Introduction
“IftheInternetwereacitystreet,Iwouldnottravelitindaylight,” lamentsachiefinformation securityofficerforaprestigiousuniversity.
TheInternetiscriticalinfrastructureattheworld’scommerce.Cybercrimeisescalating;oncethe domainofhackersandscriptkiddies,cyber-gangsandorganizedcriminalorganizationshavediscoveredthebusinessopportunitiesforextortion,embezzlement,andfraudthatnowsurpasses incomefromillegaldrugtrafficking.Criminalsaregoingforthegold,theinformationheldininformationsystemsthatareofteneasilyaccessedanonymouslyfromtheInternet.
Theinformationsecurityindustryisbarelyabletokeepup.Cybercriminalsandhackersalways seemtobeonestepahead,andnewthreatsandvulnerabilitiescropupataratethatoftenexceeds ourabilitytocontinueprotectingourmostvitalinformationandsystems.LikeothersectorsinIT, securityplanners,analysts,engineers,andoperatorsareexpectedtodomorewithless.Cybercriminalshaveneverhaditsogood.
Therearenotenoughgoodsecurityprofessionalstogoaround.Asaprofession,informationsecurityinallitsformsisrelativelynew.Fiftyyearsagotherewereperhapsadozeninformationsecurity professionals,andtheirjobsconsistedprimarilyofmakingsurethedoorswerelockedandthatkeys wereissuedonlytopersonnelwhohadanestablishedneedforaccess.Today,wholesectorsofcommercearedoingvirtuallyalloftheirbusinessonline,andothercriticalinfrastructuressuchaspublic utilitiesarecontrolledonlineviatheInternet.It’shardtofindsomethingthat’snotonlinethese days.Therateofgrowthintheinformationsecurityprofessionisfallingwaybehindtherateof growthofcriticalinformationandinfrastructuresgoingonline.Thisismakingitallthemore criticalfortoday’sandtomorrow’sinformationsecurityprofessionalstohaveagoodunderstanding xxv
ofthevastarrayofprinciples,practices,technologies,andtacticsthatarerequiredto protectanorganization’sassets.
TheCISSP(CertifiedInformationSystemsSecurityProfessional)iseasilythemostrecognizedsecuritycertificationinthebusiness.CISSPisalsooneofthemostdifficult certificationstoearn,becauseitrequiresknowledgeinalmosteverynookandcrannyof informationtechnologyandphysicalsecurity.TheCISSPisajack-of-all-tradescertification that,likethatofageneralpractitionerphysician,makesusreadyforanythreatthatcould comealong.
TherequiredbodyofknowledgefortheCISSPcertificationispublishedandupdatedregularly.Thisbookcoversallofthematerialinthepublishedbodyofknowledge,witheach chapterclearlymappingtoeachofthetencategorieswithinthatbodyofknowledge.
Withthedemandforsecurityprofessionalsatanall-timehigh,whetheryouareasecurity professionalinneedofareference,anITprofessionalwithyoursightsontheCISSPcertification,oracourseinstructor, CISSPGuidetoSecurityEssentials hasarrivedjustintime.
IntendedAudience
Thisbookiswrittenforstudentsandprofessionalswhowanttoexpandtheirknowledgeof computer,network,andbusinesssecurity.Itisnotnecessarythatthereaderspecifically targetCISSPcertification;whilethisbookisdesignedtosupportthatobjective,thestudent orprofessionalwhodesirestolearnmoreaboutsecurity,butwhodoesnotaspiretoearn theCISSPcertificationatthistime,willbenefitfromthisbookasequallyasaCISSPcandidate.
CISSPGuidetoSecurityEssentials isalsoidealforsomeoneinaself-studyprogram.The endofeachchapterhasnotonlystudyquestions,butalsoHands-OnProjectsandCase ProjectsthatyoucandoonyourownwithacomputerrunningWindows,MacOS,or Linux.
Thestructureofthisbookisdesignedtocorrespondwiththetendomainsofknowledgefor theCISSPcertification,calledtheCommonBodyofKnowledge(CBK).WhilethisalignmentwillbehelpfulfortheCISSPcandidatewhowantstoalignherstudywiththeCBK, thisisnotadetrimenttootherreaders.ThisisbecausetheCBKdomainsalignnicelywith professionalpracticessuchasaccesscontrol,cryptography,physicalsecurity,andothersensiblyorganizedcategories.
