Evaluation of treatment of late-onset tibia vara using gradual angulation translation high tibial osteotomy

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1 Act Orthop. Belg., 2010, 76, ORIGINAL STUDY Evlution of tretment of lte-onset tii vr using grdul ngultion trnsltion high tiil osteotomy Adel Rhmn Adel Ltif AMER, Ashrf A. KHANFOUR From the Dmnhour Ntionl Medicl Institute, Egypt Lte-onset tii vr or Blount s disese is the most common cuse of pthologic genu vrum in children nd dolescents. Tretment remins controversil. Mny studies in the pst hve shown tht n osteo - tomy with cute correction is the most pproprite tretment. More recently however, there hs een growing interest, especilly in severe cses, in using grdul correction with the Ilizrov technique fter single high tiil osteotomy. A retrospective study in 20 children with lte-onset tii vr, who were treted y grdul ngultion trnsltion high tiil osteotomy using the Ilizrov technique, ws performed. The men follow-up period ws 2.9 yers (rnge : 2-4 yers ; SD 0.75). Recurrence of vrus deformity to vrious degrees ws noted in 10 of 22 cses (45.5%). Recurrence of deformity ws found to e significntly relted to oth the degree of pre-opertive devition nd the durtion of follow-up. No sttisticlly significnt reltionship ws found etween recurrence nd the ge of the ptients t the time of the opertion. Angultion trnsltion high tiil osteotomy using the Ilizrov technique is unique method for re - lignment of the mechnicl xis in lte onset tii vr. It lso llows for correction of ssocited deformities. The rte of recurrence of vrus deformity is however reltively high. Keywords : tii vr ; Blount s disese ; osteotomy ; Ilizrov. INTRODUCTION Blount s disese, or tii vr, is the most common cuse of pthologic genu vrum in children nd dolescents. Tii vr hs een clssified s infntile, juvenile, nd dolescent, the infntile form occurring efore the ge of 4, the juvenile form etween 4 nd 10 yers of ge nd the dolescent form fter 10 yers. The term lte-onset tii vr includes oth the juvenile nd the dolescent forms (14). In lte-onset tii vr, the deformity is comintion of proximl tiil vrus nd procurvtum s well s internl tiil torsion resulting in complex three-dimensionl deformity. Leg length discrepncy my e present nd dds to the complexity of tretment. Two other secondry deformities my e present, which re distl femorl vrus Adel Rhmn Adel Ltif Amer, MD, Orth, Professor of Orthopedics nd Trumtology. Fculty of Medicine, University of Alexndri, Egypt. Ashrf A. Khnfour, FRCS Irelnd, MD, Orth, Alex. Dmnhour Ntionl Medicl Institute, Egypt. Correspondence : Ashrf Khnfour, Ali El-Grim St. In front of Omr Afndi stores. Boher stte, Rsheed, Egypt. E-mil : Dr_shrfkhnfour@hotmil.com 2010, Act Orthopædic Belgic. No enefits or funds were received in support of this study

2 GRADUAL ANGULATION TRANSLATION HIGH TIBIAL OSTEOTOMY 361 nd distl tiil vlgus. The former is the result of excessive lod on the medil hlf of the distl femorl epiphysis, while the ltter is compenstory deformity to the severe proximl tiil vrus (10,14). The gols of surgery re to relieve pin, when present, nd to correct lim lignment with horizontl knee joint for weight-ering. The long-term outcome of lower lim mllignment is not well understood. It is elieved, however, tht significnt devition from the norml mechnicl xis my not only cuse knee pin, ut lso predisposes the joint to osteorthritis in the future (10,27). Tretment of lte onset tii vr remins controversil. Although severl surgicl options exist for its correction, corrective osteotomy is still the gold stndrd (2,28). Mny types of osteotomies hve een descried in literture, iming t cute correction, including n opening wedge (23), closing wedge, spike (4) nd n olique osteotomy (21), elevtion of the medil plteu (7,24,26), nd finlly comintion of different methods (7,8). Different modlities of internl fixtion lso hve een descried (1,5,16). Guided growth technique y hemiepiphysiodesis hs een reported s n ttrctive lterntive in the growing child to llow correction of n ngulr deformity in generl. Using this technique, however, in ptients with norml physes (eg, Blount s disese, skeletl dysplsis) hs n unpredictle outcome. These cses showed higher compliction rte nd were significntly more likely to require n osteotomy to correct residul ngulr deformity due to filure of hemiepiphysiodesis (2,28). Medil plteu elevtion procedures either lone or in comintion with high tiil osteotomy hve een performed in ptients with the severe forms of Blount s disese (Lngenskiöld-IV, V, nd VI) (9,17). More recently, there is growing interest in using grdul correction y the Ilizrov technique in which, through single high tiil osteotomy relignment of the mechnicl xis is otined, in comintion with the correction of possile other ssocited deformities, including leg length discrepncy (6,25). The im of this study is to evlute the results, fter follow-up period of t lest 2 yers, of grdul ngultion trnsltion high tiil osteotomy in the tretment of lte-onset tii vr. PATIENTS AND METHODS Twenty children (tle I) from the Sporting Helth Insurnce Student Hospitl Alexndri, with dignosis of lte onset tii vr nd older thn 4 yers of ge t their first presenttion, were evluted fter minimum follow-up period of 2 yers post-opertively. Two were ilterl. All cses were treted y the uthors etween Decemer 2005 nd Jnury There were 9 mles nd 11 femles. The two ilterl cses were mles. Men ge of the ptients t time of opertion ws 11 yers (rnge : 8-14, SD 1.8). Ten cses were left sided, eight right sided nd two ilterl. Fourteen legs were operted upon for the first time (63.6%) nd eight cses were recurrences fter prior tretment (36.4%). The men follow-up period ws 2.9 yers (rnge : 2-4, SD 0.75) The surgicl procedure consisted of single high tiil osteotomy, excision of prt of the fiul, cute intr-opertive correction of the tiil internl rottion nd grdul ngultion with trnsltion with the Ilizrov pprtus, to correct the vrus deformity using the so clled juxt-rticulr hinge ssemly (fig 1) (19,20). The im ws to otin t the end n overcorrection of 10 vlgus. Shortening, if present, ws lso corrected grdully. Grdul correction of the vrus deformity ws strted one week post-opertively nd took 3-5 weeks depending on the degree of the pre-opertive deformity. At the end the frme ws locked nd further weeks were llowed for consolidtion, guided y regulr rdiologicl follow-up efore frme removl. If lengthening ws performed, further 4-6 weeks were needed for every dditionl centimetre. Although lim length discrepncy ws determined pre-opertively cliniclly nd y scnogrm, the evlution of lim length equliztion ws determined only cliniclly, s the presence of the Ilizrov pprtus prevented pproprite lim positioning during rdiologicl lim length ssessment. At lest 2 yers post-opertively, the chrts nd the initil rdiogrphs of the 20 children (22 lower extremities) were studied. The ptient ge, gender nd ffected side were noted. The initil deformity ngle (DA) of vrus deformity ws mesured. The DA ngle ws formed etween line drwn from the center of the hip joint to the center of the knee joint nd nother line from the center of the knee joint to the center of the nkle joint. All mesurements were red from stnding nteroposterior rdiogrphs or CT-scnogrms. A negtive DA represents vrus deformity. The degree of surgicl correction (the sum of the initil degrees of the

