Improved Function and Joint Kinematics After Correction of Tibial Malalignment

Transcription

1 An Originl Study Improved Function nd Joint Kinemtics After Correction of Tibil Mllignment Jck Engsberg, PhD, Stephne Leduc, MD, Willim Ricci, MD, nd Joseph Borrelli, Jr, MD Abstrct Mlunion fter tibi frcture cn hve negtive effect on ptient s git, joint kinemtics, nd functionl outcome. We conducted study to determine whether surgicl correction of mlunited tibis improves git, joint kinemtics, nd ptients perception of their helth nd overll well-being. Eleven ptients with tibil mlunions were treted with osteotomy, deformity correction, nd open reduction nd internl fixtion (ORIF). Minimum follow-up ws 7 months (men, 11 months; rnge, 7-17 months). In ll cses, the osteotomy eventully heled. Two ptients needed revision surgery: One hd lte collpse of the regenerte bone nd underwent revision ORIF wy from the site of deformity correction; the other required exchnge intrmedullry niling. Surgicl correction of mlunited tibi frctures resulted in significnt improvement towrd the normtive in lower extremity joint kinemtic vlues nd ptients perceptions of their helth nd overll well-being. Surprisingly, there ws little effect on git. Symptomtic mlunited tibi frctures should undergo surgicl correction, s it is likely to improve overll lower extremity function nd ptient stisfction. The tibi is the most commonly frctured long bone in dults, nd tibil mlunions occur in up to 60% of these ptients. 1,2 Persistent tibil mllignment, prticulrly vrus lignment, negtively lters git nd joint kinemtics, leding to ltered weight-bering forces cross the knee nd nkle joints. These ltered forces my led to osteorthritis. 3-8 Severl studies hve identified reltionship between extent of tibil mllignment nd chnges in joint rection forces. 3,5-7,9-13 Puno nd collegues 14 developed mthemticl model to better define the chnges in neighboring joints reltive to the pttern of the tibi mllignment. Not surprisingly, their work showed tht, with distl tibil mlunions, ltered stress concentrtions were relized t the nkle joint, nd more proximl tibil deformities led to lrger ltertions in the joint stresses t the knee. More recently, vn der Schoot nd collegues 8 found high prevlence of ipsilterl nkle osteorthritis with tibil mllignment of 5 or more, nd Greenwood nd collegues 15 showed higher incidence of knee pin, lower limb osteorthritis, nd disbility in ptients with previous tibi frctures. Given these findings, it would seem tht correction of tibil mllignment would led to normtive lower extremity joint kinemtic vlues, joint rection forces, nd overll qulity of life (QOL). The bility to mbulte hs been recognized s n importnt milestone in functionl recovery fter lower extremity injury. 2,16,17 Git nlysis, ssessment of joint kinemtics, nd QOL nd helth sttus questionnires cn provide informtion to evlute rehbilittion protocols, tretment lgorithms, nd surgicl outcomes. Recently, these mesures hve been used to ssess ptients recovering from cetbulr frctures, femorl shft frctures, nd clcnel frctures. 4,11,17-24 However, no study hs used these mesures to ssess the benefits of surgicl correction of mlligned tibis. We conducted study to determine improvement in git, joint kinemtics, nd ptients perceptions of overll wellbeing fter surgicl correction of tibil mlunions. The null hypothesis ws tht correction of tibil mlunion would hve no effect on git, joint kinemtics, or ptients perceptions of function nd QOL. Mterils nd Methods This prospective double-time-point study, which ws pproved by the Institutionl Review Bord of Wshington University/ Brnes-Jewish Hospitl, evluted 11 consecutive ptients with vrus tibil mlunion treted by single surgeon between September 2003 nd Jnury All ptients were treted using technique tht included oblique osteotomy nd open reduction nd internl fixtion (ORIF) or osteotomy nd intrmedullry niling. Study inclusion criteri were ge 18 yers or older; symptomtic vrus mlunion of the tibi of 10º or more; bsence of developmentl or pthologic process leding to the frcture nd subsequent deformity; no neurologic deficit of either lower extremity or contrlterl lower extremity deformity; nd bility to mbulte 9 meters with or without use of n ssistive device. Authors Disclosure Sttement: Dr. Borrelli wishes to report tht he is member of the Spekers Bureu for Eli Lilly. The other uthors report no ctul or potentil conflict of interest in reltion to this rticle. December 2014 The Americn Journl of Orthopedics E313

