Interruption of the blood supply of femoral head: an experimental study on the pathogenesis of Legg-Calve-Perthes Disease

Can large doses of glucocorticoids lead to Perthes? a case report and review of the literature

Background

Perthes disease (Legg-Calvé-Perthes, LCP) is a self-limited and non-systemic disease occurring in the femoral heads of children, which is mainly manifested as an ischemic necrosis of the femoral head epiphysis, leading to subchondral ossification injury of the femoral head.

Case presentation

Here we report a case of 11-year-old child with long-term use of high-dose glucocorticoids. With MRI examination finding the epiphyseal necrosis of right humeral head, femur and tibia, and X-ray examination finding bilateral femoral head necrosis, the child was diagnosed as Perthes disease based on his clinical and imaging data.

Conclusions

Long-term and high-dose glucocorticoids may be one of the causes of Perthes disease.

Legg Calvé Perthes disease in the dog

Legg Calvé Perthes disease (LCPD) is a developmental abnormality that usually affects young small breed dogs. Although the etiology is still uncertain, the pathogenesis is very similar to that described in humans. Diagnosis with physical examination and medical imaging is relatively easy. Treatments offered in dogs, mainly surgical, are also presented. Legg Calvé Perthes disease has many similarities between children and puppies. Dog is therefore an interesting spontaneous model of aseptic osteonecrosis.

Endothelial nitric oxide synthase gene polymorphism is associated with Legg-Calvé-Perthes disease

The aim of this study was to assess the association of 27-bp variable number tandem repeat (VNTR) polymorphism in intron 4 and G894T polymorphism in exon 7 of the endothelial nitric oxide synthase (eNOS) gene with Legg-Calvé-Perthes disease (LCPD), and to provide a scientific basis for further research into the pathogenic mechanism. A total of 80 patients with LCPD and 100 healthy subjects were recruited in this case-control study. The 27-bp VNTR and G894T polymorphisms of the eNOS gene were genotyped using polymerase chain reaction (PCR) and PCR-restriction fragment length polymorphism, respectively, followed by agarose gel electrophoresis and DNA sequencing. Allelic and genotypic frequencies were computed in the two groups and subjected to statistical analysis. For the 27-bp VNTR polymorphism, individuals with LCPD showed a higher frequency of the ab genotype [27.5 vs. 14%; odds ratio (OR), 2.33; 95% confidence interval (CI), 1.10-4.92; P=0.024]. For the G894T polymorphism, the LCPD case group showed a higher frequency of the heterozygous genotype GT than the healthy control group (35 vs. 17%; OR, 2.67; 95% CI, 1.33-5.36; P=0.005). The results indicate that these eNOS gene polymorphisms may be a risk factor for LCPD. The 27-bp VNTR polymorphism in intron 4 and G894T polymorphism in exon 7 may be involved in the etiology of LCPD.

Spontaneous and bilateral necrosis of the femoral head in a young experimental beagle dog

This report describes the pathological characterizations of a rare case of necrosis of the femoral head that was spontaneous, bilateral, avascular and nontraumatic. A 14-month-old beagle dog was presented with pain in the hind limbs. At necropsy, the articular surface in the bilateral femoral head was markedly irregular. There were no gross abnormalities other than in the hip joints. Microscopically, a wide range of trabecular bone necrosis localized in the subchondral area was observed in both femoral heads. In the right femoral head, fibrosis and proliferative vessels were noted in the subchondral area. The articular cartilage was thickened irregularly, but there was no evidence of cartilage necrosis. The bone marrow adjacent to the affected area showed severe depression. In the metaphysis, atrophic bone marrow, but not bone necrosis, was observed. This was a rare case of spontaneous necrosis of the femoral head in an experimental beagle dog.

Effect of arterial deprivation on growing femoral epiphysis: quantitative magnetic resonance imaging using a piglet model

Objective

To investigate the usefulness of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and diffusion MRI for the evaluation of femoral head ischemia.