3 362 A. R. A. L. AMER, A. A. KHANFOUR Loss of correc - tion Follow up period (Y) Degrees of correction Pre-Op LLD (Cm) Tle I. Dt of the ptients Pre-Op Internl rottion Pre-Op DA Lngens - kiöld clssifiction Presen - ttion Side Sex Age (Y) II Recent Rt. Mle Lt. -25 VI Recent Bil Mle Rt. -20 VI II Recurrent Lt Femle Rt. -40 Lt. -25 II II Recent Bil Mle I Recent Lt Mle VI Recent Rt. Femle IV Recurrent Rt. Mle VI Recurrent Lt Femle II Recent Lt Femle VI Recurrent Lt Femle IV Recurrent Rt. Femle III Recent Lt Mle I Recurrent Rt. Femle I Recent Lt Mle III Recent Rt. Femle VI Recent Lt Femle I Recurrent Rt. Mle III Recent Rt. Femle II Recurrent Lt Femle I Recent Lt Mle vrus deformity plus 10 vlgus overcorrection) ws noted fter grdul correction ws otined. Loss of correction or the difference etween the overcorrection chieved nd the DA t the end of follow-up, ws lso evluted. The men preopertive deformity ngle ws (rnge : -20 to -45 ; SD 7.2 ). The men pre - opertive lim length discrepncy ws 1.5 cm (rnge : ; SD 1.5). The preopertive internl rottion of the tii ws 10.9 (rnge : ; SD 12.2 ). Internl rottion of the tii ws mesured using the thigh-foot xis test. In internl tiil torsion, the foot xis points inwrd nd the ngle is negtive. The ngle ws mesured with goniometer. According to the Lngenskiöld clssifiction, we divided the ptients into two groups : grde I, II, III, nd IV s the mild-to-moderte-group nd grde V nd VI s the severe group. The first group included 16 cses nd hd men pre-opertive vrus deformity of 34.7 (rnge : ). The second group included 6 cses with men pre-opertive vrus deformity of 34.2 (rnge : ) The men ngulr correction ws 45 (rnge : ; SD 6.9 ). Recurrence of deformity ws defined s loss of correction of more thn 10 t the end of followup. In dt nlysis, Student s t-test ws used, p < 0.05 eing considered significnt. RESULTS New full-leg stnding rdiogrms or CT- Scnogrms of the lower lims were evluted fter men follow-up period of 2.9 yers (rnge : 2-4 yers ; SD 0.75) (fig 2). The men loss of correction ws (rnge : ; SD 9.78 ).

4 GRADUAL ANGULATION TRANSLATION HIGH TIBIAL OSTEOTOMY 363 Fig. 1. () juxt-rticulr hinge ssemly mounted on tii vr in which the CORA lies ner the joint line. To mtch the hinge of the fixtor to the level of the CORA, the hinge must e ove the ring. So, with correction of ngultion, trnsltion will result. () After correction, the mechnicl xis is religned. Fig. 3. () Preopertive CT-scnogrm of 10-yer-old femle with left recurrent lte onset tii vr with preopertive DA ngle of -40. She hd 20 of internl tiil torsion which ws corrected cutely intropertively () follow up scnogrm fter 3 yers shows recurrence of 25. severe group. The difference in vrus recurrence rtes etween the two groups ws found to e sttisticlly significnt (p = 0.008). There ws lso sttisticlly significnt correltion etween the rte of recurrence nd the length of the follow-up period (p < 0.001). There ws no sttisticlly significnt reltion etween the ge of the ptients t the time of opertion nd the recurrence (p = 0.87). No leg length discrepncy ws recorded t the end of follow-up. Fig. 2. () Preopertive CT-scnogrm of 12-yer-old femle with right sided lte onset tii vr with preopertive DA ngle of -45. () follow-up scnogrm fter 2 yers shows no recurrence. Recurrence of vrus deformity ws noted in 10 of 22 cses (45.5%) (fig 3 & 4). The men vrus recurrence, in 5 out of 16 cses in the mild-to-moderte group, ws 18 (rnge 15-20, SD 2.7 ) nd 22 (rnge 15-35, SD 4.8 ) in 5 out of 6 cses in the DISCUSSION Pin nd knee rthrosis re the nturl long-term result of untreted cses of Blount s disese (3,10-12). Although metphysel osteotomy with cute correction nd internl or externl fixtion is the stte of the rt tretment of infntile tii vr, this hs een found to e less pproprite in treting lte-onset tii vr, where n extrfocl osteotomy

