Long-Term Bisphosphonate Therapy in Osteogenesis Imperfecta

Prevalence, number of fractures, and hospital characteristics among the pediatric population with osteogenesis imperfecta: results from the nationwide registry of Türkiye

OBJECTIVE

Osteogenesis imperfecta is a rare connective tissue disorder with an estimated number of 4-20 cases per 100 000 inhabitants. Although the prevalence differs among regions, there are only a few number of national registry studies published previously. The aim of this study was to determine the prevalence of osteogenesis imperfecta among the pediatric age group in Türkiye, together with the patient and hospital characteristics.

METHODS

Via the e-health database of the Turkish Ministry of Health, we collected and retrospectively evaluated the medical records of the patients who were under 18 years of age with the diagnosis of osteogenesis imperfecta between 2016 and 2022. Total number of fractures, treatment modalities, and the hospital characteristics were also recorded. Two thousand seven hundred forty patients were extracted with a mean age of 9.77 ± 4.81 years.

RESULTS

The prevalence of osteogenesis imperfecta in Türkiye among the pediatric population was calculated as 11.6 per 100 000 individuals. The median annual incidence was 31.5 per 100 000 live births between 2016 and 2022. There were 17.4 hospital admissions per patient per year. The mean age at the time of in-hospital mortality was 4.08 ± 5.03 years. The fracture rate per patient per year was 0.56 and conservative treatment was the most commonly preferred modality for all ages.

CONCLUSION

This is the first registry-based nationwide study of osteogenesis imperfecta patients in Türkiye, providing important characteristics of the disease. Together with the help of the ongoing development of national health database systems, precision in patient identification would yield substantial benefits in terms of management of osteogenesis imperfecta.

Co-delivery of rhBMP-2 and zoledronic acid using calcium sulfate/hydroxyapatite carrier as a bioactive bone substitute to enhance and accelerate spinal fusion

Recombinant human bone morphogenetic protein-2 (rhBMP-2) has been FDA-approved for lumbar fusion, but supraphysiologic initial burst release due to suboptimal carrier and late excess bone resorption caused by osteoclast activation have limited its clinical usage. One strategy to mitigate the pro-osteoclast side effect of rhBMP-2 is to give systemic bisphosphonates, but it presents challenges with systemic side effects and low local bioavailability. The aim of this in vivo study was to analyze if posterolateral spinal fusion (PLF) could be improved by utilizing a calcium sulfate/hydroxyapatite (CaS/HA) carrier co-delivering rhBMP-2 and zoledronic acid (ZA). Six groups were allocated (CaS/HA, CaS/HA + BMP-2, CaS/HA + systemic ZA, CaS/HA + local ZA, CaS/HA + BMP-2 + systemic ZA, and CaS/HA + BMP-2 + local ZA). 10-week-old male Wistar rats, were randomly assigned to undergo L4-L5 PLF with implantation of group-dependent scaffolds. At 3 and 6 weeks, the animals were euthanized for radiography, μCT, histological staining, or biomechanical testing to evaluate spinal fusion. The results demonstrated that the CaS/HA biomaterial alone or in combination with local or systemic ZA didn't support PLF. However, the delivery of rhBMP-2 significantly promoted PLF. Combining systemic ZA with BMP-2 didn't enhance spinal fusion. Notably, the co-delivery of rhBMP-2 and ZA using the CaS/HA carrier significantly enhanced and accelerated PLF, without inhibiting systemic bone turnover, and potentially reduced the dose of rhBMP-2. Together, the treatment regimen of CaS/HA biomaterial co-delivering rhBMP-2 and ZA could potentially be a safe and cost-effective off-the-shelf bioactive bone substitute to enhance spinal fusion.

Psychosocial Outcomes of Pain and Pain Management in Adults with Osteogenesis Imperfecta: A Qualitative Study

Osteogenesis imperfecta (OI) is a genetic disorder characterized by bone fragility and fractures, short stature, dental abnormalities, hearing loss, scoliosis, and chronic pain. Despite a growing literature on the functional outcomes of OI, limited research has explicitly examined the psychosocial outcomes of pain within OI. Adults with OI (N = 15) were interviewed to understand pain-related experiences through a thematic analysis of semi-structured interview data. Research team members, genetic research experts, and OI clinicians developed an interview guide focused on topics related to pain and mental health challenges. Participants' transcripts were coded by two independent coders; codes were then merged across coders and quotation outputs were subsequently abstracted (paraphrased then thematically classified) to identify common themes. Themes related to pain management variability regarding pain type, pain risk management and accessibility, pain outcomes (e.g., behavior, cognitive, affective), and pain exacerbating factors (e.g., individual, contextual) were identified. Participants reported chronic and acute pain, and despite the inaccessibility and stigmatization of pain medications (e.g., opioids), pharmacological treatments were the most common pain management approach. Participants reported negative pain outcomes, such as limited daily functioning and activity participation, fear, anger, anxiety, depression, and difficulty concentrating. Lastly, participants suggested that lack of physician and community knowledge on chronic pain in OI indirectly exacerbates both subjective pain intensity and outcomes. Although limited by a small, nondiverse sample, the current study provides valuable exploration of the unique pain experiences of adults with OI that may have implications for proactive management, treatment development, and clinician training.

Dysregulation of MicroRNAs in Adult Osteogenesis Imperfecta: The miROI Study

As epigenetic regulators of gene expression, circulating micro-RiboNucleic Acids (miRNAs) have been described in several bone diseases as potential prognostic markers. The aim of our study was to identify circulating miRNAs potentially associated with the severity of osteogenesis imperfecta (OI) in three steps. We have screened by RNA sequencing for the miRNAs that were differentially expressed in sera of a small group of OI patients versus controls and then conducted a validation phase by RT-qPCR analysis of sera of a larger patient population. In the first phase of miROI, we found 79 miRNAs that were significantly differentially expressed. We therefore selected 19 of them as the most relevant. In the second phase, we were able to validate the significant overexpression of 8 miRNAs in the larger OI group. Finally, we looked for a relationship between the level of variation of the validated miRNAs and the clinical characteristics of OI. We found a significant difference in the expression of two microRNAs in those patients with dentinogenesis imperfecta. After reviewing the literature, we found 6 of the 8 miRNAs already known to have a direct action on bone homeostasis. Furthermore, the use of a miRNA-gene interaction prediction model revealed a 100% probability of interaction between 2 of the 8 confirmed miRNAs and COL1A1 and/or COL1A2. This is the first study to establish the miRNA signature in OI, showing a significant modification of miRNA expression potentially involved in the regulation of genes involved in the physiopathology of OI. © 2023 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Developmental Foot Deformities in Patients with Connective Tissue Disorders

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Foot deformities make up a large percentage of all orthopaedic complaints in patients with Down syndrome, Marfan syndrome, Ehlers-Danlos syndrome, Larsen syndrome, and osteogenesis imperfecta.

