Annals of the Royal College of Surgeons of England (1979) vol 6i
ASPECTS OF TREATMENT*
Management of the diabetic foot John A Dormandy FRCS St James's and St George's Hospitals, Londont
Surrmmary
IT IS ESSENTIAL THAT THESE INSTRUCTIONS SHOULD BE FOLLOWED
If the diabetic foot fails to respond adequately CAREFULLY TO AVOID DANGEROUS COMPLICATIONS DEVELOPING to a short period of basic primary treatment IN THE FEET OF ANY DIABETIC. surgery must be considered. The main factor 1. Wash feet daily. Dry carefully especially between toes. determining its nature and extent is the severity 2. Cut nails straight across and avoid rough edges. of large-vessel disease. If investigation shows 3. If feet sweat, apply foot powderafter washing and drying. this to be of minor significance local surgery 4. Make sure shoes fit comfortably. Break them in gently. is usually successful. In the presence of definite 5. Do not go barefoot. Use woollen socks. large-vessel disease, however, major ampu- 6. Do not treat a corn or callous yourself. See a chiropodist. tation is utsually necessary, though arterial re- 7. Pain, redness, swelling, tenderness, are danger signals. construction with local distal amputation may If any of these symptoms appear, see your doctor immediately occasionally be feasible. The factors to be taken into consideration in the choice of treat- FIG. I List of instructions for all diabetics regarding foot care. ment are discussed. Introduction The feet of diabetics may present to us in a 'In the thirty-ninth year of his reign King Asa bewide variety of ways because of the pathocame affected with gangrene of his feet; he did not seek guidance from the Lord but resorted to logical processes that may be involved, ranging physicians. He rested with his forefathers in the from atherosclerosis and diabetic microangioforty-first year of his reign.' II Chronicles xvi, pathy and sensory or motor neuropathy to I 2-14. abnormalities in fibrinolysis, platelet behaviour, This is probably the first description of dia- and haemorheology. In the past unnecessary betic gangrene; and the life expectancy of a emphasis has been placed on trying to assess diabetic with gangrenous feet has not changed the relative importance of these aetiological very much. There are more hospital beds factors in particular patients. This is often an eccupied by diabetics with complications in academic exercise which has little bearing on their legs than by all other diabetics. Lacking the patient's practical management. If we look the glamour of a classic surgical set-piece, the hard enough we can always demonstrate some treatment of these patients is too often con- degree of neuropathy, vascular disease, and sidered an unwelcome cross that surgeons have haematological abnormality in all diabetic to bear. Not only are the diabetics' feet some- patients. times neglected by doctors, but often also by the patients; as Bloom has said, 'The elderly Basic primary treatment diabetic is often divorced from his feet, unable to see them because of poor eyesight and un- The flow chart shown in Figure 2 illustrates able to feel them because of sensory loss'. the basic plan of clinical management. It the relatively few options we Prophylaxis is therefore of paramount import- demonstrates have and the that genuinely need an questions ance and must be constantly emphasised to all answer from the practical point of view. diabetics. Not only should they be issued with a card such as that illustrated in Figure i, but The first, non-operative, phase of treatment both patients and relatives should be repeat- is a few days' bed rest to give the acute lesion edly reminded of its contents. Surgeons are a chance of being brought under control, after usually called in because such prophylaxis has which the patient should be mobilised using failed. carefully padded footwear such as Plastozoate The Editor would welcome any observations on this paper from readers *Fellows and Members interested in submitting papers for consideration with a view to publication in this series should first write to the Editor
