PowerPoint Presentation - Orthopaedic Osseointegration

OSSEOINTEGRATIONRickard Brånemark, MD MSc PhDCentre of Orthopaedic Osseointegration (COO)Department of OrthopaedicsSahlgren University HospitalGöteborg, Sweden

HistoryIn 1952 Per-Ingvar Brånemark useda titanium implant chamber to studyblood flow in rabbit bone and notedthat the chambers could not beremoved at the end of theexperiment. He called the discovery“osseointegration.”

The success of osseointegrationis due to the careful surgicaltechnique where, for instance,only low-speed drilling is done,the use of specially designedpure titanium implants, and acareful and controlled period ofrehabilitation. This slide showsbone growing within the implant.This photomicrographshows the threads ofthe titanium implant(left) in direct andintimate contact withbone, which hasremodeled to occupythe thread space.Once the bone hasformed there isadditional time requiredfor it to mature andharden, and thisprocess is also part ofosseointegration.

Over 40 Ph.D. dissertationshave been conducted inGothenburg, Sweden toinvestigate the basic scientificfoundations ofosseointegration in the dentaland orthopaedic sciences.While the scientific basis ofosseointegration is notcompletely understood, it isclear that there is a specialrelationship between puretitanium that promotesactivation ofosteoclasts/osteoblasts andbone remodeling.

In fact, the presence ofpure titanium maystimulate stem cells todifferentiate intoosteoblasts, the bonebuilding cells, as thisscanning electronmicrograph depicts. Thecell is in contact with apure titanium implant.The surface TiO2 layer is extremely inert to corrosion. The Tiperoxy compound that forms on this layer deactivatesinflammatory cells, thus reducing the “foreign body reaction”and enhancing the biocompatibility of pure titanium and theestablishment of osseointegration.

A patient with a 30 year history ofosseointegration. Osseointegrationwas first implemented in the dentalsciences in 1965. There are nowapproximately 1,000,000 peoplethroughout the world withosseointegrated devices.

Osseointegrated dental fixtures can beused to support a single tooth prosthesis,or it can support more complicatedprostheses in the cranial facial area, as isshown below. Extensive biomechanicaltests have been performed on thestresses affecting these devices.

What is it like to be a transfemoral amputee?Consequences of non-vasculartransfemoral amputationa survey of quality of life,prosthetic use and problems.Kerstin Hagberg, RPT and Rickard Brånemark, MD, PhDDep of Orthopaedics, Göteborg UniversitySahlgren University Hospital,Gothenburg, SwedenThis issue is being quantified with scientific techniques;See, Prosthet Orthot Int. 2001 Dec;25(3):186-94.Prosthetics and Orthotics International, 2001, vol. 25, pp 186-194

ConclusionsPersons with an established non-vascular unilateral transfemoralamputation.make extensive use of the prosthesishave impaired quality of lifehave considerable problems related to the amputation and the prosthesisone fourth consider themselves to have a poor or extremely poor overall situationThus,Improving the physical as well as the psychological well-beingfor this group of individuals is an important and challenging task!We think this challenge may be met in carefully selectedindividuals by osseointegrated bone-anchored prostheses.

Amputation prosthesesSocket prosthesis pressure pain sores difficult don/doff volume changes new socketsBone anchored prosthesis no pain no pressure easy don/doff improved function no remaking osseoperception

Early bone-anchored amputationprosthesesBeforeosseointegration,the permanentattachment ofprostheses to bonewas not possible.Early attempts failedbecause of theformation of fibroustissue between theimplant and bone.

OSSEOINTEGRATEDAMPUTATION PROSTHESESIn 1990, the first patient was implantedwith a transfemoral osseointegratedprosthesis (bilaterally) in Gothenburg,Sweden. She is now happily marriedwith two daughters and is doing well.

The surgery is performed in two stagesStage 1During this initial stage, thefemur is prepared as is themuscle tissue and skin. Usinga special surgical techniquethat respects the viability ofbone, a specially designed”fixture” is threaded into themedullary cavity. The woundis completely closed.

Healing phase of osseointegrationAfter Stage 1 surgery, it is important that theimplant not be loaded until the bone hasgrown into the threads. Movement of theimplant before this time may causeloosening. This phase of osseointegration isnormally 6 months, although there is recentunpublished data suggesting that this periodmay be shortened in selected patients withadequate bone quality. This is incorroboration with dental applications, whereit is even possible to start loadingimmediately.

Stage 2During Stage 2 surgery, theimplanted ”fixture” is reexposedand an ”abutment” is connectedto the fixture. The abutment isdesigned to be one of the ”failsafe” components of the systemand will break (instead of thefixture) if there were to beexcessive loading. The woundis closed with the abutmentpenetrating the skin. Woundcare is routine, and superficialinfections sometimes requireantibiotics.

MobilizationThis final phase of the osseointegration process typically takes 6months. During this phase the prosthesis is gradually loadeduntil the implant can accept full body weight. Thus, the totalosseointegration process takes typically 12 months, although insome patients with poor bone quality a longer total rehabilitationtime of up to 18 months is required.

Improved FunctionQuickTime and aTIFF (LZW) decompressorare needed to see this picture.Substantially improved function canbe obtained with osseointegratedimplants. This patient leads a veryactive life without concern for skinirritation or socket pain. Theprothesis is interfaced to theabutment with a fail-safe device tofurther protect the fixture and thebone.

Professors Brånemark and MyersThere is a long history ofscientific collaborationbetween Professor P.-I.Brånemark and Dr.Rickard Brånemark atGothenburg University(and the BrånemarkInstitute) and ProfessorRobert Myers at the SanDiego VA HealthcareCenter and the Universityof California, San Diego.

