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Special Articles

METALLIC CORROSION IN ORTHOPÆDICSURGERY

F. P. BOWDEN

C.B.E., D.Sc. Tasmania, Ph.D., Sc.D. Camb., F.R.S.

J. B. P. WILLIAMSONPh.D. Camb.

OF THE RESEARCH LABORATORY FOR THE PHYSICS AND

CHEMISTRY OF SURFACES, DEPARTMENT OF PHYSICAL

CHEMISTRY, CAMBRIDGE

P. G. LAINGM.B. Lond., F.R.C.S.

OF THE SCHOOL OF MEDICINE, UNIVERSITY OF PITTSBURG, PA.

WHENEVER metal is inserted in the human body it

becomes subjected to the corrosive attack of the body-fluids. Venable et al. (1937) drew attention to this

phenomenon and suggested that a simple means of

reducing the risk of corrosion would be to avoid the useof more than one metal in any particular operation.Discussions of the dangers accompanying the insertion of" mixed metals," and descriptions of investigationscarried out to discover a metal which could confidentlybe adopted as standard, have been published periodicallythroughout the last two decades. But, although thiswork is well known to many surgeons, the recent paperby Cater and Hicks (1956) shows that in some hospitalsinsufficient attention has been paid to this aspect ofsurgery. Until the basic principles put forward in a

series of papers by Venable and Stuck some twentyyears ago are clearly understood and accepted (and if

necessary protected by an official standardisation of thematerials used for implants), there is little point in takingprecautions to avoid the secondary causes of corrosionand the possible tissue reactions which can result fromthem. The first step in preventing metallic corrosion insurgery must be the use of a single passive metal forall the components of an implant.The physiological behaviour of the body during trauma

and the subsequent healing processes create the environ-ment within which the metal implant has to fulfil its

purpose. The pH value and the redox potential will varywith time, and also from place to place on the surfaceof the metal. These variations cannot readily be con-trolled : but their effect could be minimised by thecareful selection of the particular metal best suited towithstand these electrochemical conditions. Clearly theuse of two different metals in a region with such acomplex electrochemical nature is an invitation to disas-ter. Most metal implants are subjected to mechanicalstress when fixed in the body ; in many cases there mayalso be fretting between different components of the

appliance. Both these phenomena can influence thecorrosion of metal, and they too should be borne in mindwhen selecting the most suitable metal for use in ortho-pædic surgery. It would be dangerous, however, to believethat such a standardisation will solve all the problemscreated by the use of metals in orthopaedic surgery. Theinsertion of " mixed metals " is by far the most importantcause of corrosion, but it is by no means the only one.The factors which can influence the corrosion resistanceof metals have been fully discussed by Evans (1946).There is clear evidence that even when a single

passivated metal is used, a tissue reaction is occasionallyobserved in the region surrounding the implant ; andit is important that the need to select the metal mustnot obscure the complementary need for proper treat-ment of the implants both before and during insertion.Many metals derive their high resistance to corrosionfrom an impervious layer of oxide which protects them

from the surrounding liquid. But such an insulatingbarrier is effective only so long as it remains intact. Ifit is damaged, corrosion will occur at the places wherethe metal- and the liquid come into contact; the attackwill continue unless the product of the electrochemicalreaction is insoluble and is deposited at the corrosionsite, thus making good the protective coating.The special characteristic of stainless steels is that they

are clothed in a protective film which in normal circum-stances is self-sealing. In this respect they differ fromthe noble metals which are intrinsically inert. It is clearthat the selection and use of a stainless steel will bevitiated if, during the operation, the passivating surfacefilm is so damaged that the sealing process cannot re-formthe protective layer before continuing corrosion isestablished. Any treatment which increases the chanceof a breakdown in the passivity of the metal ought to beavoided whenever possible, and especially during theoperation. The manner in which the implants are handledcan have an important influence on their subsequentchemical behaviour.The importance of the correct choice of tools should be

appreciated. Experiments using radio-isotope techniqueshave shown that during an orthopaedic operation smallfragments of metal are plucked from the surface of thetools and become welded to the implant. These particlesfrom the tool are buried with the appliance in the body.The composition of the metal tools is usually different

from that of the implant. There is evidence that such

foreign fragments can initiate a reaction resulting inthe corrosion of the buried metal. Analytical evidencesupports this view : the concentration of metal ions inthe tissues surrounding parts of the implant which havebeen handled by tools are many times higher thannormal, even when there is no visible sign of corrosionor tarnishing : whereas the concentration in the tissuesadjacent to unhandled parts of the same appliance arenormal. A full account of these experiments has beengiven by Bowden, Williamson, and Laing (1955).