2 Improved Function nd Joint Kinemtics After Correction of Tibil Mllignment Tble 1. Ptient Chrcteristics Pt Sex Age, y Side Loction Mechnism of Injury Yer of Injury Preopertive Alignment Degrees of Deformity Time to Corrective Surgery, y 1 F 47 R Midshft Motor vehicle crsh 1976 Vrus/recurvtum 8 / F 51 L Proximl Motor vehicle crsh 1975 Vrus/neutrl 20 / M 62 L Proximl Gunshot 1970 Vrus/procurvtum 17 / F 62 R Proximl/midshft Motor vehicle crsh 1990 Vrus/neutrl 12 / F 43 L Distl Motor vehicle crsh 2003 Vrus/neutrl 10 /0 1 6 M 57 R Midshft Motor vehicle crsh 1995 Vrus/procurvtum 13 /9 8 7 M 46 L Distl Fll 1972 Vrus/neutrl 15 / M 68 L Proximl Fll 1988 Vrus/procurvtum 20 / M 44 L Midshft Pedestrin vs motor vehicle 1994 Vrus/procurvtum 13 / M 44 L Midshft Fll 1996 Vrus/recurvtum 10 / F 55 L Midshft Motor vehicle crsh 2000 Vrus/procurvtum 13 /4 6 Complictions occurred in ptients 4 (collpse of regenerte) nd 5 (nonunion). The 11 ptients (6 men, 5 women) who met these criteri enrolled in the study. Men ge ws 53 yers (rnge, yers). Eight mlunions involved the left tibi. The mechnisms of injury were motor vehicle crsh (6 ptients), fll from gret height (3), being struck by motor vehicle (1), nd gunshot (1). Men time from injury to corrective surgery ws 16.9 yers (rnge, 1-34 yers). Before surgery, ech ptient hd thorough physicl exmintion, with plin rdiogrphs, including nteroposterior (AP), lterl, nd oblique views, obtined to ssess degree of limb mllignment. Ptients completed the Short Form-36 (SF-36) nd the Musculoskeletl Function Assessment (MFA) nd underwent joint kinemtics nd git nlysis. Five mlunions were locted in the mid-diphysis of the tibi, 3 in the proximl third, nd 2 in the distl third of the tibil shft. One ptient hd posttrumtic deformity involving the proximl nd the mid-diphysis (Tble 1). After surgery, ech ptient ws followed t regulr intervls in the surgeon s privte office. Minimum follow-up ws 7 months (men, 11 months; rnge 7-17 months). At follow-up, rdiogrphs were obtined, nd ech ptient completed the SF-36 nd the MFA nd underwent joint kinemtics nd git nlysis. We obtined preopertive AP nd lterl rdiogrphs of the Tble 2. Rdiogrphic Mesurements of Deformity Plne Coronl: vrus (+) / vlgus ( ) Sgittl: procurvtum (+) / recurvtum ( ) Significntly different from preopertive (P <.05). Preopertive Postopertive Men SD Men SD mlligned nd contrlterl norml tibis for ech ptient. Angulr deformity ws determined in the sgittl nd coronl plnes to determine loction nd mgnitude of the deformity. Specificlly, on ech AP nd lterl rdiogrph, line ws drwn the length of the tibi proximl nd distl to the re of the deformity. The ngle generted by the intersection of these lines on the AP nd lterl rdiogrphs ws then plotted on grid to determine the precise plne nd mgnitude of the deformity (Tble 2). 1,12 Cliniclly, relevnt rottionl deformity of the involved limb ws ssessed by physicl exmintion, nd the results were compred with those of the contrlterl limb. Owing to the lck of considerble rottionl deformity in ny of these 11 ptients, we did not obtin computed tomogrphy scns for further ssessment of rottion. Periopertive intrvenous ntibiotics were dministered: 2 g cefzolin 30 minutes before incision nd 1 g every 8 hours for 24 hours fter surgery. A pneumtic tourniquet ws plced on the proximl thigh, nd the entire leg ws prepred nd drped in sterile fshion. The limb ws elevted nd exsnguinted with n Esmrk bndge nd the tourniquet rised to 250 mm Hg. With fluoroscopy, the site of the tibil deformity ws identified. Generlly, n incision ws mde centered over the pex of the deformity nd one fingerbredth lterl to the plpble tibil crest. In most cses, the nterolterl spect of the tibi ws exposed while minimizing soft-tissue nd periostel stripping. The plne of the mximum deformity ws identified with both direct visuliztion nd fluoroscopy. The osteotomy ws performed with n oscillting sw, nd in ech cse fibulr osteotomy ws lso performed. Mllignment ws corrected using combintion of mnul mnipultion nd femorl distrctor. 25,26 Intropertive biplnr rdiogrphs were compred with our preopertive pln nd with reversed imges of the contrlterl tibi to ssess correction of the deformity. If E314 The Americn Journl of Orthopedics December

