Bisphosphonate treatment of children and adults with osteogenesis imperfecta: unanswered questions

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.

A roadmap to surgery in osteogenesis imperfecta: results of an international collaboration of patient organizations and interdisciplinary care teams

Background and purpose - Involvement of patient organizations is steadily increasing in guidelines for treatment of various diseases and conditions for better care from the patient's viewpoint and better comparability of outcomes. For this reason, the Osteogenesis Imperfecta Federation Europe and the Care4BrittleBones Foundation convened an interdisciplinary task force of 3 members from patient organizations and 12 healthcare professionals from recognized centers for interdisciplinary care for children and adults with osteogenesis imperfecta (OI) to develop guidelines for a basic roadmap to surgery in OI.Methods - All information from 9 telephone conferences, expert consultations, and face-to-face meetings during the International Conference for Quality of Life for Osteogenesis Imperfecta 2019 was used by the task force to define themes and associated recommendations.Results - Consensus on recommendations was reached within 4 themes: the interdisciplinary approach, the surgical decision-making conversation, surgical technique guidelines for OI, and the feedback loop after surgery.Interpretation - The basic guidelines of this roadmap for the interdisciplinary approach to surgical care in children and adults with OI is expected to improve standardization of clinical practice and comparability of outcomes across treatment centers.

Temporomandibular Joint and Cervical Spine Mobility Assessment in the Prevention of Temporomandibular Disorders in Children with Osteogenesis Imperfecta: A Pilot Study

Osteogenesis imperfecta is a heterogeneous group of hereditary disorders of connective tissue diseases characterized by increased bone fragility, low growth, sometimes accompanied by abnormalities within the dentine, blue sclera, and partial or total hearing impairment. The changes may affect all joints, including the cervical spine and temporomandibular joints in the future, resulting in pain. The aim of the present study was to assess whether there is a relationship between the active range of motion of the cervical spine and the mobility of temporomandibular joints due to differential diagnosis in children with osteogenesis imperfecta, and to present a prevention algorithm for temporomandibular disorders. The study involved a group of 34 children with osteogenesis imperfecta, and the control group included 23 children (age 9.1 ± 3.8 years). Data were collected through an interview based on the author’s questionnaire, and the physical examination consisted in measuring the mobility of the cervical spine using an inclinometer (Cervical Range of Motion Instrument), the Helkimo scale, and linear measurements. In children with congenital bone fragility, there were acoustic symptoms from the temporomandibular joints more often than in healthy children. A correlation was found between the mobility of the cervical spine and temporomandibular joints in the study group. In the case of detecting irregularities in the temporomandibular joints, children were ordered to perform jaw-tongue coordination exercises.

The effect of bisphosphonate medication on orthodontics and orthognathic surgery in patients with osteogenesis imperfecta

Introduction: Osteogenesis imperfecta (OI) is a genetic disease that primarily affects bone formation and metabolism. Craniofacial malformations belong to the broad spectrum of the OI phenotype. The introduction of bisphosphonate medications was intended to counteract the significant brittleness of the bones of OI patients. In connection with the application of bisphosphonates, drug-associated osteonecrosis of the jaw has become known as an undesirable effect of the therapeutically intended reduction of osteoclast activity. Originally, the pharmacological inhibition of bone loss was mainly used in oncological therapy. For some time now, osteoporosis has also been treated with substances that inhibit bone resorption.

In OI, malposition of the jaws is relatively common, in particular retrognathia of the maxilla and progeny of the mandible. The literature discloses complications of orthognathic surgery in OI patients. Previous literature reviews suggest that bisphosphonate medication has no significant impact on the performance of and healing after oral surgery in OI patients.

Materialandmethods: An essential prerequisite of a therapy adapted to the patient’s condition is the knowledge of the patient's medical history. This case report describes the orthodontic-surgical treatment of an OI patient and the treatment experience derived in dealing with the condition. The unusual circumstance of this case is that the patient had concealed both his underlying disease and his medication during the current treatment period. In addition, the relevant literature is evaluated for combining the keywords OI, orthodontic therapy, bisphosphonates, and orthognathic surgery.