Thisbook’spedagogicalfeatureswillhelpallreaderswhowishtobroadentheirskillsand experienceincomputerandbusinesssecurity.EachchaptercontainsseveralHands-OnProjectsthatguidethereaderthroughseveralkeysecurityactivities,manyofwhicharetruly hands-onwithcomputersandnetworks.EachchapteralsocontainsCaseProjectsthattake thereaderintomoreadvancedtopicstohelpthemapplytheconceptsinthechapter.
ChapterDescriptions
Hereisasummaryofthetopicscoveredineachchapterofthisbook: Chapter1, “InformationSecurityandRiskManagement,” beginswiththefundamentalsof informationandbusinesssecurity securityandriskmanagement byexplaininghowan organization’ssecurityprogramneedstosupporttheorganization’sgoalsandobjectives.The
chaptercontinueswithriskmanagement,securitymanagementandstrategies,personnelsecurity,andprofessionalethics.
Chapter2, “AccessControls,” discussesaccesscontrolprinciplesandarchitectures,and continueswithdescriptionsofthetypesofattacksthatarecarriedoutagainstaccesscontrol systems.Thechapteralsodiscusseshowanorganizationcantestitsaccesscontrolstomake suretheyaresecure.
Chapter3, “ApplicationSecurity,” beginswithadiscussionofthetypesofapplicationsoftware,applicationmodels,andtechnologies.Thechaptercontinuesbyexploringthreatsto softwareapplicationsandcountermeasurestodealwiththem.Itexploreshowtosecure thesoftwaredevelopmentlifecycle theprocessusedforthecreationandmaintenanceof applicationsoftware.Thechapterdiscussesapplicationenvironmentandsecuritycontrols, andconcludeswithadiscussionofthesecurityofdatabasesanddatawarehouses.
Chapter4, “BusinessContinuityandDisasterRecoveryPlanning,” explorestheconcepts andpracticesinbusinesscontinuityplanninganddisasterrecoveryplanning.Thechapter providesalengthydiscourseonapracticalapproachtorunningaBCP/DRPproject. Next,thechapterdescribesseveralapproachestotestingBCPandDRPplans,andhow suchplansaremaintainedovertime.
Chapter5, “Cryptography,” beginswithanintroductiontothescienceofcryptography,the practiceofhidingdatainplainsight.Thechaptercontinueswithadiscussionoftheapplicationsandusesofcryptography,andonthemethodologiesusedbycryptographicalgorithms.Thechapteralsoincludesadiscussionofcryptographyandkeymanagement.
Chapter6, “Legal,Regulations,Compliance,andInvestigations,” startswithadiscussionof thedifferenttypesofcomputercrimeandthevariouswaysthatcomputersareinvolvedin criminalactivity.Thenextdiscussionfocusesonthetypesandcategoriesoflawsinthe U.S.andothercountries,withaparticularfocusoncomputer-relatedlaws.Thechapter continueswithadiscussionofsecurityincidentresponse,investigations,andcomputer forensics,andconcludeswithadiscussionofethicalissuesintheworkplace.
Chapter7, “OperationsSecurity,” introducesanddiscussesthebroadtopicofputtingsecuritycontrols,concepts,andtechnologiesintooperationinanorganization.Thespecific topicsdiscussedincludesrecordsmanagement,backup,anti-virus,remoteaccess,administrativeaccess,resourceprotection,incidentmanagement,vulnerabilitymanagement,change management,andconfigurationmanagement.Thechapterdiscussesresourceprotection, high-availabilityapplicationarchitectures,andattacksandcountermeasuresforIT operations.
Chapter8, “PhysicalandEnvironmentalSecurity,” beginswithadiscussionofsiteaccess controlsforthephysicalprotectionofworksitesthatmayincludeITsystems.Thechapter discussessecuresiting,whichistheprocessofidentifyingriskfactorsassociatedwiththe locationandfeaturesofanofficebuilding.Thechapterprovidesanoverviewoffirepreventionandsuppression,theftprevention,andbuildingenvironmentalcontrolsincludingelectricpowerandheating,ventilation,andairconditioning.
Chapter9, “SecurityArchitectureandDesign,” discussessecuritymodelsthathavebeen developedandarestillinusefromthe1970stothepresent.Thechaptercontinueswith adiscussionofinformationsystemevaluationmodelsincludingtheCommonCriteria.
Thechapterdiscussescomputerhardwarearchitectureandcomputersoftware,including operatingsystems,tools,utilities,andapplications.Securitythreatsandcountermeasuresin thecontextofcomputersoftwarearealsoexplored.