It has been suggested (Capener 1956) that surgeons andmanufacturers should have official guidance in theirchoice of suitable metal for implants. It might be usefulif this included recommendations on the methods of

handling the implants, and on the nature and compositionof the tools used for inserting them, so that their corrosionresistance shall not be needlessly impaired.

REFERENCES

Bowden, F. P., Williamson, J. B. P., Laing, P. G. (1955) J. BoneJt Surg. 37B, 676.

Capener, N. (1956) Lancet, ii, 1107.Cater, W. H., Hicks, J. H. (1956) Ibid, ii, 871.Evans, U. R. (1946) Metallic Corrosion, Passivity and Protection.

London.

Venable, C. S., Stuck, W. G. (1947) The Internal Fixation of Frac-tures. Oxford. (This book gives a comprehensive bibliographyup to 1946.)- - Beach, A. (1937) Ann. Surg. 105, 917.

PROFESSIONALISM AND BUREAUCRACY

IN his Winchester Address, given on May 15 under theauspices of the Winchester division of the British MedicalAssociation, Mr. GRAHAM HUTTON began by consideringwhat has been happening in all kinds of human societiesduring " this terrible but exciting 20th century."

THREEFOLD CHANGE

1. Technical.—The techniques of control over Naturehave immeasurably multiplied and accelerated, and it isgood that human powers over inhuman powers are beingso rapidly increased. But it is bad that increased humanpower is used-or abused-to stress human beingsbeyond their normal tolerances, or to frustrate theirnatural modes of expression and development, or to

compel them to behave as machines.

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2. jPMccfL—Whereas the course of last century, allover the world, was liberal, in humanistic terms, thecourse of the 20th century has been towards more andmore collective restraint of individuals. Everywhere theState has steadily increased its power over individuallives, and in almost every walk of life. Because of thefirst or technical change, this second or political changehas brought benefit to millions in many nations : it has

permitted the removal of old evils. But, both in democ-racies and in dictatorships, power over the individualand the family has been concentrated in a more and morecentralised form of State apparatus.

" We realise that in our own country and society todayeconomic, professional, trade-union, legal, travel, and otherfreedoms are not what they were. They are narrower, not atthe administrative centres of these sectors of life, but on theperiphery where the individual members live and operate.Even apart from, and under, the centralising political powerof the State, these other sectors of individual life-in business,trade-unions, professions, vocations, sport, commercialisedpleasures and leisures, and media of publication and radiocommunication-are all of them more centralised, more

collectively organised in larger administrative units...."

As the first or technical change has shrunk the wholeworld and crammed the human race cheek by jowl, sohas the second or political change unfolded everywhere-the concentration of vastly enhanced social or politicalpower in the hands of the few; and the once--vaunted" rule of Law" has given way everywhere to the con-temporary rule of laws and regulations affecting moreand more of individual life.

3. Specialisation.-The third change is an ever-deepen-ing, ever-narrowing specialisation which further weakensthe powers, potentials, and freedoms of the citizen. Theindividual-learner, researcher, operative, technician,professional man, trade-unionist, or manager-sees hisown mastery of only a little part of a widening fieldbecoming smaller and smaller, and himself becoming evermore dependent upon the results of other people’s work,which he cannot understand or control.

