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1、Thumb ReconstructionJeffrey B.Friedrich,MDa,b,*,Nicholas B.Vedder,MDa,bWhen thumb loss occurs because of trauma,replantation is the best method of reconstructionformostpatients.Whenreplantationisnotpossible,thumb reconstruction is necessary.Thelevel of thumb amputation guides the type ofreconstructi
2、on,and the level is based on physicalexamination and radiographic results.The recon-struction should be tailored to the patientspersonal and professional needs.Because signifi-cant rehabilitation may be required,the patientmust be a willing participant in the reconstructionand rehabilitation.Functio
3、nal compensation after distal third thumbloss is easily achieved;therefore,reconstruction atthis level typically involves soft tissue only.Tech-niques such as the neurovascular advancement(Moberg)flap and the cross-finger flap reconstruc-tion are reliable methods for reconstruction at thislevel.For
4、losses in the middle third of the thumb,restoration of length is a priority.This priority canbe addressed via absolute length restoration withmetacarpal lengthening,osteoplastic reconstruc-tion,ortoetransfer;orviarelativelengthrestorationusing phalangization of the thumb.Proximal thirdthumb losses a
5、re best treated with microsurgicalreconstruction.However,insome cases,microsur-gical reconstruction may not be possible.In thesesituations,transfer of another finger can providean excellent thumb replacement.A normal finger(typically the index)can be pollicized to becomea thumb.A damaged index finge
6、r can also betransferred(on-top plasty)to become a stablepost for opposition,pinch,and grip.Hand rehabilitation after reconstruction is abso-lutely necessary,especially after middle and prox-imal third reconstructions.Rehabilitation can lastfor months,and,for some procedures,such asneurovascular isl
7、and flap reconstruction and digittransfer,sensory reeducation is an important partof the rehabilitation.By far,the most common cause necessitatingthumb reconstruction is trauma.Within the largertrauma classification,thumb injury can be theresult of a variety of mechanisms,which includesharp cut,avul
8、sion,and crush.There are somemechanisms that have characteristics of morethan 1 injury type.This phenomenon is best illus-trated by saw and lawn mower injuries,whichhave both cutting and crushing components,re-sulting in a larger zone of injury.Other insults that can result in thumb lossrequiring re
9、construction include infections andneoplasms.Thumb reconstruction planning fortumor can be more deliberate than traumaticreconstruction and can often be performed at thetime of tumor extirpation.1Because there are many ways to reconstructa deficient thumb,patients must be educatedabout the various o
10、ptions so that they may makean informed decision as to which type of recon-struction will serve them best in both the personaland professional settings.In addition to patientinputregardingreconstructivemethods,thepatient must also commit to the reconstructiveprocess and must be a good candidate medi
11、cally,socially,and psychologically.In many patients,thumb injuries occur in theworkplace,and these patients are affected bythe injury because their work requires significanthand use.In these patients,it is essential to worktoward a thumb that has adequate length forboth gripping and pinching,is stab
12、le during activ-ities,has reasonable motion,and is sensate to givetactile input during these actions and to preventrecurrent ulceration or injury.However,adequatelength,stability,motion,and sensibility are theThe authors have nothing to disclose.aDivision of Plastic Surgery,University of Washington,
13、Seattle,WA,USAbDepartment of Orthopedics,University of Washington,Seattle,WA,USA*Corresponding author.325 9th Avenue,Box 359796(FedEx:Room 7EH70),Seattle,WA 98104.E-mail address:jfriedriuw.eduKEYWORDS?Thumb?Reconstruction?Microsurgery?Hand?AmputationClin Plastic Surg 38(2011)697712doi:10.1016/j.cps.