Osseoperception rat modelIn addition to extensiveexperimental studies in rats, rabbits,and dogs to explore thebiomechanics of osseointegratedfixtures, the Gothenburg-San Diegocollaboration has established a ratmodel of transfemoralosseointegration to study thephenomenon of osseoperception.Ysander, Branemark, Olmarker, Myers, 2001, JRehabil Res Dev

OsseoperceptionOsseoperception is the term given to the patient-reported feelingof heightened perception of the environment that occurs withosseointegrated prostheses. Research suggests this issecondary to nerve ingrowth into remodeling bone, as controlledby neuropeptides such as calcitonin gene-related peptide(shown here with immunohistochemistry).

Quantifying OsseoperceptionOsseoperception has been quantifiedusing vibrametry as a measure ofneural sensory function (Jacobs et al.,Prosthet. Orthot. Int. 2000).

There is ongoing research work on osseoperception inSweden and San Diego focused on the relationship betweennerve injury and remapping of the somatosensory cortex.

Development of the OPRA ProtocolLEARNING GROUP 90-96VaryingAnatomySurgical techniqueHealing timeMobilisationCustom designDeep infections/loosening 45 %Success rate 85 %A human-use protocol forthe Osseointegration ofProstheses forRehabilitation Amputees(OPRA) has beendeveloped and approved inSweden, Norway and theEU. It is a work-in-progresssince 1990. Approximately75 patients have beenimplanted as the protocolhas developed. Outcomesuccess has continuallyimproved.

Development of the OPRA Protocol - 2REFINEMENT GROUP 96-99IndicationsSurgical equipmentHealing timeMobilisationDeep infections/loosening decreasingSuccess rate increasingThe second phaseof the protocoldevelopmentrefined the patientselection criteria,surgical techniqueand rehabilitationprocedures. Thissignificantlyreducedcomplications.

Development of the OPRA Protocol - 3ROUTINE GROUP 99Defined indicationsStandardised surgical techniqueStandardised componentsStandardised mobilisation programStandardised follow up programSafety devicesAdditional surgeons and centres:London, Melbourne, Montreal,San Diego/Long Beach VAsThe current protocolimplements a stableprocedure withexcellent outcomes(although limited infollow-up period) inmultiple centersthroughout the world.The treatment isapproved in the EU.IRB approval in SanDiego is pending inpreparation for FDAapplication.

PATIENTS TO BE CONSIDEREDAmputations in Sweden between 1980-1991Diagnoses: arteriosclerosis without diabetes arteriosclerosis with diabetes trauma tumour other46,4 %35,3 %6,3 %2,9 %9,2 %

Other uses of osseointegrationthat might be useful in VApatients include digitattachment (particularly thumb).

The upper limb is also a target for osseointegrated prostheses.Altogether 16 patients in Gothenburg with transradial ortranshumeral amputations have received such prosthesessince the early 1990s with 15 out of 16 successful.

The stable fixation of prosthesis to arm provided byosseointegration enhances the reproducible use of myoelectricinterfaces

Transhumeral amputee with osseointegrated prosthesis.

Osseointegration InternationalQuebec City GMMontreal GMEdmontonVancover GM Toronto GOttawa GSeattle GSpokane GMZN Iowa MCRochester GMC BostonLos Angeles GDallas NNew YorkSan Antonio G Washington DCBoden NStockholm GFalun N Umeå G ZUppsala ZNJönköping ZBergen Z Örebro GGöteborgGMCZN Linköping GMölndal ZBorås GCZ Åbo NHalmstad ZDublin GNMalmö GMZNLondon GMZErlangen ZN Hannover NLeuven GMNBryssel GMZ Wien N Grabs NBarcelona GZNOderzo GN Zurich NBeijing Pyongyang Tokyo GMZNMadrid GZNVerona NMarseille NBeirut GMSeoul GShanghaiDharwad GMSao Paulo GMZNBauru GMCZSantiago GMCZNG - GraftM - MaxillectomyC - CleftZ - ZygomaticusN - Novum(Brånemark)Perth MZNMelbourne GMZNSydney GMZ

CONCLUSIONSOsseointegration is an establishedmedical procedure that is ofsignificant benefit in selected patientswith limited traditional options. It issupported by a history of: Basic science Anchorage and perception Dentistry CMF Orthopaedics

While not fully validated for morewide-spread use in transfemoralamputations from an evidencebased perspective, ongongclinical trials in the EU andelsewhere outside the USA areproviding valuable long-term datafor scientific analysis. We believethat in the carefully selectedpatient it is of value now and cansignificantly increase the“I will never usea socket prosthesis again.”QUALITY OF LIFE

Thank you!We recognize that there is a lack of general understanding of the many detailsconcerning the orthopaedic application of osseointegration, caused in part by therelative lack of formal publication of the rapidly changing patient population. One recentpublication from the Roehampton group of surgeons trained in transfemoralosseointegration procedures reports on a very limited subset (11) of the total populationof patients, which is now 71.For instance, there has been concern expressed by some about the divorce rate in theEnglish population receiving transfemoral osseointegration procedures, but in the largerSwedish population there have been no divorces. Rather, there have been threemarriages and four new-born children.Concerning the issue of deep infection, it is recognized that this is a slight yet highlysignificant potential problem, like death during anesthesia is a very slight but highlysignificant problem. Using the current OPRA protocol, infection has not been aproblem. Only one of 23 patients has had a deep infection, and this patient can againuse his osseointegrated prosthesis. The deep infections observed in the early 1990swere presumably secondary to early implant loosening. This hypothesis is supportedby the dramatic reduction of deep infections seen following the decrease of earlyimplant loosening.