The Pathogenesis and Treatment of Legg-Calvé-Perthes Disease

Effectiveness of therapeutic methods for Legg-Calvé-Perthes disease according to staging, limits of conservative treatment: a systematic review with meta-analysis

Legg-Calvé-Perthes disease (LCPD) is known as a self-limiting pediatric orthopedic pathology that affects the hip due to ischemia with consequent aseptic avascular necrosis of the femoral head. This is a systematic literature review carried out in the databases indexed in the Medical Literature Analysis and Retrieval System Online (MEDLINE) in accordance with the precepts established by the PRISMA methodology (Preferred Reporting Items for Systematic Reviews and Meta-Analyses). The aim was to compare the effectiveness of treatment for Legg-Calvé-Perthes disease in relation to its staging: the limits of conservative treatment. Conservative treatment was used in four studies, and most patients under the age of 6.5 had Stulberg I and II results. Older patients, between eight and ten years old, had a relatively better classification when they underwent surgical treatment. In this context, the data collected did not show significant variations; however, it was possible to observe that conservative treatment was more effective in this population, while surgical treatment is better recommended at older ages.

Proximal femoral varus osteotomy for Legg-Calvé-Perthes disease: Do age and lateral pillar classifications influence short-to-mid-term clinical and radiological outcomes?

INTRODUCTION

Proximal femoral varus osteotomy (FVO) is one of the most used treatment methods with acceptable outcomes for Legg-Calvé-Perthes disease (LCPD). We aimed to investigate the influence of age at disease onset and the Lateral Pillar classification on clinical and radiological outcomes of FVO surgery LCPD patients between 6-12years of age.

HYPOTHESIS

Proximal FVO surgery in the early fragmentation phase of LCPD patients led to acceptable clinical and radiographic outcomes in a 3-year follow-up, regardless of preoperative age and Herring type.

MATERIAL AND METHODS

Fifty patients with LCPD (Herring groups B, B/C, and C) who underwent FVO were retrospectively reviewed. We evaluated radiological [center-edge angle, extrusion index, epiphyseal index, acetabular index, articulo-trochanteric distance (ATD)] and clinical [hip abduction range of motion (ROM), Trendelenburg sign, pain, and Harris hip score (HHS)] outcomes with a follow-up of 37.3±10.5months (range: 24-180months). Finally, the overall treatment outcome was assessed using the Stulberg classification.

RESULTS

The ROC curve analysis did not reveal any significant relationship between age and clinical or radiological outcomes, and there was no predictable age cut-off for surgical outcomes (p=0.13). No significant difference was found in Stulberg classification at the follow-up between patients with type B, B/C, and C of the lateral pillar (p>0.05).

DISCUSSION

Our results demonstrated that open-wedge proximal FVO surgery in the early fragmentation phase of LCPD patients led to acceptable clinical and radiographic outcomes in a 3-year follow-up. Each sample of our study was very small and a lot of variables were measured, making this result not adequately strong enough to draw a robust conclusion. However, FVO surgery remains a possible suggestion for patients in the early fragmentation phase, and age and lateral pillar type may not be limiting factors.

LEVEL OF EVIDENCE

IV; therapeutic retrospective cohort.

OSTEOCHONDRITIS DISSECANS OF THE HIP IN LEGG-CALVÉ-PERTHES DISEASE: CASE REPORT AND REVIEW

Introduction

Legg-Calvé-Perthes disease (LCPD) is the idiopathic osteonecrosis of the capital femoral epiphysis in children. It is a self-healing condition, and the morphology of the hip may vary according to the severity of the disease, among several other factors. The treatment focuses on attempts to prevent femoral head collapse, obtain functional hip motion recovery, and reduce pain. Osteochondritis Dissecans (OCD) of the femoral head has been reported in 2% to 7% of patients diagnosed with healed LCPD. Although OCD may remain asymptomatic, the osteochondral fragment has the potential to become unstable, evolving into symptoms of pain, locking, catching, and snapping.

