John A. Herring

The Lateral pillar classification of Legg-Calve-Perthes disease

To determine the predictive value of a new classification system for Legg-Perthes, 93 hips in 86 patients with radiographic follow-up to maturity were reviewed. All patients were treated by bracing at the Texas Scottish Rite Hospital from 1970 to 1980. Hips were classified during the fragmentation stage of disease into three groups based on radiolucency in the lateral pillar of the femoral head. Final radiographs were reviewed at skeletal maturity, and the outcome was determined according to the Stulberg classification. Group A had a uniformly good outcome (100% Stulberg I and II results); Group B had a good outcome in patients who were <9 years at onset (92% Stulberg I and II, 8% Stulberg III results), but a less favorable outcome in patients who were >9 years at onset (30% Stulberg II, 50% Stulberg III, and 20% Stulberg IV results). In Group C, the majority of femoral heads became aspherical in both age groups (29% Stulberg II, 52% Stulberg III, and 19% Stulberg IV results). The group C hips also had a longer duration of fragmentation and reossification stages. Members of the Legg-Perthes study group agreed 78% of the time when applying the classification to unknown radiographs. The classification group was a stronger determinant than age of onset in predicting final outcome. This classification system is easy to apply during the active stage of the disease and has a high correlation in predicting the amount of flattening of the femoral head at skeletal maturity. When combined with age at onset, it can be used to predict the natural history of the disease and evaluate various forms of treatment.

Legg-Calvé-Perthes disease.

Background: The treatment of Legg-Calve-Perthes disease has been based on uncontrolled retrospective studies with relatively small numbers of patients. This large, controlled, prospective, multicenter study was designed to determine the effect of treatment and other risk factors on the outcome in patients with this disorder. Methods: We enrolled 438 patients with 451 affected hips in a prospective multicenter study in which each investigator applied the same treatment method to each of his or her patients[*][1]. The five treatment groups consisted of no treatment, brace treatment, range-of-motion exercises, femoral osteotomy, and innominate osteotomy. All patients were between 6.0 and 12.0 years of age at the onset of the disease, and none had had prior treatment. Three hundred and forty-five hips in 337 patients were available for follow-up at skeletal maturity. All hips were classified with the modified lateral pillar classification and the system of Stulberg et al. Results: There were no differences in outcome among the hips with no treatment, those treated with bracing, and those treated with range-of-motion therapy. There were also no differences between the hips treated with a femoral varus osteotomy and those treated with an innominate osteotomy. Treatment did not have a significant effect on children who had a chronologic age of 8.0 years or less or a skeletal age of 6.0 years or less at the onset of the disease. In the lateral pillar B group and B/C border group, the outcomes of surgical treatment were significantly better than those of nonoperative treatment in children over the age of 8.0 years at the onset of the disease (p ≤ 0.05). Patients who were 8.0 years old or less at the onset of the disease in lateral pillar group B did equally well with nonoperative and operative treatment. Hips in lateral pillar group C had the least favorable outcomes, with no differences between the operative and nonoperative groups. The lateral pillar classification (p < 0.0001) and the age at the onset of the disease (p = 0.0001) were both strong prognostic factors. Female patients did significantly worse than male patients if they were over the age of 8.0 years at the onset of the disease (p = 0.004). Conclusions: The lateral pillar classification and age at the time of onset of the disease strongly correlate with outcome in patients with Legg-Calve-Perthes disease. Patients who are over the age of 8.0 years at the time of onset and have a hip in the lateral pillar B group or B/C border group have a better outcome with surgical treatment than they do with nonoperative treatment. Group-B hips in children who are less than 8.0 years of age at the time of onset have very favorable outcomes unrelated to treatment, whereas group-C hips in children of all ages frequently have poor outcomes, which also appear to be unrelated to treatment. Level of Evidence: Therapeutic study, Level II-1 (prospective cohort study). See Instructions to Authors for a complete description of levels of evidence. [1]: #fn-1

Legg-Calve-Perthes disease. Part II: Prospective multicenter study of the effect of treatment on outcome.