306
John A Dormandy
shoes. The other elements of this phase are control of the diabetes, infection, and oedema. Control of hyperglycaemia and infection are interrelated and it may be necessary to change temporarily to a variable dose of insulin until the infection is controlled. All infected material should be cultured and the choice of systemic antibiotics governed by the results of sensitivity tests. Local treatment of infection should consist in twice-daily cleaning with antiseptics such as povidone-iodine and irrigation of sinuses with i% noxythiolin (Noxyflex) solution. Debridement of superficial . neroi tisu ma be aciee g p eroxi, one of o the the enzymatic of hydrogen peroxide, debriding agents like Varidase (streptokinasestreptodornase), or possibly the recently introduced dextranomer (Debrisan). Extensive debridement and drainage of pus will r
there is no merit in preserving them at all costs if they will never be able to carry out these functions and will merely be a source of discomfort and danger to the patient. If there is no significant response after I-2 weeks in hospital we shall have to answer the first important question: what is the extent of significant large-vessel disease? Ischaemia may be very localised, possibly because of a microangiopathy peculiar to diabeti vessel onlv be vse dsease be made histoloicall. Can dioseaseiScan and biopsy clearlyly not made safe or However the state . . of. the large arteries is much easier to establish clinically: if either the dorsalis pedis or the posterior tibial pulse is palPable at the ankle one can assume that largevessel disease does not play a significant role surgery undergeneralanaesthesia. r e *in the aetiology of the diabetic foot. (It is to remember that even in a normal o It isiS essential to control the oedema by important other of these vessels may be abone or treating such underlying medical conditions as leg or pulsations may be absent normally placed congestive cardiac failure or hypoproteinaemia, for some other reason.) the normal in position by the symptomatic use of diuretics, and b The most useful single investigation to supelevation of the foot, although this may be tho sse the determination of the systolic or m ot plement this is These a to al withundlig arterial pressure at the ankle, using a apply Doppler flowmeter with a sphymomanofet,irrespective meter cuff above it. In a normal subject lying aetiology. down the systolic pressure at the ankle should be approximately the same as the brachial What is the extent of large-vessel systolic pressure, but narrowing of the arteries disease? in the leg will introduce a pressure gradient. Non-operative care should be intensive but Rarely, if the artery under the cuff is severely not prolonged uselessly. The functions of the calcified false high readings may be obtained. feet are to support and move the patient; As a rough guide, if the ankle pressure is less
histolof call-
oievd .th
ofehydrogictissuenmay
practical.
dessenialt cntrlthes
painful pati cayemia patientsvers .c.m. pricps aese ptincfples diaeti.
SHORT COURSE OF INTENSIVE --- Failure Success
NON - OPERATIVETREATMENT
simple
PROPHYLAXIS
Failure SIGNIFICANT LA GE VESSEL DISEASE?
/
No
Yes
\
0~
POSSIBLE RECONSTRUCTION
LOCAL SURGERY
AR ERIAL SURGERY?
_No
MAJOR AMPUTATION I -LEVEL?
es
ARTERIAL ? LOCAL RECONSTRUCTION SURGERY
Also consider adding SYMPATHECTOMY and PRELIMINARYGUILLOTINEAMPUTATION.
FIG. 2
Basic flow chart for
management of the diabetic foot.
Management of the diabetic foot than two-thirds of the arm pressure there is very significant large-vessel disease and if this is combined with ischaemic lesions in the foot the usual criteria have to be applied in deciding whether reconstructive arterial surgery is feasible. Ihis will, of course, require formal arteriography. Although in diabetics atherosclerosis tends to affect vessels distal to the knee more often than in non-diabetics, reconstructive arterial surgery for limb salvage has been shown to be well worth attempting'.