Chapter10, “TelecommunicationsandNetworkSecurity,” isabroadexplorationoftelecommunicationsandnetworktechnologies.ThechapterexaminestheTCP/IPandOSI protocolmodels,andcontinueswithadissectionoftheTCP/IPprotocolsuite.Thechapter addressesTCP/IPnetworkarchitecture,protocols,addressing,devices,routing,authentication,accesscontrol,tunneling,andservices.Thechapterconcludeswithadiscussionof network-basedthreatsandcountermeasures.
AppendixA, “TheTenDomainsofCISSPSecurity,” providesabackgroundontheCISSP certification,andthendescribesthetendomainsintheCISSPCommonBodyofKnowledge.
AppendixB, “The(ISC)2 CodeofEthics,” containsthefulltextofthe(ISC)2 Codeof Ethics,whicheveryCISSPcandidateisrequiredtosupportanduphold.TheCodeofEthics isasetofenduringprinciplestoguidethebehaviorofeverysecurityprofessional.
Glossary,listscommoninformationsecurityandriskmanagementtermsthatarefoundin thisbook.
Features
Toaidyouinfullyunderstandingcomputerandbusinesssecurity,thisbookincludesmany featuresdesignedtoenhanceyourlearningexperience.
• MapstotheCISSPCommonBodyofKnowledge(CBK). Thematerialinthistext coversalloftheCISSPexamobjectives.AsidefromInformationSecurityandRisk Managementbeingaddressedfirstinthebook,thesequenceofthechaptersfollows thetenCISSPdomains.
• CommonBodyofKnowledgeobjectivesincluded. Eachchapterbeginswiththepreciselanguagefromthe(ISC)2 CommonBodyofKnowledgefortherespectivetopicin theCISSPcertification.ThishelpstoremindthereaderoftheCISSPcertification requirementsforthatparticulartopic.
• ChapterObjectives. Eachchapterbeginswithadetailedlistoftheconceptstobe masteredwithinthatchapter.Thislistprovidesyouwithbothaquickreferencetothe chapter’scontentsandausefulstudyaid.
• IllustrationsandTables. Numerousillustrationsofsecurityvulnerabilities,attacks, anddefenseshelpyouvisualizesecurityelements,theories,andconcepts.Inaddition, themanytablesprovidedetailsandcomparisonsofpracticalandtheoretical information.
• ChapterSummaries. Eachchapter’stextisfollowedbyasummaryoftheconcepts introducedinthatchapter.Thesesummariesprovideahelpfulwaytoreviewtheideas coveredineachchapter.
• KeyTerms. Allofthetermsineachchapterthatwereintroducedwithboldtextare gatheredinaKeyTermslistwithdefinitionsattheendofthechapter,providing additionalreviewandhighlightingkeyconcepts.
• ReviewQuestions. Theend-of-chapterassessmentbeginswithasetofreviewquestionsthatreinforcetheideasintroducedineachchapter.Thesequestionshelpyou
evaluateandapplythematerialyouhavelearned.Answeringthesequestionswill ensurethatyouhavemasteredtheimportantconceptsandprovidevaluablepractice fortakingtheCISSPexam.
• Hands-OnProjects. Althoughitisimportanttounderstandthetheorybehindnetwork security,nothingcanimproveuponreal-worldexperience.Tothisend,eachchapter providesseveralHands-OnProjectsaimedatprovidingyouwithpracticalsecurity softwareandhardwareimplementationexperience.Theseprojectscanbecompleted onWindowsXPorVista(and,insomecases,Windows2000,MacOS,Linux).Some willusesoftwaredownloadedfromtheInternet.
• CaseProjects. LocatedattheendofeachchapterareseveralCaseProjects.Inthese extensiveexercises,youimplementtheskillsandknowledgegainedinthechapter throughrealanalysis,design,andimplementationscenarios.
• (ISC)2 CodeofEthics. Theentire(ISC)2 CodeofEthicsisincludedattheendofthis book.Itisthisauthor’sopinionthatthesecurityprofessional’seffectivenessinthe workplaceisadirectresultofone’sprofessionalethicsandconduct.
TextandGraphicConventions
Whereverappropriate,additionalinformationandexerciseshavebeenaddedtothisbook tohelpyoubetterunderstandthetopicathand.Iconsthroughoutthetextalertyoutoadditionalmaterials.Theiconsusedinthistextbookaredescribedbelow.
TheNoteicondrawsyourattentiontoadditionalhelpfulmaterialrelatedto thesubjectbeingdescribed.
Hands-OnProjectsinthisbookareprecededbytheHands-Oniconand descriptionsoftheexercisesthatfollow.
CaseProjecticonsmarkCaseProjects,whicharescenario-basedassignments. Intheseextensivecaseexamples,youareaskedtoimplementindependently whatyouhavelearned.