BACKGROUND The treatment of Legg-Calve-Perthes disease has been based on uncontrolled retrospective studies with relatively small numbers of patients. This large, controlled, prospective, multicenter study was designed to determine the effect of treatment and other risk factors on the outcome in patients with this disorder. METHODS We enrolled 438 patients with 451 affected hips in a prospective multicenter study in which each investigator applied the same treatment method to each of his or her patients. The five treatment groups consisted of no treatment, brace treatment, range-of-motion exercises, femoral osteotomy, and innominate osteotomy. All patients were between 6.0 and 12.0 years of age at the onset of the disease, and none had had prior treatment. Three hundred and forty-five hips in 337 patients were available for follow-up at skeletal maturity. All hips were classified with the modified lateral pillar classification and the system of Stulberg et al. RESULTS There were no differences in outcome among the hips with no treatment, those treated with bracing, and those treated with range-of-motion therapy. There were also no differences between the hips treated with a femoral varus osteotomy and those treated with an innominate osteotomy. Treatment did not have a significant effect on children who had a chronologic age of 8.0 years or less or a skeletal age of 6.0 years or less at the onset of the disease. In the lateral pillar B group and B/C border group, the outcomes of surgical treatment were significantly better than those of nonoperative treatment in children over the age of 8.0 years at the onset of the disease (p < or = 0.05). Patients who were 8.0 years old or less at the onset of the disease in lateral pillar group B did equally well with nonoperative and operative treatment. Hips in lateral pillar group C had the least favorable outcomes, with no differences between the operative and nonoperative groups. The lateral pillar classification (p < 0.0001) and the age at the onset of the disease (p = 0.0001) were both strong prognostic factors. Female patients did significantly worse than male patients if they were over the age of 8.0 years at the onset of the disease (p = 0.004). CONCLUSIONS The lateral pillar classification and age at the time of onset of the disease strongly correlate with outcome in patients with Legg-Calve-Perthes disease. Patients who are over the age of 8.0 years at the time of onset and have a hip in the lateral pillar B group or B/C border group have a better outcome with surgical treatment than they do with nonoperative treatment. Group-B hips in children who are less than 8.0 years of age at the time of onset have very favorable outcomes unrelated to treatment, whereas group-C hips in children of all ages frequently have poor outcomes, which also appear to be unrelated to treatment.

Legg-Calve-Perthes disease. Part I: Classification of radiographs with use of the modified lateral pillar and Stulberg classifications.

BACKGROUND Accurate and reliable radiographic classifications of the relative severity and outcome of Legg-Calve-Perthes disease are essential in the study of that disease. As part of a prospective multicenter study, we sought to define more clearly the lateral pillar classification of severity and the Stulberg classification of outcome; we sought especially to define the borderlines between classification groups. METHODS We performed interobserver and intraobserver trials of the lateral pillar and Stulberg classifications using sets of twenty radiographs chosen from a prospective study of 345 hips. To establish reliable definitions of the lateral pillar classification, we added a new, intermediate group termed the B/C border group, which includes femoral heads with a thin or poorly ossified lateral pillar and those with a loss of exactly 50% of the original height of the lateral pillar. The resulting classification consists of four groups: A, B, B/C border, and C. In our application of the classification system of Stulberg et al., we defined a class-II femoral head as round and fitting within 2 mm of a circle on both anteroposterior and frog-leg lateral radiographs. We defined a Stulberg class-III femoral head as out of round by more than 2 mm on either view and a Stulberg class-IV femoral head as one with at least 1 cm of flattening of the weight-bearing articular surface. To assess interobserver and intraobserver agreement, we performed two trials of each classification with six orthopaedic surgeons reviewing twenty radiographs or pairs of radiographs. RESULTS In the first trial of the lateral pillar classification, there was 81% agreement per radiograph and the average weighted kappa was 0.71. In the second trial, there was 85% agreement per radiograph and the weighted kappa averaged 0.79. Intraobserver reliability testing showed a 77% match between Trials 1 and 2, an average weighted kappa of 0.81, and an average generalizability coefficient of 0.91. In Trial 1 of the Stulberg classification, there was 91% agreement per radiograph and an average weighted kappa of 0.82. In Trial 2, there was 92% agreement per radiograph and an average weighted kappa of 0.82. Intraobserver reliability testing showed an 89% match between Trials 1 and 2, an average weighted kappa value of 0.88, and an average generalizability coefficient of 0.92. CONCLUSIONS The interobserver and intraobserver trials of these classifications produced kappa values and generalizability coefficients in the excellent range. The modified lateral pillar classification and the redefined Stulberg classification are sufficiently reliable and accurate for use in studies of Legg-Calve-Perthes disease.

