Efficacy and Safety of Bisphosphonate Therapy in Children with Osteogenesis Imperfecta: A Systematic Review

New Perspectives of Therapies in Osteogenesis Imperfecta-A Literature Review

(1) Background: Osteogenesis imperfecta (OI) is a rare skeletal dysplasia characterized as a heterogeneous disorder group with well-defined phenotypic and genetic features that share uncommon bone fragility. The current treatment options, medical and orthopedic, are limited and not efficient enough to improve the low bone density, bone fragility, growth, and mobility of the affected individuals, creating the need for alternative therapeutic agents. (2) Methods: We searched the medical database to find papers regarding treatments for OI other than conventional ones. We included 45 publications. (3) Results: In reviewing the literature, eight new potential therapies for OI were identified, proving promising results in cells and animal models or in human practice, but further research is still needed. Bone marrow transplantation is a promising therapy in mice, adults, and children, decreasing the fracture rate with a beneficial effect on structural bone proprieties. Anti-RANKL antibodies generated controversial results related to the therapy schedule, from no change in the fracture rate to improvement in the bone mineral density resorption markers and bone formation, but with adverse effects related to hypercalcemia. Sclerostin inhibitors in murine models demonstrated an increase in the bone formation rate and trabecular cortical bone mass, and a few human studies showed an increase in biomarkers and BMD and the downregulation of resorption markers. Recombinant human parathormone and TGF-β generated good results in human studies by increasing BMD, depending on the type of OI. Gene therapy, 4-phenylbutiric acid, and inhibition of eIF2α phosphatase enzymes have only been studied in cell cultures and animal models, with promising results. (4) Conclusions: This paper focuses on eight potential therapies for OI, but there is not yet enough data for a new, generally accepted treatment. Most of them showed promising results, but further research is needed, especially in the pediatric field.

Efficacy of antiresorptive agents in fibrous dysplasia and McCune Albright syndrome, a systematic review and meta-analysis

Fibrous dysplasia (FD) is a rare skeletal disorder in which normal bone is replaced by a fibro-osseous tissue, resulting in possible deformities and fractures. The aim of this systematic review and meta-analysis was to synthesize the available evidence on the use of antiresorptive drugs in FD in terms of changes in bone turnover markers (BTMs), bone mineral density (BMD), and reducing pain. Three databases were searched in October 2022, with an update in July 2023. Of the 1037 studies identified, 21 were retained after eligibility assessment. A random-effects model was used to calculate global effect size and the corresponding standard error. Pamidronate and Denosumab were the most reported drugs in a total of 374 patients assessed. The initiation of treatments was accompanied by an average reduction of 40.5% [CI95% -51.6, -29.3] in the bone resorption parameters, and 22.0% [CI95% -31.9, -12.1] in the parameters of bone formation after 6-12 months. BMD was increased in both FD lesions and in the unaffected skeleton. Pain was reduced by 32.7% [CI95% -52.7, -12.6] after 6-12 months of treatment, and by 44.5% [CI95% -65.3, -23.6] after a mean 41.2 months of follow-up. The variation in pain was highly correlated to variation in bone resorption (R2 = 0.08, p < 0.0001) and formation parameters (R2 = 0.17, p < 0.0001). This study supports the overall efficacy of antiresorptive therapies in terms of reducing bone remodeling, improving bone density, and pain in FD.

The Natural History of Symptomatic Fractures in Children and Adolescents with Osteogenesis Imperfecta Type 1: A Cohort Study from Western Australia

The fracture experience of children and adolescents with osteogenesis imperfecta (OI) type 1 is not well described in the literature. We present data on symptomatic long bones and axial skeleton fractures of all patients aged 0 to 18 years with OI type 1 seen at a specialized bone clinic in Western Australia in the period 2008 to 2020 using a retrospective chart review method. The cohort consisted of 44 patients (21 males, 23 females). Median (interquartile range [IQR]) age was 11.3 (6.2 to 17) years, giving a total of 520 patient-years in the study during which 197 fractures were experienced. The mean fracture rate was 379 fractures per 1000 patient-years (95% confidence interval [CI]: 310 to 440); however, the experience for fractures varied from ≤1 fracture in 23% (n = 10) to two to 20 in 77% (n = 34) of the cohort. Twenty-one patients (48.5%) received bisphosphonates during the study period. In logistic regression, age, but not sex or family history of OI, was a significant predictor of fracture risk. The highest total fracture rate was observed in the age group 0 to <3 years at 469 fractures/1000 patient-years, which declined to 140 fractures/1000 patient-years in the age group 15 to 18 years. The lower limbs were the site of 49.7% of all fractures. The highest rate for lower limb fracture was in the age group 0 to <3 years at 331 fractures/1000 patient-years, decreasing to 0 fractures/1000 patient-years in the age group 15 to 18 years. Upper limb fracture rates increased from 100 fractures/1000 patient-years in the 0 to <3 years age group to 307 fractures/1000 patient-years in the 9 to <12 years age group and then declining to 70 fractures/1000 years in the 15 to 18 years age group. In pediatric patients with OI type 1, fracture risk is highest in early life, especially in the lower limbs. Multidisciplinary care of children with OI should have a particular focus on strategies to prevent these fractures. © 2023 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