CompanionCD-ROM
TheaccompanyingCDincludes250sampleexamquestions.
InformationSecurityCommunitySite
TheInformationSecurityCommunitySitewascreatedforstudentsandinstructorstofind outaboutthelatestininformationsecuritynewsandtechnology.
Visitwww.community.cengage.com/securityto:
■ Learnwhat’snewininformationsecuritythroughlivenewsfeeds,videos,andpodcasts.
■ Connectwithyourpeersandsecurityexpertsthroughblogsandforums.
■ Downloadstudentandinstructorresources,suchasadditionallabs,instructional videos,andinstructormaterials.
■ Browseouronlinecatalog.
Instructor’sMaterials
Thefollowingadditionalmaterialsareavailablewhenthisbookisusedinaclassroom setting.Allofthesupplementsavailablewiththisbookareprovidedtotheinstructorona singleCD-ROM(ISBN:143542820X).Youcanalsoretrievethesesupplementalmaterials fromtheCourseTechnologyWebsite, www.course.com ,bygoingtothepageforthis book,andclickingthe “DownloadInstructorFiles&TeachingTools” link.
ElectronicInstructor’sManual TheInstructor’sManualthataccompaniesthistextbook providesadditionalinstructionalmaterialtoassistinclasspreparation,includingsuggestionsforlecturetopics,suggestedlabactivities,tipsonsettingupalabforthehands-on assignments,andsolutionstoallend-of-chaptermaterials.
ExamViewTestBank ThisWindows-basedtestingsoftwarehelpsinstructorsdesignand administertestsandpretests.Inadditiontogeneratingteststhatcanbeprintedandadministered,thisfull-featuredprogramhasanonlinetestingcomponentthatallowsstudentsto taketestsatthecomputerandhavetheirexamsautomaticallygraded.
PowerPointPresentations ThisbookcomeswithasetofMicrosoftPowerPointslidesfor eachchapter.Theseslidesaremeanttobeusedasateachingaidforclassroompresentations,tobemadeavailabletostudentsonthenetworkforchapterreview,ortobeprinted forclassroomdistribution.Instructorsarealsoatlibertytoaddtheirownslidestocover additionaltopics.
HowtoEarnandMaintainaCISSPCertification
InordertobecomeCISSPcertified,youmust:
1.Selectatestlocationanddatefromthescheduleonthe(ISC)2 website,www.isc2.org.
2.Registerforanexaminationbycompletingandreturninganapplicationandpayingthe registrationfee.
3.TakeandpasstheCISSPcertificationexam.
4.Provideevidenceoftherequiredfiveyearsofworkexperience.
5.Submitacompletedendorsementform.
6.Haveacriminalrecordthatisfreeofdisqualifyingcriminalconvictions.
7.Beingoodstandingintheinformationsecurityindustry. Notethatsomecandidateswillbeaudited,inordertoconfirmthefactsoftheirapplication, beforetheCISSPcertificationisissued.
Youwillalsoberequiredtosignanagreementofsupportofthe(ISC)2 codeofethics. EveryCISSPisrequiredtosupportthecodeofethics;violationsmayresultinthelossof yourcertification.
OnceyouearnyourCISSPcertification,youarerequiredtoearnCPEcreditsinorderto retainyourcertification.Youarerequiredtocomplete120CPEcreditseverythreeyears, withnolessthan20CPEcreditseachyearofyourcertificationcycle.(ISC)2 recognizes thatsecuritypracticesandtechnologiesconstantlychange,whichiswhystayingcurrentis arequirementforkeepingyourCISSP.Youwillalsoberequiredtopayanannualfeeto maintainyourcertification.
YouareencouragedtovolunteeryourtimeandtalentintheCISSPcommunity.OpportunitiesincludeproctoringCISSPexams,writingCISSPexamquestions,publicspeaking,at (ISC)2 andotherevents,teaching,mentoringnewcertificationcandidates,writingarticles, andmore.Moreinformationcanbefoundonthe(ISC)2 websiteatwww.isc2.org.
FormoreinformationabouttheCISSPcertification,visitthe(ISC)2 websiteatwww.isc2. org.Adocumentcalledthe CISSPCandidateBulletinofInformation isahelpfuldocument thatexplainstheentirecertificationprocess.Youwillberequiredtoregisteronthe(ISC)2 websiteinordertoreceiveacopyofthedocument.Youmayalsocontact(ISC)2 byphone at(703)891-6781.