So universal is this third change in mankind’s socialprocess that precisely the same kind of complaints aboutit arise in America, in Russia, in India, in Africa-inschool and university and other training curricula, in

religions, castes, social classes, income brackets of alllevels, and so on. The burden of complaint is the same-that distinguishing individualities are tending to beironed out, that differentials and varieties are beingflattened, and that frustration of human potentialsfollows specialisation. Then, through such frustration,bad social outbreaks occur: the system of law and customrights and duties, sentiments and beliefs and values

begins to lose its binding force. Either as individuals oras functional or other groups, men begin to rebel, tobecome " anti-minded," against their own society.Today this phase-the era of social revolution-is world-wide for the first time.

RUSSIAN LABORATORY

Perhaps the most significant event of the post-war era,Mr. Hutton thought, will prove to be the working-out ofthese revolutionary social changes in Communist Russia.Western and other countries can learn much fromwhat has happened inside the Russian social laboratoryduring the past decade or two.At its beginning, forty years ago, Russian society was

dedicated to equality, and it soon took away all powersand privileges of trades-unions, professions, vocations, andother self-governing voluntary and functional groupings.But because of the technical needs of all society every-where (in our time as in Plato’s) a new set of groupings,orders, castes, classes, and functional elites speedily cameabout-nearly all of them necessarily organised on thelines of the former professional and other functional

groups. As modern techniques advanced-in economic!-.science, medicine, the arts-it was the professions, notmerely the State’s agents or functionaries, who gatheredesteem, powers, and privileges.One feature of the convulsions in Russia and other

Communist lands during the past three years needs tobe noted for its long-term significance. It is that the

uprush of protest against flattening and standardisationby the omnipotent State, against unqualified eo-alitaii,anism, and against the tyrannies of an all-pervadebureaucracy have occurred in the ranks of the experts-the people with long-acquired and long-trained voca-tions whom a modern society needs more and more.It is among this younger generation of Communists-among the experts and artists, the technicians, and theprofessional persons above all-that the ferment ofdissatisfaction with the bureaucracy is greatest.

DIFFERENTIALS

" At both the superficially seeming opposite poles ofworld politics today, in North America and in SovietRussia, really substantial differential rewards for differ-ential responsibilities and differential expertnesses are theorder of the day," said Mr. Hutton ; " while here inBritish society, which is lagging behind those in materialprogress and mixed-up between them in its social andpolitical organisation, our skilled workers moan aboutthe erosion of their differentials ’ in wages, the salariedfolk can complain of the same process, and the folk oftechnical prowess and professional responsibility are

the most savagely penalised and discriminated againstof all."

The material sacrifices due to the last war have fallen,net and on balance, upon only about one-fifth of theBritish people, which includes three-twentieths who arethe old and retired at all levels of income (some verypoor and on National Assistance) and all the skilled,trained, and responsible paid leaders of the nation. Justas an examination and a justification of equality oftreatment for everybody is long overdue in our politicaland social system, so is an examination of the distributionof rewards for responsibilities. " Somewhere around thecurrent figure of £1000-£1500 a year gross for a bread-winner-no matter what his training or responsibilities,or how big his family, or what his hours, of work orconditions of service-British society seems to shut upshop in consideration of him."Looking at the needs of medicine, of the expanded

atomic energy programme, of the highway and railwaynetworks, of slum clearance, of education in all its forms,and of new equipment for all our industries, " we shallbetter appreciate our overriding need not to penalise, butpositively to stimulate and increase differential rewardsfor, any and every citizen who can command suchenhanced rewards in virtue of his abilities, responsibilities.and social contributions."

" What we have undergone in the past eleven post-waryears, in a world of technical revolution, has merely been arevolution in the apparatus of the State and in its adminis-tration. We have had no post-war revolution of thought andidealsand imagination."

THE PROFESSIONS

If P ’itish professional bodies are to play their part inthe reshaping of our people’s thought and the reform ofour national institutions, they must first be sure that onbalance what they propose to do will primarily benefitthe community or communities they serve.

" The justification for a profession, which guards its ownstandards of training, can only be that in so doing it constantlyproves its contributive power to the community is kept attop pitch. Any profession will lapse in public esteem if eitherit fails to do that, or fails to make public why the State orsome other factor beyond its power prevents it from doing it.