Case report

We present a case report of a ten-year-old boy with an OCD lesion following LCPD who underwent effective osteochondral fixation through the surgical hip dislocation approach. The patient evolved to excellent functional recovery at 1 year post-operatively.

Discussion

The surgical hip dislocation approach allows anatomical fixation of the OCD fragment, as well as improvement of hip biomechanics, decreasing pain, improving range of motion and joint congruency, and preserving the native articular cartilage. It also gives the surgeon the opportunity to assess hip stability, femoroacetabular impingement and labral tears, allowing a wide variety of options for the treatment of the healed LCPD. Level of Evidence IV; Type of study Case Report.

Does transepiphyseal drilling and closure of the greater trochanter in early Legg-Calve-Perthes disease improve natural history?

PURPOSE

There is no consensus regarding treatment of Legg-Calve-Perthes disease (LCPD). The most common sequel of the disease is coxa breva and overgrowth of the greater trochanter (GT). Our purpose was to examine the effectiveness of transepiphyseal drilling combined with closure of the GT apophysis in patients with LCPD.

METHODS

During 2013-2018, we treated 16 consecutive cases of LCPD. Average age was 7.5 (range 6-10) years; nine patients were in early fragmentation, five in late fragmentation and one in reossification stages. Treatment protocol included hip arthrography, percutaneous drilling of the femoral head epiphysis, percutaneous tenotomy of adductor longus and epiphysiodesis of the GT apophysis.

RESULTS

Mean follow-up was 38 months. One patient was lost to follow-up. All patients had a limp prior to surgery. However, at latest follow-up, 10/15 patients had no limp, 11 patients had substantial improvement in hip range of motion. On radiographs, nine patients had Stulberg type 1-2, one type 3 and five type 4-5. There was no change in the epiphysio-trochanteric distance in any patient. Eight out of nine patients treated in the early fragmentation stage had good clinical and radiographic outcome. Most patients treated in late fragmentation stage had Stulberg 4-5 hip and required additional procedures.

CONCLUSIONS

Based on our preliminary experience, our protocol can be effective in the treatment of patients with LCPD in the initial or early fragmentation stages by improving the clinical and radiographic outcomes of the disease. This minimally invasive approach does not compromise any future treatment options.

LEVEL OF EVIDENCE

IV.

Early disc degeneration in radiotherapy-treated childhood brain tumor survivors

BACKGROUND

Childhood brain tumor (BT) survivors have an increased risk of treatment-related late effects, which can reduce health-related quality of life and increase morbidity. This study aimed to investigate lumbar disc degeneration in magnetic resonance imaging (MRI) in adult survivors of radiotherapy-treated childhood BT compared to age and sex-matched population controls.

METHODS

In this cross-sectional comparative study, 127 survivors were identified from hospital registries. After a mean follow-up of 20.7 years (range 5-33.1), 67 survivors (mean age 28.4, range 16.2-43.5) were investigated with MRI and compared to 75 sex-matched population-based controls. Evaluated MRI phenotypes included Pfirrmann grading, , intervertebral disc protrusions, extrusions, and high-intensity-zone-lesions (HIZ). Groups were also compared for known risk factors of lumbar intervertebral disc (IVD) degeneration.

RESULTS

Childhood BT survivors had higher Pfirrmann grades than controls at all lumbar levels (all p < 0.001). Lumbar disc protrusions at L4-5 (p = 0.02) and extrusions at L3-4 (p = 0.04), L4-5 (p = 0.004), and L5-S1 (p = 0.01) were significantly more common in the BT group compared to the control. The survivor cohort also had significantly more HIZ-lesons than the controls (n=13 and n=1, p=0.003). Age at diagnosis was associated with lower degree of IVD degeneration (p < 0.01). Blood pressure correlated with IVD degeneration (P < 0.05).

CONCLUSIONS

Signs of early disc degeneration related to tumor treatment can be seen in the IVDs of survivors. Disc degeneration was more severe in children treated in adolescence.