PhotoandImageCredits
Figure2-4Courtesyofxkcd.com
Figure2-6Imagecopyright,2009.Usedunderlicensewithistockphoto.com
Figure3-5RedrawnwithpermissionfromS.Staniford,V.Paxon,andN.Weaver,"Howtoownthe InternetInYourSpareTime,"Proc.USENIXSecuritySymposium2002.
Figure4-1CourtesyofUSGeologicalSurvey
Figure6-1Copyright2002CarnegieMellonUniversitywithspecialpermissionfromtheSoftware EngineeringInstitute
Figure8-3CourtesyofRebeccaSteele
Figure8-4CourtesyofRebeccaSteele
Figure8-5Imagecopyright,2009.Usedunderlicensefromistock.com
Figure8-6CourtesyofU.S.ArmyResearchLaboratory
Figure8-8Imagecopyright,2009.Usedunderlicensefromistock.com
Figure8-9Imagecopyright,2009.Usedunderlicensefromistock.com
Figure8-12CourtesyofDeltaScientific
Figure9-2CourtesyofRebeccaSteele
Figure9-3CourtesyofRebeccaSteele
Figure9-4CourtesyofRebeccaSteele
Figure10-2CourtesyofRebeccaSteele
Figure10-3CourtesyofRebeccaSteele
TheillustrationinFigure6-1isreproducedfrom “Cyberterrorism” byTimShimeall,www. cert.org/archive/ppt/cyberterror.ppt,Copyright2002CarnegieMellonUniversitywithspecialpermissionfromtheSoftwareEngineeringInstitute.
ANYCARNEGIEMELLONUNIVERSITYANDSOFTWAREENGINEERINGINSTITUTEMATERIALCONTAINEDHEREINISFURNISHEDONAN"AS-IS"BASIS. CARNEGIEMELLONUNIVERSITYMAKESNOWARRANTIESOFANYKIND, EITHEREXPRESSEDORIMPLIED,ASTOANYMATTERINCLUDING,BUTNOT LIMITEDTO,WARRANTYOFFITNESSFORPURPOSEORMERCHANTABILITY, EXCLUSIVITY,ORRESULTSOBTAINEDFROMUSEOFTHEMATERIAL. CARNEGIEMELLONUNIVERSITYDOESNOTMAKEANYWARRANTYOFANY KINDWITHRESPECTTOFREEDOMFROMPATENT,TRADEMARK,ORCOPYRIGHTINFRINGEMENT.
TheSoftwareEngineeringInstituteandCarnegieMellonUniversitydonotdirectlyorindirectlyendorsethispublication.
Acknowledgments
First,Iwanttothankmywifeandbestfriend,Rebekah.Withoutherpatienceandsupport, writingthisbookcouldnothavebeenpossible.
Ittakesateamofprofessionalstoproduceateachingbook.ThosewithwhomIworked directlyarementionedhere.
SeveralindividualsatCengageLearninghavealsobeeninstrumentalintheproductionof thisbook.First,ExecutiveEditorSteveHelbaestablishedthescopeanddirectionforthis book.SeniorProductManagerMichelleRuelosCannistracimanagedtheauthorthrough theentirewriting,reviewing,andproductionprocess.Next,ContentProjectManager AndreaMajotkepttrackofthedetailsastheauthorsentinchapterfiles,images,and othermaterials.AssociateProjectManagerMarieDesrosiersassistedinkeepingpeopleand contentorganized.Certainlytherewereothers:editors,compositors,graphicartists,who werealsoinvolvedinthisbookproject.Heartfeltthankstoallofyou.
Specialrecognitiongoestothebook’stechnicalreviewers.Theseareindustryandacademic subjectmatterexpertswhocarefullyreadthroughthemanuscripttomakesurethatitis bothtechnicallyaccurateandalsowellorganized,withaccurateandunderstandable descriptionsandexplanations.Thisbook’stechnicalreviewersare:
• Dr.BarbaraEndicott-Popovsky,theDirectorfortheCenterofInformationAssurance andCybersecurityattheUniversityofWashington,designatedbytheNSAasaCenterforAcademicExcellenceinInformationAssuranceEducation.
• MichaelSimon,aleadingexpertincomputersecurity,informationassurance,and securitypolicydevelopment.MikeandIhavealsowrittentwobookstogether.
• JimDrennanatPensacolaJuniorCollegeCenterforInformationandEngineering Technology,whoprovidedvaluableandthoughtfulfeedbackinseveralimportant areas.
• FaisalAbdullahatLewisUniversityalsoprovidedvaluableinformationthatprompted metoproduceadditionalcontent.