Materials and Methods

Unilateral femoral head ischemia was induced by selective embolization of the medial circumflex femoral artery in 10 piglets. All MRIs were performed immediately (1 hour) and after embolization (1, 2, and 4 weeks). Apparent diffusion coefficients (ADCs) were calculated for the femoral head. The estimated pharmacokinetic parameters (Kep and Ve from two-compartment model) and semi-quantitative parameters including peak enhancement, time-to-peak (TTP), and contrast washout were evaluated.

Results

The epiphyseal ADC values of the ischemic hip decreased immediately (1 hour) after embolization. However, they increased rapidly at 1 week after embolization and remained elevated until 4 weeks after embolization. Perfusion MRI of ischemic hips showed decreased epiphyseal perfusion with decreased Kep immediately after embolization. Signal intensity-time curves showed delayed TTP with limited contrast washout immediately post-embolization. At 1-2 weeks after embolization, spontaneous reperfusion was observed in ischemic epiphyses. The change of ADC (p = 0.043) and Kep (p = 0.043) were significantly different between immediate (1 hour) after embolization and 1 week post-embolization.

Conclusion

Diffusion MRI and pharmacokinetic model obtained from the DCE-MRI are useful in depicting early changes of perfusion and tissue damage using the model of femoral head ischemia in skeletally immature piglets.

[Experimental induction of Perthes disease in lambs]

OBJECTIVE

To establish a simple, reproducible and safe experimental model, for the development of ischemic vascular necrosis of the hip in the lamb.

MATERIAL AND METHODS

We used 15 lambs (10 males and 5 females) aged four weeks, divided into a control group (7 animals) and an experimental group (8 animals) producing ischemia in the proximal femur. Standard radiography and MRI were performed. The animals were euthanised at the 4th, 8th and 12th weeks after surgery. The femoral heads were extracted and measured and a histological analysis was performed with hematoxylin-eosin staining.

RESULTS

Decreased height and increased width of the femoral head was observed in the X-Rays, particularly after the 4th week. We did not observe any changes in the height of the lateral pillar or trochanteric distance. The experimental group showed macroscopical hypertrophy and progressive flattening of the head. At 4 weeks necrotic areas in articular cartilage were observed, bone marrow was dense and the growth cartilage height was lower. The vessels were thickened by proliferation of the medial and adventitia layers. At 8 weeks, we found fibrosis in the subchondral bone with thinned and devitalized angiogenesis fat areas. The articular cartilage showed irregularities. At 12 weeks the closure of the physis was noted, as well as chondral areas in the trabecular bone and fat cells in the methaphysis.

CONCLUSION

Although the histological changes are consistent with necrosis of the femoral head, the images obtained did not resemble Perthes disease, so we do not advise this experimental model for the study of this disease.

Legg-Calve-Perthes disease in two generations of male family members: a case report

Legg-Calve-Perthes disease (LCPD) is a type of avascular necrosis of the femoral head occurring mainly in male children and causing early osteoarthritis. We report 2 generations of 4 male family members with LCPD-like features and mutation of the COL2A1 gene of the 12q13 chromosome. If LCPD occurs in any family member, we recommend genetic analysis and counselling as well as early radiological screening of related children.

Legg-Calvé-Perthes disease and the risk of injuries requiring hospitalization: a register study involving 2579 patients

BACKGROUND AND PURPOSE

Previous studies have suggested that Legg-Calvé-Perthes disease (LCPD) is associated with repetitive trauma, coagulation problems and anatomical abnormalities of the blood supply to the femoral head. The hypothesis that repetitive trauma can affect the blood supply of the femoral head, leading to LCPD, is supported by an animal model. For evidence of an increased risk of repetitive trauma, we investigated whether patients with LCPD have a higher risk for severe injuries requiring hospitalization.