3 J. Engsberg et l lengthening ws required, in ddition to the tibil osteotomy, corticotomy ws creted, nd circulr externl fixtor pplied nd distrction osteogenesis performed. We mintined the limbs in short-leg splint for bout 10 dys fter surgery nd then initited ctive-ssisted rnge of motion of neighboring joints. Ptients were mintined on toe-touch weight-bering for the initil 6 weeks nd were then dvnced to prtil weight-bering (23 kg). Physicl therpy for lower extremity strengthening nd git trining ws strted 6 weeks fter surgery. Three months fter surgery, ptients were dvnced to weight-bering s tolerted nd were llowed to return to their ctivities of dily living without restrictions if rdiogrphs nd clinicl exmintion were consistent with heling of the osteotomy. Ech ptient ws exmined nd rdiogrphs obtined t regulr intervls (2, 6, nd 12 weeks nd then bout every 3 months) fter surgery until heling. Bone union ws determined by history nd physicl exmintion with pin-free weightbering without use of ssistive devices nd by return of functionl use of the extremity. Rdiogrphic union ws considered to hve occurred when bridging trbecule were present cross the osteotomy nd there ws no loosening or filure of the implnts. Occsionlly, if there were questions regrding heling, musculoskeletl rdiologist ws consulted. Acceptble tibi lignment ws defined s lignment of less thn 5 vrus or less thn 10 vlgus in the coronl plne nd less thn 15 procurvtum or recurvtum in the sgittl plne. Immedite postopertive rdiogrphs nd most recent rdiogrphs were used to determine the finl mount of ngulr correction. 27 Two ptients subsequently required secondry opertive procedures. One hd vrus collpse through the regenerte, nd the other developed nonunion of the osteotomy site nd required exchnge intrmedullry niling. In ech cse, the finl ssessment ws done fter the ptient hd heled fter the second surgery nd hd fully recovered. Perceived Functionl Assessment The MFA is 100-item self-dministered QOL questionnire designed to ssess self-perception of physicl, psychologicl, nd socil well-being in ptients with musculoskeletl injury or condition. The MFA provides summry score nd seprte score for ech of 10 functionl domins. The lower the score, the better the ptient s perception of function. Vlidted nd published norms re vilble. 20,28-30 Perceived Helth Sttus The Short Form-36 is 36-item multipurpose self-dministered helth survey questionnire. The SF-36, which ssesses overll helth sttus, provides Physicl Component Score (PCS) nd Mentl Component Score (MCS). The higher the score, the better the ptient s perception of function. Vlidted nd published norms re vilble. 31 Git Anlysis Video dt from 6-cmer high-resolution system (Motion Anlysis, Snt Ros, Cliforni) were used to ssess git. A set of 3 reflective surfce mrkers ws plced on ech of 4 res: trunk, thighs, legs, nd feet. 18,19 The ptient wlked brefoot long 9-meter wlkwy, nd video dt were collected during the middle 2 meters. For ech ptient, dt from 4 to 7 trils were collected. Computerized softwre produced dt describing the verged joint ngle s function of the git cycle for ech of the 3 principl plnes of the body. Specific points in the git cycle were nlyzed. Vribles included mximum knee vrus in stnce phse; mximum knee vlgus in swing; mximum knee flexion in stnce nd swing; minimum knee flexion in stnce; mximum nkle inversion in terminl stnce; mximum nkle eversion in stnce; mximum nkle dorsiflexion in stnce nd swing; nd mximum nkle plntrflexion t tkeoff. In ddition to the lower extremity joint kinemtics, ngulr mesurements, bsic git mesurements of step length, stride length, cdence, nd speed were lso recorded. Sttisticl Anlysis Pired t tests were used to determine if significnt chnges occurred s consequence of the surgery for the outcome vribles (P <.05). Normtive git dt were used to ssess the qulity of ny chnges tht occurred in the vribles, but no sttisticl nlysis ws performed to determine significnt differences. 