5 364 A. R. A. L. AMER, A. A. KHANFOUR Fig. 4. () Preopertive CT-scnogrm of 9 yer old mle with left recurrent lte onset tii vr with preopertive DA ngle of -45. He hd 25 of tiil internl tosion which ws corrected cutely intropertively ; () follow-up scnogrm fter 2 yers shows recurrence of 15. with grdul ngultion trnsltion using the Ilizrov technique is gining populrity (6). Different resons hve een put forwrd. Firstly, the center of rottion nd ngultion (CORA) is usully locted juxt-rticulrly, which mkes focl correction techniquely impossile. On the other hnd, the upper tiil epiphysel growth plte lies just distl to the CORA where osteotomies crry high risk of potentil injury of this growth plte, possily dding more growth disturnce to the proximl tii. So, the preferred loction for the tiil osteotomy in this ge is typiclly in the metdiphysis, distl to oth the tiil epiphysis nd the insertion of the ptellr tendon. The loction of the osteotomy eing wy from the CORA (extr-focl correction), this necessittes pproprite lterl nd often nterior trnsltion of the distl frgment in order to relign the ntomic xis of the tii. Disregrding this principle cretes secondry trnsltionl dog-leg deformity t the metdiphysis s well s vlgus mlorienttion of the nkle (20). A smiling fce dome osteotomy will hve its center of rottion closer to the CORA nd will induce pproprite trnsltion nd void injury to the proximl tiil epiphysis (18). Secondly, most of these ptient re moridly oese, which mkes the ppliction of well fitting ove- knee cst difficult, if not impossile, nd prevents dequte control of the position of the osteotomy site. In ddition, the older ge nd size of the ptient mkes ptient moility highly desirle. The prolems ssocited with non-weight ering on the ffected extremity mkes wlking extremely difficult for these ptients. Furthermore, ssessing lim lignment either intropertively or postopertively is difficult with cst nd crries the risk of residul proximl tiil vrus or undercorrection (6). Thirdly, y using the Ilizrov technique the prolem of lim length discrepncy is ddressed comprehensively. As regrd the method of ssessing the ngulr deformity round the knee, we chose the deformity ngle (3), s discussed efore, s the mesure for oth the pre-opertive vrus deformity s well s for the ssessment of the results. This is ecuse in these ptients the upper tiil epiphysis is deformed with depression of its medil plteu, which mkes mesuring of the knee joint orienttion ngles such s lower lterl femorl ngle nd upper medil tiil ngle less reproducile. There is no consensus in the literture regrding the idel lignment of the lower extremity following opertive reconstruction in ptient with Blount s disese (22). Most uthors hve dvocted tht some degree of overcorrection should e ttempted (8,23,24,26,27). In this series 10 of overcorrection ws imed for t the end of tretment ut still, recurrence occurred in 45.5% of cses. We still recommend overcorrection like other uthors since overcorrection my decrese the incidence of the expected recurrence efore the epiphysel closure. In this series, recurrence ws evidently more frequent in Lngenskiöld grdes V nd VI. It occurred in 5 out of 6 cses (83%) in the severe group, nd only in 5 out of 16 cses (31.3%) in the mild-tomoderte group. This my support the need for n djuvnt procedure such s medil tiil plteu

6 GRADUAL ANGULATION TRANSLATION HIGH TIBIAL OSTEOTOMY 365 elevtion (9,17) or lterl tiil upper epiphysel epiphyseodesis for Lngenskiöld grdes V nd VI (2,28). Lim length discrepncy in these ptients is result of two types of shortening, geometric (not true shortening) nd true shortening. Geometric shortening results from loss of co-linerity of the hip, knee, nd nkle, which mkes the overll lim length to e less thn the summtion of the individul lengths of oth the tii nd the femur. True shortening results from compression of the medil physis due to the vrus lignment with medil growth suppression