193

and their wives, by county, from which regional figurescould be calculated as follows:

All these data are omitted from the 1961 Supplement.How important is it to get nearer to the truth on

these questions ? Of analyses by social class, theauthors write:

"Mortality rates for such vague groups of individualsare useful in two ways. Firstly, the finding that mortalityfrom a disease is higher in unskilled labourers than inprofessional men may provoke useful hypotheses about thecause of such a difference ... social class gradients maysuggest possible agents and lead to fruitful detailed studies.Secondly, the availability of recent estimates of mortalityby social class provides a method of assessing the need totake into account differences in income, intelligence, etc.,when comparing the mortality of groups of people. Incontrolled studies groups can, if necessary, be matched forsocial class... and in uncontrolled studies, the publishedrates can be used to standardise for these variables, as forage and sex."

If these were the only uses of the Supplement,these omissions, and the unexplained (indeed, un-mentioned) delay in its publication might matter little.But they are not. The Supplements have defined theareas of greatest need for improved medical care,

helped to measure inequalities that we seek to reduce,and drawn attention to new or unexpectedly persistentsocial trends. They have been, and should continueto be, bases for informed action.

It is possible that the authors think that the dwind-ling numbers of miners and unskilled labourers maketheir mortality-rates a marginal problem, and thatthese groups will soon have the social advantages andimprovements in delivery of care that others nowenjoy. If progress is sufficiently rapid, inequality indistributing its benefits may not seem an urgentproblem. If so, recent events have been unkind to theauthors. The process of relegating occupationalgroups, and the communities dependent on them, tothe periphery of society, is incomplete; it may be

accelerating. More should have been done to help usto study, and to remedy, the situation of the increasingclass of unprofitable people.Can we have a Supplement to the Supplement,

please ?

I am grateful to Dr. A. M. Adelstein, chief medical statisticianto the Office of Population Censuses and Surveys, for the calcu-lations of infant mortality for 1959-63 in table n.

Influenza in England and WalesIn the week ended Jan. 7, influenza deaths rose for the

fourth week in succession to 180, compared with 87 theprevious week; the number was well above the total of 33for the corresponding week last year. An increasing numberof isolations of the Hong Kong variant of influenza A2 virusare being reported in different parts of the country by thePubiic Health Laboratory Service.

Occasional Survey

LONG-POSTERIOR-FLAP MYOPLASTICBELOW-KNEE AMPUTATION IN ISCHÆMIC

DISEASE

Review of Experience in 1967-71

KINGSLEY ROBINSON

Queen Mary’s Hospital, London SW15 5PR

Summary The results of fifty-four primarybelow-knee amputations performed in

47 patients with ischæmic disease are reviewed.These patients, who had an average age of 73 years,were treated by a long-posterior-flap myoplasticamputation technique. 68% of these patients weredischarged home walking; the mortality-rate was15%; and of the 11 patients who required bilateralamputation 9 were able to walk independently at theirtime of hospital discharge.

INTRODUCTION

IN many cases of ischaemic disease where vascular

surgery cannot restore sufficient blood-flow to relieverest pain or avert gangrene, amputation is unavoid-able. Many such patients are elderly, and alreadyhave defective vision and hearing, impaired motilityfrom osteoarthritis, or other manifestations ofdiabetes and arteriosclerosis; they are often living onlow incomes and in unsuitable accommodation.To enable these patients to remain mobile and

independent after amputation of one leg (and all toofrequently both legs) is a considerable problem.Much of the difficulty is due to the weight and com-plexity of the prosthesis required for many high levelsof amputation, but where a below-knee amputationcan be done then the prosthesis can be a Universityof California patellar-tendon-bearing prosthesis 1;this appliance fixes with one buckle above the kneeand can be fitted by a patient with arthritic fingerswithout assistance. The comfort of the total contactsocket and the satisfactory appearance encourage thepatients to make the effort to walk again. To use theadvantages of this prosthesis we introduced a policyof treating lower-limb ischxmia not amenable to

arterial surgery by below-knee amputation wheneverpossible, in preference to amputation at a higherlevel.