Patient Adherence to Wide Abduction Brace Treatment for Legg-Calvé-Perthes Disease

BACKGROUND

A wide abduction brace called the A-frame brace is used to contain the deformed femoral head and improve femoral head remodeling in patients with Legg-Calvé-Perthes disease (LCPD). While there is some data showing the efficacy of brace treatment, little is known about patient adherence. The purpose of this study was to measure A-frame brace adherence using temperature sensors and to identify factors that influence adherence.

METHODS

This is an IRB-approved retrospective study of 61 patients with LCPD treated with an A-frame brace between ages 5 and 11. Brace wear was measured using built-in temperature sensors. Pearson correlation coefficient and multiple regression were used to determine relationships between patient characteristics and brace adherence.

RESULTS

Of 61 patients, 80% were male. Mean age at LCPD onset was 5.9±1.8 years and the mean age at initiation of brace treatment was 7.1±1.5 years. Fifty-eight patients (95%) were in the fragmentation or reossification stage at the start of bracing, with 23 patients (38%) having lateral pillar B, 7 (11%) lateral pillar B/C, and 31 (51%) lateral pillar C. Forty-two (69%) patients were treated with a Petrie cast for 6 weeks before the A-frame brace. Mean adherence, defined as the ratio of measured over prescribed brace wear, was 0.69±0.32. Mean adherence improved with age (P<0.05), increasing from 0.57 in patients less than 6 to 0.84 in patients aged 8 to 11. Patients first treated with a Petrie cast had significantly better adherence than those without (0.77 vs. 0.50; P<0.005). Adherence was negatively associated with the amount of prescribed brace wear per day (P<0.005). Adherence did not change significantly between the start and end of treatment and was not significantly associated with sex or attention deficit hyperactivity disorder.

CONCLUSIONS

A-frame brace adherence was significantly associated with age at treatment, prior Petrie casting, and the amount of daily prescribed brace wear. These findings provide new insight into A-frame brace treatment, which will lead to better patient selection and counseling to optimize adherence.

LEVEL OF EVIDENCE

III Therapeutic Study.

Tripleosteotomie bei Morbus Perthes

Operationsziel

Durch die Osteotomie des Ischium‑, Pubis- und Iliumknochens kann das Acetabulum über den Hüftkopf geschwenkt werden, sodass der meist anterolateral vorstehende Anteil des Hüftkopfes wieder überdacht wird. Das Ziel ist der Erhalt des Containments der Hüfte, hiermit ist die Wiederherstellung der Kongruenz zwischen dem lateralisierten Hüftkopf und dem Acetabulum gemeint. Das Acetabulum wirkt so als eine Art Schablone für den Hüftkopf, um eine möglichst sphärische Ausheilung des Hüftkopfes zu erreichen.

Indikationen

Schwere Morbus-Perthes-Erkrankung mit radiologisch sichtbarer Lateralisation des Hüftkopfes und Head-at-risk-Zeichen. Voraussetzung ist, dass der Hüftkopf sich konzentrisch reponieren lässt (Abduktionsaufnahme oder Arthrographie).

Kontraindikationen

„Hinged abduction“. Keine konzentrische Reposition des Hüftkopfes möglich.

Operationstechnik

Arthrographie des Hüftgelenkes zur Bestätigung der Operationsindikation. Darstellung und Osteotomie des Ischiums über einen modifizierten Ludloff-Zugang, Osteotomie des Iliums und Pubis über einen modifizierten Smith-Petersen-Zugang. Verbesserung der Hüftkopfüberdachung durch Schwenken des Acetabulums über den Hüftkopf. Fixation des azetabulären Fragmentes mit Vollgewinde-Kirschner-Drähten oder 3,5-mm-Kortikalisschrauben.

Weiterbehandlung

Mobilisation an Gehstöcken (kleine Kinder im Rollstuhl). Abstellen des Fußes erlaubt. Teilbelastung für 4 bis 6 Wochen (je nach Alter des Patienten). Danach bei im Röntgen guten Konsolidationszeichen Belastungsaufbau innerhalb 1 bis 2 Wochen.