in ccordnce with the Heuter- Volkmnn principle (13). Tretments tht suppress lterl growth s lterl epiphysel epiphyseodesis either y stpling or plting my lso contriute to lim shortening (2,28). Mnging this shortening, Kessler et l (13) found in their work tht simple summtion of femorl nd tiil lengths predicts corrected lim length within men error of 0.7 cm, nd tht the corrected length is usully less thn predicted, secondry to tiil shortening relted to the osteotomy. However, shortening nd recurrence of the deformity re expected s forthcoming prolems when the osteotomy is performed prior to physel closure. This ws explined y Kessler et l to e due to imlnced growth of the medil nd lterl upper tiil epiphysel plte, when this plte is still hving potentil for growth (13). This conclusion correltes well with the result of this study, in tht recurrence ws found to e ffected significntly y the length of follow-up period which gives the chnce for the imlnced growth of the upper tiil epiphysis to result in recurrence of the deformity. This ws lso noted y Chotigvnichy et l (3). As regrd the reltion of recurrence with the degree of the preopertive DA, this my e explined on the sis of the higher degree of pthologicl ffection of the upper epiphysel plte in higher DA vlue cses. REFERENCES 1. Beck CL, Burke SW, Roerts JM, Johnston CE. Physel ridge resection in infntile Blount disese. J Peditr Orthop 1987 ; 7 : Bushnell BD, Cmpion ER, Schmle GA, Henderson RC. Hemiepiphyseodesis for Lte-Onset Tii Vr. J Peditr Orthop 2009 ; 29 : Chotigvnichy C, Slins G, Green T, Moseley CF, Otsuk NY. Recurrence of vrus deformity fter proximl tiil osteotomy in Blount disese : long-term follow-up. J Peditr Orthop 2002 ; 22 : Dietz FR, Weinstein SL. Spike osteotomy for ngulr deformities of the long ones in children. J Bone Joint Surg 1988 ; 70-A : Ferriter P, Shpiro F. Infntile tii vr : fctors ffecting outcome following proximl tiil osteotomy. J Peditr Orthop 1987 ; 7 : Gordon JE, Heidenreich FP, Crpenter CJ, Hhn JK, Schoenecker PL. Comprehensive tretment of lte-onset tii vr. J Bone Joint Surg 2005 ; 87-A : Gregosiewicz A, Wosko I, Kndzierski G, Drik Z. Doule-elevting osteotomy of tiie in the tretment of severe cses of Blount s disese. J Peditr Orthop 1989 ; 9 : Hyek S, Segev E, Ezr E, Lokiec F, Wientrou S. Serrted W/M osteotomy : results using new technique for the correction of infntile tii vr. J Bone Joint Surg 2000 ; 82-B : Hefny H, Shly H, El-Kwy S Thke M, Elmotsem E. A new doule elevting osteotomy in mngement of severe neglected infntile tii vr using the Ilizrov technique. J Peditr Orthop 2006 ; 26 : Hofmnn A, Jones RE, Herring JA. Blount s disese fter skeletl mturity. J Bone Joint Surg 1982 ; 64-A : Ingvrsson T, Hgglund G, Rmgren B, Jonsson K, Zyer M. Long-term results fter dolescent Blount s disese. J Peditr Orthop 1997-B ; 6 : Ingvrsson T, Hgglund G, Rmgren B, Jonsson K, Zyer M. Long-term results fter infntile Blount s disese. J Peditr Orthop 1998 ; 7-B : Kessler AC, Pugh LI, Stsikelis PJ. Length chnges in tiil osteotomy with ngulr correction. J Peditr Orthop 2005 ; 14-B : Kling TF. Angulr deformities of the lower lims Orthop Clin North Am 1987 ; 18 : Loder RT, Schffer JJ, Brdenstein MB. Lte-onset tii vr. J Peditr Orthop ; 11 : Mrtin SD, Morn MC, Mrtin TL, Burke SW. Proximl tiil osteotomy with compression plte fixtion for tii vr. J Peditr Orthop 1994 ; 14 : McCrthy JJ, McIntyre NR, Hooks B, Dvidson RS. Doule osteotomy for the tretment of severe Blount disese. J Peditr Orthop 2009 ; 29 : Miller S, Rdomisli T, Ulin R. Inverted rcute osteotomy nd externl fixtion for dolescent tii vr. J Peditr Orthop 2000 ; 20 : Pley D, Herzenerg JE, Tetsworth K, McKie J, Bhve A. Deformity plnning for frontl nd sgittl plne

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