PATIENTS AND METHODS

PatientsThe patients were drawn from the area around the

hospital or were referred from the London EmergencyBed Service (E.B.S.) or from other surgeons. The patientsfrom the E.B.S. accounted for many of the older patientsand contributed to the high average age.

InvestigationAll the patients were assessed with a view to direct

arterial surgery, and unless the extent of gangrene or the

presence of severe intercurrent disease was a contraindi-cation, aortography was performed. Age alone was not con-sidered to be a contraindication to arterial surgery. Diabeteswas controlled, infection was treated with antibiotics,and surgical drainage before amputation was considered.

194

However, most diabetics requiring major amputation inthis age-group had associated large-vessel occlusion, andwhere possible direct arterial surgery was done.

PreparationInvestigation and treatment were regarded as a matter

of urgency, because each day of inactivity and each nightof rest pain increased the problem of rehabilitation andcontributed to depression and apathy. Before surgery,smoking was strongly discouraged and physiotherapywas given to strengthen all the limbs and to clear the chest.Congestive cardiac failure, bronchitis, and intercurrentdisease were rapidly treated. The patient was taken to theadjacent limb-fitting centre for measurement for a

temporary pylon, but, more valuable, while there could seeother patients walking with their prostheses.

Before operation, bacteriological swabs were taken fromthe nose and throat and any infected areas of the limb.Sputum and fseces were also cultured to check on the riskof autoinfection, especially with clostridial spores fromthe bowel. Penicillin was given 24 hours before operationand continued for 5 days afterwards. The patients werebathed with germicidal soap and the limb washed andshaved before the preparation of the skin with a povidone-iodine application. After this the limb was wrapped insterile towels overnight, and on the morning of operationthe povidone-iodine preparation was repeated and thefoot was enclosed in a sealed polyethylene bag to isolateit from the operation field. Cotton briefs with a thick

perineal woollen pad were put on to prevent dispersal ofclostridial spores from the rectum. A contributory factorin this dispersal is paralysis of the anal sphincter, and forthis reason epidural anaesthesia was avoided if possible.

OperationBelow-knee amputation was performed according to the

method described by Burgess and Romano,2,a in whichthe bone section is 5t in. (14 cm.) below the knee-jointand a long posterior flap is fashioned incorporating partof the gastrocnemius and soleus muscle mass. There is noanterior flap, but the posterior flap with the gastrocnemiusmuscle is swung forward and attached to the anteriortibial fascia and the anterior tibial skin-this constitutes amyoplasty which maintains the knee flexor activity of thegastrocnemius muscle, and the resulting suture line liesabove and anterior to the bone end. The use of finematerials, delicate handling of the tissues, and haemostasisare emphasised. ’ Sterivac’ suction drainage is preferredfor the first 48 hours. Healing at this level of amputationis slow in the elderly patient, and skin sutures are kept inplace for 21 days. To avoid multiple stitch abscesses,fine nylon sutures are used with intervening ’ Steristrips’applied to the skin edges. The stump is covered withgauze and crepe bandage, with only a small strip of woolover the anterior crest of the tibia, and special care in thebandaging is required to prevent oedema from any proximalconstricting ring of bandage.The level of amputation is determined solely by the

TABLE I-PRIMARY AMPUTATION ISCHaeMlC DISEASE : 1967-711 1 1 1 I

appearance of the tissues at the time of operation; if thecut edges fail to bleed, then healing will not occur and abelow-knee level of amputation is abandoned for a higherlevel, usually a myoplastic above-knee amputation.The patients were encouraged to move in bed the day

after operation and could get up if they felt able. In anycase physiotherapy was resumed. Hip flexure was pre-vented by two periods of 30 minutes lying prone in bedeach day. 48 hours after the operation the drain wasremoved and the end of it was cultured. After many varia-