14、2011.08.0020094-1298/11/$see front matter?2011 Elsevier Inc.All rights Downloaded for Anonymous User(n/a)at Shanghai Jiao Tong University School of Medicine from ClinicalK by Elsevier on January 29,2023.For personal use only.No other uses without permission.Copyright 2023.Elsevier Inc.All rights res
15、erved.end goals for any patient requiring thumb recon-struction,regardless of profession or vocation.2The most important factor in patient selection isthe amount and nature of tissue loss that must bereconstructed.The level of amputation is theeasiest way to classify thumb deficiencies and islisted
16、in thirds.3The distal third extends from theinterphalangeal(IP)joint to the thumb tip.Themiddle third is the portion between IP joint andthe metacarpal neck,and the proximal third isfrom the metacarpal neck to the carpometacarpaljoint.Each amputation level presents uniquechallenges for the patient a
17、nd the physician,andeach level can be reconstructed with multiplemodalities.TREATMENT OPTIONS BASED ON INJURYZONEDistal Third ThumbThumb distal third amputations rarely requirerestoration of length because a thumb amputatedthrough the IP joint remains functional.3Therefore,the chief goals of thumb t
18、ip reconstruction are softtissue coverage of bone and length preservation.When there is no bone exposed at the tip of thethumb,closure can be achieved with either healingby secondary intention or skin grafting.Secondaryhealing of tip amputations up to 1.5 cm diameterwith no exposed bone has been sho
19、wn to resultin good 2-point discrimination and is thereforea fairly easy method of achieving coverage.4Secondary healing by wound contraction has theadvantage of bringing stable sensate skin togetherto close the defect,as opposed to skin grafts,which can remain insensate.Daily washing anddressing ch
20、anges with nonadherent gauze arerelatively easy for patients.Larger defects witha stable base,however,require skin grafting.Full-thickness grafts are usually preferred becausethey are more durable and stable,especially in thecontact areas subject to pressure and shear.Smallfull-thickness skin grafts
21、 can be harvested fromthe hypothenar eminence or the volar wrist crease,whereas larger grafts are easily harvested from thegroin crease.When phalangeal bone is exposed at the thumbtip,vascularized coverage is required to preservelength,and there are several flaps that can accom-plish this.The main c
22、riteria for flap selection aredefect size and location of soft tissue loss,specif-ically if it is volar,dorsal,or at the tip.The AtasoyV-Y advancement flap provides good coverageof the tip of the distal phalanx when only a verysmall amount of bone is exposed.5The techniqueinvolves incising the volar
23、 pulp of the thumb in a Vshape.Scissors are then used to carefully spreadthesubcutaneoustissue.Thesubcutaneousattachments deep to the flap,which provide theneurovascular supply to the flap,are left intact.The flap is then advanced distally to close thedefect,and the proximal aspect of the V incision
24、is closed side to side,thereby creating the Y shapeof the final scar.In practice,this flap is useful foronly small defects because of the limited advance-ment that is possible.The Moberg or neurovascular volar advance-ment flap is well suited to cover volar and tipdefects of the thumb.2It is describ
25、ed as anadvancement flap,but the amount of advance-ment achieved with the conventional rectangularMoberg flap is limited(Fig.1).Instead,elevationof the flap combined with flexion of the IP joint ofthe thumb allows the flap to appear to advancedistally.To elevate the flap,the midlateral linesare inci
26、sed on either side of the thumb down tothe base of the proximal phalanx.The flap is thenelevated from the deeper tissues(flexor sheath)with sharp dissection.The flap includes both neu-rovascular bundles and all the subcutaneoustissue down to the flexor tendon sheath.The IPjoint is flexed,and the fla
27、p is inset at the tip.Ifnecessary,a Kirschner wire can be placed acrossthe IP joint to stabilize it.This flap can covera defect of 1 to 2 cm2.A variation of the Mobergflap is the island flap that is incised transverselyacross the proximal base,and the only remainingattachments are the 2 neurovascula
28、r bundles.Unlike the conventional Moberg flap,this methodallows a small amount of actual advancement,thereby coveringmore distal defects.The proximalgap at the base of the flap requires a small skingraft.The cross-finger flap from the index finger is anexcellent reconstructive technique for larger v
29、olarand tip defects of the thumb(up to 23 cm2).6The tissue transferred is reliable and durable.7The chief disadvantages of this technique arethumb coaptation to the index finger for 2 to 3weeks and the need for a skin graft on the indexdonor site.A radially based rectangular flap ismarked on the dor
30、sum of the index proximalphalanx(Fig.2).The flap is incised and elevatedulnarly to radially in the plane between the subcu-taneous tissues and the extensor mechanism.It isvery important to leave the paratenon on theextensor to allow skin grafting.When the radialaspect of the flap is reached,Clelands
31、 ligamentmust be released along the length of the base ofthe flap to prevent kinking at the flap hinge.Theflap is then inset to the thumb.A full-thicknessskin graft is sutured to the dorsum of the indexfinger.At 2 or 3 weeks,the flap is divided,andthe inset to the thumb is completed.After division,F