Ergebnisse

Sehr gute Ergebnisse hinsichtlich Operationstechnik und Ausheilung in der eigenen Klinik. In einer eigenen noch nicht veröffentlichten Studie mit einem durchschnittlichen Untersuchungszeitraum von 5 Jahren zeigten sich bei 30 Patienten sehr gute klinische und radiologische Ergebnisse nach Tripleosteotomie bei Morbus Perthes.

Outcomes in Pediatric Hip FAI Surgery: a Scoping Review

PURPOSE OF REVIEW

Femoracetabular impingement (FAI) is a common source of hip pain in children and adolescents. While nonoperative therapies and open surgical procedures can be effective, hip arthroscopy is a minimally invasive treatment option with substantial benefit. The purpose of this paper is to evaluate the current role of hip arthroscopy in treating FAI within the pediatric population. This article examines its efficacy through a review of hip arthroscopy outcomes in the contemporary orthopaedic literature.

RECENT FINDINGS

Morphologic changes in the acetabulum and proximal femur seen in FAI can be attributed to a multitude of etiologies-including idiopathic FAI, Legg-Calve-Perthes, and slipped capital femoral epiphysis. In general, arthroscopic treatment of FAI secondary to these conditions leads to statistically significant improvements in pain and patient-reported outcomes in the short and long term. In the pediatric athlete, repetitive stress on the hip perpetuates FAI and can drastically hinder performance. Hip arthroscopy allows for a high rate of return to sport with minimal morbidity in this population. Overall, pediatric hip arthroscopy is effective in treating FAI secondary to a wide variety of conditions. Despite its clinical benefits, patients and their families should be counseled regarding alternative treatments, potential complications, and return to play.

Bone Infarcts and Tumorigenesis—Is There a Connection? A Mini-Mapping Review

(1) Background: Avascular necrosis (AVN) may affect every part of the bone. Epiphyseal infarcts are likely to be treated early because most are symptomatic. However, meta- and diaphyseal infarcts are silent and are diagnosed incidentally. Sarcomas developing in the necrotic bone are extremely rare, but they have been reported in the literature. (2) Methods: We conducted a mapping review of recent evidence regarding these malignancies. Methods: A mapping review using a systematic search strategy was conducted to answer research questions. We limited our research to the last ten years (2012–2022). (3) Results: A total of 11 papers were identified, including 9 case reports and 3 case series. The pathomechanism of carcinogenesis in AVN was not investigated to date. Histologically, most tumors were malignant fibrous histiocytoma. The prognosis is relatively poor, especially for patients with metastases, but adjuvant chemotherapy may increase short- and long-term survival. (4) Conclusions: Since AVN-related malignancies are sporadic, no prospective studies have been conducted. The majority of evidence comes from small case series. More research is needed to identify the risk factors that would justify follow-up of patients after bone infarcts at higher risk of developing a malignancy.

Perthes Disease in a Child With Osteogenesis Imperfecta From a Rare Genetic Variant: A Case Report

Background: Although certain genetic components have been reported as contributing factors for Perthes disease, its etiology remains unclear. We present a rare case of Perthes disease in a child with osteogenesis imperfecta (OI) caused by a mutation in the COL1A1 gene (NM_000088):exon25:c.1726C>T, (p.Gln576X).

Case presentations: A 7-year-old boy was initially treated at our medical facility in March 2016 with a history of chronic pain in right hip joint and limping for a year. He was diagnosed as Perthes disease in the right hip joint. He underwent acetabular osteotomy and ipsilateral proximal femoral varus osteotomy for better containment. During the follow-ups, the right hip demonstrated a normal range of motion without pain, and the pelvic X-ray demonstrated Stulberg Type II hip joint with a round femoral head. In the latest admission in 2022, he suffered from a right femoral shaft fracture after petty violence. After reviewing his medical history, he was suspected of having OI. The whole exome sequencing demonstrated a gene mutation in COL1A1 (OMIM 166200) and confirmed the diagnosis of OI. Telescopic nailing was used to treat the femoral shaft fracture. After the nailing of the right femur, the appearance of the lower extremity seemed normal and symmetrical.

Conclusion: This study revealed that there might be an association between OI and Perthes disease. Our case report enriches the phenotypes of osteogenesis imperfecta and provides insight into the pathogenesis of LCPD.