SpecialthankstoKirkBaileyforhiskeeninsightovertheyearsandforfightingthegood fight.
IamhonoredtohavehadtheopportunityworkwiththisoutstandingandhighlyprofessionalgroupofindividualsatCengageLearning,togetherwiththereviewersandothersof youwhonevercompromisedonthepursuitofexcellence.
AbouttheAuthor
PeterH.Gregory,CISA,CISSP,DRCE,istheauthoroftwentybooksoninformationsecurityandtechnology,including ITDisasterRecoveryPlanningForDummies,BiometricsFor Dummies,SecuringtheVistaEnvironment, and SolarisSecurity.Hehasspokenatnumeroussecurityconferences,includingRSA,SecureWorldExpo,InfraGard,andtheWest CoastSecurityForum.
PeteristhesecurityandriskmanageratafinancialmanagementservicesfirminSeattle.He istheleadinstructorandadvisoryboardmemberfortheUniversityofWashington’scertificateprogramininformationsecurity,andanadvisoryboardmemberandguestlecturerfor theUniversityofWashington’scertificateprogramininformationassurance.Heisonthe boardofdirectorsfortheWashingtonStatechapterofInfraGard,agraduateoftheFBI CitizensAcademy,andisactiveintheFBICitizensAcademyAlumniAssociation.
InhisfreetimeheenjoystheoutdoorsinWashingtonStatewithhiswifeandfamily.
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the cavity is still discharging. Motion should be begun as early as is considered feasible in order to guard against a false joint.
The remote consequences of joint excisions are usually very satisfactory. The best results are obtained in the young, i. e., those whose tissues are still undergoing natural changes and whose bones are growing. In the course of time, by condensation of surrounding tissues, a new joint capsule is formed, its interior smoothed off, apparently covered with endothelium and filled with a sufficient amount of fluid, similar to that of normal joints, to serve the purpose; in this way a new joint becomes gradually substituted for the old, which serves the original purpose, in a surprising and gratifying way. Even in those of advanced years a satisfactory result is often obtained. It is often necessary to afford some support, by which too great a range of motion may be avoided; thus at the elbow the result at first is what may be called a “flail-joint,” which permits much undesirable lateral movement. This can be avoided by having light leather corsets fitted to the forearm and arm, connected by two lateral hinged braces. This being constantly worn, and no motion permitted which is not an imitation of the normal, the parts in time adapt themselves to the purpose, so that all apparatus can after a while be removed.
Excisions, like amputations, may be practised and the general methods learned on the cadaver, but their actual performance in the presence of extensive disease will be found to be a different procedure from that learned upon the dead body. For reasonably representative cases typical operations can be devised, with explicit directions. It is not advisable to try to do such work through too short incisions. A long incision heals as kindly as one shorter and affords more room for operative work. The incision should be so planned and executed as to afford the maximum of exposure with the minimum of damage to important structures. The region of the great vessels is avoided in all the classical operations, while nerve trunks, if exposed, are retracted and kept out of harm’s way. After the knife has once laid open the joint it is used but little except for the division of resisting structures, e.g., ligaments. The greater part of the work is then done with elevators, or periostomes with
reasonably sharp edges and sufficiently broad surface, so that the periosteum can be divided with the latter and separated with the former to the necessary extent. Obviously epiphyseal junctions should be spared whenever possible, especially in the young. To remove an entire epiphysis is to materially impair the later growth of the limb. In some of the most serious cases it will be found already loosened and lying as a sequestrum in the joint cavity. In this case it may be easily lifted out of place. Tendons should never be divided unless absolutely necessary. Incisions in their neighborhood should be so planned as to be parallel with their direction and permit their displacement without division. The sharp spoon should be employed for curetting the interior of a joint capsule or cleaning out a bone focus (erasion). A capsule involved in tuberculous disease should be completely extirpated. Diseased bone ends should be sufficiently exposed to permit of the use of an ordinary saw or a chain or wire saw.[34] Considerable force will often be necessary in making bone ends accessible for this purpose. The chisel is rarely used except in cases of bony ankylosis, where it is not possible to force bone ends through the opening in order to attack them with the saw. As remarked above, clean cases may be closed without drainage. Visible vessels should be secured, and, while a certain amount of oozing may be expected, if the part be enclosed in suitable compressive dressings and elevated, it need not cause alarm. The gentle application of an elastic bandage for three or four hours may afford additional security. It should not, however, be allowed long to remain. The terminal portion of the limb will always afford an indication as to the condition of the circulation. Should it become cyanotic or cold the dressing should be renewed and the wound examined promptly.
