Acknowledgements I am deeply indebted to my colleagues for their co-operation-to Mr H. Proctor (Case lo), Mr J. E. M. Smith (Case 13), and especially Mr J. S. Cason who worked on most of these cases with me; also to Dr Mary Davies for collecting many of the cases, Mr N. R. Gill for the photographs and Miss S. Miles for her secretarial help. REFERENCES ARTZ C. P. and REISSE.
(1957) TheTreatmentof Burns. Philadelphia, W. B. Saunders, p. 140.
BROWN J. B. and FRYER M. P. (1956) Repair of industrial electrical burns. Plast. iieconstr. Surg. 18, 177. FREEMANN. V. and CUDMORER. E. (1973) . , Personal communication. GATEW~~D J. W. and MCCARTHY H. H. (1957) The treatment of electric burns of the skull. Am. J. Surg.
9, 93, 525. JACKSOND. M. (1975) Burns of bone: can these bones live? 1. Burns 1, 342. JOHNSONR. W. (1927) A physiological study of the blood supply of the diaphysis. J. Bone Joint Surg.
9, 153. LAWRENCEJ. C. and LILLEY H. A. (1972) A quantitative method for investigating the bacteriology of skin: its application to burns. Br. J Exp. Pathol. 53,
5.50. LUCE E. A. and H~~PES J. E. (1974) Electrical burn of the scalp and skull. Plast. Reconstr. Surg. 54, 359. NORTH J. P. (1948) Electric burns of head and arms with residual damage to eyes and brain. Am. J. Surg.
76, 631. PHEMISTER D. B. (1926) Radium necrosis of bone. Am.
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RANEV D.and SHINDARSKYB. (1969) Operative treatment of deep burns of the scalp. Br. J. Plast. Surg. 22,
309. SEVITTS. (1975) Personal communication. STUCKEY J. G. (1963) The surgical management of massive electrical burns of the scalp. Plast. Reconstr.
Surg. 32,538. TRAPNELL D. H. and JACK~XIND. (1965) Bone and joint changes following burns. Clin. Radiol. 16, 180. WORTHENE. F. (1971) Regeneration of the skull following a deep electrical burn. Plast. Reconstr. Surg.
48, 1. FRCS,
Burns
Unit, Birmingham
Accident
Hospital,
Bath Row,