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.

Operative Management of Avascular Necrosis of the Femoral Head in Skeletally Immature Patients: A Systematic Review

Purpose: Osteonecrosis of the femoral head (ONFH) is common in skeletally immature patients. The management of ONFH is controversial, with limited evidence and unpredictable results. This study systematically reviewed the current operative modalities and clinical outcomes of surgical management for ONFH in skeletally immature patients. Methods: The present study was conducted according to the PRISMA 2020 guidelines. PubMed, Google Scholar, Embase, and Web of Science databases were accessed in October 2021. All the published clinical studies reporting data concerning the surgical management of ONFH in skeletally immature patients were included. Results: This review included 122 patients (127 hips). 38.2% (46 of 122) were female. The mean age of the patients was 14.2 ± 2.3 years. The mean duration of the follow-up was 55.3 ± 19.6 months. The Harris Hip Score improved from 68.8 ± 11.9 at baseline to 90.5 ± 6.5 at last follow-up (p < 0.0001). Femoral head collapse and secondary hip degeneration were the most common complications. Conclusion: Several surgical techniques are available and effective for the management of ONFH in skeletally immature patients. This study evidenced high heterogeneity of the surgical procedures and eligibility criteria. Further high-quality investigations are required to establish proper indications and surgical modalities.

Microarray analysis of lncRNA and mRNA expression profiles in patients with Legg-Calve-Perthes disease

BACKGROUND

The etiology and underlying pathogenic mechanisms of Legg-Calve-Perthes disease (LCPD) still remain unclear. A disruption of blood supply to the femoral head, producing ischemic necrosis, appears to be the critical pathological event. The lncRNAs play crucial roles in many biological processes and are dysregulated in various human diseases. However, its expression profiles and the potential regulatory roles in the development of LCPD have not been investigated.

METHODS

In this study, differentially expressed lncRNA and mRNA of Legg-Calve-Perthes disease patients were profiled. Several GO terms and pathways that play important roles in the regulation of vascular structure, function or coagulation were selected for further analysis. The lncRNA -mRNA interacting networks in LCPD tissues were constructed to identify novel potential targets for further investigation.

RESULTS

The microarray analysis revealed that 149 lncRNAs and 37 mRNAs were up-regulated, and 64 lncRNAs and 250 mRNAs were down-regulated in LCPD tissues. After filtering, we finally found 14 mRNAs and constructed an mRNA-lncRNA interacting network. Through the analysis of the interaction network, we finally found 13 differentially expressed lncRNAs, which may be implicated in the pathogenesis of LCPD. These mRNAs/lncRNAs were further validated with qRT-PCR.

CONCLUSION

The findings of this study established a co-expression network of disease-related lncRNAs and mRNAs which screened out from the concerned G.O. terms and Pathways, which may provide new sights for future studies on molecular mechanisms of LCPD.

Osteoblasts/Osteocytes sirtuin6 Is Vital to Preventing Ischemic Osteonecrosis Through Targeting VDR-RANKL Signaling

Ischemic osteonecrosis (ION) can produce permanent deformity and osteoarthritis in the femoral head and other joints. No biologic treatment has been established, and the molecular mechanisms involved in the pathogenesis of ION have not been elucidated. In this work, we found that treatment with sirtuin6 (Sirt6) suppressed inflammatory cytokines, bone resorption, progression of osteoarthritis, and reduced bone deformity in an ION mouse model. We used a deacetylase mutant adenovirus to confirm that those effects were caused by the deacetylase function of Sirt6. Among the osteoclastogenic factors of osteoblasts, only the receptor activator of NF-κb ligand (RANKL) level changed in response to Sirt6 knockout in primary osteoblasts. In particular, the vitamin D receptor physically interacted with Sirt6 and induced recruitment of Sirt6 around RANKL promoters. Finally, Tg mice overexpressing Sirt6 resisted osteocyte death, bone resorption, and progression of osteoarthritis after ischemic surgery, whereas osteoblast/osteocyte-specific Sirt6 knockout mice showed aggravated bone loss and severe deformity. Our findings demonstrate that administration of Sirt6 prevents bone loss and osteoarthritis in ischemic conditions. Activation of Sirt6 in osteoblasts/osteocytes could be a new therapeutic approach to treating ION of the femoral head and other bone regions. © 2020 American Society for Bone and Mineral Research (ASBMR).