307
Above or below the knee? In some patients with large-vessel disease and distal gangrene arterial reconstruction with a local distal amputation can give good results, and it is reasonable to carry out limited preoperative arteriography in the theatre to see if arterial reconstruction is feasible. Usually, however, patients with an ischaemic diabetic foot and significant large-vessel disease require a major amputation. The aim should be to try to recognise this group quickly and avoid a long hospital stay while successive amputations progressing up the foot and leg are seen to fail. Local amputations in the foot will not heal in the presence of large-vessel disease. The very difficult question now arises regarding the level of the major amputation: should it be below or above the knee? Figure 3 illustrates the more important factors influencing this choice. Above-knee healing is almost certain, but the knee may have been sacrificed unnecessarily. Clinical judgement about the potential viability of the skin which would be used in below-knee flaps is frequently wrong and there is a very real need for a predictive test in the large number of doubtful cases. Measurements of the ankle systolic pressure, the skin blood pressure, and thermography have all been proposed. Unfortunately, so far none of these tests has proved to be of value in the difficult clinically doubtful cases. Concentration on the actual procedure of the
Treatment of small-vessel disease If the foot lesion does not heal with simple non-surgical measures and there is no significant large-vessel disease it is usually presumed that ischaemia is due to localised diabetic small-vessel disease. The diagnosis tends to be made by exclusion, and there is indeed some doubt about its relevance in the aetiology of diabetic ischaemia. Few histological studies of small vessels have been performed in diabetic feet, but in the retina and kidney diabetic microangiopathy is characterised by basement membrane thickening, which is in fact very rarely associated with a reduction in the vessel lumen2. Therefore if diabetic microangiopathy does not interfere with blood flow by narrowing of the vessels, then either it is of no relevance to diabetic ischaemia or it must influence tissue nutrition by interfering with diffusion through the capillary walls. However, reduced blood flow need not necessarily be due to vessel disease at all; it could be caused by abnormalities in the blood itself. Increased blood viscosity, decreased red cell deformability3, and abnormal platelet aggregation combined with impaired fibrinolysis have all been documented in diabetics. So far as the diabetic foot is concerned, the term 'small-vessel disease' may hide a multitude of pathological sins. But whatever the exact nature of the local ischaemia, the important practical fact is that in the absence of significant large-vessel disease local surgery is usually successful, particularly if the lesion is predominantly due to a sensory neuropathy. GOOD HEALING OF STUMP GOOD REHABILITATION WITH BUTPOOR REHABILITATION A POTENTIALLY NORMAL GAIT The minimum amount of tissue should be re- DUE PROSTHES IS, B UT POOR HEAL ING OF STU MP. moved and this may mean the amputation of LESSTOHEAVIER PROPRIOCEPTIONAND a single toe, a ray resection, or, if more than vREATER ENERGY REQU IRE two toes are involved, a transmetatarsal am- MENTS. putation, all of which can give excellent func- FIG. 3 Factors influencing the choice between tional results. below-knee and above-knee amputation.
308
John A Dormandy
amputation may be a more profitable approach to improving the proportion of healed belowknee stumps. Although in principle we are all aware of the importance of the various technical details of an amputation, in practice the operation is too often left to a junior surgeon without adequate training or supervision. There are few operations in which obsessive attention to small points of technique is so essential for a successful outcome. Of almost equal importance is preoperative physiotherapy to prepare the patient and rapid mobilisation following amputation, using a temporary pneumatic pylon while waiting for a definitive prosthesis. Provided the patient does not already have an autonomic neuropathy, a simultaneous lumbar sympathectomy at the time of amputation will increase the blood flow to the vital skin flaps. Although the benefit of sympathectomy may wear off after a few weeks, far more blood flow is required to heal the skin flaps than to keep them healed. Two other new experimental techniques may also have a temporary beneficial effect: therapeutic defibrination and normovolaemic haemodilution, but neither of these has yet been adequately tested clinically.