[34] Wyeth’s “exsector” is an admirable substitute, especially at the shoulder and hip.
Special Incisions.
The Shoulder.
—A longitudinal incision suffices for most cases (Fig. 214). This may be made posteriorly between the fibers of the deltoid or anteriorly and externally over the bicipital groove. It is better to separate the deltoid fibers than to divide
them, although they may be divided. Should the straight incision afford insufficient room another incision at right angles will afford ample access. The capsule, having been exposed, is opened, the wound widely separated with retractors, the arm rotated through a wide arc, while with a stout knife the capsular ligament and the various muscular attachments around the neck of the bone are divided. The greater and lesser tuberosities, with their muscles undivided, should be retained, when circumstances permit. The head of the bone, being freed, is dislocated and forced out through the wound, where it may be seized with large forceps and removed with a saw. The higher the bone is divided the better. Every other consideration, however, should be sacrificed to removal of all foci of disease. The capsule may then be extirpated and the glenoid cavity thoroughly cleaned out with a sharp spoon. Should the case be one of serious infection it is advisable to make a posterior opening, even through the deltoid, for purposes of thorough drainage. The greater part of the first incision is to be closed with sutures, the arm dressed in a comfortable position, with the elbow at a right angle, and the patient allowed to be up and around as soon as he feels in the mood for it.
Excision of the shoulder: A, regular incision; B, supplementary. (Ollier.)
The Elbow.
—Here a variety of methods have been advised, and the extent of the operation must depend, to some degree at least, on the nature and extent of the condition which necessitates it. Partial excisions have been recommended, though in the writer’s experience incomplete operations often give less satisfaction than those which are complete. However, when it is a question of removing callus or
displaced bone fragments, which, after fracture into the joint, impair its function, then partial resections may be serviceable.
Excision of the elbow-joint: A, von Langenbeck; B, Ollier.
Excision of the elbow-joint: A, Nélaton; B, C, Hueter.
Osteoplastic method: A, by external incision; B, von Mosetig-Moorhof.
The essential incision is a long posterior one, which may be somewhat modified (Figs. 215, 216 and 217). It is essential here to avoid the ulnar nerve, which passes between the internal epicondyle and the olecranon, and the vessels and nerves in front of the joint. If
FIG. 215 FIG. 216
FIG. 217
The Wrist. it be made an inviolable rule to always keep closetotheboneboth of these dangers may be avoided. Ligamentous and muscular structures, among the latter the anconeus, should be spared as much as possible. After separating the joint surfaces thoroughly, by forced flexion, it is usually easier to force out the lower end of the humerus and first remove it, after which the upper ends of the radius and ulna are exposed and removed. When there is bony ankylosis it is preferable to divide the bones of the forearm first. The tendon of the triceps is not only detached from the olecranon, but divided by the first long incision. After concluding the incision, the capsule, if it remains, is to be closed with chromic catgut sutures and the end of the triceps tendon or some of its periosteal attachment united to the periosteum of the upper end of the ulna.
The arm is now fixed in the right-angle position and held comfortably to the body by a suitable sling.
—It is rare that in disease of the wrist-joint this is found to be limited to a single bone of the carpus. Should an x-ray examination indicate such limitation then the focus can be exposed and cleaned by an incision upon the dorsum of the wrist, where it may seem best adapted for the purpose. Suppurative and tuberculous affections of the wrist usually necessitate removal of the carpal bones, including, possibly, the lower extremities of the ulna and radius. When the wrist-joint is involved it may be sufficient to remove the latter with the first row of the carpus.
Fig. 218 illustrates the incisions to be recommended for wrist resection, of which the Langenbeck line is to be preferred. Occasionally two lateral incisions, with through drainage, will better serve the purpose. It may be necessary to divide the short radial extensor, but this may be united again with suture. In most instances it is possible to retract the tendons to either side and thus clear the carpal region. By hyperextension the extensor tendons are relaxed and more room is thus made. The incision marked “A” combined with that marked “B” in Fig. 218, affords the best exposure when disease is extensive. The incision along the inner border of the wrist is made 5 Cm. above the styloid process of the ulna, and between the latter and the ulnar flexor down to the middle
of the last metacarpal bone. Here the tendon of the latter muscle should be divided at its insertion and lifted out of its groove in the ulna. The collection of extensor tendons is then separated from the back of the wrist and lifted up, it being usually necessary to divide the unciform process of the unciform bone with forceps. The knife should be kept from the palmar surfaces of the metacarpal bones in order to avoid injury to the deep arch. After dividing the anterior radiocarpal ligament the carpus is extirpated through the ulnar incision. The ends of the ulna and radius are now easily accessible for removal with forceps or a metacarpal saw. The same is also true of the proximal ends of the metacarpals. After spreading the hand and forearm upon a flat splint drainage can be made to the desired extent and the wound closed.
