FIRSTMETATARSOPHALANGEAL JOINTFUSIONMADEEASY

1 INTRODUCTIONThe firs t metatarsophal angealjoin t (MPJ ) fu sio n is an ide alpr ocedure for pat hologyof this joi nt that re qui res ade fini tive corr ect ion. Co mmo nly, the patho logy will includese vere art hrit ic chan ges of th e joi nt or a deviat ion of the jointthat can no t be surgically repa ir ed wi thou t fu sio n such as along-t er m ha llux varus (Figures1, 2). Thi s pr oce dure ca nbe done in a simp le way tha t pr ovi des for go od corr ecti onand a hi gh fu sio n ra te wit hout extens iv e use of har dwar e,and it also allows the pat ient to bear weight in a post -op erat iv e sh oe dur in g rec over e ke ys to succ ess in the fir st MPJ fusi on ar e the sameas inany typ eof arthr odes is foot diss ec ti onfo r go od visi bil it y, goodappos ition of bone wi th stabl efix ation.

2 And idea l posi tion mak e the proc edur e a succ COMPLICATIONS OFFIRST MPJ FUSIONCo mm on com plic ationsof the fir st MPJ fusi on in cl udeno nunion,wounddehiscence,pa inful inte rnal fix at io n,iatrogenic ulc er formation,and pain. Som e of thecom pl ic ationsare a resultof pa tient noncompl iance orco -mor bi dit ie s. Othertim es the comp licat ions ar e a resul t ofth e appl ication of the pr oc edur e its el f. The sol uti on is toapp ly the pro ced ure with minimal tra um a to the tiss ues withop tim al po si ti on and th e lea st amo unt of fixatio n as ne ed ons of the first MPJ fus ion may come fromeit her in ade qu ate join t resec ti on or uns table fixatio n.

3 Thefi xat ion may allo w for too much moti on or it may actuall yga p the fusionsite . Wounddehi sc ence in a pat ient wi thheal thy tissueca n be a resul t of too much dissection orpr ess ure from la rge amounts of ha rdwa re like plat es orpromi nen t screw s or wi res. When the fixationis pro mine ntor beco mes loose this can al so lead to pai n, whi ch wi llreq ui re remo val of the fixati e po si ti on of the jo in t in the fusi on of the first MPJis par amo unt to the suc cess of the pr oc ed ure. Wh en the toeis too clos e to th e gr oun d, thi s can result in pain due to thepress ure, or in so me cases can caus e the fixat io n to bre akdow n an d create a painf ul nonu ni on.

4 Poo r correction in theFIRST METATARSOPHALANGEALJOINT FUSION , DPMCHAPTER11 Figure1. Preoperativeradiographof Post surgicalview after the wire is tal planecan also caus e a cont ra ctur e of the hal luxint erph al angea l joint (IPJ) or in the case of too muchpl ant ar fl exion , an ul cer at the ha llux IP posi ti on in the tr ans ver se pl ane can caus e sho eirri tat ion in the cas e of a varu s posi ti on, or ulcer atio n in th efirs t web sp ace from pressu re agai nst the sec ond digi her an under la ppi ng or ov er lapp ing seconddigit canals o be a res ult of un der co rrec ti on in the tran sverse OF PROCEDURETh e inci si on is pl ac ed dir ectly ove r th e joi nt and onl y need sto be lo ng enoughto get ac ces s to the joi nt for comple teres ecti on, usually3 to 4 cm.

5 Bec aus e the fi xat ion is plac edco mp lete ly wi thin the fusi on site and thr oug h th e end of thedi git, ext en sive perios teal dis sect ion is not nee ded (F igu re 3).The subcutane ous tis sue is dis sec ted and ref lectedmedi al ly and la te rally. The extens or te ndonan d jo intca psule are ide ntif ied and the caps ula r inc ision is ma de onei ther sid e of the ex ten so r tend on to ex po se the jo int. Thetend on is pr eser ved an d ref lec ted to the side (Figu re 4).The amo un t of di ss ect io n at thi s poi nt depends on theamo unt of bo ne resection nts wi th a gr eat dea l of peri arti cul ar spurringwillneed more ref ec tion of the peri ost eum to get ad equa tebon e ex po su join t is the n saw-r esect ed to pl ace the halluxin th eco rre cte d all el blockcut s will be the mo ststa ble and will as sis t in limiti ng mo ti on at th e fu sio n si te dueto the buttressin g position of the bone co ntact.

6 In cases ofpse udo arthrodes is, jus t the stabilityof the bon e cut s wi lllim it mot io n an d may make the pro cedu re a succes s (Figur e5). The autho r prefers th at th e ha ll ux sh ou ld be po si ti one dsli gh tly of f th e gro und and generall y pa ral lel to the seconddi git , if it is in goo d ali gn ment,in th e tran svers e pl an expos ed bone need sto be good bl eedi ng cancel lousbon e wit h ple nt y of corticalbone on the edg es of thebon e cu ts for stabilityof the fus ion site . In cas es wher eexten sive bone resectionis neededthe Kirschnerwir esmay need to bepos ition ed deeperint othe first metatarsalforsta bili ty sinc e some of the corti cal bone arou nd the fusionsit e was re e the de si re d pos it ion is ac hieved,the fixa tion ispl ac ed acro ss the 62 Kirs ch ner wi re is drivenfro m the base of th epro xim al pha lan x throughthe end of the ha llu x an d stoppedfl us h wi th the bone secondwir e is dri ven an dpl ac ed in si mi lar fa sh ion bu t sli ghtl y non parallelto th e firstwi re.

7 Having the wir es plac ed nonpa ral lel to each ot her willhel p pr event motio n al ong th e wi res at the fus ion sit e. Thefu si on site is th en tigh tly approximated an d eac h wi re is th endriv en into the first metatarsalto the base or ou t th e sid eth ro ug h the cort ex (F igure 6). The po si ti on sh ou ld beche cke d wi th a C-arm to make sur e the fusi on sit e is notgap pi ng an d that the posi ti on of the fu si on si te isappr opri at e as well as the fixa ti 1148 Figure3. Joint IVE CAREF ollo win g the procedurea steril e sof t dre ssing is ap pli pat ient is able to performso me lim it ed ambu lation in arig id postoperative shoe.

8 The dres sing sho ul d be chan gedwee kly un til the in ci si on is hea led and ne ed s to sta y dry untilth e Ki rschne r wir es are removedat the 6 wee k mark .Peri odi c radiographs shoul d be tak en to de te rmi ne theheal ing sta tus and to see if there ha s be en any chan ge inposit ion of the fus ion site (F igur es 7, 8).CONTRAINDICATIONSAlt ho ugh thi ssi mplifiedprocedur ehas ma ny indic atio ns, it isno t reco mm endedfor rev isi onal fir st MP J fusio ns or inpatie nts wi th poor bone nts tha t ha ve pro fou ndne ur opathy shouldhav e strict limitationson wei ght -bear in gact ivi succ es sfu l outcomeof a fi rs t MPJ fusio n does not re qui reext ensi ve hardware and cast immobilizat ion.

9 Whenth e bo necut s ar e ma de and positionedin a stabl e constr uct wit hKirs chne r wir e fix at ion and the foot is imm obili zed in apost op er ative sho e, fusion of the first MP J can be achi ev 1149 Figure6. Kirschnerwire shownat the base of Radiographicview of the fusionsite fixatedwith Fusedjoint after Kirschnerwire removal.