Radiomorphometric indices and fractal dimension of the mandible in individuals with osteogenesis imperfecta: a matched cross-sectional study

OBJECTIVE

The objective was to analyze radiomorphometric indices (RMIs) of mandibular cortical bone and fractal dimension (FD) of trabecular bone of individuals with osteogenesis imperfecta (OI) and compare the findings to those of individuals without OI.

METHODS

Digital panoramic radiographs of 20 individuals with OI (case group) and 40 individuals without OI (control group) were examined. The RMIs of mandibular cortical index (MCI) and mandibular cortical thickness (MCT) were analyzed. FD of mandibular trabecular bone was calculated bilaterally in 3 regions. The chi-squared test and paired t test were used to compare the significance of differences between the groups. The effect size and minimal clinically important difference (MCID) were also determined. Significance was established at P < .05.

RESULTS

Categories C2 and C3 of the MCI were more frequent in individuals with OI (P < .001). The Mean MCT was 2.08 ± 0.79 in the OI case group and 2.91 ± 0.60 in the control group (P < .001). Mean FD in the condylar region was significantly lower in the OI case group (P = .002). The effect size for these 2 measures was large, and the difference between groups was greater than the MCID.

CONCLUSION

Radiographs of individuals with OI exhibited more porosity and diminished thickness of the mandibular cortical bone and lower FD values in the condylar trabecular bone.

The patient clinical journey and socioeconomic impact of osteogenesis imperfecta: a systematic scoping review

BACKGROUND

Osteogenesis imperfecta (OI) is a rare heritable connective tissue disorder primarily characterised by skeletal deformity and fragility, and an array of secondary features. The purpose of this review was to capture and quantify the published evidence relating specifically to the clinical, humanistic, and economic impact of OI on individuals, their families, and wider society.

METHODS

A systematic scoping review of 11 databases (MEDLINE, MEDLINE in-progress, EMBASE, CENTRAL, PsycINFO, NHS EED, CEA Registry, PEDE, ScHARRHUd, Orphanet and Google Scholar), supplemented by hand searches of grey literature, was conducted to identify OI literature published 1st January 1995-18th December 2021. Searches were restricted to English language but without geographical limitations. The quality of included records was assessed using the AGREE II checklist and an adapted version of the JBI cross-sectional study checklist.

RESULTS

Of the identified 7,850 records, 271 records of 245 unique studies met the inclusion criteria; overall, 168 included records examined clinical aspects of OI, 67 provided humanistic data, 6 reported on the economic impact of OI, and 30 provided data on mixed outcomes. Bone conditions, anthropometric measurements, oral conditions, diagnostic techniques, use of pharmacotherapy, and physical functioning of adults and children with OI were well described. However, few records included current care practice, diagnosis and monitoring, interactions with the healthcare system, or transition of care across life stages. Limited data on wider health concerns beyond bone health, how these concerns may impact health-related quality of life, in particular that of adult men and other family members, were identified. Few records described fatigue in children or adults. Markedly few records provided data on the socioeconomic impact of OI on patients and their caregivers, and associated costs to healthcare systems, and wider society. Most included records had qualitative limitations.

CONCLUSION

Despite the rarity of OI, the volume of recently published literature highlights the breadth of interest in the OI field from the research community. However, significant data gaps describing the experience of OI for individuals, their families, and wider society warrant further research to capture and quantify the full impact of OI.

Skeletal outcomes of patients with osteogenesis imperfecta during drug holiday of bisphosphonates: a real-world study

PURPOSE

This study aimed to investigate the skeletal outcomes of patients with osteogenesis imperfecta (OI) who received bisphosphonate (BP) treatment and entered drug holiday after achieving an age- and sex-specific bone mineral density (BMD) reference.