Global differences in the treatment of Legg-Calvé-Perthes disease: a comprehensive review

INTRODUCTION

Global discussions regarding the treatment of Legg-Calvé-Perthes disease (LCPD) are still controversial. The aim of this study was to characterize the worldwide regional differences in nonoperative and operative treatment for LCPD.

MATERIALS AND METHODS

Based on a comprehensive literature search, 123 studies describing the results of nonoperative and operative treatment for LCPD were included. Overall, disease and outcome parameters of 6,968 hips were recorded and compared among the continents-Europe, North America, Asia, Africa, South America, and Australia.

RESULTS

Our results showed that the continents differed regarding initial disease progression and therapeutic decision-making, but the final outcome was comparable. The reported proportion of affected hips with mild presentation tended to be higher in Europe, North America, and Africa, whereas disease progression was more severe in Asia, Australia, and South America. Nonoperative treatment was reported more frequently in Europe and North America, while operative management was more common in the rest of the world. Femoral osteotomy was performed more frequently than pelvic osteotomy worldwide, but pelvic osteotomy was comparably more common in North America, Australia, and South America.

CONCLUSIONS

The continents differed in terms of therapies for LCPD, while the final outcome was similar. Studies with greater evidence and larger sample size are needed to evaluate the effect of therapeutic measures on LCPD outcome.

LEVEL OF EVIDENCE

III (systematic review of level III studies).

Comparison of surgical and nonsurgical containment methods for patients with Legg-Calvé-Perthes disease of the onset ages between 6.0 and 8.0 years: Salter osteotomy versus a non-weight-bearing hip flexion-abduction brace

Since bone healing potential decreases with age, patients with Legg-Calvé-Perthes disease should receive treatment appropriate to their age group. Nonsurgical treatment is commonly applied to patients under 6.0 years of age at the onset and surgical treatment is recommended for those over 8.0 years of age, but it remains unclear which is better for those between 6.0 and 8.0 years. The aim of this retrospective study was to compare outcomes of Salter osteotomy and a non-weight-bearing brace in this age group. Inclusion criteria were unilateral Legg-Calvé-Perthes disease patients who were 6.0-8.0 years of age at the onset, who had more than 50% femoral head involvement without hinge abduction, and who underwent either Salter osteotomy (n = 35) or a non-weight-bearing hip flexion-abduction brace (n = 18). Radiological and clinical outcomes at skeletal maturity were compared between the two groups. The mean follow-up durations were 9.4 years in the Salter osteotomy group and 10.0 years in the brace group. There was no significant difference in the modified Waldenström classification at the beginning of treatment and the Catterall and modified lateral pillar classifications evaluated at the fragmentation stage between the groups. At skeletal maturity, the Stulberg classification, the sphericity deviation score, femoral head overgrowth, and the articulo-trochanteric distance were similar between the groups, but the Salter osteotomy group showed significantly smaller lateralization of the femoral head and better acetabular shape and coverage than the brace group: femoral head lateralization (P < 0.001), acetabular depth-to-width ratio (P = 0.002), Sharp angle (P < 0.001), lateral acetabular shape (P = 0.027), acetabular head index (P < 0.001). There was no significant difference in hip pain and motion between the groups. In this age group, Salter osteotomy provides better femoral head position and acetabular shape and coverage than a non-weight-bearing brace.

The diagnosis and management of common childhood orthopedic disorders: An update

Musculoskeletal illness represents a significant portion of office visits to primary and urgent care clinicians. Despite this, little emphasis is placed on learning pediatric orthopaedics during medical school or residency. The focus of this paper is to provide a systematic approach to this general musculoskeletal physical exam and to assist in the recognition of what conditions are normal development and what conditions require observation, workup and referral to an experienced pediatric orthopaedist.