A comparison between the Boston brace and the Charleston bending brace in adolescent idiopathic scoliosis

Study Design. The authors studied 319 patients with adolescent idiopathic scoliosis treated at the same institution with either a Boston brace or a Charleston bending brace. Objectives. To determine if both orthoses are equally effective in stopping curve progression and preventing the need for surgical correction. Summary of Background Data. Early reports suggest that the Charleston brace may be comparable to the Boston brace in its effectiveness and that both braces positively influence the natural history of idiopathic scoliosis. Methods. Skeletally immature (Risser 0, 1, or 2) patients with idiopathic scoliosis who were 10 years old or older at the time of brace prescription, had curves from 25° to 45°, and had no prior treatment were studied retrospectively. All measurements were collected by a single observer, and all patients were followed up to skeletal maturity. Results. The Boston brace is more effective than the Charleston brace, both in preventing curve progression and in avoiding the need for surgery. These findings were most notable for patients with curves of 36°-45°, in whom 83% of the those treated with a Charleston brace had curve progression of more than 5°, compared with 43% of those treated with the Boston brace (p < 0.0001). Conclusion. When given the choice between these two orthoses in the treatment of adolescent idiopathic scoliosis, the authors recommend use of the Boston brace. The Charleston brace should be considered only in the treatment of smaller single thoracolumbar or single lumbar curves.

CHD7 gene polymorphisms are associated with susceptibility to idiopathic scoliosis

Idiopathic scoliosis (IS) is the most common spinal deformity in children, and its etiology is unknown. To refine the search for genes underlying IS susceptibility, we ascertained a new cohort of 52 families and conducted a follow-up study of genomewide scans that produced evidence of linkage and association with 8q12 loci (multipoint LOD 2.77; P=.0028). Further fine mapping in the region revealed significant evidence of disease-associated haplotypes (P<1.0 x 10-4) centering over exons 2-4 of the CHD7 gene associated with the CHARGE (coloboma of the eye, heart defects, atresia of the choanae, retardation of growth and/or development, genital and/or urinary abnormalities, and ear abnormalities and deafness) syndrome of multiple developmental anomalies. Resequencing CHD7 exons and conserved intronic sequence blocks excluded coding changes but revealed at least one potentially functional polymorphism that is overtransmitted (P=.005) to affected offspring and predicts disruption of a caudal-type (cdx) transcription-factor binding site. Our results identify the first gene associated with IS susceptibility and suggest etiological overlap between the rare, early-onset CHARGE syndrome and common, later-onset IS.

Use of the Pavlik harness in congenital dislocation of the hip: an analysis of failures of treatment

In twenty-five patients, the Pavlik harness failed to obtain or maintain reduction in thirty of thirty-five congenital dislocations of the hip. All of the patients had met the clinical criteria for use of the harness in our institution: they were less than seven months old, the femoral head pointed to the triradiate cartilage on anteroposterior radiographs that were made with the child wearing the harness, and they had no evidence of neuromuscular disease or teratological dislocation. These patients were compared with seventy-one patients (eighty-one dislocations) who had also been treated with the Pavlik harness and in whom a stable reduction was obtained and maintained. Statistically significant risk factors for failure of the harness included an absent Ortolani sign at the initial evaluation, bilateral dislocation, and an age of more than seven weeks before treatment with the harness was begun. All thirty hips in which the harness failed to obtain or maintain reduction had a subsequent attempt at closed reduction after preliminary Bryant traction. Fifteen of these hips were successfully reduced closed, but two later redislocated and needed an open reduction. The remaining fifteen hips needed an open reduction, and two redislocated and needed a second open reduction.