Some other problems and treatments Two other, less common, amputations have a limited place in the treatment of diabetic feet. In the severely infected or toxaemic patient an emergency guillotine amputation removing all infected tissues is a useful first step to convert the definitive higher amputation into a clean procedure. The place of the Symes amputation has aroused continuing controversy for I30 years, its protagonists and antagonists supporting their views with mediaeval fervour. I believe it has a small but useful role in the treatment of the diabetic foot when there is no large-vessel disease and the calcaneal arteries are patent but a transmetatarsal amputation is impossible because of insufficient viable skin cover or infection of the metatarsals. A Syme's stump leaves the leg about 5 cm (2 in) shorter, but the patient can move around his home without a prosthesis and with less effort. This is extremely important and can sometimes outweigh the disadvantage of a less satisfactory prosthesis. It is as well to mention in this context the limitations of plain radiography in the assessment of the diabetic foot. Calcification
of an artery does not necessarily mean that it is blocked, and the usual criteria for the diagnosis of osteomyelitis need careful interpretation. The classic appearances of resorption and rarefaction require a good blood supply and may therefore not be seen in ischaemic osteomyelitis4. The occasional finding of air in the tissue planes, as an alarm signal of gas gangrene, is the best justification for routine radiology. Naturally there are clinical problems which do not fit into the basic pattern of management of diabetic feet already discussed and illustrated in Figure 2-for instance, the intact but painful foot, which may be an equivalent of the atherosclerotic with rest pain or a rare early manifestation of sensory neuropathy. Sympathectomy may help and intravenous naftidrofuryl (Praxilene) sometimes gives temporary symptomatic relief. However, oral Praxilene, or indeed any one of the other socalled 'vasoactive' drugs, has no place in treatment of the ischaemic foot. Another special problem is the painless, dry, black toe. This can be left alone to demarcate and separate spontaneously provided the patient can be relied on to recognise and report immediately any signs of infection.
Conclusion The currently fashionable enthusiasm for team work is probably nowhere more justified than in the management of the diabetic foot; good results can only be obtained by close collaboration between surgeons, physicians, nursing staff, physiotherapists, and limb fitters. The three golden rules for the management of this common and difficult problem are: firstly, speed in getting the patient moving and keeping him moving; secondly, intensive and enthusiastic care by a co-ordinated team; and thirdly, continuing prophylaxis to prevent recurrence.
References Birnstingl, M, and Taylor, G W (1970) Journal of Cardiovascular Surgery, I-I, 447. 2 Williamson, J R, and Kilo, C (I977) Diabetes, 26, 65. 3 Barnes, A J, Locke, P, Scudder, P R, Dormandy, T L, Dormandy, J A, and Slack, J (I977), Lancet, 2, 789. 4 Naide, M, and Schnall, C (I96I) Archives of Internal Medicine, 107, 380. I
ASPECTS OF TREATMENT*
Management of the diabetic foot John A Dormandy FRCS St James's and St George's Hospitals, Londont
Surrmmary
IT IS ESSENTIAL THAT THESE INSTRUCTIONS SHOULD BE FOLLOWED
If the diabetic foot fails to respond adequately CAREFULLY TO AVOID DANGEROUS COMPLICATIONS DEVELOPING to a short period of basic primary treatment IN THE FEET OF ANY DIABETIC. surgery must be considered. The main factor 1. Wash feet daily. Dry carefully especially between toes. determining its nature and extent is the severity 2. Cut nails straight across and avoid rough edges. of large-vessel disease. If investigation shows 3. If feet sweat, apply foot powderafter washing and drying. this to be of minor significance local surgery 4. Make sure shoes fit comfortably. Break them in gently. is usually successful. In the presence of definite 5. Do not go barefoot. Use woollen socks. large-vessel disease, however, major ampu- 6. Do not treat a corn or callous yourself. See a chiropodist. tation is utsually necessary, though arterial re- 7. Pain, redness, swelling, tenderness, are danger signals. construction with local distal amputation may If any of these symptoms appear, see your doctor immediately occasionally be feasible. The factors to be taken into consideration in the choice of treat- FIG. I List of instructions for all diabetics regarding foot care. ment are discussed. Introduction The feet of diabetics may present to us in a 'In the thirty-ninth year of his reign King Asa bewide variety of ways because of the pathocame affected with gangrene of his feet; he did not seek guidance from the Lord but resorted to logical processes that may be involved, ranging physicians. He rested with his forefathers in the from atherosclerosis and diabetic microangioforty-first year of his reign.' II Chronicles xvi, pathy and sensory or motor neuropathy to I 2-14. abnormalities in fibrinolysis, platelet behaviour, This is probably the