Legg-Calvé-Perthes Disease: A Review of Cases with Onset Before Six Years of Age

Transcription

1 This is an enhance PF from The Journal of Bone an Joint Surgery The PF of the article you requeste follows this cover page. Legg-Calvé-Perthes isease: A Review of Cases with Onset Before Six Years of Age Scott B. Rosenfel, John A. Herring an John C. Chao J Bone Joint Surg Am. 2007;89: oi: /jbjs.g This information is current as of January 17, 2008 Reprints an Permissions Publisher Information Click here to orer reprints or request permission to use material from this article, or locate the article citation on jbjs.org an click on the [Reprints an Permissions] link. The Journal of Bone an Joint Surgery 20 Pickering Street, Neeham, MA

2 2712 COPYRIGHT Ó 2007 BY THE JOURNAL OF BONE AN JOINT SURGERY, INCORPORATE Legg-Calvé-Perthes isease: A Review of Cases with Onset Before Six Years of Age By Scott B. Rosenfel, M, John A. Herring, M, an John C. Chao, BA Investigation performe at the Texas Scottish Rite Hospital for Chilren, allas, Texas Backgroun: The prognosis for chilren in whom Legg-Calvé-Perthes isease evelops before the age of six years was initially reporte to be goo, but later stuies emonstrate a less favorable prognosis. To assess the natural history of this conition in this age group, we reviewe a large cohort of chilren who ha receive minimal treatment for the isease. Methos: The meical recors an raiographs of all chilren with Legg-Calvé-Perthes isease seen at our institution between 1944 an 2000 were reviewe. The cases of 172 patients with a total of 188 affecte hips were stuie. The course of the isease an the final clinical an raiographic outcomes were evaluate in all patients. Results: Typical Legg-Calvé-Perthes isease was note in 164 hips of 160 patients. Accoring to the lateral patellar classification, seven of these hips were in group A; 101, in group B; twenty-seven, in the B/C borer group; an twenty-nine, in group C. Accoring to the Stulberg classification, there were 131 Class-I or II (goo) results, fourteen Class-III (fair) results, an nineteen Class-IV (poor) results. The lateral pillar classification was highly correlate with the outcome, whereas treatment i not correlate with the outcome. Only lateral pillar group-b/c borer an C hips with an onset of the isease between the ages of four years an five years an eleven months ha a poor prognosis. We unexpectely encountere a group of twelve patients with bilateral, simultaneous evelopment of apparent Legg-Calvé-Perthes isease. In that group, there were twenty-one Stulberg Class-I or II (goo), three Stulberg Class-III (fair), an no Stulberg Class-IV (poor) results, although fourteen of the twenty-four hips were in lateral pillar group C. The outcome in the hips in lateral pillar group C was significantly better when the patient ha bilateral simultaneous involvement than when the patient ha typical Legg-Calvé-Perthes isease. Conclusions: The prognosis for patients with the onset of Legg-Calvé-Perthes isease before the age of six years is favorable, with 80% having a goo result. Only chilren between the ages of four years an five years an eleven months with a B/C or C lateral pillar classification of involvement have a less favorable prognosis. Treatment was not foun to influence outcome. Simultaneous bilateral isease, which ha a more favorable prognosis, may represent a unique isorer. Level of Evience: Therapeutic Level III. See Instructions to Authors for a complete escription of levels of evience. In the past, Legg-Calvé-Perthes isease with an onset before the age of six years was often thought to be a benign conition requiring little treatment 1-4. More recent stuies have shown that poor results can occur in this age group, but the prevalence of these more severe cases has not been etermine The prognosis an inications for treatment of patients with Legg-Calvé-Perthes isease have recently been more clearly elineate with use of patient age an the severity of femoral hea involvement as guielines 11. The lateral pillar classification, use to estimate femoral hea involvement, has been shown to correlate strongly with prognosis in chilren with the onset of Legg-Calvé-Perthes isease after the age of six years, an the system has goo interrater reliability A few investigators have attempte to correlate the extent of femoral hea involvement with the outcome in younger patients 6,18. In a stuy of thirty-six hips in patients in whom the isclosure: The authors i not receive any outsie funing or grants in support of their research for or preparation of this work. Neither they nor a member of their immeiate families receive payments or other benefits or a commitment or agreement to provie such benefits from a commercial entity. No commercial entity pai or irecte, or agree to pay or irect, any benefits to any research fun, founation, ivision, center, clinical practice, or other charitable or nonprofit organization with which the authors, or a member of their immeiate families, are affiliate or associate. J Bone Joint Surg Am. 2007;89: oi: /jbjs.g.00191