tions, our practice is now to provide the patient with atemporary pylon 14-21 days after operation. Sometimesthe stump is mature at 21 days and a cast for a patellatendon-bearing prosthesis can be taken; if possible the

prosthesis is worn as soon as it is made. However, thefirst objective is a soundly healed stump which must notbe prejudiced by premature walking or early use of theprosthesis. If healing is at all slow or retrimming is neces-sary, then a pylon may be provided for several weeksbefore a below-knee prosthesis can be fitted. The elderlypatient is helped so that he can walk independently beforehe is discharged; independent walking may require theuse of walking aids, tetrapods, sticks, or walking-frame.Before the patient can go home many social problems mustbe overcome, and a home visit by the physiotherapist,social worker, and patient together does much to facilitatethe changes that are required and decisions on modifica-tions needed. Frequently, domestic help and financialaid are required.

RESULTS

Fifty-four long-posterior-flap myoplastic below-knee amputations were performed in 47 patientsfrom 1967-71. In this period 70% of all the amputa-tions were below knee (see table x), but from 1968to 1971 82% of all lower-limb amputations forischaemic disease were below the knee. Excluding atwenty-eight-year-old patient with Buerger’s diseasewho was rapidly rehabilitated, this series had an

average age of seventy-three. 68% of these were forarteriosclerosis and 30% for diabetes. Of the sur-

viving patients 83% were discharged home capableof independent walking whether on a pylon or pros-thesis. 11% were rehabilitated to a wheelchair exist-ence. 8 patients died while in hospital (15%), nonewithin twelve days of the operation, and 4 more thana month after the operation from unrelated causes.

In the period 1967-71, fifteen above-knee amputa-tions, two supracondylar amputations, and six through-knee amputations (all in 1967) were performed.

Bilateral amputations were done in 11 patients.In 2 simultaneous bilateral below-knee amputationswere done, and both patients were rehabilitated toindependent walking. Where it was the second legwhich was amputated all but 2 of the 9 patients walked.

. 1 patient age 28 excluded from these totals. t % of survivors discharged rehabilitated at time of writing (4 completing rehabilitation).

195

TABLE II-OUTCOME IN SOME PUBLISHED SERIES OF

LOWER-LIMB AMPUTATION

Thus, 9 of the 11 bilateral amputees with below-kneeamputations were able to walk independently; none

died; and the average age was seventy-two.Distal amputations healed slowly-in 7 cases re-

amputation was required and in 6 resuturing pro-cedures were needed, and the duration of hospital stayuntil independent walking was achieved was threemonths on average (range one to seven months).Of the below-knee amputations for ischaemic

disease 37 were for arteriosclerosis, 16 for diabetes,and 1 for Buerger’s disease-a similar distribution tothe amputations at the other levels reported in thetable.

DISCUSSION

In 1956 Kendrick 4 reported 63 % primary healingfor amputations at below-knee level in ischaemicdisease and he challenged Homans’ 6 view that

"amputation below the knee can almost never beexpected to offer a healthy stump ". However,above-knee amputation continued to be advocated.Warren and Khin, in a review, reported primaryhealing in 71 % above-knee amputations, comparedwith only 49% for below-knee amputations, but themortality for above-knee amputation was almostthree times greater than that for below-knee amputa-tion. The dilemma is clear, and surgeons began tocompromise by amputation at intermediate levels 7-9(table n). All of these workers draw attention to thelikelihood of their patients later needing a contra-lateral amputation-33% by five years according toMazet et all 0