Localization of susceptibility to familial idiopathic scoliosis

Study Design. Genome-wide linkage surveys in large multiplex families with apparent inherited idiopathic scoliosis. Objective. To identify chromosomal loci encoding genes involved in susceptibility to idiopathic scoliosis by positional cloning. Summary of Background Data. Although the inheritance of idiopathic scoliosis most often exhibits a complex pattern, autosomal dominant inheritance can be identified in some families. Families exhibiting such an inheritance pattern present an opportunity to identify the predisposing gene(s) by positional cloning. Methods. Probands having clinically relevant idiopathic scoliosis (50° Cobb angle) from large multiplex families were identified. A curve of 15°, made from standing posteroanterior radiographs, was required for a positive diagnosis. A genome-wide search in one large family (seven affected members) was conducted with 385 polymorphic microsatellite markers spaced at an approximate 10-cM resolution. Hot spots identified in this family were subsequently tested in a second large kindred. Results. Maximum evidence of allele-sharing in affected individuals from the first family was detected for three loci on chromosomes 6p, distal 10q, and 18q with nonparametric lod scores of 1.42 (P = 0.020), 1.60 (P = 0.019), and 8.26 (P = 0.002), respectively. Evidence of allele-sharing was also detected in the second family at distal chromosome 10q (nonparametric lod score = 2.02;P = 0.033). Conclusions. These data indicate a limited number of genetic loci predisposing to idiopathic scoliosis.

Genome-wide association studies of adolescent idiopathic scoliosis suggest candidate susceptibility genes

Adolescent idiopathic scoliosis (AIS) is an unexplained and common spinal deformity seen in otherwise healthy children. Its pathophysiology is poorly understood despite intensive investigation. Although genetic underpinnings are clear, replicated susceptibility loci that could provide insight into etiology have not been forthcoming. To address these issues, we performed genome-wide association studies (GWAS) of ∼327 000 single nucleotide polymorphisms (SNPs) in 419 AIS families. We found strongest evidence of association with chromosome 3p26.3 SNPs in the proximity of the CHL1 gene (P < 8 × 10(-8) for rs1400180). We genotyped additional chromosome 3p26.3 SNPs and tested replication in two follow-up case-control cohorts, obtaining strongest results when all three cohorts were combined (rs10510181 odds ratio = 1.49, 95% confidence interval = 1.29-1.73, P = 2.58 × 10(-8)), but these were not confirmed in a separate GWAS. CHL1 is of interest, as it encodes an axon guidance protein related to Robo3. Mutations in the Robo3 protein cause horizontal gaze palsy with progressive scoliosis (HGPPS), a rare disease marked by severe scoliosis. Other top associations in our GWAS were with SNPs in the DSCAM gene encoding an axon guidance protein in the same structural class with Chl1 and Robo3. We additionally found AIS associations with loci in CNTNAP2, supporting a previous study linking this gene with AIS. Cntnap2 is also of functional interest, as it interacts directly with L1 and Robo class proteins and participates in axon pathfinding. Our results suggest the relevance of axon guidance pathways in AIS susceptibility, although these findings require further study, particularly given the apparent genetic heterogeneity in this disease.

Treatment of adolescent idiopathic scoliosis using Texas Scottish Rite Hospital instrumentation.

Study Design. To determine the effectiveness of posterior TSRH instrumentation for the treatment of idiopathic scoliosis, 103 patients with a 2-year minimum followup were retrospectively studied. Methods. Patients who underwent operations between October 1988 and April 1991 were evaluated for curve correction, spinal balance, and complications. Age at surgery averaged 14.3 years. Follow-up averaged 2.5 years. Results. Thoracic curve correction averaged 65% in those with King Type III/IV curves and 54% in those with Type II curves. With follow-up, correction loss averaged approximately 13% for each group. Lumbar curve correction after instrumentation in Type I and II curves averaged 48% postop but lost approximately 20% with follow-up. Trunk balance improved 77% toward midline after surgery in those with Type III/IV curves. Improvement in trunk balance was less impressive in patients with Type II curves, particularly after selective thoracic fusions. Thoracic sagittal contour improved 43% for hypokyphotic (<20°) patients but, in the remainder, no significant radiographic change was evident. No neurologic complications occurred. Delayed deep infections developed in ten patients (10%) between 11 and 45 months postoperative. Cultures eventually grew Propionlbacterium acnes, staph epidermidis, or staph coagulese negative in eight patients. Two patients had pseudarthroses. Conclusions. Frontal and sagittal thoracic curve correction can be satisfactorily obtained using TSRH instrumentation. Continued efforts are being made to improve lumbar hook patterns and technique to achieve and maintain better lumbar curve correction.