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The great power of our professions still resides in theirvocational mission, -their safeguarding of training and educa-tion, and their role-quite apart from their particular skills-in turning out the well-rounded, socially adjusted, contributoryand responsible leaders of the nation in all its walks of life.It is perhaps this last r6le which is so often overlooked in ourland today. Without wise leaders, without a widely trainedand humanistic elite, any society on earth, both today andin the even more technical complexity of the future, will

perish. It is as much the -function of our professions-andpre-eminently of yours-to turn out members of such a nationalelite, as it is to turn out technically qualified young menwho are certified as able to perform certain skills adequately.The professions would gain, I think, if they were to emphasisethat aspect, in season and out of season ; and, above all, ifthey were to see, in their educational curricula which stillremain largely under their own safeguarding, that they didnot merely turn out technically adequate young men, butvoung men who were in addition humane, rounded, andadjustable to a rapidly changing social context."

Contemplating the hectic experimentation in NorthAmerica at one extreme and in Russia at the other, weneed not (concluded Mr. Hutton) despair or repine.Technically it is well within our scope to succeed, in anysector of social life, as well or better. There is noeconomic reason why we should not. But if we bringit off, it will primarily be due to leadership ; and thatmust still come largely from our professions. " It istherefore up to them to set their own standards, and thento fight for them until they prevail. There is nothingwrong in that for the nation. On the contrary, I thinkthis nation has everything to gain from it."

REGIONAL HOSPITAL BOARDSAND BOARDS OF GOVERNORS OF

TEACHING HOSPITALS

THE Minister of Health has appointed, or reappointed,the following as chairmen of boards. New appointmentsare indicated with an asterisk.

Leeds Regional Hospital Board.-Major J. C. Hunter, M.C.South West Metropolitan Regional Hospital Board.-A. G.

Linfield, o.B.E., i.p.Oxford Regional Hospital Board.-Sir George Schuster,

K.C.S.I., K.C.M.G., C.B.E., M.C.

Birmingham Regional Hospital Board.-* E. W. Thompson,M.A., J.P.United Newcastle upon Tyne Hospitals.-* Sir Walter

Drummond.United Leeds Hospitals.-Sir George Martin, K.B.E., LL.D.,

J.P.

United Sheffleld Hospitals.-Alderman A. Ballard, C.B.E.United Cambridge Hospitals.-Roger H. Parker,M.c.,

D.L., M.A.United Oxford Hospitals.-Sir David Lindsay Keir, M.A.,

LL.D.

United Cardiff Hospitals.-Alderman Thomas Evans,c.B.E., J.P.United Birmingham Hospitals.-Evan A. Norton, M.A.St. Bartholomew’s Hospital.-Sir George Aylwen.London Hospital.-Sir John Mann.University College H ospital.-Sir Alexander Maxwell, iK. c..-4. G.Jliddlesex Hospital.-Lord Astor of Hever. D.LITT., J.P.Charing Cross Hospital.-Lord Inman, P.C., .T.P.St. George’s Hospital.-Viscount Ingleby.Westminster Hospital.-Lord Nathan of Churt, P.C., T.D.,D.L.

St. Mary’s Hospital.-Edgar E. Lawley.Guy’s Hospital.-Lord Cunliffe.King’s College Hospital-Marquess of Normanby, M.B.E.St. Thomas’s Hospital.-Sir Arthur Howard, ic.B.E., c.v.a.,

r.i..

Harnrnersmith, West London, and St. Mark’s Hospital.-SirDesmond Morton, K.c.B., c.M.G., M.c.Royal National Throat, Nose and Ear Hospital.-Ernest

Taylor.

St. John’s Hospital for Diseases of the Skin.-J. A. M.

Ellison-Macartney.The Hospitals for Diseases of the Chest.-Sir John Gilmour.Royal National Orthopaedic Hospital.-Sir Henry Floyd,

C.B., C.B.E.National Heart Hospital.-J. M. Oakey, M.C., D.L., J.11.St. Peter’s, St. Paul’s, and St. Philip’s Hospitals.-Laurence

Bevan.

Royal Marsden Hospital.-J. M. Wallace.