first description of dia- and haemorheology. In the past unnecessary betic gangrene; and the life expectancy of a emphasis has been placed on trying to assess diabetic with gangrenous feet has not changed the relative importance of these aetiological very much. There are more hospital beds factors in particular patients. This is often an eccupied by diabetics with complications in academic exercise which has little bearing on their legs than by all other diabetics. Lacking the patient's practical management. If we look the glamour of a classic surgical set-piece, the hard enough we can always demonstrate some treatment of these patients is too often con- degree of neuropathy, vascular disease, and sidered an unwelcome cross that surgeons have haematological abnormality in all diabetic to bear. Not only are the diabetics' feet some- patients. times neglected by doctors, but often also by the patients; as Bloom has said, 'The elderly Basic primary treatment diabetic is often divorced from his feet, unable to see them because of poor eyesight and un- The flow chart shown in Figure 2 illustrates able to feel them because of sensory loss'. the basic plan of clinical management. It the relatively few options we Prophylaxis is therefore of paramount import- demonstrates have and the that genuinely need an questions ance and must be constantly emphasised to all answer from the practical point of view. diabetics. Not only should they be issued with a card such as that illustrated in Figure i, but The first, non-operative, phase of treatment both patients and relatives should be repeat- is a few days' bed rest to give the acute lesion edly reminded of its contents. Surgeons are a chance of being brought under control, after usually called in because such prophylaxis has which the patient should be mobilised using failed. carefully padded footwear such as Plastozoate The Editor would welcome any observations on this paper from readers *Fellows and Members interested in submitting papers for consideration with a view to publication in this series should first write to the Editor
306
John A Dormandy
shoes. The other elements of this phase are control of the diabetes, infection, and oedema. Control of hyperglycaemia and infection are interrelated and it may be necessary to change temporarily to a variable dose of insulin until the infection is controlled. All infected material should be cultured and the choice of systemic antibiotics governed by the results of sensitivity tests. Local treatment of infection should consist in twice-daily cleaning with antiseptics such as povidone-iodine and irrigation of sinuses with i% noxythiolin (Noxyflex) solution. Debridement of superficial . neroi tisu ma be aciee g p eroxi, one of o the the enzymatic of hydrogen peroxide, debriding agents like Varidase (streptokinasestreptodornase), or possibly the recently introduced dextranomer (Debrisan). Extensive debridement and drainage of pus will r
there is no merit in preserving them at all costs if they will never be able to carry out these functions and will merely be a source of discomfort and danger to the patient. If there is no significant response after I-2 weeks in hospital we shall have to answer the first important question: what is the extent of significant large-vessel disease? Ischaemia may be very localised, possibly because of a microangiopathy peculiar to diabeti vessel onlv be vse dsease be made histoloicall. Can dioseaseiScan and biopsy clearlyly not made safe or However the state . . of. the large arteries is much easier to establish clinically: if either the dorsalis pedis or the posterior tibial pulse is palPable at the ankle one can assume that largevessel disease does not play a significant role surgery undergeneralanaesthesia. r e *in the aetiology of the diabetic foot. (It is to remember that even in a normal o It isiS essential to control the oedema by important other of these vessels may be abone or treating such underlying medical conditions as leg or pulsations may be absent normally placed congestive cardiac failure or hypoproteinaemia, for some other reason.) the normal in position by the symptomatic use of diuretics, and b The most useful single investigation to supelevation of the foot, although this may be tho sse the determination of the systolic or m ot plement this is These a to al withundlig arterial pressure at the ankle, using a apply Doppler flowmeter with a sphymomanofet,irrespective meter cuff above it. In a normal subject lying aetiology. down the systolic pressure at the ankle should be approximately the same as the brachial What is the extent of large-vessel systolic pressure, but narrowing of the arteries disease? in the leg will introduce a pressure gradient. Non-operative care should be intensive but Rarely, if the artery under the cuff is severely not prolonged uselessly. The functions of the calcified false high readings may be obtained. feet are to support and move the patient; As a rough guide, if the ankle pressure is less
histolof call-
oievd .th
ofehydrogictissuenmay
practical.
dessenialt cntrlthes
painful pati cayemia patientsvers .c.m. pricps aese ptincfples diaeti.