METHODS

Patients with OI receiving BP treatment were enrolled when they entered drug holidays of BPs. The skeletal outcomes were evaluated in detail during the drug holiday, including BMD, X-ray of the bone, bone fracture incidence, and bone turnover biomarkers. The pathogenic mutations of OI were identified by next-generation sequencing and confirmed by Sanger sequencing.

RESULTS

A total of 149 OI patients (127 juveniles and 22 adults) who entered drug holidays after nearly 4 years of BP treatment were included. Areal BMD at the lumbar spine increased from 0.934 ± 0.151 to 0.990 ± 0.142 g/cm² and was stable in the second (1.029 ± 0.176 g/cm²) and third years (1.023 ± 0.174 g/cm²) of BP drug holidays, and BMD at the femoral neck, trochanter, and total hip had no significant change, but it was gradually inferior to that of the same-gender juveniles in the second and third years of the drug holiday. BMD at the lumbar spine and proximal hip did not change and was inferior to that of the same-gender adults. The average time of fractures fluctuated from 0.18 to 0.08 per year in juveniles, while only one adult suffered from a fracture during BP drug holidays. Bone turnover markers were in the normal range, except for a mildly high level of β-carboxy-terminal cross-linked telopeptide of type 1 collagen in the juvenile group. A total of 17 (11.4%) patients received BP retreatment because of bone loss during the drug holiday. OI type III and type IV and COL1A2 mutation were correlated to a longer duration of BP treatment to enter drug holidays (all p < 0.05). Old age at initial treatment (OR, 1.056) and OI type III (OR, 10.880) were correlated to a higher risk of BP retreatment.

CONCLUSIONS

OI patients will undergo nearly 4 years of BP treatment to achieve drug holidays. During the 3 years of the drug holiday, the patients' BMD is stable, and fracture incidence does not increase significantly. Patients are more inclined to need retreatment during drug holidays owing to the late start of BP treatment and more severe OI phenotypes.

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.

Modification of COL1A1 in Autologous Adipose Tissue-Derived Progenitor Cells Rescues the Bone Phenotype in a Mouse Model of Osteogenesis Imperfecta

Osteogenesis imperfecta (OI) is a congenital genetic disorder mainly manifested as bone fragility and recurrent fracture. Mutation of COL1A1/COL1A2 genes encoding the type I collagen are most responsible for the clinical patients. Allogenic mesenchymal stem cells (MSCs) provide the potential to treat OI through differentiation into osteoblasts. Autologous defective MSCs have not been utilized in OI treatment mainly because of their impaired osteogenesis, but the latent mechanism has not been well understood. Here, the relative signaling abnormality of adipose-derived mesenchymal stem cells (ADSCs) isolated from OI type I mice (Col1a1^+/-365 mice) was explored. Autologous ADSCs transfected by retrovirus carrying human COL1A1 gene was first utilized in OI therapy. The results showed that decreased activity of Yes-associated protein (YAP) due to hyperactive upstream Hippo kinases greatly contributed to the weakened bone-forming capacity of defective ADSCs. Recovered collagen synthesis of autologous ADSCs by COL1A1 gene modification normalized Hippo/YAP signaling and effectively rescued YAP-mediated osteogenesis. And the COL1A1 gene engineered autologous ADSCs efficaciously improved the microstructure, enhanced the mechanical properties and promoted bone formation of Col1a1^+/-365 mice after femoral bone marrow cavity delivery and might serve as an alternative source of stem cells in OI treatment. © 2021 American Society for Bone and Mineral Research (ASBMR).

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.

Comparable Effects of Strontium Ranelate and Alendronate Treatment on Fracture Reduction in a Mouse Model of Osteogenesis Imperfecta

Alendronate (Aln) has been the first-line drug for osteogenesis imperfecta (OI), while the comparable efficacy of Aln and strontium ranelate (SrR) remains unclear. This study is aimed at comparing the effects of SrR and Aln treatment in a mouse model of OI. Three-week-old oim/oim and wt/wt female mice were treated with SrR (1800 mg/kg/day), Aln (0.21 mg/kg/week), or vehicle (Veh) for 11 weeks. After the treatment, the average number of fractures sustained per mouse was significantly reduced in both SrR- and Aln-treated oim/oim mice. The effect was comparable between these two agents. Both SrR and Aln significantly increased trabecular bone mineral density, bone histomorphometric parameters (bone volume, trabecular number, and cortical thickness and area), and biomechanical parameters (maximum load and stiffness) as compared with the Veh group. Both treatments reduced bone resorption parameters, with Aln demonstrating a stronger inhibitory effect than SrR. In contrast to its inhibitory effect on bone resorption, SrR maintained bone formation. Aln, however, also suppressed bone formation coupled with an inhibitory effect on bone resorption. The results of this study indicate that SrR has comparable effects with Aln on reducing fractures and improving bone mass and strength. In clinical practice, SrR may be considered an option for patients with OI when other medications are not suitable or have evident contraindications.

