COTTONOSTEOTOMY:TechniqueandComplications

1 INTRODUCTIONThe Cot ton oste otomyis a medialcune iform openi ngwed ge oste otomywith the wedg e base d dors al ly topl ant ar flex th e media l co lu mn (1). It has been trad iti onall yus ed in co nju nctio n with oth er pro cedu res to co rrect a pe spl anovalgus foot wi th forefoot va rus defo rm it y. The authormost comm only uses the proc edure as an adjunctto anEva ns ca lcan eal os teoto my and ga str ocn emiu s rec essi on forcorr ect ion of a flexib le pedi atric pes pl ano valg us de for Cot ton oste otomy has additi onall ybeen use dfor hall uxlimi tus , me ta ta rsus primusel eva tus, as an add itiona lproc edurein adult flatfootcorr ec tion, and for efoo tsupinatus.

2 Al ter na ti ves to thi s pr oc edur e inclu de any varie tyof medial co lumn fusion s suc h as a na viculo cun eifo rm joi ntar thr ode sis or fir st met at ar soc uneiform joint art hr odesi s,a plant arf lex ory first met atar sa l osteotomy, or soft ti ssu emedia l arc h rec ons tructio nt ag es to th e Cot ton ost eoto my co mparedto thelat ter li st of pro cedu res is it s si mpli cit y, reliableresul ts, easeof intr aope ra tive adjust ab ili ty, and pr eser vat ion of themedi al columnjoints (2, 3). In addit ion, the Co tt onos teot omy len gthe ns the medi al col um n as opposed to theshort eni ng tha tocc urs typica lly wi th arth ro des is proced ures.

3 There are few doc umentedcompl ic ati on s with th e Co ttonos teot omy, an dth eau thor s own experience co rr es pon ds toth is .Howe ver ,the author has exp erienced afew in sta nces ofcompl ic at ion s in th e use of this proc edu re. Thes e instancesas we ll as pre viouslydocu mentedcom plica tions wi ll bere view ed in th is up proc edure is perfor med with the pat ie nt in a supi nepos it ion. Typ ical ly, a posteriorlengthening(gast ro cne miusreces si on or tendo -Achilleslen gth en in g) and the primar ycorr ect ive pr ocedure(Evanscal caneal osteot omy, subtalarjoint fus ion , etc.)

4 Are perfo rmed first. The su rg eon will the npl ac ethe su btalar joi nt in aneut ra lposit io nan deval uate themedia l co lumn stabili ty and posit io n. On ce th e sur ge on hasdeci ded to corr ect any res idual forefootvarus wit h th eCott on oste otomy , the inc is ion is vari ety ofinci sion plac emen ts ha ve been desc rib ed in clu din game dial ,dorso medi al, or dorsal linear incis ion ove rlying the medi alcun eifo rm. The au thor s pre fe ren ce is to make a lineardo rsal to dor som ed ial in ci si on 3-4 cm in len gth over lyi ngthe me di al cune if or m.

5 Ana tom ic di ssec ti on is perf or med toavoi d the me di al dorsa l cu ta neo us nerve and th e sa phe nous(m edi al margin al ) ve in and ner ve . Perf oratorsof the me di alma rgi na l ve in ma y be en co unte re d and ligate d as ne cessaryand th en the me dia l ma rgi nal vei n is re trac ted late ral ly (4).A lin ear cap su la r-p er io ste al in ci sio n just med ial to th eext enso r hal luci s long us te ndon is mad e wit h care no t todisr upt th e dorsa l li ga me nts of the adjace nt joint s and thetibia lis ante ri or tendontha twill be jus tmedia land pla ntar tothe pl anned oste oto my (2).

