Environmental tobacco and wood smoke increase the risk of Legg-Calvé-Perthes disease

The Effect of Vitamin D Deficiency as a Risk Factor of Early Fragmentation in Legg-Calve-Perthes Disease: A Prospective Study

INTRODUCTION

Legg-Calve-Perthes disease (LCPD) is a disorder involving the hips in young children of preschool and school-going age groups, more common in 4-8 years. The insufficient blood supply to the femoral head is the main reason behind various etiologic theories. Multiple factors affect the natural progression of the disease. The natural progression of the disease involves early avascular necrosis, fragmentation, reconstitution, and healed stages. In the fragmentation stage, the bony epiphysis begins to fragment, and the subchondral radiolucent zone (crescent sign) is the result of a subchondral stress fracture, which later on determines the extent of a necrotic fragment of the femoral head. These changes later contribute to changes in the shape of the femur head and the extent of deformity. As vitamin D plays a vital role in the onset of the fragmentation stage, we conducted a study to assess the effect of vitamin D deficiency as a risk factor for early fragmentation in Legg-Calve-Perthes disease.

METHODS

In our study, 50 patients aged 4-12 years were examined over three years and classified according to Catterall and Herring's lateral pillar classification; the length of the fragmentation stage and the vitamin D level were considered. A vitamin D level of less than 20 ng/mL was labeled as the deficient group, 20-30 ng/mL as the insufficient group, and more than 30 ng/mL as the sufficient (normal) group.

RESULTS

The critical fragmentation stage was significantly longer (more than 12 months) in vitamin D deficiency (34%), leading to a higher risk of deformity and extrusion of the femoral head, which led to higher rates of surgical intervention and containment procedures.

CONCLUSION

The fragmentation stage is critical in the course of LCPD. Vitamin D levels play a vital role in predicting the prognostic of LCPD, and it should be measured in all patients of LCPD. Patients with normal vitamin D levels have a comparatively shorter fragmentation stage duration than patients with insufficient or deficient levels, leading to a lesser duration of femoral head damage.

Epidemiology, natural evolution, pathogenesis, clinical spectrum, and management of Legg-Calvé-Perthes

Background

Legg-Calvé-Perthes disease is a self-limiting disorder that develops in children following interruption of the blood supply to the capital femoral epiphysis. This review outlines the current knowledge on the epidemiology, natural evolution, clinical spectrum, and management of the disease.

Methods

The literature pertaining to these aspects of the disease were studied and summarized in this review.

Results

Epidemiological studies suggest that environmental factors contribute to the causation of the disease. Incidence rates monitored over time indicate that the incidence of Legg-Calvé-Perthes disease is declining. The natural evolution followed on sequential plain radiographs enables division of the disease into Stages Ia, Ib, IIa, IIb, IIIa, IIIb, and IV. Reversible deformation of the capital occurs in Stages Ia-IIa simply on standing while irreversible deformation may occur in Stages IIb and IIIa. Treatment of Legg-Calvé-Perthes disease in Stages Ia-IIa aims to prevent the femoral head from getting deformed by containment and avoidance of weight-bearing. In Stages IIb and IIIa, treatment aims to remedy the effects of early irreversible deformation of the femoral head. In Stage IIIb and IV, treatment is directed to correcting the altered shape of the femoral head. The impression that these treatment methods are helpful is based on poor quality evidence.

Conclusion

There is an urgent need to undertake Level I studies to establish the efficacy of currently treatment.

Level of evidence

level V.

Association between Polymorphism eNOS4, tPA, Factor V Leiden, Prothrombin, and Methylenetetrahydrofolate Reductase and the Occurrence of Legg-Calvé-Perthes Disease

BACKGROUND

Legg-Calvé-Perthes (LCPD) disease is a complex condition affecting the femoral head's epiphysis in children. It occurs with a prevalence ranging from 0.4 to 29.0 cases per 100,000 children under the age of 15. It involves various factors, including genes associated with coagulation and fibrinolysis, pro-inflammatory factors, and vasoactive substances.

METHODS

We investigated the relationship between genetic mutations associated with coagulation and vascular disorders and the occurrence of LCPD in Polish patients. We performed a study involving 25 patients with LCPD and 100 healthy controls. All subjects were genotyped for eNOS4, Factor V Leiden, prothrombin, tPA25, and MTHFR polymorphism.