In the bilateral amputee the level of amputation iscritical. Of our series of 11 patients with bilateralbelow-knee amputations, 9 were discharged walkingon prostheses. Although a double above-knee ampu-tation has a lesser chance of independent walking,short locker pylons may give some mobility; manyfind these difficult to put on without assistance.Hall and Shucksmith 11 have reported a series of

above-knee amputations in a large number of patientsof rather lower average age than ours. They reporteda very high rehabilitation-rate. Chilvers et al.12 havelately reported 53 below-knee amputations. 58% wererehabilitated, 17 required reamputation, and 4 of these

died. Necrosis of the anterior flap was the principalcause of failure to heal (a finding noted by Kendrick),4 4but there were fewer failures where a long posteriorflap was used in 10 cases. The long posterior flap hasbeen popularised by Burgess et al.,13 and I believe it tohave been a significant factor in the healing of below-knee amputation in many of the patients in this series.Some failures were caused by application of a pros-thesis or plaster before the wound was completelyhealed. In very old patients with below-knee ampu-tation any adverse factor will delay healing-infection,haematoma, accidental trauma, uraemia, and tightbandaging-but if these can be avoided, healing willbe secure.The level of amputation is decided solely on the

vascularity of the flaps at operation; in only 3 hasreamputation been attributed to misjudgment of thelevel. In several patients, healing at below-knee levelhas occurred in the absence of a femoral pulse. Itseems that surgical teams taking a special interest inamputation can achieve satisfactory rehabilitation andsurvival regardless of the level of amputation. Never-theless, I believe that below-knee amputation is to

be preferred, since there is a low mortality for thisprocedure, and rehabilitation is easier than with anyother level in which the stump does not reach theground-a crucial factor where bilateral amputationis concerned and each patient must be considered apotential double amputee. A patellar-tendon-bearingprosthesis is cosmetically acceptable and easier to useif accurately fitted. However, the duration of hospitalstay is longer, and there may be a need for surgicalprocedures. The long-term progress of these elderlypatients is being reviewed: it is on the continued useof their prostheses and the quality of their survivalthat we must decide whether the below-knee level ofamputation does provide a significant advantage overa simple pylon and an above-knee operation. Mean-while, I suggest that below-knee amputation be donewherever healing at that level seems reasonably likely.

I thank all those who have assisted with the clinical care ofthese patients: Mr. I. Hunter Craig, Mr. J. Angel, Mr. P.Weaver, Mr. D. Dowse, Mr. A. Heath, Mr. J. Lee, Mr. R. Kip-ping, and the nurses of Queen Mary’s Hospital, Roehampton;the limb-fitting surgeons Dr. M. Vitali, Dr. E. Harris, Dr. P.Puddifoot, and Dr. R. Redhead of the Biomechanical Researchand Development Unit, who have taken a special interest in thiswork; Miss S. Marshal and the physiotherapists; and Miss RKitson for assistance in preparing the manuscript.

REFERENCES

1. Radcliffe, L. W., Foort, J. The Patellar Tendon Bearing BelowKnee Prosthesis. Berkeley, California, 1961.

2. Burgess, B. M., Romano, R. L. Clin. Orthop. 1968, 57, 137.3. Hunter Craig, I., Vitali, M., Robinson, K. P. Br. J. Surg. 1970,

57, 62. 4. Kendrick, R. R. ibid. 1956, 44, 13.5. Homans, J. Circulatory Diseases of the Extremities. New York,

1969.6. Warren, R., Khin, R. B. Surgery, St. Louis, 1968, 63, 107.7. Martin, P., Renwick, S., Maelor Thomas, E. Br. med. J. 1967, iii,

837.8. Weale, F. E. Br. J. Surg. 1969, 56, 589.9. Howard, R. R. S., Chamberlain, J., Macpherson, A. I. S. Lancet,

1969, ii, 240.10. Mazet, R., Schillet, F. J., Dunn, O. J., Neufeld, A. J. Office of

Vocational Rehabilitation Project 431. 1963.11. Hall, R., Shucksmith, H. S. Br. J. Surg. 1971, 58, 656.12. Chilvers, A. S., Briggs, J., Browse, N. L., Kinmonth, J. B. ibid.

1971, 58, 824.13. Burgess, E. M., Romano, R. L., Zettl, J. H. Prosthetic and Sensory

Aids Service. Veterans Administration, August, 1969.