18 Results All 11 ptients hd clinicl nd rdiogrphic evidence of heling nd deformity correction t most recent follow-up. Nine ptients (82%) heled fter the index procedure. Men totl ngulr correction in the coronl plne ws 21 (rnge, 14 vrus to 7 vlgus), nd men totl ngulr correction in the sgittl plne ws 9 (rnge, 21 recurvtum to 15 procurvtum) (Tble 2). For the group, men preopertive MFA score ws 39 (SD, 18; rnge, 10-69), nd men postopertive MFA score ws 28 (SD, 14; rnge, 8-53). Ptients reported the most improvement in 2 domins: In Leisure, men (SD) preopertive score ws 8 (2), nd men postopertive score ws 5 (2); in Emotionl, men preopertive score ws 5 (2), nd men postopertive score ws 4 (1). The other domins were not significntly different between the 2 ssessments. On the SF-36, men (SD) PCS significntly (P <.05) improved from 32 (8) to 43 (9). Men (SD) MCS showed little chnge: preopertive, 46 (16); postopertive, 48 (13). The PCS subctegories tht showed the most improvement were Physicl Function, men (SD) preopertive, 26 (20), to postopertive, 52 (26); Role of Physicl Helth, preopertive, 18 (24), to postopertive, 60 (41); nd Bodily Pin, preopertive, 39 (27), to 58 (18). The results from the preopertive nd postopertive git nlysis showed no significnt differences for the nkle, knee, nd hip vribles during swing phse (Tble 3). In n nlysis of the chnges in joint kinemtics during stnce, mximum hip dduction (incresed) nd mximum knee vrus (decresed) on the opertive side were significntly improved towrd normtive vlues s consequence of the surgery (Tble 3). The December 2014 The Americn Journl of Orthopedics E315

4 Improved Function nd Joint Kinemtics After Correction of Tibil Mllignment Tble 3. Preopertive nd Postopertive Vlues for Joint Git Kinemtics, With Vlues for Persons Without Disbility Presented for Comprison Joint Git Kinemtics Preopertive Postopertive Without Disbility, Men SD Men SD Men Swing Mximum knee flexion Opertive Nonopertive Mximum nkle dorsiflexion Opertive Nonopertive Mximum hip bduction Opertive Nonopertive Mximum knee vlgus Opertive Nonopertive Stnce Mximum knee flexion Opertive Nonopertive Minimum knee flexion Opertive Nonopertive Mximum nkle eversion Opertive Nonopertive Mximum nkle inversion Opertive Nonopertive Mximum nkle dorsiflexion Opertive Nonopertive Mximum nkle plntrflexion Opertive Nonopertive Mximum hip dduction Opertive b 11 Nonopertive Mximum knee vrus Opertive b 2 Nonopertive Stndrd devitions were not supplied to prevent too gret comprison between the tretment group nd the group without disbility. The purpose of the pper ws to compre the chnges within the opertive group. b Significntly different from preopertive (P <.05). other kinemtic stnce vribles were not significntly different. No significnt chnges were observed in stnce time, step length, stride length, cdence, or speed s consequence of the surgery (Tble 4). Discussion Correction of mlligned tibis leds to improved limb lignment nd ptients perceptions of functionl bilities nd helth but hd limited effect on joint kinemtics nd git. In group of like ptients, we used common techniques to relign mlunited tibis nd vlidted instruments to mesure functionl outcome, helth sttus, joint kinemtics, nd git. The gols of this study were to evlute chnges in perceived function nd helth sttus nd chnges in joint kinemtics nd git s result of correction of posttrumtic limb deformity. Other investigtors hve reported outcomes of treting symptomtic mlunions, 32 nonunions, 24 nd leg-length discrepncies. 33 In these reports, correction of deformity improved ptient stisfction nd function, though objective mens of ssessment were infrequently used. Good results were reported with use of dome-shped suprmlleolr osteotomy for the correction of tibil mlunion. 