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Some common causes of foot deformities in these conditions include increased ligament laxity, hypotonia, and hypermobility of the joints.

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Treatment options for syndromic foot deformities include the use of foot orthoses, physical therapy, bracing, and various surgical procedures.

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There is limited evidence supporting the use of surgical intervention to correct foot deformities associated with Down syndrome, Marfan syndrome, Ehlers-Danlos syndrome, Larsen syndrome, and osteogenesis imperfecta. Therefore, further research is needed to determine the short-term and long-term outcomes of these procedures.

Dysfunction of Caveolae-Mediated Endocytic TβRI Degradation Results in Hypersensitivity of TGF-β/Smad Signaling in Osteogenesis Imperfecta

Osteogenesis imperfecta (OI) is a genetic disorder caused by mutations of type I collagen-related genes, and excessive transforming growth factor-beta (TGF-β) signaling is a common mechanism. TGF-β/Smad signaling has inhibitory effects on osteoblast differentiation and maturation and is mainly transduced and regulated by the internalization of a tetrameric receptor complex comprising types I and II TGF-β receptors (TβRI and TβRII). During internalization, clathrin-mediated endocytosis enhances TGF-β/Smad signaling via Smad2/3 phosphorylation and receptors recycling, while caveolae-mediated endocytosis turns off TGF-β/Smad signaling by promoting receptor ubiquitination and degradation. In this study, using an animal model of OI (Colla2^oim , osteogenesis imperfecta murine [oim]/oim mouse), we found that osteoblastic cells of oim/oim mice were more sensitive to the inhibitory effects of TGF-β on osteoblast differentiation and maturation and had much higher cell membrane protein levels of TGF-β receptors than those of wild-type (wt)/wt mice. Further results showed that clathrin-mediated endocytosis of TβRI was enhanced, whereas caveolae-mediated TβRI endocytic degradation was reduced in oim/oim mice, combined with reduced caveolin-1 (Cav-1) phosphorylation. In addition, type I collagen downregulated TβRI via focal adhesion kinase (FAK) and Src activation-dependent Cav-1 phosphorylation. To further examine this mechanism, 4-week-old oim/oim and wt/wt mice were treated with either TβRI kinase inhibitor (SD-208) or vehicle for 8 weeks. SD-208 treatment significantly reduced the fracture incidence in oim/oim mice. Micro-computed tomography and biomechanical testing showed that femoral bone mass and strength were significantly improved with SD-208 treatment in both genotypes. Additionally, SD-208 significantly promoted osteoblast differentiation and bone formation and inhibited bone resorption. In conclusion, dysfunction of caveolae-mediated endocytic TβRI degradation is a possible mechanism for the enhanced TGF-β/Smad signaling in OI. Targeting this mechanism using a TβRI kinase inhibitor effectively reduced fractures and improved bone mass and strength in OI model and, thus, may offer a new strategy for the treatment of OI. © 2022 American Society for Bone and Mineral Research (ASBMR).

Pediatric CKD-MBD: existing and emerging treatment approaches

The effects of bone and mineral metabolism on skeletal formation, as well as vascular and soft tissue calcifications, define chronic kidney disease-metabolic bone disease (CKD-MBD). Treatment recommendations center on establishing adequate vitamin D status, phosphate control through diet restriction and phosphate binders, and the use of vitamin D analogs for specific indications. Several emerging bone-promoting therapies have now been studied in adults with CKD, including bisphosphonates and denosumab. These approaches are associated with improved bone mass and, in some cases, decreased fracture rates in adults with CKD-MBD and are of potential interest for some children with CKD-MBD. In children with CKD and immobilization and/or muscle weakness, bisphosphonates appear to be an effective treatment to increase bone mass; baseline assessment and careful monitoring of bone density and/or bone biopsy findings are important in consideration of any new bone therapies for children with CKD-MBD.

[Osteogenesis imperfecta : A multidisciplinary challenge]

Osteogenesis imperfecta (OI) describes a group of rare diseases which are associated with an increased tendency to bone fractures. In addition to the main symptom of fractures, OI is characterized by a variety of pediatric, pediatric orthopedic and anesthesiological challenges. The multidisciplinary expertise is mostly concentrated at specialized centers. The current treatment concepts aim at minimizing the fracture rate, prevention and treatment of deformities, pain reduction and improved mobility. In addition to pharmacotherapy, conservative and surgical measures are also applied. Scheduled interventions on the extremities are one of the most commonly performed operations in children with OI. Various intramedullary nailing techniques are available. This article addresses the important aspects of multidisciplinary care of children with OI concerning the treatment of the lower extremities.

Clinical, genetic characteristics and treatment outcomes of children and adolescents with osteogenesis imperfecta: a two-center experience

BACKGROUND

Osteogenesis imperfecta (OI), is a heritable, heterogeneous connective tissue disorder, characterized by fragile bones. There are conflicting results about genotype-phenotype correlations and efficiency of bisphosphonate treatment in this disorder.

AIM

We aimed to evaluate the clinical, genetic characteristics, and long-term follow-up results of children and adolescents with OI.

MATERIALS AND METHODS

A two-center retrospective study was conducted using demographic, clinical, and genetic data obtained from the medical records of the patients.

RESULTS

Twenty-nine patients (62% male, median age; 3.6 years) with OI diagnosis from 26 families were included in the study. Thirteen different variants (nine were novel) were described in 16 patients in COL1A1, COL1A2, and P3H1 genes. Our siblings with homozygous P3H1 variants had a severe phenotype with intrauterine and neonatal fractures. Twenty-two patients were treated with bisphosphonates (17 of them with pamidronate, five with alendronate) with a median duration of 3.0 (1.6-4.8) years. Eleven patients (50%) suffered from fractures after the treatment. Haploinsufficiency variants in COL1A1 caused a milder skeletal phenotype with less fracture count and better treatment outcomes than structural variants. When compared with the anthropometric measurements at the initial diagnosis time, height Z-scores were lower on the last clinical follow-up (p = 0.009).

CONCLUSIONS

We could not find an obvious genotype-phenotype correlation in Turkish OI patients with COL1A1 or COL1A2 variants. Treatment with pamidronate was effective in reducing fracture counts, without any long-term adverse effects.

Combination treatment with growth hormone and zoledronic acid in a mouse model of Osteogenesis imperfecta

INTRODUCTION

Osteogenesis imperfecta (OI) or brittle bone disease is a genetic disorder that results in bone fragility. Bisphosphonates such as zoledronic acid (ZA) are used clinically to increase bone mass and reduce fracture risk. Human growth hormone (hGH) has been used to promote long bone growth and forestall short stature in children with OI. The potential for hGH to improve bone quality, particularly in combination with ZA has not been robustly studied.

METHODS

A preclinical study was performed using n = 80 mice split evenly by genotype (WT, Col1a2^+/G610C). Groups of n = 10 were treated with +/-ZA and +/-hGH in a factorial design for each genotype. Outcome measures included bone length, isolated muscle mass, bone parameters assessed by microCT analysis, dynamic histomorphometry, and biomechanical testing.

RESULTS

Treatment with hGH alone led to an increase in femur length in WT but not OI mice, however bone length was increased in both genotypes with the combination of hGH/ZA. MicroCT showed that hGH/ZA treatment increased cortical BV in both WT (+15%) and OI mice (+14.3%); hGH/ZA were also found to be synergistic in promoting cortical thickness in OI bone. ZA was found to have a considerably greater positive impact on trabecular bone than hGH. ZA was found to suppress bone turnover, and this was rescued by hGH treatment in terms of cortical periosteal perimeter, but not by dynamic bone remodeling. Statistically significant improvements in long bone by microCT did not translate into improvements in mechanical strength in a 4-point bending test, nor did vertebral strength improve in L4 compression testing in WT/OI bone.

DISCUSSION/CONCLUSION

These data support hGH/ZA combination as a treatment for short stature, however the improvements granted by hGH alone and in combination with ZA on bone quality are modest. Increased periosteal perimeter does show promise in improving bone strength in OI, however a longer treatment time may be required to see effects on bone strength through mechanical testing.

Nanoparticles functionalized with stem cell secretome and CXCR4-overexpressing endothelial membrane for targeted osteoporosis therapy

Background

Osteoporosis is a chronic condition affecting patients’ morbidity and mortality and represents a big socioeconomic burden. Because stem cells can proliferate and differentiate into bone-forming cells, stem cell therapy for osteoporosis has been widely studied. However, cells as a live drug face multiple challenges because of their instability during preservation and transportation. In addition, cell therapy has potential adverse effects such as embolism, tumorigenicity, and immunogenicity.

Results

Herein, we sought to use cell-mimicking and targeted therapeutic nanoparticles to replace stem cells. We fabricated nanoparticles (NPs) using polylactic-co-glycolic acid (PLGA) loaded with the secretome (Sec) from mesenchymal stem cells (MSCs) to form MSC-Sec NPs. Furthermore, we cloaked the nanoparticles with the membranes from C–X–C chemokine receptor type 4 (CXCR4)-expressing human microvascular endothelial cells (HMECs) to generate MSC-Sec/CXCR4 NP. CXCR4 can target the nanoparticles to the bone microenvironment under osteoporosis based on the CXCR4/SDF-1 axis.

Conclusions

In a rat model of osteoporosis, MSC-Sec/CXCR4 NP were found to accumulate in bone, and such treatment inhibited osteoclast differentiation while promoting osteogenic proliferation. In addition, our results showed that MSC-Sec/CXCR4 NPs reduce OVX-induced bone mass attenuation in OVX rats.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s12951-021-01231-6.

A systematic review and meta-analysis on the efficacy of stem cell therapy on bone brittleness in mouse models of osteogenesis imperfecta

There is no cure for osteogenesis imperfecta (OI), and current treatments can only partially correct the bone phenotype. Stem cell therapy holds potential to improve bone quality and quantity in OI. Here, we conduct a systematic review and meta-analysis of published studies to investigate the efficacy of stem cell therapy to rescue bone brittleness in mouse models of OI. Identified studies included bone marrow, mesenchymal stem cells, and human fetal stem cells. Effect size of fracture incidence, maximum load, stiffness, cortical thickness, bone volume fraction, and raw engraftment rates were pooled in a random-effects meta-analysis. Cell type, cell number, injection route, mouse age, irradiation, anatomical bone, and follow up time were considered as moderators. It was not possible to investigate further parameters due to the lack of standards of investigation between the studies. Despite the use of oim mice in the majority of the investigations considered and the lack of sham mice as control, this study demonstrates the promising potential of stem cell therapy to reduce fractures in OI. Although their low engraftment, cell therapy in mouse models of OI had a beneficial effect on maximum load, but not on stiffness, cortical thickness and bone volume. These parameters all depend on bone geometry and do not inform on its material properties. Being bone fractures the primary symptom of OI, there is a critical need to measure the fracture toughness of OI bone treated with stem cells to assess the actual efficacy of the treatment to rescue OI bone brittleness.

X-Linked Osteogenesis Imperfecta Possibly Caused by a Novel Variant in PLS3

Osteogenesis imperfecta (OI) represents a complex spectrum of genetic bone diseases that occur primarily due to mutations and deletions of the COL1A1 and COL1A2 genes. Recent molecular studies of the network of signaling pathways have contributed to a better understanding of bone remodeling and the pathogenesis of OI caused by mutations in many other genes associated with normal bone mineralization. In this paper, a case of a rare X-linked variant of OI with a change in the gene encoding plastin 3—a protein important for the regulation of the actin cytoskeleton, is presented. A 16-year-old patient developed ten bone fractures caused by minor trauma or injury, including a compression fracture of the second lumbar vertebra during his lifetime. Next-generation sequencing analysis did not show pathologically relevant deviations in the COL1A1 and COL1A2 genes. Targeted gene analyses (Skeletal disorder panel) of the patient, his father, mother and sister were then performed, detecting variants of uncertain significance (VUS) for genes PLS3, FN1 and COL11A2. A variant in the PLS3 gene were identified in the patient, his mother and sister. Since the PLS3 gene is located on the X chromosome, the mother and sister showed no signs of the disease. Although the variant in the PLS3 gene (c.685G>A (p.Gly229Arg)) has not yet been described in the literature, nor is its pathogenicity known, clinical findings combined with genetic testing showed that this variant may explain the cause of X-linked OI in our patient. This rare case of the PLS3 variant of X-linked OI might point to a novel target for personalized therapy in patients with this severe disease.

Outcomes of Zoledronic Acid Use in Paediatric Conditions

INTRODUCTION

Limited evidence is available concerning experience with use of zoledronic acid (ZA) and treatment for conditions other than primary bone fragility.

MATERIALS AND METHODS

A retrospective review of all Royal Children Hospital patients who had been administered at least 1 dose of intravenous ZA from 2002 to 2015 was undertaken.

RESULTS

The audit included 309 children with 228 being treated for bone fragility conditions. Of the 228, 68 had height-adjusted lumbar spine bone mineral density Z-scores available over up to a 5-year period, and median increases were +2.0 SD (median absolute deviation = 0.9) (N = 36, p value for median increase of at least 0.5 in Z-score <0.001), for patients with osteogenesis imperfecta or other primary bone fragility disorders, +1.0 SD (0.9) (N = 14, p = 0.029), for immobility conditions, +0.5 SD (0.7) (N = 10, p = 0.399), and for glucocorticoid-induced secondary osteoporosis, +0.7 SD (0.6) (N = 8, p = 0.015). 81/309 children were treated for bone abnormality indications (e.g., avascular necrosis [AVN], fibrous dysplasia, and bone cysts). Of 39 with AVN, outcome data were available for 33, with joint integrity maintained for 24/33 from 6 to 24 months after last ZA, subjective reports (22/28) of reduced pain. Reduction in bone lesion size was seen in 2/4 patients with bone cysts within 12 months of ZA commencement.

DISCUSSION/CONCLUSION

This is the largest cohort of reported outcomes of ZA use in a paediatric population. Results demonstrate a good efficacy profile and associated improved bone density for osteoporotic conditions and stabilization of non-traumatic AVN with a low rate of joint collapse.

Knowledge, attitude and practices regarding health self-management among patients with osteogenesis imperfecta in China: an online cross-sectional survey

OBJECTIVES

Assessing the knowledge, attitude and practices (KAP) regarding health self-management among patients with osteogenesis imperfecta (OI) in China.

DESIGN

An online cross-sectional survey.

SETTING

A structured questionnaire was distributed online through China-Dolls Center for Rare Disorders (CCRD), a non-governmental charity in China.

PARTICIPANTS

Participants were all patients with OI from CCRD. After stratified sampling according to the economic level of residential city, 901 patients were proportionally selected and 869 patients completed the survey (response rate: 96.4%).

MAIN OUTCOME MEASURES

Demographic characteristics and KAP information were gathered using a 5-point Likert scale. The score of each dimension of KAP was the sum of the scores of all included items. Χ² test or Fisher's exact test was used to compare scores of different items. Ordinal regression was employed to determine the significant factors influencing KAP.

RESULTS

A total of 802 questionnaires were included for analysis. Male respondents accounted for 57.1%, and 29.1% of respondents were of 26~30 years. More than half (50~60%) of patients knew the main symptoms of OI and the treatment of OI-related complications. Almost 80% of patients showed positive attitude. Nearly 60~70% of the patients were relatively able to take appropriate practice regarding OI management. There was a significant correlation between scores of knowledge and attitude, attitude and practice, as well as knowledge and practice. Patients aged 26~30 years, from urban areas and big cities, had higher KAP scores. Male patients showed better performance in knowledge, and highly educated patients perform better in practice.

CONCLUSIONS

Patients with OI did not have sufficient knowledge on disease care and up-to-date caring guidelines, and their practice regarding health self-management also needs to be improved. Gender, age, educational level and economic level of residence can affect the level of KAP for patients, thus developing targeted and tailored programmes for patients with OI is highly recommended.

High Bone Mineral Density Osteogenesis Imperfecta in a Family with a Novel Pathogenic Variant in COL1A2

Osteogenesis imperfecta (OI) is a heterogenous group of heritable bone dysplasias characterized by bone fragility, typically low bone mass, joint laxity, easy bruising, and variable short stature. Classical OI is caused by autosomal dominant pathogenic variants in COL1A1 or COL1A2 that result in either reduced production of normal type 1 collagen or structurally abnormal collagen molecules. Pathogenic variants in these genes generally result in low bone mass. Here, we report a family that had 2 affected individuals who presented with minimal trauma fractures and were found to have elevated bone mineral density (BMD) and a previously unreported variant in COL1A2 c.3356C>T p.(Ala1119Val). We report the change in BMD using dual-energy X-ray and peripheral quantitative computed tomography over a 2.3-year period in the proband. This case report highlights the importance of BMD studies and genetic testing in the diagnostic process for brittle bone disorders.

Dentinogenesis Imperfecta and Caries in Osteogenesis Imperfecta among Vietnamese Children

Osteogenesis imperfecta (OI) is a genetic disorder characterized by increased bone fragility and low bone mass, caused mainly by mutations in collagen type I encoding genes. The current study aimed to evaluate dentinogenesis imperfecta (DI), oral manifestations and caries status of OI children. Sixty-eight children (41 males, 27 females) aged from 3 to 17 years old (mean 9 ± 4.13) participated in the study. Participants were classified into three OI type groups (I—2 cases, III—31 cases and IV—35 cases). Clinical examination and an orthopantomogram were used to obtain prevalences and associations of DI, caries status, malocclusion, crossbite, open bite, eruption, impaction and missing teeth with OI. The prevalence of DI among OI patients was 47.1%, more common in OI type III than type IV. The yellow-brown discoloration type was more vulnerable to attrition than the opalescent-grey one in the primary dentition. OI seemed not to have a high risk of caries; the prevalence of caries was 69.1%. A high incidence of malocclusion, crossbite and open bite was observed. In-depth oral information would provide valuable data for better dental management in OI patients. Parents and general doctors should pay more attention to dental care to prevent caries and premature tooth loss.

Revisiting Skeletal Dysplasias in the Newborn

With over 400 reported disorders, the skeletal dysplasias represent a myriad of molecularly-based skeletal abnormalities. Arising from errors in skeletal development, the clinical spectrum of disease evolves through an affected individual's life. The naming and grouping of these disorders are ever-changing, but the fundamentals of diagnosis remain the same and are accomplished through a combination of prenatal ultrasonography and postnatal physical examination, radiography, and genetic analysis. Although some disorders are lethal in the perinatal and neonatal periods, other disorders allow survival into infancy, childhood, and even adulthood with relatively normal lives. The foundation of management for an affected individual is multidisciplinary care. Medical advances have offered new insights into reducing common morbidities through pharmacologic means. This review summarizes the normal skeletal development and discusses the 3 most common skeletal dysplasias that can affect the newborn.

Osteogenesis imperfecta: treatment and surgical management

PURPOSE OF REVIEW

Osteogenesis imperfecta is a disease with many different causes and clinical presentations. Surgery at a young age is the often required in order to improve the patients' growth development and quality of life. This manuscript highlights the current approach to treat children with osteogenesis imperfecta. The main purpose of this review is to compare and discuss the latest surgical techniques and procedures.

RECENT FINDINGS

Recent studies have indicated that telescoping intramedullary Faisser-Duval rods are one of the most suitable surgical devices to correct long bone deformities. The design permits elongation with growth and helps reduce the number of revision surgeries compared to previous static devices.

SUMMARY

Osteogenesis imperfecta patients require an interdisciplinary and tailored treatment that involves both medical and surgical components. On the basis of the most recent surgical and medical findings, the authors recommend treating osteogenesis imperfecta patients early with bisphosphonates prior to surgical intervention and then utilizing Faisser-Duval rods in a surgical setting to correct lower extremity deformities and fractures.

Promoting bone health in children and adolescents following solid organ transplantation

Solid organ transplantation in children and adolescents provides many benefits through improving critical organ function, including better growth, development, cardiovascular status, and quality of life. Unfortunately, bone status may be adversely affected even when overall status is improving, due to issues with pre-existing bone disease as well as medications and nutritional challenges inherent post-transplantation. For all children and adolescents, bone status entering adulthood is a critical determinant of bone health through adulthood. The overall health and bone status of transplant recipients benefits from attention to regular physical activity, good nutrition, adequate calcium, phosphorous, magnesium and vitamin D intake and avoidance/minimization of soda, extra sodium, and obesity. Many immunosuppressive agents, especially glucocorticoids, can adversely affect bone function and development. Minimizing exposure to "bone-toxic" medications is an important part of promoting bone health in children post-transplantation. Existing guidelines detail how regular monitoring of bone status and biochemical markers can help detect bone abnormalities early and facilitate valuable bone-directed interventions. Attention to calcium and vitamin D supplementation, as well as tapering and withdrawing glucocorticoids as early as possible after transplant, can provide best bone outcomes for these children. Dual-energy X-ray absorptiometry can be useful to detect abnormal bone mass and fracture risk in this population and newer bone assessment methods are being evaluated in children at risk for poor bone outcomes. Newer bone therapies being explored in adults with transplants, particularly bisphosphonates and the RANKL inhibitor denosumab, may offer promise for children with low bone mass post-transplantation.

Bisphosphonates, Old Friends of Bones and New Trends in Clinics

Bisphosphonates, used for a long time in osteoporosis management, are currently the target of intensive research, from pre-formulation studies to more advanced stages of clinical practice. This review presents an overview of the contributions of this family of compounds to human health, starting with the chemistry and clinical uses of bisphosphonates. Following this, their pharmacology is described, highlighting administration-borne handicaps and undesirable effects. The last three sections of the review describe the research efforts that seek to curb delivery-related issues and expand bisphosphonate use. Innovative routes and strategies of administration, such as nano-encapsulation for oral intake or injectable cements for local or in-bone delivery are presented, as well as the latest results of case studies or preclinical studies proposing new therapeutic indications for the clinically approved bisphosphonates. Finally, a selection of anti-infectious bisphosphonate new drug candidates is shown, with focus on the molecules reported in the last two decades.

Outcome of COVID19 in Patients With Osteogenesis Imperfecta: A Retrospective Multicenter Study in Saudi Arabia

BACKGROUND

Although genetic diseases are rare, children with such conditions who get infected with COVID-19 tend to have a severe illness requiring hospitalization. Osteogenesis imperfecta (OI) is a rare genetic disorder of collagen resulting in fractures and skeletal deformities. Kyphoscoliosis, restrictive lung disease, and pneumonia worsen the prognosis of patients with OI. The use of bisphosphonate improves bone mineral density (BMD) and reduces fractures in OI. There is no literature describing the impact of COVID-19 in patients with OI.

METHODOLOGY

A retrospective multi-center study was performed in three hospitals in Jeddah and Riyadh, Saudi Arabia, from March 1st, 2020, until August 31st, 2021, aiming to evaluate the outcome of COVID-19 in patients with OI. Demographics, vaccination status, underlying kyphoscoliosis, functional status, use of bisphosphonate, BMD, and COVID-19 severity, and course were recorded for all patients.

RESULTS

Twelve cases of confirmed COVID-19 were identified among 146 patients with OI. 9 (75%) of patients were less than 18 years, 6 (50%) were male, 5 (41%) had kyphoscoliosis, and 5 (41%) were wheelchair-bound. 6 (50%) received bisphosphonate, and 7(58%) had normal BMD. All patients had mild disease and did not require hospitalization. None of OI the patients with COVID-19 were fully vaccinated before the infection, and some were ineligible for vaccination.

CONCLUSION

Patients with OI and COVID-19 in our study recovered without complications, unlike patients with other genetic diseases. Young age and mild illness contributed to the favorable outcome. Half of the patients received bisphosphonate and had normal BMD.

Do Bisphosphonates Alleviate Pain in Children? A Systematic Review

PURPOSE OF REVIEW

The goal of this systematic review is to analyze the effectiveness of bisphosphonates (BPs) to treat bone pain in children and adolescents who have diseases with skeletal involvement.

RECENT FINDINGS

We included 24 studies (2 randomized controlled trials, 3 non-randomized controlled trials, 10 non-randomized open-label uncontrolled studies, 8 retrospective studies, and 1 study with design not specified). The majority of included studies assessed pain from a unidimensional approach, with pain intensity the most frequently evaluated dimension. Only 38% of studies used validated tools; visual analogue scale was the most frequently employed. BPs were used to alleviate bone pain in a wide variety of pediatrics conditions such as osteogenesis imperfecta, secondary osteoporosis, osteonecrosis related to chemotherapy, chronic non-bacterial osteitis, idiopathic juvenile osteoporosis, unresectable benign bone tumor, and cancer-related pain. Twenty of the 24 studies reported a positive effect of BPs for alleviating pain in different pathologies, but 58% of the studies were categorized as having high risk of bias. Intravenous BPs are helpful in alleviating bone pain in children and adolescents. It is advised that our results be interpreted with caution due to the heterogeneity of the doses used, duration of treatments, and types of pathologies included. In addition, this review shows the paucity of high-quality evidence in the available literature and further research is needed.

TRIAL REGISTRATION

Before the completion of this review, the protocol was registered to PROSPERO (International prospective register of systematic reviews), PROSPERO 2020 ID # CRD42020158316. Available from: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42020158316.

Bone turnover markers in children and adolescents with environmentally determined short stature, living in the oil and gas processing region

In conditions of intensive development of gas fields, environmental safety issues are becoming increasingly important. High rates of gas production and growth of its chemical processing have turned gas industry enterprises into a powerful source of environmental pollution, which poses a real threat to public health and contributes to an increase in morbidities and environmentally determined pathological conditions. The development of methods for the diagnosis, treatment and prevention of such conditions is an important task for modern science. The aim of the research is to make a comprehensive assessment of serum markers of bone synthesis and resorption in children with short stature living in the oil and gas processing regions. A total of 240 children aged 8-17 years, living in the oil and gas processing region (Kenkiyak), and 409 schoolchildren (8-17 years old), living in the environmentally favourable region (Kobda village), during 3 years were examined. It was established that emissions of pollutants by oil processing enterprises account for almost 80% of all emissions into the atmosphere. Gas flaring at oil production sites plays a special role in this process. Speaking of the effects of environmental factors on children's health, it should be noted that there is no consensus on the mechanisms and consequences of exposure to low doses of chemical atmospheric pollutants in children and adolescents so far.

Bone health in childhood cancer: review of the literature and recommendations for the management of bone health in childhood cancer survivors

In the past decades, new cancer treatment approaches for children and adolescents have led to a decrease in recurrence rates and an increase in long-term survival. Recent studies have focused on the evaluation of the late effects on bone of pediatric cancer-related treatments, such as chemotherapy, radiation and surgery. Treatment of childhood cancer can impair the attainment of peak bone mass, predisposing to premature onset of low bone mineral density, or causing other bone side-effects, such as bone quality impairment or avascular necrosis of bone. Lower bone mineral density and microarchitectural deterioration can persist during adulthood, thereby increasing fracture risk. Overall, long-term follow-up of childhood cancer survivors is essential to define specific groups at higher risk of long-term bone complications, identify unrecognized long-term adverse effects, and improve patient care. Children and adolescents with a cancer history should be carefully monitored, and patients should be informed of possible late complications of their previous medical treatment. The International Osteoporosis Foundation convened a working group to review the bone complications of pediatric cancer survivors, outlining recommendations for the management of bone health, in order to prevent and treat these complications.

A Multicenter Study of Intramedullary Rodding in Osteogenesis Imperfecta

BACKGROUND

Osteogenesis imperfecta (OI), a heritable connective tissue disorder with wide clinical variability, predisposes to recurrent fractures and bone deformity. Management requires a multidisciplinary approach in which intramedullary rodding plays an important role, especially for moderate and severe forms. We investigated the patterns of surgical procedures in OI in order to establish the benefits of rodding. The main hypothesis that guided this study was that rodded participants with moderate and severe OI would have lower fracture rates and better mobility.

METHODS

With data from the Linked Clinical Research Centers, we analyzed rodding status in 558 individuals. Mobility and fracture data in OI Types III and IV were compared between rodded and non-rodded groups. Univariate regression analyses were used to test the association of mobility outcomes with various covariates pertinent to rodding.

RESULTS

Of the individuals with OI, 42.1% had undergone rodding (10.7% of those with Type I, 66.4% with Type III, and 67.3% with Type IV). Rodding was performed more frequently and at a younger age in femora compared with tibiae. Expanding intramedullary rods were used more frequently in femora. In Type III, the rate of fractures per year was significantly lower (p ≤ 0.05) for rodded bones. In Type III, the mean scores on the Gillette Functional Assessment Questionnaire (GFAQ) and Brief Assessment of Motor Function (BAMF) were higher in the rodded group. However, Type-IV non-rodded subjects had higher mean scores in nearly all mobility outcomes. OI type, the use of expanding rods in tibiae, and anthropometric measurements were associated with mobility outcomes scores.

CONCLUSIONS

Current practice in 5 orthopaedic centers with extensive experience treating OI demonstrates that most individuals with moderate and severe types of OI undergo rodding procedures. Individuals with severe OI have improved mobility outcomes and lower fracture rates compared with their non-rodded peers, which suggests that early bilateral rodding benefits OI Type III. Our analysis showed a change in practice patterns in the final years of the study in the severe forms, with earlier and more simultaneous rodding procedures performed.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Burn injury and restoration of muscle function

Burn injury in children results in a systemic inflammatory reaction as well as a stress response. Consequences of these non-specific adaptive responses include resorptive bone loss and muscle catabolism. These adverse events can result in a post-burn fracture rate of approximately 15% and long-term muscle weakness that prolongs recovery. A randomized controlled trial of a single dose of the bisphosphonate pamidronate within the first ten days of burn injury resulted in the prevention of resorptive bone loss and continuous bone accrual. Examining the muscle protein kinetics in pediatric burn patients enrolled in that randomized controlled trial revealed that those who had been given the single dose bisphosphonate experienced preservation of muscle mass and strength. An in vitro study of mouse myoblasts incubated with serum from patients who participated in the randomized controlled study demonstrated that mouse myoblasts exposed to serum from patients given the single dose bisphosphonate exhibited greater myotube diameter than those from burned children given placebo. Moreover, the serum from bisphosphonate treated patients stimulated the protein anabolic pathways and suppressed protein catabolic pathways in these cells. Inasmuch as incubation of the myotubes with an antibody to transforming growth factor beta (TGFβ) rescued myotube size in the cultures with serum from patients who received the placebo to the same magnitude as cultures with serum from patients treated with single dose bisphosphonate, we postulate that post-burn bone resorption liberates muscle catabolic factors which cause muscle wasting. Future uses of bisphosphonates could include studies designed to prevent short-term acute bone resorption in conditions that may result in muscle wasting as well as in short-term interventions in chronic inflammatory conditions which may flare and cause acute bone and muscle loss.

Dislodgement of Telescopic Nail from the Epiphysis: A Case Report with an Analysis of Probable Mechanism

Telescopic nails such as Fassier-Duval (FD) nails have become the standard treatment for stabilizing long bones and correcting deformities in osteogenesis imperfecta (OI). These nails do not require repeat surgery for their replacement when the bones outgrow them. However, they are not completely free from complications. The prohibitive costs of the original implants have led to design modifications being introduced in locally manufactured telescopic nails. While these low-cost devices work well in most cases, they can lead to complications resulting from their design flaws. We present here the complication observed in a locally manufactured telescopic nail with a design similar to the FD nail. The male component of the nail got dislodged from the distal tibial epiphysis, resulting in its proximal migration. We discuss the probable mechanism of this complication and propose possible design changes that can bring down the rates of such incidences.

The prevention and treatment of glucocorticoid-induced osteopaenia in juvenile rheumatic disease: A randomised double-blind controlled trial

BACKGROUND

Children and young people (CYP) with chronic rheumatic conditions; Juvenile Idiopathic Arthritis, Juvenile Systemic Lupus Erythematosus, Juvenile Dermatomyositis and Juvenile Vasculitis, treated with steroids, have low bone density, increased fracture risk and are likely to have suboptimal peak bone mass. There is currently no evidence base for the management of steroid-induced bone loss in children with rheumatic diseases.

METHODS

We undertook a multi-centre double dummy double-blind randomised placebo controlled trial to investigate whether the bisphosphonate risedronate was superior to alfacalcidol or calcium and vitamin D supplementation in the prevention and treatment of steroid-induced osteopaenia in these children. Patients were stratified and randomised in a 1:1 ratio, into: placebo; alfacalcidol; risedronate. The primary outcome was the change in lumbar spine bone mineral density z score (LSaBMDz) measured by dual energy x-ray absorptiometry at one year. Secondary outcome was fracture rate.

RESULTS

Two hundred and seventeen patients were recruited to the study. Seventy seven placebo, 71 alfacalcidol, and 69 risedronate. Highly statistically significant differences were observed in the change in LSaBMDz between the placebo and risedronate groups; 0.274, 95% CI (0.061, 0.487) (p < 0.001) and between the risedronate and the alfacalcidol groups; 0.326 95% CI (0.109, 0.543) (p < 0.001). The difference observed between the alfacalcidol and placebo group was not statistically significant.Highly statistically significant differences were seen in the change in Total Body Less Head aBMD-Z Score between the placebo and risedronate groups (p < 0.01) but not between the alfacalcidol and risedronate groups. No significant differences in fracture frequency, adverse or serious adverse reactions were observed between the groups.

CONCLUSIONS

Children and adolescents receiving steroids for rheumatic diseases benefit from prophylactic treatment with bisphosphonates to increase LSaBMD. Alfacalcidol is ineffective.

Immune Modulation by Transplanted Calcium Phosphate Biomaterials and Human Mesenchymal Stromal Cells in Bone Regeneration

A wide variety of biomaterials have been developed as both stabilizing structures for the injured bone and inducers of bone neoformation. They differ in chemical composition, shape, porosity, and mechanical properties. The most extensively employed and studied subset of bioceramics are calcium phosphate materials (CaPs). These materials, when transplanted alongside mesenchymal stem cells (MSCs), lead to ectopic (intramuscular and subcutaneous) and orthotopic bone formation in preclinical studies, and effective fracture healing in clinical trials. Human MSC transplantation in pre-clinical and clinical trials reveals very low engraftment in spite of successful clinical outcomes and their therapeutic actions are thought to be primarily through paracrine mechanisms. The beneficial role of transplanted MSC could rely on their strong immunomodulatory effect since, even without long-term engraftment, they have the ability to alter both the innate and adaptive immune response which is critical to facilitate new bone formation. This study presents the current knowledge of the immune response to the implantation of CaP biomaterials alone or in combination with MSC. In particular the central role of monocyte-derived cells, both macrophages and osteoclasts, in MSC-CaP mediated bone formation is emphasized. Biomaterial properties, such as macroporosity and surface microstructure, dictate the host response, and the ultimate bone healing cascade. Understanding intercellular communications throughout the inflammation, its resolution and the bone regeneration phase, is crucial to improve the current therapeutic strategies or develop new approaches.

Stakeholder views and attitudes towards prenatal and postnatal transplantation of fetal mesenchymal stem cells to treat Osteogenesis Imperfecta

The Boost Brittle Bones Before Birth (BOOSTB4) clinical trial is investigating the safety and efficacy of transplanting fetal derived mesenchymal stromal cells (MSCs) prenatally and/or in early postnatal life to treat severe Osteogenesis Imperfecta (OI). This study aimed to explore stakeholder views to understand perceived benefits or concerns, identify ethical issues and establish protocols for support and counselling. Semi-structured qualitative interviews were conducted with three groups; 1. Adults affected with OI, with and without children, and parents of children affected with OI; 2. Health professionals who work with patients with OI; 3. Patient advocates from relevant patient support groups. Interviews were digitally recorded, transcribed verbatim and analysed using thematic analysis. Interviews with 56 participants revealed generally positive views towards using fetal MSC transplantation to treat OI. Early treatment was considered advantageous for preventing fractures and reducing severity and could bring psychological benefits for parents. Common concerns were procedure safety, short/long-term side effects and whether transplantation would be effective. Difficulties inherent in decision-making were frequently discussed, as treatment efficacy is unknown and, by necessity, parents will make decisions at a time when they are vulnerable. Support needs may differ where there is a family history of OI compared to an unexpected diagnosis of OI. Explaining fetal MSC transplantation in a way that all parents can understand, clear expectation setting, psychological support and time for reflection during the decision-making process will be crucial to allow parents to make informed decisions about participation in the BOOSTB4 clinical trial.

Genetic Disorders of the Extracellular Matrix

Mutations in the genes for extracellular matrix (ECM) components cause a wide range of genetic connective tissues disorders throughout the body. The elucidation of mutations and their correlation with pathology has been instrumental in understanding the roles of many ECM components. The pathological consequences of ECM protein mutations depend on its tissue distribution, tissue function, and on the nature of the mutation. The prevalent paradigm for the molecular pathology has been that there are two global mechanisms. First, mutations that reduce the production of ECM proteins impair matrix integrity largely due to quantitative ECM defects. Second, mutations altering protein structure may reduce protein secretion but also introduce dominant negative effects in ECM formation, structure and/or stability. Recent studies show that endoplasmic reticulum (ER) stress, caused by mutant misfolded ECM proteins, makes a significant contribution to the pathophysiology. This suggests that targeting ER‐stress may offer a new therapeutic strategy in a range of ECM disorders caused by protein misfolding mutations. Anat Rec, 2019. © 2019 The Authors. The Anatomical Record published by Wiley Periodicals, Inc. on behalf of American Association of Anatomists.

Osteogenesis Imperfecta: New Perspectives From Clinical and Translational Research

Osteogenesis imperfecta (OI) is a monogenic bone fragility disorder that usually is caused by mutations in one of the two genes coding for collagen type I alpha chains, COL1A1 or COL1A2. Mutations in at least 18 other genes can also lead to an OI phenotype. As genetic testing is more widely used, mutations in these genes are also more frequently discovered in individuals who have a propensity for fractures, but who do not have other typical clinical characteristics of OI. Intravenous bisphosphonate therapy is still the most widely used drug treatment approach. Preclinical studies in OI mouse models have shown encouraging effects when the antiresorptive effect of a bisphosphonate was combined with bone anabolic therapy using a sclerostin antibody. Other novel experimental treatment approaches include inhibition of transforming growth factor beta signaling with a neutralizing antibody and the inhibition of myostatin and activin A by a soluble activin receptor 2B. © 2019 The Authors. JBMR Plus published by Wiley Periodicals, Inc. on behalf of American Society for Bone and Mineral Research

New Insights Into Monogenic Causes of Osteoporosis

Osteoporosis, characterized by deteriorated bone microarchitecture and low bone mineral density, is a chronic skeletal disease with high worldwide prevalence. Osteoporosis related to aging is the most common form and causes significant morbidity and mortality. Rare, monogenic forms of osteoporosis have their onset usually in childhood or young adulthood and have specific phenotypic features and clinical course depending on the underlying cause. The most common form is osteogenesis imperfecta linked to mutations in COL1A1 and COL1A2, the two genes encoding type I collagen. However, in the past years, remarkable advancements in bone research have expanded our understanding of the intricacies behind bone metabolism and identified novel molecular mechanisms contributing to skeletal health and disease. Especially high-throughput sequencing techniques have made family-based studies an efficient way to identify single genes causative of rare monogenic forms of osteoporosis and these have yielded several novel genes that encode proteins partaking in type I collagen modification or regulating bone cell function directly. New forms of monogenic osteoporosis, such as autosomal dominant osteoporosis caused by WNT1 mutations or X-linked osteoporosis due to PLS3 mutations, have revealed previously unidentified bone-regulating proteins and clarified specific roles of bone cells, expanded our understanding of possible inheritance mechanisms and paces of disease progression, and highlighted the potential of monogenic bone diseases to extend beyond the skeletal tissue. The novel gene discoveries have introduced new challenges to the classification and diagnosis of monogenic osteoporosis, but also provided promising new molecular targets for development of pharmacotherapies. In this article we give an overview of the recent discoveries in the area of monogenic forms of osteoporosis, describing the key cellular mechanisms leading to skeletal fragility, the major recent research findings and the essential challenges and avenues in future diagnostics and treatments.

Osteogenesis imperfecta and therapeutics

Osteogenesis imperfecta, or brittle bone disease, is a congenital disease that primarily causes low bone mass and bone fractures but it can negatively affect other organs. It is usually inherited in an autosomal dominant fashion, although rarer recessive and X-chromosome-linked forms of the disease have been identified. In addition to type I collagen, mutations in a number of other genes, often involved in type I collagen synthesis or in the differentiation and function of osteoblasts, have been identified in the last several years. Seldom, the study of a rare disease has delivered such a wealth of new information that have helped our understanding of multiple processes involved in collagen synthesis and bone formation. In this short review I will describe the clinical features and the molecular genetics of the disease, but then focus on how OI dysregulates all aspects of extracellular matrix biology. I will conclude with a discussion about OI therapeutics.