REGIONAL HOSPITAL BOARDS

The following doctors have been appointed or

reappointed to the boards. They will hold office tillMarch 31, 1960.Newcastle.-C. N. Armstrong, R. E. Jowett, R. S. Venters.Leeds.-W. A. Hyslop, G. Whyte Watson.Sheffield.-G. H. Gibson, J. L. A. Grout, C. S. O’Flvnn.East Anglia.-A. Leslie Banks, K. J. Grant.North West Metropolitan.-E. C. Warner, Katharine Lloyd-

Williams, *F. C. Wilkinson.North East Metropolitan.-T. Rowland Hill, J. Arthur

Moody, R. W. Reid.South East Metropolitan.-Sir William Kelsey Fry, V. F.

Hall, W. G. Masefield, * H. W. L. Molesworth.South West Metropolitan.-A. Lawrence Abel, Sir Geoffrey

Todd.

Oxford.-C. V. Gledhill.South Western.-R. J. Brocklehurst, L. C. Hill, A. V. Neale.Wales.-J. P. J. Jenkins, A. Trevor Jones, Emyr Wyn Jones,

E. K. Roy Thomas.Birmingham.-J. H. Sheldon, A. P. Thomson.Manchester.-V. F. Lambert, R. W. Luxton, Miles Parkes,

Sir Harry Platt.Liverpool. W. M. Frazer, H. L. Sheehan.

BOARDS OF GOVERNORS

The following doctors have been appointed or

reappointed to boards of governors. They will hold office,till March 31, 1960.

St. Bartholomew’s Hospital.-Charles Harris, J. Basil Hume,E. G. Tuckwell.London Hospital.-J. Graham, G. T. Hankey, * William

Evans, * Dorothy Russell.Royal Free Hospital.-Gladys Hill, Katharine Lloyd-

Williams, Margaret MacPherson, * Una Ledingham.University College Hospital.-Sir George MacRobert, Wilson

Smith, * Sir James Kilpatrick.Middlesex Hospital.-* A. J. B. Goldsmith, * C. A. Keele,

* B. R. M. Johnson, * D. H. Patey.Charing Cross Hospital.-D. H. Campbell, E. Grundy,

H. G. E. Williams, * Norman Tanner.St. George’s Hospital.-C. Bowdler Henry, Rodney Smith,

* H. W. Gordon.Westminster Hospital.-A. Lawrence Abel, H. E. Harding,

Edward Stanley Lee, R. J. V. Pulvertaft.St. Mary’s Hospital.-A. G. Cross, Robert Cruickshank,

G. B. Mitchell Heggs, Leonard Simpson, * Denis ]3rinton,* W. D. W. Brooks. ’

Guy’s Hospital.-Maurice Campbell, Sir William Kelsey Fry,* G. F. Gibberd.King’s College Hospital.-H. L. Glyn Hughes, Sir Cecil

Wakeley, * Wilfrid Sheldon.St. Thomas’s Hospital.-T. Pomfret Kilner, Sir Max Page,

A. J. Wrigley.Hammersmith, West London, and St. Mark’s Hospitals.-

R. Cove-Smith, Sir Allen Daley, Cuthbert Dukes, Sir FrancisFraser.

Hospital for Sick Children.-G. H. Newns, Bernard

Schlesinger, D. Innes Williams, * R. E. Bonham Carter,* J. A. Scott.National Hospital for Nervous Diseases.-Sir Russell Brain,

J. St. C. Elkington, M. Kremer.Royal National Throat, Nose and Ear Hospital.-J. C. Hogg,

G. H. Howells, * T. V. L. Critchlow.111[00rftelds Hospital.-* G. G. Penman.Bethlem Royal and Maudsley Hospitals.-C. P. Blacker.St..John’s Hospital for Diseases of the Skin.-Janet Aitken,

S. Cochrane Shanks, * L. Forman.Hospitals for Diseases of the Chest.-Sir Russell Brock,

J. L. Livingstone, K. Robson, Vernon Thompson.Royal National Orthopcedic Hospital.-C. H. Lack, R. N assim-