32 In this study, suprmlleolr osteotomy ws performed on 8 ptients for correction of mlunited tibi. Postopertive ssessment included subjective ssessment of pin, limp, ppernce, instbility, nd ctivity. Of these 8 ptients, 7 reported overll symptomtic improvement fter heling, nd the 1 who lost the deformity correction remined symptomtic. Significnt improvement in overll helth hs been reported fter successful tretment of tibi nonunions. 24 The investigtors used the SF-36 to ssess ptients who underwent tretment for tibil nonunion. Anlysis of these ptients results showed significnt improvement in physicl nd mentl functioning fter heling. In ddition, improved git symmetry ws reported in ptients successfully treted for leg-length discrepncies. 33 Unfortuntely, how improvement in git relted to overll ptient function ws not ssessed. In the present study, we used stringent objective nd subjective vlidted instruments to ssess chnges in joint git kinemtics nd functionl outcome before nd fter tretment of tibil mlunion. In generl, our results re consistent with published results nd indicte tht relign- E316 The Americn Journl of Orthopedics December

5 J. Engsberg et l ment of tibil mlunions improves ptients perceptions of function. Our results lso indicte improvements towrd normtive vlues in mximl hip dduction nd knee vrus, thus confirming the efficcy of the surgery from functionl perspective. Unfortuntely, we did not show significnt improvements in the remining joint kinemtics mesurements or temporl git prmeters. It is not entirely cler whether tibil mllignment leds to degenertive chnges of the ipsilterl knee nd/or nkle nd wht role this might ply in functioning. In retrospective nlysis of 92 ptients, ngulr deformity within 15 of norml lignment did not led to nkle rthrosis. 9 Milner nd collegues 4 found tht, though vrus mlunion of the tibi my led to rthrosis of the medil comprtment of the knee, other fctors were more importnt in cusing rthrosis of the nkle. Wu nd collegues 34 used tibil osteotomies in New Zelnd white rbbits to investigte crtilge nd bone chnges of the knee fter cretion of vrus or vlgus tibil deformities. Thirty-four weeks fter osteotomy, rbbits with up to 30 of deformity hd severe crtilge chnges with osteophytes, fibrilltion, derngement of cell columns, nd ssocited incresed subchondrl bone density of the knees. Cdveric studies hve lso shown incresed contct pressures within the knees nd nkles with ever incresing mounts of tibil deformity. 6,10 In ech cdveric study, mllignment in the distl third of the tibi cused the lrgest chnges in the nkle, nd chnges in the lignment in the proximl third cused the lrgest chnges in the knee. Consistent with these niml nd cdveric studies re severl retrospective clinicl studies tht hve correlted tibil mllignment (prticulrly vrus) with development of knee nd nkle rthrosis. 3,5,8 Kettelkmp nd collegues 3 found direct correltion between mgnitude of deformity nd length of time with development of knee rthrosis. These findings hve led mny to recommend tht surgeons try to restore tibil lignment to s ner norml s possible to reduce the likelihood of rthrosis fter tibi frcture. We found significnt improvement towrd normtive vlues for mximum hip dduction (incresed) nd tibil vrus (decresed) fter surgery. These improvements would shift the weight-bering forces bck to the centrl prt of the knee nd therefore more uniformly distribute weight-bering forces. Posttrumtic rthrosis tht develops fter frcture is thought to result from incresed joint pressures nd possibly fctors relted to the injury. Although surgicl correction of tibil lignment is unlikely to reverse these crtilge chnges, it my restore joint pressure symmetry nd offlod compromised comprtments. Offloding of lredy degenertive comprtments my explin our ptients improved perceptions of function nd overll helth sttus. There were severl limittions to our study. First, plin Tble 4. Preopertive nd Postopertive Temporl Vribles for Git, With Vlues for Persons Without Disbility Presented for