PATIENTS AND METHODS

We identified 2579 patients with LCPD in Sweden during the period 1964-2005. 13,748 individuals without LCPD were randomly selected from the Swedish general population, matched by year of birth, sex and region (control group). Cox proportional hazard regression estimated the risks.

RESULTS

Compared to the control group, patients with LCPD had a modestly raised hazard ratio (HR) of 1.2 (95% CI 1.1-1.3) for injury requiring hospitalization. The risks were slightly higher for soft tissue injuries (HR = 1.3, 95% CI:1.1-1.4) than for fractures (HR = 1.1, 95% CI: 1.0-1.3) and more pronounced among females. Compared to the control group, the higher risk for injury only applied to the lower extremities (HR = 1.2, 95% CI: 1.0-1.4) in patients with LCPD.

INTERPRETATION

Patients with LCPD are vulnerable to injuries which could be interpreted as a marker of hyperactive behavior. It could also implicate that anatomical changes in the bone formation or blood supply of the femoral head - increasing its sensibility for trauma - contribute to the etiology of LCPD.

Bisphosphonate-modified gold nanoparticles: a useful vehicle to study the treatment of osteonecrosis of the femoral head

Legg-Calvé-Perthes disease (LCPD) is a juvenile form of osteonecrosis of the femoral head that presents in children aged 2-14 years. To date, there is no effective medical therapy for treating LCPD largely due to an inability to modulate the repair process, including the predominance of bone resorption. This investigation aims to evaluate the feasibility of using gold nanoparticles (GNPs) that are surface modified with a bisphosphonate compound for the treatment of osteonecrosis at the cellular level. Studies have found osteoclast-mediated resorption to be a process that contributes significantly to the pathogenesis of femoral head deformities arising from Perthes disease. Our in vitro model was designed to elucidate the effect of alendronate-(a bisphosphonate) modified GNPs, on osteoclastogenesis and osteoclast function. RAW 264.7 macrophage cells were cultured with recombinant mouse receptor activator of NF-κB ligand (RANKL), which stimulates osteoclastogenesis, and were then treated with alendronate-modified GNPs for 24, 48, and 72 h. Cell proliferation, osteoclast function, and osteoclast morphology were evaluated by trypan blue dye exclusion assay, tartrate-resistant acid phosphatase (TRAP) staining, and transmission electron microscopy (TEM) imaging. Comparative studies were performed with GNPs that were only stabilized with citrate ions and with alendronate alone. Neither osteoclastogenesis nor osteoclast function were adversely affected by the presence of the citrate-GNP. Alendronate-modified GNPs had an enhanced effect on inducing osteoclast apoptosis and impairing osteoclast function when compared to unbound alendronate populations.

Legg-Calve-Perthes disease and risks for cardiovascular diseases and blood diseases

OBJECTIVE

We hypothesized that patients with Legg-Calvé-Perthes disease (LCPD) might have higher risks of cardiovascular and blood diseases.

METHODS

A total of 3141 patients, 2 to 15 years of age, with LCPD diagnosed between 1965 and 2005 were identified with the Swedish Inpatient Register. A total of 15 595 individuals without LCPD were selected randomly from among the Swedish general population, with matching according to year of birth, age, gender, and region of residence. Cox proportional-hazard regression analyses, with adjustment for socioeconomic index, were used to estimate relative risks. The patients also were compared with their same-gender siblings.

RESULTS

Patients with LCPD had a hazard ratio (HR) of 1.70 (95% confidence interval [CI]: 1.39-2.09) for cardiovascular diseases, compared with individuals without LCPD. The point estimate was slightly higher among subjects >30 years of age at the follow-up (HR: 2.10 [95% CI: 1.52-2.91]). There were statistically significantly higher risks for blood diseases, including anemias and coagulation defects (HR: 1.41 [95% CI: 1.07-1.86]), which were more pronounced among subjects >30 years of age at the follow-up (HR: 2.70 [95% CI: 1.50-4.84]). Patients also had statistically significantly higher risks of hypertensive disease (HR: 2.97 [95% CI: 1.87-4.72]) and nutritional anemia (HR: 2.92 [95% CI: 1.58-5.40]). Analyses using siblings as the comparison group showed consistent results for cardiovascular diseases.