3 2713 L EGG-CALVÉ-PERTHES ISEASE:AREVIEW OF C ASES Fig. 1-A Figs. 1-A through 1-E A boy with the onset of Legg-Calvé-Perthes isease at the age of four years. Fig. 1-A Anteroposterior raiograph mae at the age of four years. There is increase ensity of the left femoral hea an narrowing of the lateral pillar. The femoral hea has yet to reach the fragmentation stage for efinitive classification. isease ha evelope before the age of five years, Fabry et al. reporte an association between the lateral pillar classification an outcome in that 78% of group-c hips ha a poor outcome 18. Their meta-analysis of the literature showe that results are quite mixe with regar to any correlation between age an outcome but that the extent of hea involvement was of prognostic importance. Many of the stuies of younger chilren with Legg- Calvé-Perthes isease have inclue a small number of patients, an the reporte results have been variable. Since 1944, Fig. 1-B Anteroposterior raiograph mae at the age of five years an two months. There is now loss of the lateral pillar with lucency of the femoral hea, a lateral pillar classification of C.

4 2714 L EGG-CALVÉ-PERTHES ISEASE:AREVIEW OF C ASES Fig. 1-C Anteroposterior raiograph mae at the age of seven years an seven months. The femoral hea is in the reossification stage. more than 300 patients with the onset of Legg-Calvé-Perthes isease prior to the age of six years have been treate at the Texas Scottish Rite Hospital. This stuy was performe to etermine the outcome in an untreate or minimally treate group of patients in whom Legg-Calvé-Perthes isease evelope before the age of six years an to etermine if the lateral pillar classification is preictive of outcome in this younger patient population. Materials an Methos A search of the Texas Scottish Rite Hospital atabase ientifie 373 patients who ha been iagnose, between Fig. 1- Anteroposterior raiograph mae at the age of fifteen years an two months. The femoral hea is fully reossifie, an the physis is close. The hea is ovoi, an the acetabulum is oblique.

5 2715 L EGG-CALVÉ-PERTHES ISEASE:AREVIEW OF C ASES Fig. 1-E Frog-leg lateral raiograph mae at the age of fifteen years an two months, showing an ovoi femoral hea. This is a Stulberg Class-III result an 2000, with Legg-Calvé-Perthes isease prior to the age of six years, an the meical charts an raiographs of those patients were reviewe. Criteria for inclusion were a iagnosis of Legg-Calvé- Perthes isease prior to the age of six years, aequate raiographs incluing initial raiographs mae when the isease was in the fragmentation stage or earlier, an later raiographs showing complete healing of the femoral hea. When available, raiographs of other joints were reviewe to exclue chilren with evience of multiple epiphyseal ysplasia. Patients with bilateral Legg-Calvé-Perthes isease who were inclue in this stuy ha the onset of the isease in both hips prior to the age of six years. If the onset in the contralateral hip occurre after the age of six, only the first hip was inclue. Each hip was evaluate separately. Each patient s raiographs were reviewe throughout the course of treatment. ata recore inclue the sie that was affecte, the lateral pillar classification, the Stulberg classification at the time of healing, an whether the triraiate cartilage was close on the final raiograph. All raiographs were reviewe by the two senior authors (S.B.R. an J.A.H.), an the lateral pillar classification was etermine from raiographs mae when the isease was in the fragmentation stage with use of the criteria escribe by Herring et al. 19. The Stulberg classification was etermine from the raiographs at the time of final follow-up, after the femoral hea ha completely heale, also with use of the criteria of Herring et al. 19. Stulberg Class-I an II results were consiere goo; Stulberg Class-III, fair; an Stulberg Class-IV, poor. Because the practice at our institution in the early years of this stuy was to ischarge an asymptomatic patient with a heale, roun femoral hea, many of the patients ha not reache skeletal maturity at the time of final follow-up. Previous stuies have shown that an immature, roun femoral hea will remain roun an that flat an ovoi femoral heas often remoel to become rouner as the patient approaches skeletal maturity 6. Therefore, patients with an open triraiate cartilage an a completely heale femoral hea seen on the final raiograph were inclue in this stuy (Figs. 1-A through 1-E), although we realize that this may skew our results towar being worse than those that woul be seen in a stuy of skeletally mature hips. When a patient ha bilateral Legg-Calvé-Perthes isease, we compare the two hips to etermine if the onset of the isease ha been concurrent or sequential (Figs. 2-A through 2-E). If the onset ha been concurrent, we compare the isease progression of the two hips. Raiographs of other joints, incluing the spine, knee, ankle, wrist, an shouler, were mae for the patients with bilateral involvement to exclue a iagnosis of epiphyseal ysplasia. Meical recors of each patient were reviewe to obtain clinical ata, incluing gener, age at iagnosis, treatment, symptoms at the time of final follow-up, an age at the time of final follow-up.