Comprison Vrible Stnce time, s Preopertive Postopertive Without Disbility, Men SD Men SD Men Opertive side Nonopertive side Step length, cm Opertive side Nonopertive side Stride length, cm Cdence, steps/min Men speed, cm/s Stndrd devitions were not supplied to prevent too gret comprison between the tretment group nd the group without disbility. The purpose of the pper ws to compre the chnges within the opertive group. rdiogrphs of mlligned nd uninjured tibi nd fibul were used, nd these do not llow complete ssessment of the weight-bering ccess of the limb. Our ptients, however, hd isolted tibi frctures, which involved norml limb before injury, so ny ltertions in joint kinemtics, git, or function would likely be the result of the frcture. Another limittion of our study is its nonrndomized design. However, the ptients reflect the typicl heterogeneous trum ptient popultion, who typiclly develop tibil mlunions nd seek correction. Another limittion ws the lck of tretment protocol regrding exct surgicl technique nd implnts used to stbilize the osteotomies. In generl, the ptients were treted similrly, nd their preopertive nd postopertive ssessments were exctly the sme, s ws their stte-of-the-rt joint kinemtics nd git nlysis, combined with the use of previously vlidted outcome mesures. In ddition, the lck of improvement in git could hve resulted from postopertive physicl therpy tht focused on joint mobiliztion nd muscle strengthening nd not on correction of bnorml git prmeters noted on preopertive git nlysis. Despite the potentil limittions of the study, surgicl correction of these symptomtic tibil mlunions resulted in significnt improvement in functionl outcome nd improved joint kinemtics on the opertive side. Conclusion Significnt effort should be mde to restore nd mintin nerntomicl tibil lignment until tibi frcture is heled. In ptients who develop symptomtic tibil mlunion, surgicl correction should be undertken with the intent to restore norml limb lignment nd improve joint kinemtics, function, nd overll helth sttus. Dr. Engsberg is Professor of Occuptionl Therpy, Neurosurgery nd Orthopedics, Wshington University School of Medicine, St. December 2014 The Americn Journl of Orthopedics E317

6 Improved Function nd Joint Kinemtics After Correction of Tibil Mllignment Louis, Missouri. Dr. Leduc is Associte Professor, Hopitl Scré- Coeur de Montrél, Université de Montrél, Montrél, Cnd. Dr. Ricci is Professor, Wshington University School of Medicine, St. Louis, Missouri. Dr. Borrelli is Physicin, Orthopedic Medicine Specilists, Texs Helth Physicins Group, Arlington, Texs. Acknowledgment: The uthors thnk Bethny Gllgher, MD, for ssistnce in the erly development of this investigtion nd in demogrphic dt collection nd colltion. Address correspondence to: Joseph Borrelli, Jr, MD, Orthopedic Medicine Specilists, Texs Helth Physicins Group, 902 W Rndol Mill Rd, Suite 120, Arlington, TX (tel, ; fx, ; e-mil, josephborrelli@texshelth.org). Am J Orthop. 2014;43(12):E313-E318. Copyright Frontline Medicl Communictions Inc All rights reserved. References 1. Probe RA. Lower extremity ngulr mlunion: evlution nd surgicl correction. J Am Acd Orthop Surg. 2003;11(5): vn der Linden W, Lrsson K. Plte fixtion versus conservtive tretment of tibil shft frctures. A rndomized tril. J Bone Joint Surg Am. 1979;61(6): Kettelkmp DB, Hillberry BM, Murrish DE, Heck DA. Degenertive rthritis of the knee secondry to frcture mlunion. Clin Orthop. 1988;(234): Milner SA, Dvis TR, Muir KR, Greenwood DC, Doherty M. Long-term outcome fter tibil shft frcture: is mlunion importnt? J Bone Joint Surg Am. 2002;84(6): Puno RM, Vughn JJ, Stetten ML, Johnson JR. Long-term effects of tibil ngulr mlunion on the knee nd nkle joints. J Orthop Trum. 1991;5(3): Trr RR, Resnick CT, Wgner KS, Srmiento A. Chnges in tibiotlr joint contct res following experimentlly induced tibil ngulr deformities. Clin Orthop. 1985;(199): Ting AJ, Trr RR, Srmiento A, Wgner K, Resnick C. The role of subtlr motion nd nkle contct pressure chnges from ngulr deformities of the tibi. Foot Ankle. 