4-Phenylbutyric acid enhances the mineralization of osteogenesis imperfecta iPSC-derived osteoblasts

Osteogenesis imperfecta (OI) is a heritable brittle bone disease mainly caused by mutations in the two type I collagen genes. Collagen synthesis is a complex process including trimer formation, glycosylation, secretion, extracellular matrix (ECM) formation, and mineralization. Using OI patient-derived fibroblasts and induced pluripotent stem cells (iPSCs), we investigated the effect of 4-phenylbutyric acid (4-PBA) on collagen synthesis to test its potential as a new treatment for OI. Endoplasmic reticulum (ER) retention of type I collagen was observed by immunofluorescence staining in OI patient-derived fibroblasts with glycine substitution and exon skipping mutations. Liquid chromatography-mass spectrometry analysis revealed excessive glycosylation of secreted type I collagen at the specific sites in OI cells. The misfolding of the type I collagen triple helix in the ECM was demonstrated by the incorporation of heat-dissociated collagen hybridizing peptide in OI cells. Type I collagen was produced excessively by OI fibroblasts with a glycine mutation, but this excessive production was normalized when OI fibroblasts were cultured on control fibroblast-derived ECM. We also found that mineralization was impaired in osteoblasts differentiated from OI iPSCs. In summary, treatment with 4-PBA normalizes the excessive production of type I collagen, reduces ER retention, partially improves misfolding of the type I collagen helix in ECM, and improves osteoblast mineralization. Thus, 4-PBA may improve not only ER retention, but also type I collagen synthesis and mineralization in human cells from OI patients.

Parents' Perceptions of Health-Related Quality of Life of Children Diagnosed with Osteogenesis Imperfecta

PURPOSE

The purpose of this research was to describe the health-related quality of life (HRQoL) perceptions of parents of children diagnosed with osteogenesis imperfecta (OI).

DESIGN AND METHODS

This research used a descriptive design with a comparative sample. The Child Health Questionnaire (CHQ-PF 28) parent form was used to assess HRQoL in a sample of 37 parents from a mid-western tertiary pediatric hospital OI specialty clinic. Comparisons were made with a sample of parents of well children.

RESULTS

Parent HRQoL perception scores were described in both the physical and psycho-social-emotional domains. The domains of physical function (PF), bodily pain (BP), general health (GH), parent impact-emotional (PE), and child self-esteem (SE) were the lowest HRQoL mean domain scores for the parents of the children diagnosed with OI. Ceiling and floor scores were calculated to describe the magnitude of the differences between the mean HRQoL perception domain scores of the two parent groups.

CONCLUSIONS

Low HRQoL physical and psycho-social-emotional mean domain scores in conjunction with small percentage scores in the ceiling (and greater percentage scores in the floor) for parents of children diagnosed with OI were described. Findings suggest the on-going need for research to identify interventions to promote physical functioning for the child diagnosed with OI. Outcome based programs for parent and family-centered psycho-social self-care should be developed. PracticeImplications: ip Comprehensive and longitudinal assessment of HRQoL for both parents and their children diagnosed with OI will assist in documenting the outcomes of interventions for the management of chronic care.

Bladder and bowel symptoms experienced by children with osteogenesis imperfecta

OBJECTIVE

To estimate the prevalence and presentation of bladder, bowel, and combined bladder and bowel symptoms experienced by children with osteogenesis imperfecta and to describe the socio-demographic and clinical profile of these children.

METHOD

A descriptive study was conducted with a convenience sample of parent-child pairs of toilet-trained children aged from 3 to 18 years. Pairs were interviewed using three tools: (1) Socio-Demographic and Clinical Questionnaire; (2) Dysfunctional Voiding Scoring System; (3) Rome III Criteria along with the Bristol Stool Scale. Data were stratified by socio-demographic and clinical variables and analyzed using descriptive statistics.