6 2716 L EGG-CALVÉ-PERTHES ISEASE:AREVIEW OF C ASES The final stuy group inclue 172 patients (152 boys an twenty girls) with 188 affecte hips. Two hunre an one patients were exclue from the stuy. Ninety-seven were exclue because meical recors coul not be locate; sixtythree, because of inaequate raiographs; thirty-one, because the femoral hea was not seen to be fully reossifie on the final raiograph; six, because the earliest raiographs ha been mae when the isease was past the fragmentation stage; three, because the femoral hea involvement was too slight for it to be classifie as Legg-Calvé-Perthes isease; an one, because raiographs of other joints reveale multiple joint abnormalities. Fifty-four patients (31%) were treate with a brace or cast. An Atlanta brace was use for twenty-six patients; a Craig splint, for ten; an A-frame brace, for four; an unspecifie abuction brace, for six; an a Petrie cast, for eight. Seven hips treate with a Petrie cast also ha an auctor tenotomy, an three of them also ha an iliopsoas tenotomy at the time of cast application. One hunre an fourteen patients (66%) were observe or ha treatment of symptoms only. Charts coul not be locate for four patients. The Fisher exact test was use to compare rates, an multiple logistic regression methos were use to preict the TABLE I Outcome Relate to Lateral Pillar Group for All Hips* Pillar Group Goo Outcome (Stulberg Class I or II) Fair Outcome (Stulberg Class III) Poor Outcome (Stulberg Class IV) Total A or B B/C borer C Total *The values are given as the number of hips. probability of a particular outcome. Significance was efine as a p value of <0.05. Results The entire group inclue 188 hips iagnose in 172 patients before they were six years ol. The average age at the onset of the Legg-Calvé-Perthes isease was 4.6 years (range, 2.0 to 5.9 years). On the final raiograph, eighty-six Fig. 2-A Figs. 2-A through 2-E A chil with the bilateral onset of Legg-Calvé-Perthes isease at the age of five years an four months. Fig. 2-A Initial raiograph showing that both femoral heas are in the early stage of Legg-Calvé- Perthes isease. Both hips show a metaphyseal reaction. The right hip has increase ensity in the portion of the femoral hea next to the physis.