CONCLUSION

The results are consistent with the hypothesis that an insufficient blood supply to the femoral head, attributable to vascular pathologic conditions, is involved in the pathogenesis of LCPD.

Maternal smoking during pregnancy, other prenatal and perinatal factors, and the risk of Legg-Calvé-Perthes disease

OBJECTIVE

The causes of Legg-Calvé-Perthes disease are largely unknown, but this pediatric disease seems to result from interruption of the blood supply to the proximal femur and is considered a vascular disease. Because maternal smoking during pregnancy influences fetal development and is associated with cardiovascular diseases in offspring, we hypothesized that this exposure is a risk for Legg-Calvé-Perthes disease and also investigated other markers of impaired fetal development and early-life exposures.

MATERIALS AND METHODS

The Swedish Inpatient Register identified 852 individuals with a diagnosis of Legg-Calvé-Perthes disease from 1983 to 2005, individually matched by year of birth, age, sex, and region of residence with 4432 randomly selected control subjects. Linkage with the Swedish Medical Birth Register provided information on prenatal factors, including maternal smoking. Conditional logistic regression examined associations of maternal smoking during pregnancy and the other measures with the risk of Legg-Calvé-Perthes disease in offspring, adjusted for socioeconomic index and other potential confounding factors.

RESULTS

Maternal smoking during pregnancy was associated with an increased Legg-Calvé-Perthes disease risk, and heavy smoking was associated with a risk increase of almost 100%. Very low birth weight and cesarean section were independently associated with approximately 240% and 36% increases in the risk of Legg-Calvé-Perthes disease, respectively.

CONCLUSION

Maternal smoking during pregnancy and other factors indicated by impaired fetal development may be associated with an increased risk of Legg-Calvé-Perthes disease.

Age at onset-dependent presentations of premature hip osteoarthritis, avascular necrosis of the femoral head, or Legg-Calvé-Perthes disease in a single family, consequent upon a p.Gly1170Ser mutation of COL2A1

OBJECTIVE

To identify the genetic abnormality responsible for osteoarthritis (OA), avascular necrosis (AVN) of the femoral head, and Legg-Calvé-Perthes disease in a single family, and to determine factors responsible for the distinct phenotypes manifested by different family members.

METHODS

Forty-two members of a 5-generation family were recruited and investigated. Diagnosis was made by independent orthopedic surgeons and radiologists. Histopathologic changes of the diseased tissue were examined. Linkage analysis was performed with markers spanning the COL2A1 locus. Haplotypes were constructed and mutation of the gene was detected. Structures of the wild-type and mutant proteins were modeled.

RESULTS

Sixteen affected members were identified (5 with isolated precocious hip OA, 6 with AVN of the femoral head, and 5 with Legg-Calvé-Perthes disease). A p.Gly1170Ser mutation of COL2A1 cosegregated with the 3 diseases and was absent in controls. Of note, age at onset in relation to the closure status of the femoral head epiphysis was associated with the diseases, with Legg-Calvé-Perthes disease presenting prior to closure (at ages 6-14 years), AVN of the femoral head presenting during closure (at ages 15-18 years), and precocious OA of the hip presenting after closure (at ages 21-34 years). Molecular modeling predicted that the serine-to-glycine substitution loosens the helical structure of the protein.

CONCLUSION

The p.Gly1170Ser mutation of COL2A1 in the family described is responsible for pathology confined to the hip joint, which presents as isolated precocious hip OA, AVN of the femoral head, or Legg-Calvé-Perthes disease. Age at onset in relation to closure of the femoral head epiphysis appears to be a critical factor in determining disease pattern.