RESULTS

The analysis revealed that the frequencies of eNOS4 genotypes were significantly different in LCPD patients than in the control group (p = 0.018). The frequencies of 4a allele were significantly higher in patients with LCPD than in the healthy population (26% vs. 9%, p = 0.0012). There were no significant differences in genotype and allele frequencies for Factor V Leiden, prothrombin tPA 25, and MTHFR gene polymorphisms between patients with LCPD and the controls.

CONCLUSIONS

Genotype and allele frequencies of eNOS4 were significantly higher in patients with LCPD. These findings suggest a potential association between the eNOS gene polymorphism and an increased risk of developing LCPD.

Declining Rates of Legg-Calvé-Perthes Surgery in the United States: National Trends Using the Kids' Inpatient Database and Pediatric Health Information System

BACKGROUND

In 2004 and 2008 two large prospective, multicenter studies were published which resulted in improved understanding of operative indications for the treatment of Legg-Calvé-Perthes disease (LCPD) based on patient age, disease severity, and resultant radiographic outcomes. The primary aim of this study is to evaluate the trends in surgical management of LCPD in the United States prior, and subsequent to, the publication of these landmark studies.

METHODS

Cross-sectional retrospective analysis of US pediatric hospitalizations for the surgical management of LCPD was conducted using the Kids' Inpatient Database from 2000 to 2016. Patients 12 years of age and younger were included who had a primary admission diagnosis of LCPD and a LCPD-related procedure during the hospitalization. Data was subsequently weighted to produce national-level estimates and variables pertaining to patient age group, procedure, demographics, and hospital characteristics were analyzed. In a post hoc analysis, the results of the Kids' Inpatient Database were also corroborated with the Pediatric Health Information System database.

RESULTS

A weighted sample of 2786 LCPD surgical admissions met inclusion and exclusion criteria; 11.2% of surgical admissions were patients below 6 years of age, 35.9% were 6 to 8 years of age, and 52.9% were above 8 years of age. There was a significant decrease in admissions for surgical management of LCPD in all age groups over time, however there was no appreciable change in the proportion of LCPD surgical admissions performed among the above 8 to below 12, above 6 to below 8, or below 6 years age groups. Femoral osteotomy remained the most common surgical procedure, while other osteotomy types, including pelvic and unspecified osteotomies involving the hip, decreased over time ( P <0.001).

CONCLUSIONS

There is a decreasing rate of hospital admissions for LCPD surgery since 2000, perhaps indicating a decline in incidence of disease. Furthermore, despite evidence supporting LCPD surgical outcomes related to patient age, there has been no change in the proportion of patients undergoing surgery by age group over time.

LEVEL OF EVIDENCE

Level III-retrospective study.

Legg-Calvé-Perthes disease overview

Background

Legg–Calvé–Perthes Disease (LCPD) is a necrosis of the femoral head which affects the range of motion of the hips. Its incidence is variable, ranging from 0.4/100,000 to 29.0/ 100,000 children. Although LCPD was first described in the beginning of the past century, limited is known about its etiology. Our objective is to describe the main areas of interest in Legg–Calve–Perthes disease.

Methods

A review of the literature regarding LCPD etiology was performed, considering the following inclusion criteria: Studies reporting clinical or preclinical results. The research group carried out a filtered search on the PubMed and Science Direct databases. To maximize the suitability of the search results, we combined the terms ‘‘Perthes disease” OR “LCPD” OR “children avascular femoral head necrosis” with “diagnostic” OR “treatment” OR “etiology” as either key words or MeSH terms.

Results

In this article been described some areas of interest in LCPD, we include topics such as: history, incidence, pathogenesis, diagnosis, treatment and possible etiology, since LCPD has an unknown etiology.

Conclusions

This review suggests that LCPD has a multifactorial etiology where environmental, metabolic and genetic agents could be involved.

Demographics and Clinical Presentation of Early-Stage Legg-Calvé-Perthes Disease: A Prospective, Multicenter, International Study

BACKGROUND

Children with Legg-Calvé-Perthes disease (LCPD) are classically described as small, thin, high-energy children presenting with a painless limp. Epidemiologic studies have historically been retrospective and regional in nature. The purpose of this study was to determine the demographic and clinical features of children presenting in the early stages of LCPD in an international, multicenter cohort.

METHODS

Children (6 to 10 years) in the early stages of LCPD (modified Waldenström stage I to IIa) were enrolled in a prospective, multicenter study. Demographic and clinical data at presentation were analyzed. Body mass index percentiles were determined using country-specific growth charts for children in the United States and India, two countries with largest enrollment. Statistical analyses included t-tests and chi-square.