7 2717 L EGG-CALVÉ-PERTHES ISEASE:AREVIEW OF C ASES patients were seen to have an open triraiate cartilage an eighty-six ha a close triraiate cartilage. Accoring to the lateral pillar system, seven hips (4%) were in group A, 108 (57%) were in group B, thirty (16%) were in the B/C borer group, an forty-three (23%) were in group C. Since there were so few group-a hips an all ha a goo outcome, they were inclue with the group-b hips (for a total of 115 group-a or B hips [61%]) for statistical analysis (Table I). There were 156 patients with unilateral isease an sixteen with bilateral isease. One hunre an fifty-two results (81%) were goo (Stulberg Class I or II), seventeen (9%) were fair (Stulberg Class III), an nineteen (10%) were poor (Stulberg Class IV). There was a significant correlation between the lateral pillar classification an the outcome (p < 0.001). The 172 patients were ivie into two groups on the basis of the raiographic appearance an progression of the isease. The first group consiste of patients with unilateral or bilateral Legg-Calvé-Perthes isease with typical characteristics. The secon group comprise those with concurrent onset an progression of bilateral Legg-Calvé-Perthes isease. Typical Legg-Calvé-Perthes isease (Group I) This group consiste of 160 patients with 164 affecte hips. Accoring to the lateral pillar classification, there were seven group-a hips (4%), 101 group-b hips (62%), twenty-seven TABLE II Outcome Relate to Lateral Pillar Group for All Hips Except the Concurrent Bilateral Cases* Pillar Group Goo Outcome (Stulberg Class I or II) Fair Outcome (Stulberg Class III) Poor Outcome (Stulberg Class IV) Total A or B B/C borer C Total *The values are given as the number of hips. group-b/c-borer hips (16%), an twenty-nine group-c hips (18%) (Table II). One hunre an thirty-one results (80%) were goo (Stulberg Class I or II), fourteen (9%) were fair (Stulberg Class III), an nineteen (12%) were poor (Stulberg Class IV). The Fisher exact test showe a significant correlation between the lateral pillar classification an the final outcome (p < 0.001). When the patients were ivie into two groups accoring to their age at onset (newborn to three years an eleven months or four years to five years an eleven months), the Fig. 2-B Initial frog-leg lateral raiograph showing the femoral hea to have a crescent sign of a subchonral fracture. Both hips show a metaphyseal reaction.

8 2718 L EGG-CALVÉ-PERTHES ISEASE:AREVIEW OF C ASES combination of the younger age group an a lateral pillar group-a or B classification was foun to be significantly correlate with a better outcome (p = 0.002) with use of logistic regression methos. The resulting logistic regression moel correctly classifie the hips in terms of outcome 83.7% of the time an also estimate the probability of a goo outcome as shown in Table III. A logistic regression moel was use to etermine whether treatment (bracing with or without auctor tenotomy) affecte the Stulberg outcome (goo, fair, or poor) after ajustment for the lateral pillar classification (A or B, B/C, or C). The lateral pillar classification significantly affecte outcome (p < ), but brace treatment i not regarless of the lateral pillar classification (p = 0.75) (Table IV). We also coul not ientify a correlation between gener an outcome. Bilateral Legg-Calvé-Perthes isease with Concurrent Onset an Progression (Group II) Twelve patients were iagnose with bilateral Legg-Calvé- Perthes isease with a concurrent onset prior to the age of six years. Each patient ha also ha concurrent bilateral progression through the stages of fragmentation an reossification. Ten of these twelve patients ha raiographs of the spine an other joints, which i not reveal any abnormalities. Of the twenty-four hips, none were in group A, accoring to the lateral pillar classification, seven were in group B, three were in the B/C borer group, an fourteen were in group C. Final ra- TABLE III Probability of a Goo Outcome (Stulberg Class I or II) Relative to Lateral Pillar Group an Age Group Age (yr 1 mo) Lateral Pillar Group Probability 0to31 11 A or B to51 11 A or B to B/C borer or C to51 11 B/C borer or C 0.43 iographs reveale twenty-one goo results (Stulberg class I or II), three fair results (Stulberg Class III), an no poor results (Stulberg Class IV). All three fair results occurre in group-c hips. With the numbers stuie, we coul not ientify a correlation between the lateral pillar classification an outcome. Comparison of Groups I an II Ten of the twenty-nine lateral pillar group-c hips in the group with typical Legg-Calvé-Perthes isease (Group I) an none of the fourteen group-c hips in the group with concurrent bilateral isease (Group II) ha a poor outcome. This ifference was significant (p = 0.038). Typical Features of Group II There were raiographic changes that coul be interprete as inicating Meyer ysplasia in two patients (four hips) in Group Fig. 2-C Initial abuction, internal rotation raiograph showing a istinct metaphyseal cyst on the right.