32、riedrich&Vedder698Downloaded for Anonymous User(n/a)at Shanghai Jiao Tong University School of Medicine from ClinicalK by Elsevier on January 29,2023.For personal use only.No other uses without permission.Copyright 2023.Elsevier Inc.All rights reserved.aggressive range of motion therapy for both the
33、thumb and index finger should begin.The Littler neurovascular island flap is a valuabletool in thumb reconstruction.8This flap is not typi-cally used as a primary coverage flap,although it ispossible to use it in that manner.The flaps mostcommon use is for the restoration of sensation tothe thumb pu
34、lp after reconstruction.8,9The flap isbased on the ulnar neurovascular bundle of eitherthe middle or ring finger.The ulnar side of the digitis chosen because its loss has minimal effect ongrip and pinch activities.The dimensions of theflap needed are marked on the ulnar pulp of thechosen donor finge
35、r.Often,the flap requires har-vestingofskinoverthedistalandmiddlephalanges of the donor finger.The flap is incised,and a midlateral or Bruner incision proceedingfrom the proximal aspect of the flap is made.Theflap is elevated distally to proximally,and the entireulnar neurovascular bundle is elevate
36、d in conti-nuity with the flap.It is important to take the neuro-vascular bundle with a fairly thick sleeve ofsurrounding fatty tissue containing the vasa vaso-rum of the artery because that is the only source ofvenous outflow for the flap.Skeletonization of theartery results in venous congestion.Th
37、e dissectionmust be done fairly proximally in the palm to allowadequate transposition to the thumb,and theother branch of the common digital artery(theradial digital artery to the ring or small finger)must be divided.The common digital nerve canundergo intrafascicular splitting to allow adequateflap
38、 mobility.The flap is transposed to the thumbvia subcutaneous tunnel,or a connecting incisionfrom the donor site to the thumb can be made.The flap is then inset into the volar defect of thethumb.Thedonorsiteisgraftedwithfull-thickness skin.In addition to postoperative resto-ration of motion,patients
39、 must work with a handtherapist on sensory re-education of the thumb.The proximally based first dorsal metacarpalartery(FDMA)flap is very useful for thumbcoverage,although it is better suited for dorsalthumb defects than palmar defects.10,11The flapsharvest causes virtually no donor site functionall
40、oss.The FDMA is found using a Doppler device,beginning proximally with the radial artery at theanatomic snuffbox.The radialartery thenbranchesinto the princeps pollicis artery radially and theFDMA ulnarly.The flap is centered over theFDMA.It is incised and dissected distally to prox-imally,leaving p
41、aratenon over the extensor mech-anism for later skin grafting.To ensure inclusion ofthe FDMA with the flap,the thin fascia over the firstdorsal interosseous muscle is included with theflap.Like the neurovascular island flap,the arteryFig.1.(A)Thumb demonstrating tip amputation,(B)neurovascular advan
42、cement(Moberg)flap advanced tocover defect of tip,(C,D)healed thumb tip with good IP joint motion.Thumb Reconstruction699Downloaded for Anonymous User(n/a)at Shanghai Jiao Tong University School of Medicine from ClinicalK by Elsevier on January 29,2023.For personal use only.No other uses without per
43、mission.Copyright 2023.Elsevier Inc.All rights reserved.should not be skeletonized because this damagesthe venae comitantes.Once the flap is elevated,itcan then be tunneled to the thumb in the subcuta-neous plane or a connecting incision can be made.The donor defect is closed with a skin graft.Middl
44、e Third ThumbLoss in the middle third of the thumb is more func-tionally limiting than that of the distal third.There-fore,the priorities are both soft tissue coverageand functional restoration.Commonly,the softtissue coverage of amputations at this level willhave been achieved acutely by revision a
45、mputa-tion in which the skeletal components are short-ened to allow primary closure.Phalangization is a set of reconstruction tech-niques that increases the effective,rather thanthe absolute,length of the thumb.The chiefcomponent of phalangization is first webspacedeepening.3Webspace deepening allow
46、s betterthumb excursion,specifically both palmar andFig.2.(A)Thumb avulsion injury with exposed distal phalanx.To preserve length,a cross-finger flap is chosen.(B)Inset cross-finger flap.(C)Donor site of index finger covered with full-thickness skin graft.(D,E)Dorsal and volarviews of reconstructed
47、thumb and index finger donor site.Friedrich&Vedder700Downloaded for Anonymous User(n/a)at Shanghai Jiao Tong University School of Medicine from ClinicalK by Elsevier on January 29,2023.For personal use only.No other uses without permission.Copyright 2023.Elsevier Inc.All rights reserved.radial abduc
48、tion,thereby improving the thumbsmotion.First webspaces with mild or moderatetightness can be deepened with skin grafts or localtissue rearrangement(commonly Z-plasties).Themain assessment of the webspace is whether thecontracture is broad or a distinct linear band.Ifthe contracture is broad,then sc
49、ar contractureincision followed by skin grafting is used,whereasif the contracture is linear,local tissue rearrange-ment(usually Z-plasties)is the preferred treat-ment.Full-thickness skin grafts are usually usedfor the first web.A single Z-plasty can be usedfor a linear scar band,although 2 combined
50、 Z-plasties(4-flap Z-plasty or double-opposing Z-plasty)are uniquely suited to this anatomic area.When using either skin graft or Z-plasty for the firstwebspace,the adductor muscle is often tight dueto scarring.A portion of the adductor muscle canbe released to allow further thumb abductionbefore sk