RESULTS

A total of 209 children (86% males; mean age 7.9 ± 1.2 years) from 25 centers (six countries) were included. Eight-four percent of children presented with pain with or without a limp. Average pain score at presentation was 3 ± 2 (range 0 to 9), and 63% of children (n = 105) used pain medications. Of these children 65% required medication more than once per week. Thirty percent of children missed school due to pain in the past month, and of those, 74% missed at least 1 day per week. Twenty-nine percent of children from the United States and 20% of children from India were overweight or obese. Nineteen percent reported household smoking.

DISCUSSION

This prospective study provides a new international multicenter representation of early LCPD. The frequency of pain and missed school highlights the substantial morbidity and potential social cost and burden for children and families. The prevalence of being overweight/obese in our LCPD cohort was comparable to rates within the pediatric cohort as a whole, and fewer children have a history of smoke exposure than in previous reports.

LEVEL OF EVIDENCE

Level II, prospective comparative study.

Influence of passive smoking on the onset of Legg-Calvè-Perthes disease: a systematic review and meta-analysis

The relationship between passive smoking and the onset of Legg-Calvè-Perthes disease is still controversial. Therefore, we conducted the study to systematically evaluate and analyze the relationship. A comprehensive search was conducted. Meta-analysis was performed with RevMan 5.3 software, with the odds ratio as the effect size. Eight English articles with a total of 1379 Legg-Calvè-Perthes disease patients were eventually included. Passive smoking type of family members smoking in indoor (odds ratio = 2.53), paternal smoking (odds ratio = 2.76), maternal smoking (odds ratio = 2.02), maternal smoking during pregnancy (odds ratio = 1.68), using stove indoor (odds ratio = 2.56) are statistically significant (P < 0.05). For the family members smoking indoor, region may be a confounding factor (European group I = 92%, odds ratio = 2.51; USA group I = 5%, odds ratio = 3.26; and Asian group I = 0%, odds ratio = 2.25). In addition, the type of maternal smoking (odds ratio = 0.80, for 1-10 per day; odds ratio = 2.73, for 10-20 per day; odds ratio = 2.78, for >20 per day) and the type of maternal smoking during pregnancy (odds ratio = 1.36, for 1-9 per day; odds ratio = 2.02, for ≥10 per day) may show a dose-effect relationship. Passive smoking is a risk factor for the onset of Legg-Calvè-Perthes disease, but the specific types of passive smoking (haze, etc.), dose, dose-effect relationship, regional confounding, pathological mechanisms, etc. also require clinicians and researchers to continue exploring.

Pediatric Hip and Pelvis

The most common pediatric orthopedic conditions of the hip and pelvis involve abnormal architecture of the joint leading to pain and dysfunction. Developmental dysplasia of the hip and femoroacetabular impingement are 2 common and distinct forms of structural pathology in the pediatric hip. The authors also discuss 2 of the more common, and often questioned, pediatric hip disorders-slipped capital femoral epiphysis and Legg-Calvé-Perthes disease. Future investigations are aimed at identifying risk factors to provide pediatric orthopedists tools to risk stratify their patients and understand when conservative approaches such as close observation versus surgical interventions are more appropriate.

Aetiology of Legg-Calvé-Perthes disease: A systematic review

BACKGROUND

Legg-Calvé-Perthes disease (LCPD) is a clinical condition affecting the femoral head of children during their growth. Its prevalence is set to be between 0.4/100000 to 29.0/100000 children less than 15 years of age with a peak of incidence in children aged from 4 years to 8 years. LCPD aetiology has been widely studied, but it is still poorly understood.

AIM

To analyse the available literature to document the up-to-date evidence on LCPD aetiology.

METHODS

A systematic review of the literature was performed regarding LCPD aetiology, using the following inclusion criteria: studies of any level of evidence, reporting clinical or preclinical results and dealing with the aetiology or pathogenesis of LCPD. Two reviewers searched the PubMed and Science Direct databases from their date of inception to the 20th of May 2018 in accordance with the Preferred Reporting Items for Systemic Reviews and Meta-Analyses guidelines. To achieve the maximum sensitivity of the search strategy, we combined the terms: ‘‘Perthes disease OR LCPD OR children avascular femoral head necrosis” with “pathology OR aetiology OR biomechanics OR genetics” as either key words or MeSH terms.