9 2719 L EGG-CALVÉ-PERTHES ISEASE:AREVIEW OF C ASES TABLE IV Outcome Accoring to Lateral Pillar Group an Whether Bracing Was Use* Bracing Stulberg Class I Stulberg Class II Stulberg Class III Stulberg Class IV Lateral pillar A Lateral pillar B 2 (7%) 25 (89%) 1 (4%) 0 Lateral pillar B/C borer 0 8 (57%) 2 (14%) 4 (29%) Lateral pillar C 0 8 (57%) 2 (14%) 4 (29%) No bracing Lateral pillar A 3 (43%) 4 (57%) 0 0 Lateral pillar B 3 (4%) 65 (89%) 4 (5%) 1 (1%) Lateral pillar B/C borer 0 7 (54%) 2 (15%) 4 (31%) Lateral pillar C 0 8 (53%) 1 (7%) 6 (40%) *The values are given as the number of hips with the percentage in parentheses. There was no significant ifference in outcomes between the group treate with an the group treate without bracing. II. In six patients (twelve hips), there was a istinct increase ensity phase not seen in Meyer ysplasia (Figs. 2-A through 2-E). Two patients (four hips) ha metaphyseal changes, an another two ha raiographic changes in the femoral hea that i not resemble those of Meyer ysplasia. iscussion No strong conclusions can be rawn from the stuies publishe to ate regaring the treatment an outcomes of Legg-Calvé-Perthes isease in patients with an onset prior to the age of six years 5-8,10,18. Small sample sizes an variable results Fig. 2- Raiograph mae at the age of six years an six months. Both femoral heas are in the reossification stage. There is bilateral metaphyseal wiening.

10 2720 L EGG-CALVÉ-PERTHES ISEASE:AREVIEW OF C ASES Fig. 2-E Raiograph mae at the age of twelve years an eight months. Both femoral heas are fully reossifie an are roun. There is a mil loss of height of the femoral heas. have mae interpretation of these ata ifficult, an to our knowlege there has been no large multicenter prospective stuy of this age group. With use of the large atabase of young patients with Legg-Calvé-Perthes isease at our institution, we attempte to answer three questions. First, o patients who have the onset of Legg-Calvé-Perthes isease prior to the age of six years have goo outcomes? Secon, is the lateral pillar classification preictive of outcome in this younger population? Thir, oes treatment affect the outcome in this group of patients? Fabry et al. performe a meta-analysis of the literature in an attempt to support or refute the belief that a young age is preictive of a goo outcome 18. They conclue that the reporte results were too variable to support any correlation between a young age an a goo outcome. Furthermore, their own stuy of thirty-six patients who ha ha the onset of Legg- Calvé-Perthes isease prior to the age of five years suggeste that the extent of femoral hea involvement was of greater prognostic importance than age. One-thir of the patients in their series ha a poor result. Of nineteen hips that were classifie as being in lateral pillar group C, only four ha a goo result an nine ha a poor result. Fabry et al. conclue that, as evience by the high percentage of hips in lateral pillar group C, patients iagnose prior to the age of five years were not protecte from severe femoral hea involvement an that greater involvement was preictive of a poor outcome. Schoenecker et al. reporte similar results in their review of the cases of 109 young patients; they conclue that the egree of femoral hea involvement was the single most important variable preicting outcome 6. Similar conclusions can be rawn from the results of the present stuy. The results for the entire group of patients were very goo, with 81% having a goo outcome an only 10% having a poor outcome. Further analysis showe that, among these younger chilren, age was not a significant inepenent variable. We foun that the severity of femoral hea involvement, as assesse with the lateral pillar classification, ha a stronger inepenent correlation with outcome than i the age at the time of the isease onset. While 95% of the lateral pillar group-a an B hips ha a goo outcome, only 58% of the lateral pillar group-c hips ha a goo outcome in this earlyonset population (p < 0.001). Excluing the bilateral cases with simultaneous onset, 48% of the group-c hips ha a goo result. Furthermore, we foun that the combination of age an the lateral pillar classification was an even stronger preictor of outcome. Patients iagnose with a lateral pillar group-a or B hip when they were between the ages of zero an three years an eleven months ha a 99% probability of having a goo outcome, whereas those iagnose with a lateral pillar group-b/c or C hip when they were between the ages of four