SHORT COURSE OF INTENSIVE --- Failure Success
NON - OPERATIVETREATMENT
simple
PROPHYLAXIS
Failure SIGNIFICANT LA GE VESSEL DISEASE?
/
No
Yes
\
0~
POSSIBLE RECONSTRUCTION
LOCAL SURGERY
AR ERIAL SURGERY?
_No
MAJOR AMPUTATION I -LEVEL?
es
ARTERIAL ? LOCAL RECONSTRUCTION SURGERY
Also consider adding SYMPATHECTOMY and PRELIMINARYGUILLOTINEAMPUTATION.
FIG. 2
Basic flow chart for
management of the diabetic foot.
Management of the diabetic foot than two-thirds of the arm pressure there is very significant large-vessel disease and if this is combined with ischaemic lesions in the foot the usual criteria have to be applied in deciding whether reconstructive arterial surgery is feasible. Ihis will, of course, require formal arteriography. Although in diabetics atherosclerosis tends to affect vessels distal to the knee more often than in non-diabetics, reconstructive arterial surgery for limb salvage has been shown to be well worth attempting'.
307
Above or below the knee? In some patients with large-vessel disease and distal gangrene arterial reconstruction with a local distal amputation can give good results, and it is reasonable to carry out limited preoperative arteriography in the theatre to see if arterial reconstruction is feasible. Usually, however, patients with an ischaemic diabetic foot and significant large-vessel disease require a major amputation. The aim should be to try to recognise this group quickly and avoid a long hospital stay while successive amputations progressing up the foot and leg are seen to fail. Local amputations in the foot will not heal in the presence of large-vessel disease. The very difficult question now arises regarding the level of the major amputation: should it be below or above the knee? Figure 3 illustrates the more important factors influencing this choice. Above-knee healing is almost certain, but the knee may have been sacrificed unnecessarily. Clinical judgement about the potential viability of the skin which would be used in below-knee flaps is frequently wrong and there is a very real need for a predictive test in the large number of doubtful cases. Measurements of the ankle systolic pressure, the skin blood pressure, and thermography have all been proposed. Unfortunately, so far none of these tests has proved to be of value in the difficult clinically doubtful cases. Concentration on the actual procedure of the
Treatment of small-vessel disease If the foot lesion does not heal with simple non-surgical measures and there is no significant large-vessel disease it is usually presumed that ischaemia is due to localised diabetic small-vessel disease. The diagnosis tends to be made by exclusion, and there is indeed some doubt about its relevance in the aetiology of diabetic ischaemia. Few histological studies of small vessels have been performed in diabetic feet, but in the retina and kidney diabetic microangiopathy is characterised by basement membrane thickening, which is in fact very rarely associated with a reduction in the vessel lumen2. Therefore if diabetic microangiopathy does not interfere with blood flow by narrowing of the vessels, then either it is of no relevance to diabetic ischaemia or it must influence tissue nutrition by interfering with diffusion through the capillary walls. However, reduced blood flow need not necessarily be due to vessel disease at all; it could be caused by abnormalities in the blood itself. Increased blood viscosity, decreased red cell deformability3, and abnormal platelet aggregation combined with impaired fibrinolysis have all been documented in diabetics. So far as the diabetic foot is concerned, the term 'small-vessel disease' may hide a multitude of pathological sins. But whatever the exact nature of the local ischaemia, the important practical fact is that in the absence of significant large-vessel disease local surgery is usually successful, particularly if the lesion is predominantly due to a sensory neuropathy. GOOD HEALING OF STUMP GOOD REHABILITATION WITH BUTPOOR REHABILITATION A POTENTIALLY NORMAL GAIT The minimum amount of tissue should be re- DUE PROSTHES IS, B UT POOR HEAL ING OF STU MP. moved and this may mean the amputation of LESSTOHEAVIER PROPRIOCEPTIONAND a single toe, a ray resection, or, if more than vREATER ENERGY REQU IRE two toes are involved, a transmetatarsal am- MENTS. putation, all of which can give excellent func- FIG. 3 Factors influencing the choice between tional results. below-knee and above-knee amputation.