RESULTS

We include 64 articles in this review. The available evidence on LCPD aetiology is still debated. Several hypotheses have been researched, but none of them was found decisive. While emerging evidence showed the role of environmental risk factors and evidence from twin studies did not support a major role for genetic factors, a congenital or acquired predisposition cannot be excluded in disease pathogenesis. One of the most supported theories involved mechanical induced ischemia that evolved into avascular necrosis of the femoral head in sensible patients.

CONCLUSION

The literature available on the aetiology of LCPD presents major limitations in terms of great heterogeneity and a lack of high-profile studies. Although a lot of studies focused on the genetic, biomechanical and radiological background of the disease, there is a lack of consensus on one or multiple major actors of the etiopathogenesis. More studies are needed to understand the complex and multifactorial genesis of the avascular necrosis characterizing the disease.

Video-based kinetic analysis of calcification in live osteogenic human embryonic stem cell cultures reveals the developmentally toxic effect of Snus tobacco extract

Epidemiological studies suggest tobacco consumption as a probable environmental factor for a variety of congenital anomalies, including low bone mass and increased fracture risk. Despite intensive public health initiatives to publicize the detrimental effects of tobacco use during pregnancy, approximately 10-20% of women in the United States still consume tobacco during pregnancy, some opting for so-called harm-reduction tobacco. These include Snus, a type of orally-consumed yet spit-free chewing tobacco, which is purported to expose users to fewer harmful chemicals. Concerns remain from a developmental health perspective since Snus has not reduced overall health risk to consumers and virtually nothing is known about whether skeletal problems from intrauterine exposure arise in the embryo. Utilizing a newly developed video-based calcification assay we determined that extracts from Snus tobacco hindered calcification of osteoblasts derived from pluripotent stem cells early on in their differentiation. Nicotine, a major component of tobacco products, had no measurable effect in the tested concentration range. However, through the extraction of video data, we determined that the tobacco-specific nitrosamine N'-nitrosonornicotine caused a reduction in calcification with similar kinetics as the complete Snus extract. From measurements of actual nitrosamine concentrations in Snus tobacco extract we furthermore conclude that N'-nitrosonornicotine has the potential to be a major trigger of developmental osteotoxicity caused by Snus tobacco.

Tönnis triple pelvic osteotomy for Legg-Calve-Perthes disease

PURPOSE

The aim of this study is to evaluate the efficacy of Tönnis triple pelvic osteotomy in patients with LCP disease.

METHODS

Between 2007 and 2011, Tönnis triple pelvic osteotomy was performed for 43 patients with LCP, in our institute. During the follow-ups of patients with LCP the indications for the surgery were lateralization of the femoral head, insufficient femoral head coverage and subluxation of the femoral head. The mean age of patients at the time of surgery was 9.4 years.

RESULTS

Before surgical intervention, according to Waldenstrom classification, three patients were in the necrosis stage (7 %), six patients in the fragmentation stage (13.9 %), 16 patients in the re-ossification stage (37.2 %) and 18 patients in the remodeling stage (41.9 %). According to Herring classification, four patients were in group B (9.3 %), one patient in group B/C (2.3 %) and 38 patients in group C (88.4 %). After the operation, patients were evaluated with Stulberg classification, and good outcome (Stulberg I/II) was achieved in 23 patients (53, 5 %), fair outcome (Stulberg III) in 16 patients (37, 2 %) and poor outcome (Stulberg IV/V) was seen in only four patients (9.3 %). The mean value of CEA was 0.37° pre-operatively and in the last follow-ups the mean value of CEA was 23.7°.

CONCLUSIONS

We recommend triple pelvic osteotomy for patients with LCP when conservative methods are not successful. According to our results we believe that Waldenstrom classification is a better option than Herring classification to determine the prognosis of disease after containment surgery.

Meta-analysis of hypercoagulability genetic polymorphisms in Perthes disease

Perthes disease is an osteonecrosis of the femoral epiphysis with unclear etiology. This study aimed to systematically review the association between genetic determinants of hypercoagulability (Factor V Leiden, prothrombin II, and methylenetetrahydrofolate reductase; MTHFR) and Perthes disease. PubMed and Scopus searched from inception to January 2012, data extraction and quality assessment were performed. The odds ratio (OR) for the allele effect was pooled, and heterogeneity and publication bias were assessed. Twelve case-control studies met inclusion criteria and had sufficient data for extraction. There were 824 cases and 2,033 controls with a mean age range of 6.1-14.7 years. The prevalence of the minor allele in controls was 0.015 (95% confidence interval (CI): 0.008, 0.023), 0.012 (95% CI: 0.008, 0.017), and 0.105 (95% CI: 0.044, 0.167) for factor V Leiden, prothrombin II, and MTHFR, respectively. The factor V Leiden allele increased the risk of Perthes with a pooled OR of 3.10 (95% CI: 1.68, 5.72), while prothrombin II and MTHFR had non-significantly pooled OR 1.48 (95% CI: 0.71, 3.08), and 0.97 (95% CI: 0.72, 1.30), respectively. The factor V Leiden mutation is significantly related to Perthes disease, and its screening in at-risk children might be useful in the future.