RESULTS

Thirty-one parent-child pairs participated in the study; 38.7% (n=12) children reported bowel symptoms, 19.4% (n=6) reported a combination of bladder issues (such as holding maneuvers and urgency) and bowel symptoms (such as hard or painful bowel movements and large diameter stools). There were no reports of isolated bladder issues. Among the child participants, 16 (51.7%) identified as female and 20 (64.5%) were 5-14 years old. The most prevalent type of osteogenesis imperfecta was type III (n=12; 38.7%) and eight (25.8%) children reported using a wheelchair.

CONCLUSION

This is the first study to examine the prevalence and presentation of bladder, bowel, and combined bladder and bowel symptoms in children with osteogenesis imperfecta, offering a preliminary socio-demographic and clinical profile of these children. This research is an important step toward effective screening, detection, and access to care and treatment, especially for clinicians working with this group of very fragile patients.

Reproductive options for families at risk of Osteogenesis Imperfecta: a review

Background

Osteogenesis Imperfecta (OI) is a rare genetic disorder involving bone fragility. OI patients typically suffer from numerous fractures, skeletal deformities, shortness of stature and hearing loss. The disorder is characterised by genetic and clinical heterogeneity. Pathogenic variants in more than 20 different genes can lead to OI, and phenotypes can range from mild to lethal forms. As a genetic disorder which undoubtedly affects quality of life, OI significantly alters the reproductive confidence of families at risk. The current review describes a selection of the latest reproductive approaches which may be suitable for prospective parents faced with a risk of OI. The aim of the review is to alleviate suffering in relation to family planning around OI, by enabling prospective parents to make informed and independent decisions.

Main body

The current review provides a comprehensive overview of possible reproductive options for people with OI and for unaffected carriers of OI pathogenic genetic variants. The review considers reproductive options across all phases of family planning, including pre-pregnancy, fertilisation, pregnancy, and post-pregnancy. Special attention is given to the more modern techniques of assisted reproduction, such as preconception carrier screening, preimplantation genetic testing for monogenic diseases and non-invasive prenatal testing. The review outlines the methodologies of the different reproductive approaches available to OI families and highlights their advantages and disadvantages. These are presented as a decision tree, which takes into account the autosomal dominant and autosomal recessive nature of the OI variants, and the OI-related risks of people without OI.

The complex process of decision-making around OI reproductive options is also discussed from an ethical perspective.

Conclusion

The rapid development of molecular techniques has led to the availability of a wide variety of reproductive options for prospective parents faced with a risk of OI. However, such options may raise ethical concerns in terms of methodologies, choice management and good clinical practice in reproductive care, which are yet to be fully addressed.

Effects of zoledronic acid on vertebral shape of children and adolescents with osteogenesis imperfecta

Vertebral compression fracture (VCF) is a common and severe complication of osteogenesis imperfecta (OI). We prospectively observe the changes of vertebral shape during zoledronic acid (ZOL) treatment and assess influence factors of VCF in OI children. 32 children with VCF and 10 children without VCF (NVCF) were included and given ZOL treatment for 2 years, who were matched in age and gender. Control group included 17 treatment naïve OI patients with VCF who were matched in age, gender and clinical severity to 17 patients in VCF group received ZOL treatment for 1 year (as ZOL treated group). We performed quantitative vertebral morphometry and calculated concavity index (mh/ph), height-length ratio (ah/LL, mh/LL, ph/LL) and projection area (PA) of vertebrae from T4 to L4 before and after treatment. At baseline, patients in VCF group had significantly lower PA, mh/ph, ah/LL, mh/LL and ph/LL than patients in NVCF group (P < 0.01). PA, mh/ph, ah/LL, mh/ LL and ph/LL of patients with VCF were raised by (35.2 ± 19.5)%, (22.9 ± 15.1)%, (19.6 ± 13.9)%, (33.6 ± 25.5)%, and (8.1 ± 8.8)% (P < 0.01) after 1-year treatment of ZOL, and were increased by (71.8 ± 28.2)%, (42.8 ± 21.8)%, (35.1 ± 20.6)%, (65.4 ± 43.2)%, and (12.5 ± 11.4)% after 2-year treatment of ZOL (P < 0.01). Compared to control group, mh/ph, ah/LL and mh/LL were significantly higher (P < 0.01) in ZOL treated group. LS-BMD and its increase were positively correlated to vertebral height and PA at baseline and the improvement of vertebral height and PA after ZOL treatment, respectively. In conclusion, the compressive vertebrae of OI children could be effectively reshaped during ZOL treatment. Low LS-BMD was an independent risk factor for VCF and its increase was positively correlated to the improvement in vertebral shape after ZOL treatment.