308
John A Dormandy
amputation may be a more profitable approach to improving the proportion of healed belowknee stumps. Although in principle we are all aware of the importance of the various technical details of an amputation, in practice the operation is too often left to a junior surgeon without adequate training or supervision. There are few operations in which obsessive attention to small points of technique is so essential for a successful outcome. Of almost equal importance is preoperative physiotherapy to prepare the patient and rapid mobilisation following amputation, using a temporary pneumatic pylon while waiting for a definitive prosthesis. Provided the patient does not already have an autonomic neuropathy, a simultaneous lumbar sympathectomy at the time of amputation will increase the blood flow to the vital skin flaps. Although the benefit of sympathectomy may wear off after a few weeks, far more blood flow is required to heal the skin flaps than to keep them healed. Two other new experimental techniques may also have a temporary beneficial effect: therapeutic defibrination and normovolaemic haemodilution, but neither of these has yet been adequately tested clinically.
Some other problems and treatments Two other, less common, amputations have a limited place in the treatment of diabetic feet. In the severely infected or toxaemic patient an emergency guillotine amputation removing all infected tissues is a useful first step to convert the definitive higher amputation into a clean procedure. The place of the Symes amputation has aroused continuing controversy for I30 years, its protagonists and antagonists supporting their views with mediaeval fervour. I believe it has a small but useful role in the treatment of the diabetic foot when there is no large-vessel disease and the calcaneal arteries are patent but a transmetatarsal amputation is impossible because of insufficient viable skin cover or infection of the metatarsals. A Syme's stump leaves the leg about 5 cm (2 in) shorter, but the patient can move around his home without a prosthesis and with less effort. This is extremely important and can sometimes outweigh the disadvantage of a less satisfactory prosthesis. It is as well to mention in this context the limitations of plain radiography in the assessment of the diabetic foot. Calcification
of an artery does not necessarily mean that it is blocked, and the usual criteria for the diagnosis of osteomyelitis need careful interpretation. The classic appearances of resorption and rarefaction require a good blood supply and may therefore not be seen in ischaemic osteomyelitis4. The occasional finding of air in the tissue planes, as an alarm signal of gas gangrene, is the best justification for routine radiology. Naturally there are clinical problems which do not fit into the basic pattern of management of diabetic feet already discussed and illustrated in Figure 2-for instance, the intact but painful foot, which may be an equivalent of the atherosclerotic with rest pain or a rare early manifestation of sensory neuropathy. Sympathectomy may help and intravenous naftidrofuryl (Praxilene) sometimes gives temporary symptomatic relief. However, oral Praxilene, or indeed any one of the other socalled 'vasoactive' drugs, has no place in treatment of the ischaemic foot. Another special problem is the painless, dry, black toe. This can be left alone to demarcate and separate spontaneously provided the patient can be relied on to recognise and report immediately any signs of infection.
Conclusion The currently fashionable enthusiasm for team work is probably nowhere more justified than in the management of the diabetic foot; good results can only be obtained by close collaboration between surgeons, physicians, nursing staff, physiotherapists, and limb fitters. The three golden rules for the management of this common and difficult problem are: firstly, speed in getting the patient moving and keeping him moving; secondly, intensive and enthusiastic care by a co-ordinated team; and thirdly, continuing prophylaxis to prevent recurrence.
References Birnstingl, M, and Taylor, G W (1970) Journal of Cardiovascular Surgery, I-I, 447. 2 Williamson, J R, and Kilo, C (I977) Diabetes, 26, 65. 3 Barnes, A J, Locke, P, Scudder, P R, Dormandy, T L, Dormandy, J A, and Slack, J (I977), Lancet, 2, 789. 4 Naide, M, and Schnall, C (I96I) Archives of Internal Medicine, 107, 380. I