Perthes disease: evaluation and management

Perthes disease refers to self-limiting idiopathic avascular necrosis of capital femoral epiphysis in a child. There is no consensus for the optimum treatment of Perthes disease even 100 years after the first description. The prime aim of the treatment is to maintain the sphericity of the femoral head and the congruency of the femur-acetabulum relationship to prevent secondary degenerative arthritis. Early diagnosis and management can help the collapse of femoral head, progressive femoral head deformity, and impingement.

Female patients with late-onset legg-calvé-perthes disease are frequently gymnasts: is there a mechanical etiology for this subset of patients?

BACKGROUND

The cause of Legg-Calvé-Perthes disease (LCPD) is unknown. We have observed a relatively high prevalence of female gymnasts presenting with LCPD. The purpose of this study was to determine: (1) the percentage of LCPD patients exposed to high-level gymnastics training, (2) the demographics of this subset of patients, and (3) their clinical outcomes.

METHODS

Several adolescent female gymnasts presented to our clinic with recent-onset LCPD. We reviewed our cases to discern the prevalence and treatment of the disorder in this patient cohort. From 1999 to 2010, 572 patients were evaluated for a diagnosis of LCPD at our tertiary referral center. Clinical records were retrospectively reviewed. Of those, 13 patients had a history of gymnastics participation with 8 patients (all females) having competitive participation.

RESULTS

For females aged 10 years and older presenting with LCPD, 7 of 9 patients (78%) were involved in high-level competitive gymnastics. These patients had disease onset between 10 and 12 years of age (mean, 11 y). Competitive gymnasts represented 6.6% (8 of 120) of females with LCPD and 1.4% (8 of 572) of all patients evaluated with LCPD during the study period. Only 1 of 111 females below 10 years with LCPD participated in competitive gymnastics (χ, P<0.0001).Patients underwent a variety of treatments. Two patients underwent nonoperative treatment, and the remainder underwent surgical management. All 7 gymnasts had a Stulberg IV result. In the nongymnast group of females 10 years and older, there were 1 Stulberg III result and 1 Stulberg IV result.

CONCLUSIONS

At our center, competitive gymnasts comprise >75% of the female patients over the age of 10 who presented with late-onset LCPD. Results in general were poor. Further studies are needed to explore the association between the physical demands of advanced gymnastic training and the development of LCPD in this subset of patients.

LEVEL OF EVIDENCE

IV, case series.

Comorbidities in Perthes' disease: a case control study using the General Practice Research database

Perthes' disease is an osteonecrosis of the juvenile hip, the aetiology of which is unknown. A number of comorbid associations have been suggested that may offer insights into aetiology, yet the strength and validity of these are unclear. This study explored such associations through a case control study using the United Kingdom General Practice Research database. Associations investigated were those previously suggested within the literature. A total of 619 cases of Perthes' disease were included, as were 2544 controls. The risk of Perthes' disease was significantly increased with the presence of congenital anomalies of the genitourinary and inguinal region, such as hypospadias (odds ratio (OR) 4.04 (95% confidence interval (CI) 1.41 to 11.58)), undescended testis (OR 1.83 (95% CI 1.12 to 3.00)) and inguinal herniae (OR 1.79 (95% CI 1.02 to 3.16)). Attention deficit hyperactivity disorder was not associated with Perthes' disease (OR 1.01 (95% CI 0.48 to 2.12)), although a generalised behavioural disorder was (OR 1.55 (95% CI 1.10 to 2.17)). Asthma significantly increased the risk of Perthes' disease (OR 1.44 (95% CI 1.17 to 1.76)), which remained after adjusting for oral/parenteral steroid use. Perthes' disease has a significant association with congenital genitourinary and inguinal anomalies, suggesting that intra-uterine factors may be critical to causation. Other comorbid associations may offer insight to support or refute theories of pathogenesis.