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.

Validation of the Adolescent Pediatric Pain Tool for the Multidimensional Measurement of Pain in Children and Adolescents Diagnosed with Osteogenesis Imperfecta

Background: The Adolescent Pediatric Pain Tool (APPT) is a self-reported, multidimensional assessment of pain location, intensity, and quality in children and adolescents. Yet, it has not been validated for use in children and adolescents with osteogenesis imperfecta (OI). Aims: This study aimed to validate and evaluate the feasibility of the APPT for pain assessment in children and adolescents with OI. Methods: A prospective observational study was conducted at a university-affiliated pediatric hospital in Canada. Thirty-three children and adolescents with OI participated by completing the APPT pre-bisphosphonate intravenous infusion and 1 week post-bisphosphonate intravenous infusion. Main outcomes were internal consistency, convergent and discriminative validity, and feasibility. Results: The Kuder-Richardson test of internal consistency was 0.863, 0.661, and 0.729 for the Sensory, Affective, and Evaluative subscales, respectively. For the entire pain quality scale, the Cronbach's alpha was 0.835. Regarding convergent validity, a moderate correlation was observed between the ratings on the pain intensity scale and the Faces Pain Scale-Revised (Spearman's rho = 0.711). Patients for whom pain was a problem reported higher pain intensity (Mann Whitney U = 41.50, P = 0.032) and more pain quality descriptors (Mann Whitney U = 45.50, P = 0.020) and painful body areas (Mann-Whitney U = 25.50, P = 0.001) than those for whom it was not (Mann-Whitney U, P < 0.05). In terms of feasibility, completing the tool may require a considerable time commitment and assistance from a clinician or parent, especially if the patient is experiencing pain and provides detailed pain location and quality information by completing the APPT. Conclusions: This study suggests that the APPT is valid for the multidimensional assessment of pain in children and adolescents with OI, but feasibility needs to be enhanced.

Biodegradable polymer promotes osteogenic differentiation in immortalized and primary osteoblast-like cells

Biodegradable polymers have been broadly used as agents that can complex with and deliver osteoinductive agents, but osteoinductivity of the polymers themselves has been rarely studied. Here we report the osteoinductivity of poly(4-hydroxy-L-proline ester) (PHPE), a biodegradable cationic polymer with cell penetrating properties. Under physiological conditions, PHPE degrades into trans-4-hydroxy-L-proline (trans-Hyp), a non-coded amino acid with essential functions in collagen fibril formation and fibril stability. Treatment of SaOS-2 osteoblast-like cells and hFOB 1.19 primary osteoblast cells with PHPE promoted earlier collagen nodule formation and mineralization of the extracellular matrix compared to untreated cells, even when mineralization activators were absent in the growth medium. Our results indicate that PHPE is a potential osteoinductive agent in vitro that can favor bone regeneration. Moreover, this osteoinductive property could be partly attributed to the degradation product trans-Hyp, which could recapitulate some, but not all of the osteogenic activity. The primary findings of this study can be summarized as follows: treatment of cells with PHPE led to (1) the induction of COL1A1 expression, collagen synthesis and secretion in osteoblast-like cells, (2) mineralization of the ECM in both SaOS-2 and hFOB 1.19 primary osteoblasts, and (3) induction of BMP2 gene and protein expression in osteoblast-like cells, which can promote mineralization of the ECM and regeneration of the bone tissue. Our results suggest that PHPE is a non-cytotoxic polymer and can be potentially used to overcome collagenopathies such as osteogenesis imperfecta.

Outcomes following intravenous bisphosphonate infusion in pediatric patients: A 7-year retrospective chart review

INTRODUCTION

Intravenous bisphosphonates (IV BP) have been used to treat children with osteoporosis for many years. Favorable side effect profile and improvements in bone mineral density (BMD) have been demonstrated in patients with osteogenesis imperfecta (OI), a primary form of osteoporosis in pediatrics. Less is known about the safety of IV BP in children with secondary osteoporosis or glucocorticoid-induced osteoporosis (GIO). We aimed to determine the prevalence of both acute and long-term side effects and assess the efficacy of IV BP treatment to increase bone mineral density in pediatric patients with varying presentations of compromised bone health.