IG. 218
Excision of the wrist: A, Lister’s radial incision; B, Lister’s ulnar incision; C, Ollier; D, von Langenbeck.
So far as the handandfingers are concerned little resecting need be done, the surgeon usually confining himself to the removal of sequestra or curetting of carious bone. In cases of compound comminuted fracture bone fragments may be removed; only in cases of lost or destroyed phalanges will amputation be necessary.
The
Hip.
—In its structure the hip-joint is one of the simplest in the body. Although it lies deeply it is easily made accessible. Fig. 219 illustrates the incisions by which the joint is attacked for the purpose of exsection. If necessary either extremity of the incision can be extended or enlarged by a cross-cut. When the joint is disintegrated
FIG. 219
Excision of the hip: A, Sayre; B, Ollier.
by disease, especially when partially dislocated, the parts will lend themselves to an easy and simple operation. When, however, the operation is done for ankylosis or for disease, by which great thickening and fixation have been produced, the measure may become difficult. For ordinary purposes the simplest method is to drive a sharp-pointed, strong-bladed knife directly down upon the neck of the bone from a point midway between the great trochanter and the crest of the ilium; then keeping the knife-blade in contact with the bone the incision is carried downward over the trochanter and along the shaft to a length making it sufficient for easy exposure of the bone and of the joint. Nothing is gained in these cases by trying to work through a short incision. A long one heals as readily and makes the operation more simple. It is as easy to make the entire incision in one cut as to divide the muscles layer by layer. The capsule of the neck of the femur being exposed by a wide retraction of wound margins, it is necessary next to divide muscular attachments to the great trochanter by raising the periosteum to which they are attached and saving both. To expose these insertions the femur should be rotated inward and outward, while the capsule is at the same time divided. The ligamentum teres, which offers a theoretical obstacle, usually disappears in the presence of any active disease and is scarcely ever encountered; it can be divided with curved scissors. Now by more or less powerful effort, including flexion and adduction to the extreme limit, with more or less rotation, the head of the bone is forced out from its socket and through the wound. Whether the bone should be decapitated with chain saw, metacarpal saw, or by the exsector of Wyeth will depend partly upon the freedom with which it can be exposed and on the equipment of the operator. It may be advisable to divide the neck with a chisel. The trochanter major should be preserved whenever its removal is not made imperative by the progress of the disease. The head and neck of the bone having been removed, the acetabulum is now more or less easily exposed, especially with retractors, and it should be cleaned with a sharp spoon. The capsule also should be removed, at least when the operation is done for tuberculous or other infectious condition. It is advisable to irrigate,
then to wipe dry all the original joint surfaces and raw bone, and finally to cauterize either with pure carbolic or with zinc chloride, which should be washed away with the irrigating stream, the intent being to close the mouths of all the absorbents and prevent absorption from fresh exposure. Sinuses if present should be thoroughly excised, scraped, and treated in the same way. A drainage tube is usually preferable to the use of gauze.
The above is the method usually relied upon for hip exsection. Other methods have been devised, especially by anteriorincision; of these the best probably is that of Barker. The cut is made along the outer border of the anterior surface of the sartorius and rectus, and through it the femoral neck is reached. By wide retraction the anterior surface of the joint can be completely exposed and opened, and through this opening the neck of the femur can be divided with a chain saw or chisel, before removal of the head from the acetabulum. The disadvantage of anterior incision is that pertaining to drainage. Nevertheless this can be obviated with capillary drains. Its advantages are that splinting and protection can be more perfectly effected, with less necessity for frequent interference. In other words it makes the subsequent care of the patient easier. Many English surgeons are in favor of it. Ollier devised a so-called osteoplastic excision, made through a curved incision with a downward convexity, the top of the great trochanter being exposed and divided with a chisel sufficiently to permit of its being turned up with the flap, and then being reunited to the main part of the bone after the removal of the neck and head. This method has its advantages in a limited number of cases, but it has not become popular in this country. It would seem to be an advantage to preserve the trochanter, although some surgeons remove it. So long, however, as disease is confined to the head and neck of the bone it is unnecessary to remove this projection.
The after-care of a hip excision is not an easy matter. Most surgeons prefer to maintain the limb in position by the aid of traction, with sufficient weight to overcome all muscle spasm. If the case be such that dressings need only be made at long intervals, then it matters little, but in a septic case in which there is