11 2721 L EGG-CALVÉ-PERTHES ISEASE:AREVIEW OF C ASES years an six years an eleven months ha only a 43% probability of having a goo outcome. While analyzing the raiographs, we note that there was a istinct group of patients whose isease pattern an progression i not fit that of typical Legg-Calvé-Perthes isease. Initially, we ientifie thirteen patients who ha bilateral Legg-Calvé-Perthes isease with concurrent onset an simultaneous progression through the raiographic stages. Typically, in patients with bilateral Legg-Calvé-Perthes isease, the onset of isease in the two hips occurs at ifferent ages an there is asymmetric progression. Analysis of raiographs of the spine an other joints reveale only one patient who ha features consistent with multiple epiphyseal ysplasia, an this patient was then exclue from the stuy. The remaining twelve patients ha normal finings on raiographs of the spine an the other extremities an ha no other isorers. Fourteen of these twenty-four hips were classifie as being in lateral pillar group C, an many woul have been expecte to have a poor raiographic outcome 5,10. However, none ha a poor result, an twenty-one (88%) of the twenty-four hips ha a goo result. Since these results were much better than expecte, one may question the iagnosis of Legg-Calvé- Perthes isease in those patients. All patients who ha raiographs of the spine or other joints showe none of the features of an epiphyseal ysplasia. As escribe by Meyer in 1964, ysplasia epiphysealis capitis femoris is characterize as a elaye appearance of bilateral capital femoral epiphyseal ossification 20. Once the nucleus oes appear, the epiphysis is fragmente but then it emonstrates constant improvement to the en point of a normal, roun femoral hea, an increase ensity is never seen on raiographs. This isorer is also characterize by a normal femoral neck without metaphyseal reaction or wiening, an there is never flattening of the femoral hea. As escribe by Rowe et al., the average age of onset of Meyer ysplasia (2.5 years) is earlier than that of Legg- Calvé-Perthes isease 21. Taking these factors into consieration, we o not believe that these twelve patients shoul be classifie as having Meyer ysplasia. Our theory is that this group with atypical Legg-Calvé-Perthes isease may have ha an as yet unescribe isorer of the femoral hea, which will require further stuy. The thir question that we hope to answer with this stuy was whether treatment affecte the outcome in this young population. In a multicenter prospective stuy, Herring et al. emonstrate that patients who are over eight years of age at the time of the onset of Legg-Calvé-Perthes isease an have a lateral pillar classification of B or B/C have a better outcome with surgical treatment than they o with nonoperative treatment 11. These authors note that nonoperative treatments such as bracing or casts ha no influence on outcomes. Since the preominant approach to treatment for the patients in our stuy was observation an treatment of symptoms, all were treate essentially nonoperatively. Those that i receive some form of treatment unerwent one of several forms of abuction bracing. The Craig brace, use in the early years, is an abuction bar attache to the shoes with which the patient can flex the knees an auct the hip an hyperabuct the unaffecte hip. Of the 172 patients stuie, fifty-four were treate with bracing or splinting. Of these, seven ha an auctor an/or iliopsoas tenotomy prior to bracing. One hunre an fourteen patients ha only observation or treatment of symptoms. We coul not etect a significant effect of bracing on outcome, regarless of the lateral pillar classification, compare with the outcomes in the untreate hips. We foun that hips in lateral pillar groups B/C an C ha a higher risk of a poor outcome. We cannot comment on the use of surgical containment of the femoral hea for these lateral pillar groups since none of the hips in our series were treate surgically. On the basis of the very goo results in this age group with lateral pillar group-a or B hips, it seems that more aggressive treatment is not inicate for these hips. In conclusion, most patients with the onset of Legg- Calvé-Perthes isease before the age of six years have a goo result. The lateral pillar classification is a strong preictor of outcome in this group of patients, an only those with a lateral pillar group-b/c borer or C hip are at risk for a poor outcome. The age at onset is not an inepenent preictor of outcome in this group of younger patients. However, the combination of the age of onset an the lateral pillar classification is strongly correlate with outcome. n Scott B. Rosenfel, M John C. Chao, BA epartment of Orthopeic Surgery, The University of Texas Southwestern Meical Center, 5323 Harry Hines Boulevar, allas, TX John A. Herring, M Texas Scottish Rite Hospital for Chilren, 2222 Welborn Street, allas, TX aress: tony.herring@tsrh.org References 1. Salter RB, Thompson GH. Legg-Calvé-Perthes isease. The prognostic significance of the subchonral fracture an a two-group classification of the femoral hea involvement. J Bone Joint Surg Am. 1984;66: Ratliff AH. Perthes isease. A stuy of thirty-four hips observe for thirty years. J Bone Joint Surg Br. 1967;49: O Hara JP, avis N, Gage JR, Sunberg AB, Winter RB. Long-term followup of Perthes isease treate nonoperatively. Clin Orthop Relat Res. 1977;125: Ippolito E, Tuisco C, Farsetti P. The long-term prognosis of unilateral Perthes isease. J Bone Joint Surg Br. 1987;69: Snyer CR. Legg-Perthes isease in the young hip oes it necessarily o well? J Bone Joint Surg Am. 1975;57: Schoenecker PL, Stone JW, Capelli AM. Legg-Perthes isease in chilren uner 6 years ol. Orthop Rev. 1993;22: Ismail AM, Macnicol MF. Prognosis in Perthes isease: a comparison of raiological preictors. J Bone Joint Surg Br. 1998;80:310-4.