6 A va rie ty of method s can be uti li zed to ident if y the firstmeta tars ocun ei fo rm an dnavi cu loc un ei fo rm joints to ensureth at th e ost eo to my wi ll be extra-art ic ul ar. Th ese in cl udepa lpatio nof the se jo in ts an dthe sec on dmetata rsocuneiformjoi nt, use of a25 or 27 ga ug ene edleinser te dint oth ejoi nts,and int raop erat ive C- ar m flu or osco py. The le vel of theost eot om y is best place d, in th e aut ho r s opi nion , justpr ox imal to the levelofth ese con dme tat arsocu nei form thou gh ot he rs hav e sug gest ed th at th e seco ndme ta ta rso cune if orm joi nt le vel allow s easie r mobil iz at ion ofth e oste oto my, on e of the com pli cat ions the auth or hasexp eri ence d is th at of in te rp os it io n of the graft int o th ese con d metat ars ocu ne if or m joi nt req ui ri ng su rg icalre-i nt er vent ion.

7 Th e tra ns verse ost eot om y is tha n crea tedus ing asagi ttal saw from dor sa lto planta rpara lleling the fir stme ta ta rso cune if orm joi nt (not para ll el to the we ig htbe ari ngsu rf ac e) while ta kingcare to pres erve th emedial cuneif or m spl an ta r corte x (Figu re 1).Com pl et evisualizat ion of the medial and lat eral edg es ofth e me di al cun eifo rm ar e necessa ry to ensu re both th eme dial and lat eral co rt ic es are cu t pri or to at temp tedop eni ng of the ost eot om y (Fi gu re 2). If one of theseco rtic es fa il to be cut, tha n the pla nta r hi nge may fra ctu rein to th e prox imal or di st al joi nt when the os teot om y isope ned (4).

8 Onc e th e cut is pe rf orm ed, the osteot omy canth en be ope ned a var ie ty of way s in clu di ng osteo to mes, aSy nthe s mini -di stractor, a We inr aub dist ract or (I nnome d,Sa vanna h, GA) , or smoo th la mi na spr eade r (2) . The autho rpre fe rs us in g eit he r the mini -di stract or or Wei nrau bdist ractor , which all ows pi n place ment di stal and pro xim alto th e ost eot omy. Thi s all ow s adju st abili ty of distraction toin tr aop erat ively de te rmin e th e amo un t of desiredCOTTON OSTEOT OMY:Technique and ComplicationsAnnette li at rault,DPMCHAPTER32 CHAPTER32167pl an tar fl ex ion for deformity correc tion and it off er s anun obst ruc ted view for mea surementof the desir ed graftwid th/ di mensi on s on ce th at ha s been det ermin ed.

9 It alsoallowsan ea sier insertionof the gra ft by openi ng theost eoto my slightlygreat er tha n the pl annedgraf t uponinser tion. The dim ensio ns ofth egr aft deter mine the amo untof pla nta rflexi on achi e gener al id ea is to re-est ab li sh wei ghtbearingof th efi rst met ata rsa l he ad equal to the fi fth met at ars al head asdic tate dby Co tton sconcep tof the foot as atri pod (1). Thegra ft is ta mpe d into the osteotomywith care taken to noten ter the se cond metatarsoc unei for m joint or bur y thedor sal cor tex of the gra ft past the dorsal edg e of the me dialcun ei form (Figure3).

10 The author typ icall y uses a fr eez e-dri ed il iac cre st wedgeallog ra ft (usua lly le ft over fr oman Eva ns proce dure) cut toth edes ire ddimens ions (typic ally4-8 mm at the dorsal wedg e bas e ta peringplanta rly in atrape zo ida l manne r) for correction wi th the cortexbaseddor sa ll y, alt houghautog raft coul d certainlybe used as th esurgeonfeels ap pr opri ate. It ha s been the exp erienceof theauthoras well as others th at gra ft inc orp or at io n is ty pi cal lynot apro bl em wi th fr eeze-driedallograft(5) ,al th ou gh it hasbe en obse rv ed that time to incorp orationmay be pr ol on gedin adult pa tie nts (8-16 week s, avera ge 12) compa red topedia tri c patients (6-8 weeks)(6).