Results: Based on the literature and our own experience, it is concluded that orthodontic treatment with bisphosphonate medication can also be carried out in OI patients. However, considerably greater forces and longer time intervals should be scheduled for each treatment. Orthognathic surgery with bisphosphonate medication turned out to be uncomplicated in our own case, considering the underlying disease in the planning of surgical procedures. However, there have been very few reports of OI patients in whom orthodontic-surgical treatment of jaw malformation has been performed with bisphosphonate medication.

Conclusion: Taking into account the reported experience of severe complications of orthognathic surgery, the multiple documented adjustments to the treatment strategy of OI patients should be taken seriously. The basic condition of therapy adapted to the disease is that the patient informs the practitioner in an appropriate manner about his or her state of health.

A Multicenter Observational Cohort Study to Evaluate the Effects of Bisphosphonate Exposure on Bone Mineral Density and Other Health Outcomes in Osteogenesis Imperfecta

Osteogenesis imperfecta (OI) is characterized by low bone mass and bone fragility. Using data from a large cohort of individuals with OI from the Osteogenesis Imperfecta Foundation's linked clinical research centers, we examined the association between exposure to bisphosphonate (BPN) treatment (past or present) and lumbar spine (LS) areal bone mineral density (aBMD), fractures, scoliosis, and mobility. From 466 individuals, we obtained 1394 participant‐age LS aBMD data points. Though all OI subtypes were examined, primary analyses were restricted to type I OI (OI‐1). Using linear regression, we constructed expected OI‐1 LS aBMD‐for‐age curves from the data from individuals who had never received BPN. LS aBMD in those who had been exposed to BPN was then compared with the computed expected aBMD. BPN exposure in preadolescent years (age <14 years) was associated with a LS aBMD that was 9% more than the expected computed values in BPN‐naïve individuals (p < 0.01); however, such association was not observed across all ages. Exposure to i.v. BPN and treatment duration >2 years correlated with LS aBMD in preadolescent individuals. BPN exposure also had a significant association with non‐aBMD clinical outcome variables. Logistic regression modeling predicted that with BPN exposure, a 1‐year increase in age would be associated with an 8.2% decrease in fracture probability for preadolescent individuals with OI‐1, compared with no decrease in individuals who had never received any BPN (p < 0.05). In preadolescent individuals with OI‐1, a 0.1 g/cm² increase in LS aBMD was associated with a 10.6% decrease in scoliosis probability, compared with a 46.8% increase in the BPN‐naïve group (p < 0.01). For the same changes in age and LS aBMD in preadolescent individuals, BPN exposure was also associated with higher mobility scores (p < 0.01), demonstrating that BPN treatment may be associated with daily function. © 2018 The Authors. JBMR Plus Published by Wiley Periodicals, Inc. on behalf of American Society for Bone and Mineral Research.

Long-Term Bisphosphonate Therapy in Osteogenesis Imperfecta

PURPOSE OF REVIEW

Osteogenesis imperfecta (OI) is a genetic bone disorder resulting in bone fragility. It has a heterogeneous phenotype which typically includes reduced bone mass, multiple fractures, deformity, and chronic disability. Bisphosphonate treatment remains the first-line medical management, but there is still debate on aspects of its effectiveness. This review summarizes current knowledge about long-term bisphosphonate use in OI with recommendations on clinical application.

RECENT FINDINGS

Bisphosphonates increase bone mineral density, most notably of the vertebrae, and reduce fracture risk in the pediatric OI population. Gains in strength and mobility, together with the permissive effect on orthopedic surgery (e.g., in combination with intramedullary rodding) and physiotherapy, have resulted in improved quality of life for those with OI. As experience in its use continues, the risks and benefits of long-term bisphosphonate treatment in OI are slowly emerging. Patient registries containing data on genotype, phenotype, fractures, bisphosphonate treatment, orthopedic intervention, and functional outcomes are essential for systematic evaluation given the lack of large multi-centered randomized control trials.