12 2722 L EGG-CALVÉ-PERTHES ISEASE:AREVIEW OF C ASES 8. Kelly FB Jr, Canale ST, Jones RR. Legg-Calvé-Perthes isease. Long-term evaluation of non-containment treatment. J Bone Joint Surg Am. 1980;62: ekelver L, Fabry G. Legg-Calve-Perthes follow-up stuy. Arch Orthop Trauma Surg. 1982;100: Mukherjee A, Fabry G. Evaluation of the prognostic inices in Legg-Calve- Perthes isease: statistical analysis of 116 hips. J Peiatr Orthop. 1990;10: Herring JA, Kim HT, Browne R. Legg-Calvé-Perthes isease. Part II: prospective multicenter stuy of the effect of treatment on outcome. J Bone Joint Surg Am. 2004;86: Pietrzak S, Napiontek M, Tomaszewski M. [Inter-observer variation of the Caterall an Herring classification in Perthes isease]. Chir Narzaow Ruchu Ortop Pol. 2000;65:33-8. Polish. 13. Poeszwa A, Stanitski CL, Stanitski F, Woo R, Menelow MJ. The effect of peiatric orthopaeic experience on interobserver an intraobserver reliability of the Herring lateral pillar classification of Perthes isease. J Peiatr Orthop. 2000;20: Specchiulli F, Cofano RE. Long-term follow-up of Perthes isease in aolescence. Chir Organi Mov. 2001;86: Ritterbusch JF, Shantharam SS, Gelinas C. Comparison of lateral pillar classification an Catterall classification of Legg-Calvé-Perthes isease. J Peiatr Orthop. 1993;13: Grzegorzewski A, Bowen JR, Guille JT, Glutting J. Treatment of the collapse femoral hea by containment in Legg-Calvé-Perthes isease. J Peiatr Orthop. 2003;23: Specchiulli F, Scialpi L. Catterall versus Herring classification in Perthes isease. Chir Organi Mov. 1997;82: Fabry K, Fabry G, Moens P. Legg-Calvé-Perthes isease in patients uner 5 years of age oes not always result in a goo outcome. Personal experience an meta-analysis of the literature. J Peiatr Orthop B. 2003;12: Herring JA, Kim HT, Browne R. Legg-Calvé-Perthes isease. Part I: classification of raiographs with use of the moifie lateral pillar an Stulberg classifications. J Bone Joint Surg Am. 2004;86: Meyer J. ysplasia epiphysealis capitis femoris. A clinical-raiological synrome an its relationship to Legg-Calvé-Perthes isease. Acta Orthop Scan. 1964;34: Rowe SM, Chung JY, Moon ES, Yoon TR, Jung ST, Kim SS. ysplasia epiphysealis capitis femoris: Meyer ysplasia. J Peiatr Orthop. 2005; 25:18-21.