METHODS

We conducted a retrospective chart review of pediatric patients (<21 years old) treated for osteoporosis with intravenous pamidronate (PAM) or zoledronic acid (ZA) at Cincinnati Children's Hospital Medical Center from 2010 to 2017. Patient demographics, diagnosis, infusion type and dose, acute phase reactions (APR), electrolyte abnormalities, and bone density measurements were collected from the electronic medical records. Diagnoses were grouped into 3 categories: primary osteoporosis, secondary osteoporosis, and GIO. Descriptive characteristics and adverse events were compared among categories. Change in bone mineral density (BMD) over time was compared among groups.

RESULTS

123 patients (56% male) received 942 infusions (83% PAM and 17% ZA). APR was reported in 7% of all infusions and more common in secondary osteoporosis (16%, p < 0.0001). There was a higher percentage of acute adverse events after the first infusion (27% vs 5%, p < 0.0001). Hypocalcemia following IV BP infusions occurred in 7% (27/379) of infusions and was significantly associated with ZA use (p = 0.04). Severity of hypocalcemia was generally mild, requiring intravenous calcium in 3% (13/379) of infusions. Hypophosphatemia occurred frequently, however rarely required intravenous supplementation. In 468 patient years of IV BP exposure, there were no reports of osteonecrosis of the jaw (ONJ) nor atypical femoral fracture (AFF). Lumbar spine (LS) aBMD Z-score 1 year after IV BP initiation increased overall for all groups (p < 0.0001) but did not significantly differ for those who did or did not fracture following IV BP treatment.

CONCLUSIONS

APR due to intravenous BP treatment for pediatric osteoporosis were infrequent and generally mild. APR were more likely to occur in patients with secondary osteoporosis, a group who may require closer monitoring. A higher proportion of hypophosphatemia occurred in the patients with GIO. Long-term serious adverse events including ONJ and AFF were not identified in our patient population. LS aBMD Z-score increased following initiation of IV BP. However, the change in BMD was not associated with risk of fracture during the follow-up interval. These data provide reassurance and suggest that IV BP can be safely used in pediatric patients with osteoporosis.

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

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.

Osteogenesis imperfecta - A clinical update

Osteogenesis imperfecta (OI) is the most common inherited form of bone fragility and includes a heterogenous group of genetic disorders which most commonly result from defects associated with type 1 collagen. 85%-90% of cases are inherited in an autosomal dominant manner and are caused by mutations in the COL1A1 and COL1A2 genes, leading to quantitative or qualitative defects in type 1 collagen. In the last decade, defects in several other proteins involved in the normal processing of type 1 collagen have been described. Recent advances in genetics have called for reconsideration of the classification of OI, however, most recent classifications align with the classic clinical classification by Sillence. The hallmark of the disease is bone fragility but other tissues are also affected. Intravenous bisphosphonates (BPs) are the most widely used intervention, having significant favorable effects regarding areal bone mineral density (BMD) and vertebral reshaping following fractures in growing children. BPs have a modest effect in long bone fracture incidence, their effects in adults with OI concerns only BMD, while there are reports of subtrochanteric fractures resembling atypical femoral fractures. Other therapies showing promising results include denosumab, teriparatide, sclerostin inhibition, combination therapy with antiresorptive and anabolic drugs and TGF-β inhibition. Gene targeting approaches are under evaluation. More research is needed to delineate the best therapeutic approach in this heterogeneous disease.

Sleep-Disordered Breathing in Children with Rare Skeletal Disorders: A Survey of Clinical Records

OBJECTIVE

Craniofacial disharmony in skeletal diseases is strongly associated with sleep-disordered breathing. This study was aimed at studying the sleep respiratory patterns in young children with rare skeletal disorders.

DESIGN

This retrospective study included children with achondroplasia (ACH), osteogenesis imperfecta (OI) and Ellis van Creveld Syndrome. Our subjects underwent an in-laboratory overnight respiratory polygraph between January 2012 and April 2016. All medical records were reviewed and brain Magnetic Resonance Imaging was conducted on patients with ACH, nasopharynx, oropharynx and laryngopharynx spaces.

PATIENTS

Twenty-four children were enrolled, 13 with ACH, 2 with spondyloepiphyseal dysplasia, 1 with odontochondrodysplasia, 6 with OI and 2 with Ellis van Creveld Syndrome.