Non-Lethal Type VIII Osteogenesis Imperfecta Has Elevated Bone Matrix Mineralization

CONTEXT

Type VIII osteogenesis imperfecta (OI; OMIM 601915) is a recessive form of lethal or severe OI caused by null mutations in P3H1, which encodes prolyl 3-hydroxylase 1.

OBJECTIVES

Clinical and bone material description of non-lethal type VIII OI.

DESIGN

Natural history study of type VIII OI.

SETTING

Pediatric academic research centers.

PATIENTS

Five patients with non-lethal type VIII OI, and one patient with lethal type VIII OI.

INTERVENTIONS

None.

MAIN OUTCOME MEASURES

Clinical examinations included bone mineral density, radiographs, and serum and urinary metabolites. Bone biopsy samples were analyzed for histomorphometry and bone mineral density distribution by quantitative backscattered electron imaging microscopy. Collagen biochemistry was examined by mass spectrometry, and collagen fibrils were examined by transmission electron microscopy.

RESULTS

Type VIII OI patients have extreme growth deficiency, an L1-L4 areal bone mineral density Z-score of -5 to -6, and normal bone formation markers. Collagen from bone and skin tissue and cultured osteoblasts and fibroblasts have nearly absent 3-hydroxylation (1-4%). Collagen fibrils showed abnormal diameters and irregular borders. Bone histomorphometry revealed decreased cortical width and very thin trabeculae with patches of increased osteoid, although the overall osteoid surface was normal. Quantitative backscattered electron imaging showed increased matrix mineralization of cortical and trabecular bone, typical of other OI types. However, the proportion of bone with low mineralization was increased in type VIII OI bone, compared to type VII OI.

CONCLUSIONS

P3H1 is the unique enzyme responsible for collagen 3-hydroxylation in skin and bone. Bone from non-lethal type VIII OI children is similar to type VII, especially bone matrix hypermineralization, but it has distinctive features including extremely thin trabeculae, focal osteoid accumulation, and an increased proportion of low mineralized bone.

Novel mutations in FKBP10 in Chinese patients with osteogenesis imperfecta and their treatment with zoledronic acid

Osteogenesis imperfecta (OI) is a group of hereditary disorders characterized by decreased bone mass and increased fracture risk. The majority of OI cases have an autosomal dominant pattern of inheritance and are usually caused by mutations in genes encoding type I collagen. OI cases of autosomal recessive inheritance are rare, and OI type XI is attributable to mutation of the FKBP10 gene. Here, we used next-generation sequencing and Sanger sequencing to detect mutations in FKBP10 and to analyze their relation to the phenotypes of OI type XI in three Chinese patients. We also evaluated the efficacy of zoledronic acid treatment in these patients. Two of the affected patients had novel compound heterozygous mutations, one patient with c.343C>T (p.R115X) in exon 2 and c.1085delC (p.A362fsX1) in exon 7, and the other patient with c.879C>G (p.Y293X) in exon 5 and c.918-3C>G in intron 5. In the third proband, we identified a homozygous single base-pair duplication, c.831dupC (p.G278RfsX95) in exon 5. In conclusion, we report for the first time that these novel pathogenic mutations of FKBP10 can lead to the extremely rare type XI OI without contractures, which expands the genotypic spectrum of OI. The phenotypes of these patients are similar to patients with types III or IV OI, and zoledronic acid is effective in increasing BMD, inhibiting bone resorption biomarkers and reducing fractures of these patients.

An Evaluative History of Bisphosphonate Drugs: Dual Physiologic Effects of Pyrophosphate as Inspiration for a Novel Pharmaceutical Class

The documented history of the development of the bisphosphonate drugs is reviewed in sufficient detail to permit independent evaluation of the consistency of the conclusions reached from the available data. The evidence developed during the early interval of these studies 1960-1975 was sufficient to establish that pyrophosphate shares the subsequently established dual bisphosphonate characteristics of bone resorption inhibition and prevention of tissue mineralization.