Osteonecrosis of Femoral Head is Associated with Congenital Multiple Pituitary Hormone Deficiency: Report of Three Cases and Literature Review

Objective: Pituitary hormones are critical for bone development and maturation. It is currently unknown whether congenital multiple pituitary hormone deficiency (CMPHD) is associated with osteonecrosis of femoral head (ONFH). Methods: Clinical presentations and hormonal profiles of three patients with CMPHD and ONFH were retrospectively described. The incidence of ONFH in this population was studied. Results: (1) Congenital hypopituitarism was diagnosed in three patients. Femoral epiphyseal fusion in these patients was markedly delayed, and they had very low bone mineral density. (2) Hip pain, which is the main presentation of ONFH, occurred at the age of 20-30 years. ONFH induced by excessive glucocorticoids was excluded. (3) The estimated incidence of ONFH was approximately 694:100,000. Conclusions: CMPHD, especially a lack of growth and sex hormones, may contribute to ONFH.

A comparison of subtraction MRI with the standard contrast-enhanced imaging in Perthes' disease

PURPOSE

Perthes' disease (PD) results from loss of blood supply to the hip and can progress to femoral head deformity. MRI in the early course of the disease can provide data on the initial extent of infarct. Vascularity of the femoral head is assessed by gadolinium-enhanced MRI (contrast MRI), which may be improved by the digital subtraction technique (subtraction MRI). We hypothesized that gadolinium-enhanced MRI without subtraction was comparable with subtraction MRI in depicting the femoral head perfusion.

METHODS

In all, 34 patients (34 hips) with unilateral PD had gadolinium-enhanced MRI as part of a prospectively randomized study. Nine patients had three MRIs, 15 had two and ten had a single MRI. Measurement of perfusion of the femoral head (MRI perfusion index) was obtained using digital image analysis on all the MRIs, including both before and after subtraction. A paired sample t-test was performed to compare the measurements.

RESULTS

The mean age of the patients was 8.9 years (sd 1.6). At the time of diagnosis, the subtraction MRI did not elicit a statistically significant difference in MRI perfusion index measurements when compared with the contrast MRI (p = 0.19). The same findings were found when including all patients at various stages of the disease (p = 0.30). Qualitatively, although some subtraction MRI images showed superior delineation of epiphysis, there are no significant differences throughout the whole series.

CONCLUSION

Although the current literature supports the increasing role of the subtraction MRI for PD management, our study proposed that the contrast MRI without subtraction technique appears adequate in assessing femoral head perfusion.

LEVEL OF EVIDENCE

Level I - Diagnostic study.

Drilling Combined with Adipose-derived Stem Cells and Bone Morphogenetic Protein-2 to Treat Femoral Head Epiphyseal Necrosis in Juvenile Rabbits

This study was designed to evaluate the effects of drilling through the growth plate and using adipose-derived stem cells (ADSCs) and bone morphogenetic protein-2 (BMP-2) to treat femoral head epiphyseal ischemic necrosis, which can be done in juvenile rabbits. Passagefour bromodeoxyuridine (BrdU)-labeled ADSCs were cultured, assayed with MTT to determine their viability and stained with alizarin red dye to determine their osteogenic ability. Two-month-old, healthy male rabbits (1.2 to 1.4 kg, n=45) underwent ischemic induction and were randomly divided into five groups (group A: animal model control; group B: drilling; group C: drilling & ADSCs; group D: drilling & BMP-2; and group E: drilling & ADSCs & BMP-2). Magnetic resonance imaging (MRI), X-ray imaging, hematoxylin and eosin staining and BrdU immunofluorescence detection were applied 4, 6 and 10 weeks after treatment. Approximately 90% of the ADSCs were labeled with BrdU and showed good viability and osteogenic ability. Similar results were observed in the rabbits in groups C and E at weeks 6 and 10. The animals of groups C and E demonstrated normal hip structure and improved femoral epiphyseal quotients and trabecular areas compared with those of the groups A and B (P<0.01). Group D demonstrated improved femoral epiphyseal quotients and trabecular areas compared with those of groups A and B (P<0.05). In summary, drilling through the growth plate combined with ADSC and BMP-2 treatments induced new bone formation and protected the femoral head epiphysis from collapsing in a juvenile rabbit model of femoral head epiphyseal ischemic necrosis.