RESULTS

Children with ACH, who had adenotonsillectomy, showed fewer sleep respiratory involvement than untreated children. Among 13 patients with ACH, brain magnetic resonance imaging was available in 10 subjects and significant negative correlation was found between sleep respiratory patterns, nasopharynx and oropharynx space (p < 0.05). In 2 patients with spondyloepiphyseal dysplasia, mild-to-moderate sleep respiratory involvement was found. Both subjects had a history of adenotonsillectomy. Mild sleep respiratory involvement was also observed in 4 out of 6 patients with OI. One patient with Ellis van Creveld syndrome had mild sleep respiratory disturbance.

CONCLUSIONS

Sleep respiratory disturbances were detected in children with ACH, and with less severity also in OI and Ellis van Creveld syndrome. Adenotonsillectomy was successful in ACH in reducing symptoms. In light of our findings, multicenter studies are needed to obtain further information on these rare skeletal diseases.

Osteogenesis imperfecta: diagnosis and treatment

PURPOSE OF REVIEW

Here we summarize the diagnosis of osteogenesis imperfecta, discuss newly discovered genes involved in osteogenesis imperfecta, and review the management of this disease in children and adults.

RECENT FINDINGS

Mutations in the two genes coding for collagen type I, COL1A1 and COL1A2, are the most common cause of osteogenesis imperfecta. In the past 10 years, defects in at least 17 other genes have been identified as responsible for osteogenesis imperfecta phenotypes, with either dominant or recessive transmission. Intravenous bisphosphonate infusions are the most widely used medical treatment. This has a marked effect on vertebra in growing children and can lead to vertebral reshaping after compression fractures. However, bisphosphonates are less effective for preventing long-bone fractures. At the moment, new therapies are under investigation.

SUMMARY

Despite advances in the diagnosis and treatment of osteogenesis imperfecta, more research is needed. Bisphosphonate treatment decreases long-bone fracture rates, but such fractures are still frequent. New antiresorptive and anabolic agents are being investigated but efficacy and safety of these drugs, especially in children, need to be better established before they can be used in clinical practice.

Treatment with neridronate in children and adolescents with osteogenesis imperfecta: Data from open-label, not controlled, three-year Italian study

INTRODUCTION

The present study assessed the long-term efficacy and safety of intravenous (i.v.) neridronate in children and adolescents affected by osteogenesis imperfecta (OI).

METHODS

55 young patients (mean age 12.6±3.9years) affected by OI were included in the study. Neridronate was administered by i.v. infusion at a dose of 2mg/kg (maximum dose of 100mg) at intervals of three-months for three years. Dual X-ray absorptiometry of the lumbar spine, hip and ultradistal and proximal radius were evaluated every 6months. Blood calcium, phosphate, albumin, fasting urinary calcium/creatinine ratio were obtained at baseline and every 3months. Serum bone turnover markers total and bone alkaline phosphatase were performed every 12months in a proportion of patients.

RESULTS

Mean lumbar spine and total hip bone mineral density (BMD) and bone mineral content significantly increased from baseline compared to all subsequent time points (p<0.001). Mean ultradistal radius BMD significantly increased from month 18 (p=0.026). Levels of bone turnover markers significantly decreased from baseline to all post-baseline observation time points. There was no statistically significant effect on fracture risk (p=0.185), although a significant reduction was observed in the mean number of fractures occurring during treatment compared to pre-treatment values. The most frequent adverse events were arthralgia, fever, joint sprain. An acute phase reaction was reported in 26 (22.8%) patients. None of the reported serious adverse events was considered as treatment-related.

CONCLUSION

Long-term i.v. neridronate treatment has positive effects on BMD, bone turnover markers and fracture risk with a good safety profile.

Splenomegaly, myeloid lineage expansion and increased osteoclastogenesis in osteogenesis imperfecta murine

Osteogenesis imperfecta (OI) is a disease caused by defects in type I collagen production that results in brittle bones. While the pathology is mainly caused by defects in the osteoblast lineage, there is also elevated bone resorption by osteoclasts resulting in high bone turnover in severe forms of the disease. Osteoclasts originate from hematopoietic myeloid cells, however changes in hematopoiesis have not been previously documented in OI. In this study, we evaluated hematopoietic lineage distribution and osteoclast progenitor cell frequency in bone marrow, spleen and peripheral blood of osteogenesis imperfecta murine (OIM) mice, a model of severe OI. We found splenomegaly in all ages examined, and expansion of myeloid lineage cells (CD11b⁺) in bone marrow and spleen of 7-9week old male OIM animals. OIM spleens also showed an increased frequency of purified osteoclast progenitors. This phenotype is suggestive of chronic inflammation. