Recent developments in osteogenesis imperfecta

Hypophosphatasia diagnosis: current state of the art and proposed diagnostic criteria for children and adults

BACKGROUND

This manuscript provides a summary of the current evidence to support the criteria for diagnosing a child or adult with hypophosphatasia (HPP). The diagnosis of HPP is made on the basis of integrating clinical features, laboratory profile, radiographic features of the condition, and DNA analysis identifying the presence of a pathogenic variant of the tissue nonspecific alkaline phosphatase gene (ALPL). Often, the diagnosis of HPP is significantly delayed in both adults and children, and updated diagnostic criteria are required to keep pace with our evolving understanding regarding the relationship between ALPL genotype and associated HPP clinical features.

METHODS

An International Working Group (IWG) on HPP was formed, comprised of a multidisciplinary team of experts from Europe and North America with expertise in the diagnosis and management of patients with HPP. Methodologists (Romina Brignardello-Petersen and Gordon Guyatt) and their team supported the IWG and conducted systematic reviews following the GRADE methodology, and this provided the basis for the recommendations.

RESULTS

The IWG completed systematic reviews of the literature, including case reports and expert opinion papers describing the phenotype of patients with HPP. The published data are largely retrospective and include a relatively small number of patients with this rare condition. It is anticipated that further knowledge will lead to improvement in the quality of genotype-phenotype reporting in this condition.

CONCLUSION

Following consensus meetings, agreement was reached regarding the major and minor criteria that can assist in establishing a clinical diagnosis of HPP in adults and children.

Postoperative screw pullout of severe spondylolisthesis in osteogenesis imperfecta: a case report with 3-year follow-up

Introduction and importance

Osteogenesis imperfecta (OI) is a rare skeletal disorder characterized by bone fragility and deformities in both paediatric and adult populations. The occurrence of severe spondylolisthesis in OI patients is even more infrequent. However, there is no consensus regarding the optimal treatment approach for OI patients afflicted with severe spondylolisthesis. The selection of surgical procedures and the effective management of postoperative complications present significant challenges in this context.

Case presentation

A 30-year-old male patient diagnosed with OI type IV (Sillence classification) underwent the lumbar laminectomy and postero-lateral fusion due to severe spondylolisthesis (grade Ⅲ). Following the surgery, the patient experienced postoperative screw pullout while on bedrest. However, aside from experiencing back pain, there were no neurological symptoms present. To address this issue, the patient received salvage treatment in the form of cast immobilization combined with bisphosphonates. At the 3-year follow-up, the patient exhibited absence of sciatic nerve pain and reported mild numbness in the lower extremities. Moreover, the patient demonstrated the ability to ambulate a distance exceeding 1500 m. Nevertheless, the persistence of sexual dysfunction was observed.

Clinical discussion

This study presented the initial instance of surgical complications observed in patients with severe spondylolisthesis and OI. This highlights the importance to exercise meticulous caution and thoroughness when assessing surgical interventions.

Conclusion

In cases where the fixation fails to offer adequate biomechanical stability, the administration of bisphosphonates and robust immobilization remains crucial, even in the presence of complications.

Sustainable Approach of Functional Biomaterials-Tissue Engineering for Skin Burn Treatment: A Comprehensive Review

Burns are a widespread global public health traumatic injury affecting many people worldwide. Non-fatal burn injuries are a leading cause of morbidity, resulting in prolonged hospitalization, disfigurement, and disability, often with resulting stigma and rejection. The treatment of burns is aimed at controlling pain, removing dead tissue, preventing infection, reducing scarring risk, and tissue regeneration. Traditional burn wound treatment methods include the use of synthetic materials such as petroleum-based ointments and plastic films. However, these materials can be associated with negative environmental impacts and may not be biocompatible with the human body. Tissue engineering has emerged as a promising approach to treating burns, and sustainable biomaterials have been developed as an alternative treatment option. Green biomaterials such as collagen, cellulose, chitosan, and others are biocompatible, biodegradable, environment-friendly, and cost-effective, which reduces the environmental impact of their production and disposal. They are effective in promoting wound healing and reducing the risk of infection and have other benefits such as reducing inflammation and promoting angiogenesis. This comprehensive review focuses on the use of multifunctional green biomaterials that have the potential to revolutionize the way we treat skin burns, promoting faster and more efficient healing while minimizing scarring and tissue damage.

A Comprehensive Review on Collagen Type I Development of Biomaterials for Tissue Engineering: From Biosynthesis to Bioscaffold

Collagen is the most abundant structural protein found in humans and mammals, particularly in the extracellular matrix (ECM). Its primary function is to hold the body together. The collagen superfamily of proteins includes over 20 types that have been identified. Yet, collagen type I is the major component in many tissues and can be extracted as a natural biomaterial for various medical and biological purposes. Collagen has multiple advantageous characteristics, including varied sources, biocompatibility, sustainability, low immunogenicity, porosity, and biodegradability. As such, collagen-type-I-based bioscaffolds have been widely used in tissue engineering. Biomaterials based on collagen type I can also be modified to improve their functions, such as by crosslinking to strengthen the mechanical property or adding biochemical factors to enhance their biological activity. This review discusses the complexities of collagen type I structure, biosynthesis, sources for collagen derivatives, methods of isolation and purification, physicochemical characteristics, and the current development of collagen-type-I-based scaffolds in tissue engineering applications. The advancement of additional novel tissue engineered bioproducts with refined techniques and continuous biomaterial augmentation is facilitated by understanding the conventional design and application of biomaterials based on collagen type I.

Risk of eye diseases in osteogenesis imperfecta - A nationwide, register-based cohort study

BACKGROUND

Osteogenesis imperfecta (OI) is a hereditary disease caused by affected collagen type 1. Collagen type 1 is an important structural component of the eye. Ocular manifestations in OI are described in literature, but little is known about the risk of eye diseases in OI.

OBJECTIVE

To investigate the risk of eye diseases in OI.

DESIGN

A Danish nationwide register-based cohort study based on data from the Danish National Patient Register.

PARTICIPANTS

All patients registered with an OI diagnosis between January 1977 and December 2018 matched 1:5 with a reference population on gender and birth month and birth year.

MEASUREMENTS

Incidence rates (IR) per 1000 patient years and sub-hazard ratio (SHR) for any eye disease, corneal diseases, cataract, refraction disorders, vitreous haemorrhage, retinal detachment, retinopathy, angiopathy, retinal haemorrhage, retinal degeneration, retinal changes, optic nerve disorders, and traumatic eye lesions.

RESULTS

We identified 907 OI patients (493 women) and 4535 persons (2465 women) in the reference population. The IR for any eye disease was 4.07 [95% CI 3.41-4.85] in the OI cohort and 1.96 [95% CI 1.89-2.12] in the reference cohort. The two diseases with highest incidence was cataract (2.41 [95%CI 1.93-3.03] vs 1.29 [95% CI 1.12-1.47], SHR 1.76 [95% CI 1.34-2.33]) and glaucoma (1.08 [95% CI 0.77-1.51] vs 0.42 [95% CI 0.33-0.54], SHR 2.33 [95% CI 1.55-3.53]). The absolute risk of most other eye diseases was low, but the SHR indicated a higher risk in the OI cohort compared to the reference group showing statistically increased risk of refractive disorders, vitreous haemorrhage, retinal detachment or ruptures, other retinal diseases (i.e., retinopathy, angiopathy, retinal haemorrhage, degeneration, retinal changes), and optic nerve disorders. Corneal diseases and traumatic eye lesions were not statistically significantly increased in OI-patients.

CONCLUSION

Patients with OI have a higher risk of cataract, refractive disorders, glaucoma, vitreous haemorrhages, retinal detachment/ruptures, retinal diseases, and optic nerve disorders.

Effects of Long-Term Pamidronate Treatment on Bone Density and Fracture Rate in 65 Osteogenesis Imperfecta Patients

OBJECTIVE

Osteogenesis imperfecta (OI) is a clinically and genetically heterogeneous disease characterized by recurrent fractures, blue sclera, and hearing loss. Bisphosphonate treatment has been reported to decrease the annual number of fractures and improve the quality of life in patients with OI. The aim of this study is to evaluate the effect of bisphosphonate treatment in the Turkish OI cohort.

METHODS

Sixty-five patients with OI, who were treated with pamidronate, were included in this study. The mean treatment duration was 47.1 ± 40 months (range:12-168 months). Bone mineral densitometry (BMD) and the mean number of annual fractures were compared before and after the treatment within groups, and the difference after treatment compared between the OI types.

RESULTS

After pamidronate treatment, a significant decrease in the mean annual fracture, along with an increase in BMD Z-score was detected in all patients. Treatment duration did not affect BMD Z-score. However, there was a significant decrease in the mean annual number of fractures after 5 years of treatment (P = .048). After treatment, the decrease in the number of fractures was significant in OI type 3, and the increase in BMD Z-score was significant in OI type 4 when compared with OI type 1. Besides, pamidronate treatment relieved pain, and also corrected the platyspondyly radiologically in all OI groups.

CONCLUSION

We demonstrated that pamidronate treatment improves the quality of life by reducing the number of fractures, relieving pain, and also protecting from deformities in all patients with OI.

Neuraxial and regional anesthesia in surgical patients with osteogenesis imperfecta: a narrative review of literature

Background and objectives

Regional and neuraxial anesthesia techniques have become instrumental in the perioperative period yet have not been well described in patients with osteogenesis imperfecta (OI), a congenital connective tissue disorder characterized by skeletal dysplasia and fragility. Patients with skeletal dysplasia present unique perioperative challenges that warrant consideration of these techniques despite their relative contraindication in this population due to reports of increased bleeding with surgery, skeletal fragility concerns with positioning, and risk of spinal cord injury with continuous neuraxial catheters. The aim of this narrative review was to evaluate literature describing the use of regional and neuraxial techniques in patients with OI and any associated clinical outcomes.

Methods

All available literature from inception to July 2020 was retrieved, according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, from MEDLINE, Embase, Google Scholar and The Cochrane Library. Three authors reviewed all references for eligibility, abstracted data, and appraised quality.

Results

Of 412 articles initially identified, 42 met our inclusion criteria, yielding 161 cases with regional and/or neuraxial techniques described. In 117 (72.6%) of the 161 cases, neuraxial technique was performed, including 76 (64.9%) epidural, 7 (5.9%) caudal, 5 (4.2%) combined spinal epidural, and 29 (24.7%) spinal procedures. In 44 (27.4%) of the 161 cases, the use of regional anesthesia was described. Our review was confounded by incomplete data reporting and small sample sizes, as most were case reports. There were no randomized controlled trials, and the two single-center retrospective data reviews lacked sufficient data to perform meta-analysis. While complications or negative outcomes related to these techniques were not reported in any of the cases, less than half specifically discuss outcomes beyond placement and immediate postoperative course.

Conclusions

There is insufficient evidence to validate or refute the potential risks associated with the use of regional and neuraxial techniques in patients with OI. This review did not uncover any reports of negative sequelae related to the use of these modalities to support relative contraindication in this population; however, further research is needed to adequately assess clinically relevant outcomes such as complications and opioid-sparing effect.

Osteogenesis imperfecta in a male holstein calf associated with a possible oligogenic origin

Background: Neuromusculoskeletal anomalies generally in combination with severe clinical symptoms, comprise a heterogeneous group of fairly common and mostly fatal disorders in man and animals. Osteogenesis imperfecta (OI), also known as brittle bone disease, causes bone fragility and deformity. Prominent extra-skeletal accessory manifestations of OI comprise blue/gray sclerae, hearing impairment, lung abnormalities and hypercalciuria. Cases of OI in cattle have been reported. However, no causative mutations have been identified in cattle so far.Aim: To report a possible oligogenic origin identified in a calf from clinically healthy parents suffering from OI.Materials and Methods: A neonatal embryo transfer male Holstein calf developing multiple fractures with bone tissue showing marked osteopenia was used for whole genome re-sequencing as well as its parents. In addition, 2,612 randomly chosen healthy Holstein cattle were genotyped as well as controls.Results: Sixteen candidate genes with potential protein-altering variants were selected revealing non-synonymous variants only within IFITM5 and CRTAP genes. However, in-depth gene analysis did not result in the identification of a single causative mutation in the OI calf.Conclusion: The analysis of the OI case revealed a possible oligogenic origin of the disease attributable to additive effects of three candidate genes, i.e., ABCA13, QRFPR, and IFTIM5.Clinical relevance: Most OI cases in humans and domestic animals reported so far are caused by distinct dominant or recessive monogenic mutations, therefore a potential oligogenic additive genetic effect is a novel finding. Furthermore, the case presented here demonstrates that cross-species genetic analyses might not always be straightforward.

Total hip arthroplasty for Protrusio Acetabuli in a young adult Osteogenesis Imperfecta features and Marfanoid features: A case report

Osteogenesis Imperfecta is an inherited disease characterized by easily-broken bones, which manifests as multiple fractures with minimal trauma, joint laxity, sclerosis, blue sclera, and several other manifestations. Protrusio acetabuli is defined as the displacement of the femoral head so that it lies medial to the ischioilial line. In a skeletally mature patient with both Marfan syndrome and PA, an eventual hip arthroplasty is the only method available for correction of the deformity. However, in patients with Osteogenesis Imperfecta and PA, THA remains a controversial treatment. A 14-year-old male patient diagnosed with Osteogenesis Imperfecta Type 1A presented to the orthopedic surgery clinic complaining of groin pain of 1-year duration radiating to the thigh and knee. The patient was found to have radiologic signs of protrusion acetabuli. The patient was started with bisphosphonate and after medical failure, underwent a Total Hip Arthroplasty (THA). In post-operative follow-ups, the patient had relief of pain and was able to walk more comfortably and without a lump. The previously operated hip was examined and showed no signs of infection, dislocation, or fracture. Radiographic studies show no evidence of prosthesis failure or loosening with valgus position of the femoral stem and neutral acetabular angle. Ten years after the primary arthroplasty, the previously operated hip had maintained its stability and had no related complications. Despite the controversy surrounding the treatment of younger patients with hip failure, using total hip arthroplasty, this patient exhibited excellent results, with vast improvement in their symptoms and stability.

Zebrafish Models of Human Skeletal Disorders: Embryo and Adult Swimming Together

Danio rerio (zebrafish) is an elective model organism for the study of vertebrate development because of its high degree of homology with human genes and organs, including bone. Zebrafish embryos, because of the optical clarity, small size, and fast development, can be easily used in large-scale mutagenesis experiments to isolate mutants with developmental skeletal defects and in high-throughput screenings to find new chemical compounds for the ability to revert the pathological phenotype. On the other hand, the adult zebrafish represents another powerful resource for pathogenic and therapeutic studies about adult human bone diseases. In fish, some characteristics such as bone turnover, reparation, and remodeling of the adult bone tissue cannot be found at the embryonic stage. Several pathological models have been established in adult zebrafish such as bone injury models, osteoporosis, and genetic diseases such as osteogenesis imperfecta. Given the growing interest for metabolic diseases and their complications, adult zebrafish models of type 2 diabetes and obesity have been recently generated and analyzed for bone complications using scales as model system. Interestingly, an osteoporosis-like phenotype has been found to be associated with metabolic alterations suggesting that bone complications share the same mechanisms in humans and fish. Embryo and adult represent powerful resources in rapid development to study bone physiology and pathology from different points of view.

Surgical Treatment of Bilateral Tibia Deformity in a 9-Year-Old Child Suffering from Osteogenesis Imperfecta Type III: A Case Report

Patient: Male, 9

Final Diagnosis: Osteogenesis imperfecta type III

Symptoms: Walking difficulties

Medication: —

Clinical Procedure: Osteotomies and realignment of bone deformity

Specialty: Orthopedics and Traumatology

Effect of Bisphosphonates on Function and Mobility Among Children With Osteogenesis Imperfecta: A Systematic Review

Osteogenesis imperfecta (OI) is a rare genetic connective tissue disorder that results in bone fragility and deformity. Management is multi-disciplinary. Although pharmacologic intervention with bisphosphonates (BP) is a standard of care for individuals with severe OI, no consensus or reviews were found that focus on the effects of bisphosphonates on function and mobility. PubMed, CINAHL, Cochrane Library, Web of Science, and PEDro databases were searched for eligible articles for this review. Methodological quality was assessed using the Cochrane Collaboration's tool for risk of bias. Twenty-six studies (801 children) were reviewed and five showed a low risk of bias. Included studies showed significant variability among clinical protocols for administering BP. Randomized controlled trials did not demonstrate a significant improvement in function and mobility with oral BP administration, while non-randomized open-label uncontrolled studies demonstrated that oral and intravenous BP administration objectively improved function and mobility. The most common outcome measure used by the studies included in this review was the Bleck score. Effect sizes (d = 0.28 - 4.5) varied among studies. This systematic review also summarized the apparent confounding variables affecting results of previous studies and provided suggestions to improve the quality of future studies.

Rotational Osteotomy of the Humeral Shaft for Malunion in Osteogenesis Imperfecta: A Case Report

CASE

We report a case of an adult with osteogenesis imperfecta, who underwent humeral shaft osteotomy to correct an internal rotation deformity results from a humeral shaft malunion. The patient incurred a temporary radial nerve palsy.

CONCLUSIONS

Humeral shaft malunion can be successfully treated with rotational osteotomy of the humerus through an anterior approach; however, the risk of radial nerve palsy exists and may be minimized by a posterior approach.

A Unique Association of Osteogenesis Imperfecta with Bilateral Renal Osteodystrophy and Gastroenteritis in a Three-year-old Boy

We describe a three-year-old male child who presented to the pediatrics out-patient department with a history of decrease in appetite, generalized weakness, on and off loose motions for one year, inability to walk and sit for eight months with a loss of neck holding for 14 days. On examination, the patient had a classic frog-shaped leg posture. X-rays of chest, skull, pelvis and long bones were performed which showed osteopenic bones, frontal bossing and multiple microfractures, which were classic for osteogenesis Imperfecta but the child did not have other salient features such as blue sclera, otosclerosis, and respiratory difficulty. The patient also had urinary complaints due to which ultrasound of kidney ureters and bladder (KUB) was performed, which showed bilateral renal calculi and grade 2 renal parenchymal changes. This case report illustrates the evaluation of the child with osteogenesis imperfecta, as well as the unique association of renal osteodystrophy and gastroenteritis with it.

Anesthesia in children with osteogenesis imperfecta: Retrospective chart review of 83 patients and 205 anesthetics over 7 years

BACKGROUND

Osteogenesis imperfecta is the collective term for a heterogeneous group of connective tissue syndromes characterized by bone fragility with multisystem involvement and perioperative implications.

AIMS

Literature review of anesthetic management of patients with osteogenesis imperfecta revealed a paucity of data on the incidence of perioperative challenges. We sought to determine the rates of these challenges in our study cohort.

METHODS

Data were collected in a specialty orthopedic hospital from 2008 to 2015 for 83 osteogenesis imperfecta patients undergoing 205 surgeries: 203 orthopedic surgeries and 2 mid-face reconstructive surgeries. Airway management, intravenous access, surgical blood loss, use of peripheral nerve blockade and/or neuraxial techniques, presence of perioperative fracture, and peak intraoperative temperature were evaluated and analyzed.

RESULTS

Difficult airway was encountered in 3/205 (1.5%) cases and perioperative fracture in 2/205 (1%) cases. Neuraxial anesthesia was attempted in 64/205 cases with an 87.5% success rate. All peripheral nerve block attempts (33/205 cases) were successful. Difficult intravenous catheter placement was noted in 8/205 (4%) cases. Estimated blood loss >10% of estimated blood volume was considered significant, and occurred in 35/205 (17%) cases. Significant blood loss occurred more often in severe osteogenesis imperfecta types: 18/76 (23.7%) in Type III and 11/65 (16.9%) in Type IV, whereas only 4/47 (8.5%) occurred in mild Type I. In our 205 case cohort, osteogenesis imperfecta Type III had 5.6 times the odds [(95% CI = 1.8-17.2) P = 0.003] of having an anesthetic complication as compared to osteogenesis imperfecta Type I.

CONCLUSION

Patients with osteogenesis imperfecta undergo frequent anesthetic exposures, but anesthetic challenges in our series were uncommon. Odds of challenges are greater in severe osteogenesis imperfecta Type III, with significant blood loss and difficulty placing intravenous catheters more likely encountered in the more severe types.

Mucolipidosis type III, a series of adult patients

BACKGROUND

Mucolipidosis type III α/β or γ (MLIII) are rare autosomal recessive diseases, in which reduced activity of the enzyme UDP-N-acetyl glucosamine-1-phosphotransferase (GlcNAc-PTase) leads to intra-lysosomal accumulation of different substrates. Publications on the natural history of MLIII, especially the milder forms, are scarce. This study provides a detailed description of the disease characteristics and its natural course in adult patients with MLIII.

METHODS

In this retrospective chart study, the clinical, biochemical and molecular findings in adult patients with a confirmed diagnosis of MLIII from three treatment centres were collected.

RESULTS

Thirteen patients with MLIII were included in this study. Four patients (31%) were initially misdiagnosed with a type of mucopolysaccharidosis (MPS). Four patients (31%) had mild cognitive impairment. Six patients (46%) needed help with activities of daily living (ADL) or were wheelchair-dependent. All patients had dysostosis multiplex and progressive secondary osteoarthritis, characterised by cartilage destruction and bone lesions in multiple joints. All patients underwent multiple orthopaedic surgical interventions as early as the second or third decades of life, of which total hip replacement (THR) was the most common procedure (61% of patients). Carpal tunnel syndrome (CTS) was found in 12 patients (92%) and in eight patients (61%), CTS release was performed.

CONCLUSIONS

Severe skeletal abnormalities, resulting from abnormal bone development and severe progressive osteoarthritis, are the hallmark of MLIII, necessitating surgical orthopaedic interventions early in life. Future therapies for this disease should focus on improving cartilage and bone quality, preventing skeletal complications and improving mobility.

Live Imaging of Type I Collagen Assembly Dynamics in Osteoblasts Stably Expressing GFP and mCherry-Tagged Collagen Constructs

Type I collagen is the most abundant extracellular matrix protein in bone and other connective tissues and plays key roles in normal and pathological bone formation as well as in connective tissue disorders and fibrosis. Although much is known about the collagen biosynthetic pathway and its regulatory steps, the mechanisms by which it is assembled extracellularly are less clear. We have generated GFPtpz and mCherry-tagged collagen fusion constructs for live imaging of type I collagen assembly by replacing the α2(I)-procollagen N-terminal propeptide with GFPtpz or mCherry. These novel imaging probes were stably transfected into MLO-A5 osteoblast-like cells and fibronectin-null mouse embryonic fibroblasts (FN-null-MEFs) and used for imaging type I collagen assembly dynamics and its dependence on fibronectin. Both fusion proteins co-precipitated with α1(I)-collagen and remained intracellular without ascorbate but were assembled into α1(I) collagen-containing extracellular fibrils in the presence of ascorbate. Immunogold-EM confirmed their ultrastuctural localization in banded collagen fibrils. Live cell imaging in stably transfected MLO-A5 cells revealed the highly dynamic nature of collagen assembly and showed that during assembly the fibril networks are continually stretched and contracted due to the underlying cell motion. We also observed that cell-generated forces can physically reshape the collagen fibrils. Using co-cultures of mCherry- and GFPtpz-collagen expressing cells, we show that multiple cells contribute collagen to form collagen fiber bundles. Immuno-EM further showed that individual collagen fibrils can receive contributions of collagen from more than one cell. Live cell imaging in FN-null-MEFs expressing GFPtpz-collagen showed that collagen assembly was both dependent upon and dynamically integrated with fibronectin assembly. These GFP-collagen fusion constructs provide a powerful tool for imaging collagen in living cells and have revealed novel and fundamental insights into the dynamic mechanisms for the extracellular assembly of collagen. © 2018 American Society for Bone and Mineral Research.

Effects of a telescopic intramedullary rod for treating patients with osteogenesis imperfecta of the femur

PURPOSE

To introduce a new model of telescopic intramedullary rod (TIR), evaluate its effects on treating patients presenting with moderate and severe osteogenesis imperfecta (OI) and to compare the findings with those of other telescopic rods.

METHODS

A total of 21 patients (nine girls and 12 boys; mean age at first operation, 6.6 years, 1.52 to 13.18) who underwent 52 femoral operations were monitored during a mean of 9.96 years (3.39 to 14.54). Patient characteristics, telescoping rod capability and its complications were examined.

RESULTS

According to the Sillence classification, we investigated one patient with type I, nine with type III and 11 with type IV OI. Revision rates at up to five years (36%) were inferior to those found for the Fassier-Duval rod (46%). The main cause of revision was fracture (15 patients), followed by rod migration (nine), and infection (two). The rod exhibited higher telescopic capacity in boys than girls. Type III most commonly required an operation; the age group with the highest number of procedures was five to ten years. Male migration was the main cause of rod migration.

CONCLUSION

The TIR has a satisfactory cost-benefit ratio with less complication rates and low production costs. The TIR is a feasible alternative to the commonly used Fassier-Duval rod.

LEVEL OF EVIDENCE

IV.

Bilateral giant retinal tears in Osteogenesis Imperfecta

Background

Osteogenesis imperfecta (OI) is a rare primarily autosomal dominant condition in which the connective tissues of bones, ligaments and sclerae do not form properly. Typically, mutations in COL1A1 and COL1A2 genes lead to the defective formation or quantity of type I collagen, the principle matrix in these tissues. Molecular genetic studies have now elucidated multiple genetic subtypes of the disorder but little literature exists on the risk of retinal tears and detachments in OI.

Case presentation

We report the first case of a child with a rare recessive type of OI, subtype VIII, resulting from a P3H1 (also known as LEPRE1) gene mutation presenting with bilateral giant retinal tears and the surgical challenges encountered in performing retinal detachment repair due to scleral thinning. The P3H1 gene encodes for prolyl 3-hydroxylase 1 which is involved in the post-translational modification of not only collagen type I but also types II and V which when mutated may result in pathological posterior vitreous detachment (PVD) and giant retinal tear detachments.

Conclusions

Genetic analyses are increasingly important in such cases and may guide patient monitoring and potential prophylactic treatment, known to significantly reduce the probability of giant retinal tear detachments in other high-risk collagenopathies such as Stickler Syndrome Type I.

Developments in rare bone diseases and mineral disorders

In the last decade, there have been a number of significant advances made in the field of rare bone diseases. In this review, we discuss the expansion of the classification system for osteogenesis imperfecta (OI) and the resultant increase in therapeutic options available for management of OI. Bisphosphonates remain the most widely used intervention for OI, although the effect on fracture rate reduction is equivocal. We review the other therapies showing promising results, including denosumab, teriparatide, sclerostin, transforming growth factor β inhibition and gene targeted approaches. X-linked hypophosphataemia (XLH) is the most common heritable form of osteomalacia and rickets caused by a mutation in the phosphate regulating endopeptidase gene resulting in elevated serum fibroblast growth factor 23 (FGF23) and decreased renal phosphate reabsorption. The traditional treatment is phosphate replacement. We discuss the development of a human anti-FGF23 antibody (KRN23) as a promising development in the treatment of XLH. The current management of primary hypoparathyroidism is replacement with calcium and active vitamin D. This can be associated with under or over replacement and its inherent complications. We review the use of recombinant parathyroid hormone (1-84), which can significantly reduce the requirements for calcium and vitamin D resulting in greater safety and quality of life for individuals with hypoparathyroidism. The use of receptor activator of nuclear factor κB ligand infusions in the treatment of a particular form of osteopetrosis and enzyme replacement therapy for hypophosphatasia are also discussed.

Dental Manifestations of Pediatric Bone Disorders

PURPOSE OF REVIEW

Several bone disorders affecting the skeleton often are manifest in the maxillofacial region. This review presents the most common bone disorders in children and their dental-oral manifestations: fibrous dysplasia, Paget's disease, osteogenesis imperfecta, renal osteodystrophy, hypophosphatasia, and osteoporosis. The specific intraoral characteristics will reviewed in detail.

RECENT FINDINGS

Recent studies confirmed the close relationship between the mandible and the maxilla with the most prevalent systemic bone disorders in children. This review will help practitioners to integrate the oral health into the systemic health and improve the multidisciplinary approach of pediatric patients between medicine and dentistry.

Managing the patient with osteogenesis imperfecta: a multidisciplinary approach

Osteogenesis imperfecta (OI) is a heterogeneous heritable connective tissue disorder characterized by low bone density. The type and severity of OI are variable. The primary manifestations are fractures, bone deformity, and bone pain, resulting in reduced mobility and function to complete everyday tasks. OI affects not only the physical but also the social and emotional well-being of children, young people, and their families. As such, medical, surgical, and allied health professionals’ assessments all play a role in the management of these children. The multidisciplinary approach to the treatment of children and young people living with OI seeks to provide well-coordinated, comprehensive assessments, and interventions that place the child and family at the very center of their care. The coordinated efforts of a multidisciplinary team can support children with OI to fulfill their potential, maximizing function, independence, and well-being.

Skeletal Dysplasias: Growing Therapy for Growing Bones

Skeletal dysplasias represent a large and diverse group of rare conditions affecting collagen and bone. They can be clinically classified based on radiographic and physical features, and many can be further defined at a molecular level (Bonafe et al., 2015). Early diagnosis is critical to proper medical management including pharmacologic treatment when available. Patients with severe skeletal dysplasias often have small chests with respiratory insufficiency or airway obstruction and require immediate intubation after birth. Thereafter a variety of orthopedic, neurosurgical, pulmonary, otolaryngology interventions may be needed. In terms of definitive treatment for skeletal dysplasias, there are few pharmacotherapeutic options available for the majority of these conditions. We sought to describe therapies that are currently available or under investigation for skeletal dysplasias.

Osteogenesis imperfecta in children and adolescents-new developments in diagnosis and treatment

Osteogenesis imperfecta (OI) is the most prevalent heritable bone fragility disorder in children. It has been known for three decades that the majority of individuals with OI have mutations in COL1A1 or COL1A2, the two genes coding for collagen type I alpha chains, but in the past 10 years defects in at least 17 other genes have been linked to OI. Almost all individuals with a typical OI phenotype have a mutation in one of the currently known genes. Regarding medical treatment, intravenous bisphosphonate therapy is the most widely used medical approach. This has a marked effect on vertebra in growing children and can lead to vertebral reshaping after compression fractures, but there is little effect of bisphosphonate therapy on the development of scoliosis. Bisphosphonate treatment decreases long-bone fracture rates, but such fractures are still frequent. Newer medications with anti-resorptive and bone anabolic action are being investigated in an attempt to improve on the efficacy of bisphosphonates but the safety and efficacy of these new approaches in children with OI is not yet established.

Paleodysmorphology and paleoteratology: Diagnosing and interpreting congenital conditions of the skeleton in anthropological contexts

Most congenital conditions have low prevalence, but collectively they occur in a few percent of all live births. Congenital conditions are rarely encountered in anthropological studies, not least because many of them have no obvious effect on the skeleton. Here, we discuss two groups of congenital conditions that specifically affect the skeleton, either qualitatively or quantitatively. Skeletal dysplasias (osteochondrodysplasias) interfere with the histological formation, growth and maturation of skeletal tissues leading to diminished postural length, but the building plan of the body is unaffected. Well- known skeletal dysplasias represented in the archeological record include osteogenesis imperfecta and achondroplasia. Dysostoses, in contrast, interfere with the building plan of the body, leading to e.g. missing or extraskeletal elements, but the histology of the skeletal tissues is unaffected. Dysostoses can concern the extremities (e.g., oligodactyly and polydactyly), the vertebral column (e.g., homeotic and meristic anomalies), or the craniofacial region. Conditions pertaining to the cranial sutures, i.e., craniosynostoses, can be either skeletal dysplasias or dysostoses. Congenital conditions that are not harmful to the individual are known as anatomical variations, several of which have a high and population-specific prevalence that could potentially make them useful for determining ethnic origins. In individual cases, specific congenital conditions could be determinative in establishing identity, provided that ante-mortem registration of those conditions was ensured. Clin. Anat. 29:878-891, 2016. © 2016 The Authors Clinical Anatomy published by Wiley Periodicals, Inc. on behalf of American Association of Clinical Anatomists.

Mutation analysis of the COL1A1 and COL1A2 genes in Vietnamese patients with osteogenesis imperfecta

Background

The genetics of osteogenesis imperfecta (OI) have not been studied in a Vietnamese population before. We performed mutational analysis of the COL1A1 and COL1A2 genes in 91 unrelated OI patients of Vietnamese origin. We then systematically characterized the mutation profiles of these two genes which are most commonly related to OI.

Methods

Genomic DNA was extracted from EDTA-preserved blood according to standard high-salt extraction methods. Sequence analysis and pathogenic variant identification was performed with Mutation Surveyor DNA variant analysis software. Prediction of the pathogenicity of mutations was conducted using Alamut Visual software. The presence of variants was checked against Dalgleish’s osteogenesis imperfecta mutation database.

Results

The sample consisted of 91 unrelated osteogenesis imperfecta patients. We identified 54 patients with COL1A1/2 pathogenic variants; 33 with COL1A1 and 21 with COL1A2. Two patients had multiple pathogenic variants. Seventeen novel COL1A1 and 10 novel COL1A2 variants were identified. The majority of identified COL1A1/2 pathogenic variants occurred in a glycine substitution (36/56, 64.3 %), usually serine (23/36, 63.9 %). We found two pathogenic variants of the COL1A1 gene c.2461G > A (p.Gly821Ser) in four unrelated patients and one, c.2005G > A (p.Ala669Thr), in two unrelated patients.

Conclusion

Our data showed a lower number of collagen OI pathogenic variants in Vietnamese patients compared to reported rates for Asian populations. The OI mutational profile of the Vietnamese population is unique and related to the presence of a high number of recessive mutations in non-collagenous OI genes. Further analysis of OI patients negative for collagen mutations, is required.

The unfolded protein response in skeletal development and homeostasis

Osteoblasts and chondrocytes produce a large number of extracellular matrix proteins to generate and maintain the skeletal system. To cope with their functions as secretory cells, these cells must acquire a considerable capacity for protein synthesis and also the machinery for the quality-control and transport of newly synthesized secreted proteins. The unfolded protein response (UPR) plays a crucial role during the differentiation of these cells to achieve this goal. Unexpectedly, however, studies in the past several years have revealed that the UPR has more extensive functions in skeletal development than was initially assumed, and the UPR critically orchestrates many facets of skeletal development and homeostasis. This review focuses on recent findings on the functions of the UPR in the differentiation of osteoblasts, chondrocytes, and osteoclasts. These findings may have a substantial impact on our understanding of bone metabolism and also on establishing treatments for congenital and acquired skeletal disorders.

[Diagnostics in osteology]

Clinical diagnostics in metabolic bone diseases cover a broad spectrum of conventional and state of the art methods ranging from the medical history and clinical examination to molecular imaging. Patient treatment is carried out in an interdisciplinary team due to the multiple interactions of bone with other organ systems. Diagnosis of osteoporosis is supported by high level national guidelines. A paradigm shift concerning the clinical relevance of bone mineral density measurement renders this now to be a strong risk factor rather than a diagnostic parameter, while strengthening the value of other clinical factors for risk assessment. The impact of parameters for muscle mass, structure and function is steadily increasing in all age groups. In order to identify underlying diseases that influence bone metabolism a panel of general laboratory diagnostic parameters is recommended. Markers for bone formation and resorption and specific parameters for the regulation of calcium and phosphate metabolism should be evaluated by specialists because they require diligence in preanalytics and experience in interpretation. Genetic diagnosis is well established for rare bone diseases while diagnostic panels are not yet available for routine diagnostics in polygenetic diseases such as osteoporosis. Conventional radiology is still very important to identify, e. g. fractures, osteolytic and osteoblastic lesions and extraosseous calcifications; however tomography-based methods which combine, e. g. scintigraphy or positron emission technologies with anatomical imaging are of increasing significance. Clinical diagnostics in osteology require profound knowledge and are subject to a dynamic evolution.

Emerging targeted drug therapies in skeletal dysplasias

Quantum advances have occurred in the field of human genetics in the six decades since Watson and Crick expressed their "wish to suggest a structure for the salt of deoxyribose nucleic acid." These culminated with the human genome project, which has opened up myriad possibilities, including that of individualized genetic medicine, the ability to deliver medical advice, management, and therapy tailored to an individual's genetic blueprint. Advances in genetic diagnostic capabilities have been rapid, to the point where the genome can be sequenced for several thousand dollars. Crucially, it has facilitated the identification of targets for "precision" treatments to combat genetic diseases at their source. This manuscript will review the innovative, pathogenesis-based therapies that are revolutionizing management of skeletal dysplasias, giving patients and families new options and outcomes. © 2016 Wiley Periodicals, Inc.