A simple, precocious, and reliable way to assess future clinical outcome in children with Perthes disease and mild femoral head involvement: correlation between MRI with diffusion-weighted and dynamic gadolinium-enhanced subtraction and Catterall and Herring classifications

BACKGROUND

In children older than 5 years with a mild form of Legg-Calvé-Perthes disease, the outcome is difficult to predict. In this study, we retrospectively correlated gadolinium-enhanced subtracted (DGS) and diffusion (DWI) MRI findings to the radiographic assessment according to the Catterall and Herring et al. classifications and to the final score according to Stulberg et al.: the aim was to identify a precocious, simple, and objective criterion to differentiate between forms evolving favourably and forms requiring an early surgical treatment in order to avoid femoral head deformity and subsequent osteoarthritis.

METHODS

Twelve boys with unilateral mild femoral head involvement (Catterall grade 2 or grade 3) underwent DSG and DWI MR during the early phase of the disease. The absence of enhancement of the external pillar on DSG MRI and the presence of metaphyseal hyperintensity on DWI were considered to be the signs of poor outcome. These findings were correlated with the Catterall and Herring et al. classifications at the initial sclerotic stage and early fragmentation phase and with the Stulberg et al. classifications at least 5 years after the onset of the disease.

RESULTS

DSG MRI findings correctly discriminated three out of four patients with a good outcome but underestimated two out of eight patients with a poor outcome. DWI findings correlated with the Catterall and Herring et al. classifications in 12 out of 12 cases. In only one case, DWI findings did not correlate with the Stulberg et al. classification.

CONCLUSION

DWI MR provides an objective and accurate prognostic criterion that is relatively easy to recognise. DGS MR findings are less accurate, thus underestimating the gravity of the disease in one-fourth of the patients with a poor outcome.

Protocol for a randomised control trial of bisphosphonate (zoledronic acid) treatment in childhood femoral head avascular necrosis due to Perthes disease

INTRODUCTION

Perthes disease (PD) is an idiopathic disorder presenting with avascular necrosis to the femoral head, which frequently results in flattening. Long-term function is directly related to the subsequent femoral head sphericity. Current treatment includes mechanical modalities and surgical procedures, which are therapeutic but are not uniformly able to prevent collapse. The use of the nitrogen-containing bisphosphonate zoledronic acid (ZA) to inhibit osteoclastic bone resorption is aimed at preserving femoral head strength, reducing collapse and thus maintaining shape. The proposed multicentre, prospective, randomised controlled trial intends to evaluate the efficacy of ZA treatment in PD.

METHODS AND ANALYSIS

An open-label randomised control trial recruiting 100 children (50 each treatment arm) 5 to 16 years old with unilateral PD. Subjects are randomly assigned to either (a) ZA and standard care or (b) Standard care. The primary outcome measure is deformity index (DI), a radiographic parameter of femoral head roundness assessed at 24 months, following 12 months of ZA treatment (3-monthly doses of ZA 0.025 mg/kg at baseline, 3, 6, 9 and 12 months) plus 12 months observation (group A) or 24 months of observation (group B). Secondary outcome measures are femoral head subluxation, Faces Pain scale, Harris hip score and quality of life. Assessments are made at baseline, 3 monthly during the first year of follow-up and then 6 monthly, until the 24th month.

ETHICS AND DISSEMINATION

The study commenced following the written approval from the Human Research Ethics Committee. Safety considerations regarding the effects of ZA are monitored which include the subject's symptomatology, mineral status, bone mass and turnover activity, and metaphyseal modelling. Data handling plan requires that all documents, clinical information, biological samples and investigation results will be held in strict confidence by study investigators to preserve its safety and confidentiality.

TRIAL REGISTRATION NUMBER

Australian and New Zealand Clinical Trials ACTRN12610000407099, pre-results.