1987;7(5): vn der Schoot DK, Den Outer AJ, Bode PJ, Obermnn WR, vn Vugt AB. Degenertive chnges t the knee nd nkle relted to mlunion of tibil frctures. 15-yer follow-up of 88 ptients. J Bone Joint Surg Br. 1996;78(5): Kristensen KD, Kier T, Blicher J. No rthrosis of the nkle 20 yers fter mlligned tibil-shft frcture. Act Orthop Scnd. 1989;60(2): McKellop HA, Sigholm G, Redfern FC, Doyle B, Srmiento A, Luck JV Sr. The effect of simulted frcture-ngultions of the tibi on crtilge pressures in the knee joint. J Bone Joint Surg Am. 1991;73(9): Merchnt TC, Dietz FR. Long-term follow-up fter frctures of the tibil nd fibulr shfts. J Bone Joint Surg Am. 1989;71(4): Pley D, Herzenberg JE, Tetsworth K, McKie J, Bhve A. Deformity plnning for frontl nd sgittl plne corrective osteotomies. Orthop Clin North Am. 1994;25(3): Perry J. Git Anlysis: Norml nd Pthologicl Function. Thorofre, NJ: Slck; Puno RM, Vughn JJ, von Frunhofer JA, Stetten ML, Johnson JR. A method of determining the ngulr mllignments of the knee nd nkle joints resulting from tibil mlunion. Clin Orthop. 1987;(223): Greenwood DC, Muir KR, Doherty M, Milner SA, Stevens M, Dvis TR. Conservtively mnged tibil shft frctures in Nottinghm, UK: re pin, osteorthritis, nd disbility long-term complictions? J Epidemiol Community Helth. 1997;51(6): Dehne E, Deffer PA, Hll RM, Brown PW, Johnson EV. The nturl history of the frctured tibi. Surg Clin North Am. 1961;41(6): Kitok HB, Schp EJ, Cho EY, An KN. Displced intr-rticulr frctures of the clcneus treted non-opertively. Clinicl results nd nlysis of motion nd ground-rection nd temporl forces. J Bone Joint Surg Am. 1994;76(10): Borrelli J Jr, Goldfrb C, Ricci W, Wgner JM, Engsberg JR. Functionl outcome fter isolted cetbulr frctures. J Orthop Trum. 2002;16(2): Borrelli J Jr, Ricci WM, Anglen JO, Gregush R, Engsberg J. Muscle strength recovery nd its effects on outcome fter open reduction nd internl fixtion of cetbulr frctures. J Orthop Trum. 2006;20(6): Jgll S, Lkhni Z, Schtzker J. Relibility, vlidity, nd responsiveness of the lower extremity mesure for ptients with hip frcture. J Bone Joint Surg Am. 2000;82(7): Mdsen MS, Ritter MA, Morris HH, et l. The effect of totl hip rthroplsty surgicl pproch on git. J Orthop Res. 2004;22(1): Mittlmeier T, Morlock MM, Hertlein H, et l. Anlysis of morphology nd git function fter intrrticulr clcnel frcture. J Orthop Trum. 1993;7(4): Song KM, Hllidy SE, Little DG. The effect of limb-length discrepncy on git. J Bone Joint Surg Am. 1997;79(11): Zlowodzki M, Obremskey WT, Thomison JB, Kregor PJ. Functionl outcome fter tretment of lower-extremity nonunions. J Trum. 2005;58(2): Snders R, Anglen JO, Mrk JB. Oblique osteotomy for the correction of tibil mlunion. J Bone Joint Surg Am. 1995;77(2): Sngeorzn BJ, Sngeorzn BP, Hnsen ST Jr, Judd RP. Mthemticlly directed single-cut osteotomy for correction of tibil mlunion. J Orthop Trum. 1989;3(4): Borrelli J Jr, Leduc S, Gregush R, Ricci WM. Tricorticl bone grfts for tretment of mlligned tibis nd fibuls. Clin Orthop. 2009;467(4): Engelberg R, Mrtin DP, Agel J, Obremsky W, Corondo G, Swiontkowski MF. Musculoskeletl Function Assessment instrument: criterion nd construct vlidity. J Orthop Res. 1996;14(2): Engelberg R, Mrtin DP, Agel J, Swiontkowski MF. Musculoskeletl Function Assessment: reference vlues for ptient nd non-ptient smples. J Orthop Res. 1999;17(1): Swiontkowski MF, Engelberg R, Mrtin DP, Agel J. Short Musculoskeletl Function Assessment questionnire: vlidity, relibility, nd responsiveness. J Bone Joint Surg Am. 1999;81(9): Wre JE Jr, Sherbourne CD. The MOS 36-item short-form helth survey (SF-36). I. Conceptul frmework nd item selection. Med Cre. 1992;30(6): Grehl PM, Hersh MR, Heckmn JD. Suprmlleolr osteotomy for the tretment of symptomtic tibil mlunion. J Orthop Trum. 1987;1(4): Bhve A, Pley D, Herzenberg JE. Improvement in git prmeters fter lengthening for the tretment of limb-length discrepncy. J Bone Joint Surg Am. 1999;81(4): Wu DD, Burr DB, Boyd RD, Rdin EL. Bone nd crtilge chnges following experimentl vrus or vlgus tibil ngultion. J Orthop Res. 1990;8(4): E318 The Americn Journl of Orthopedics December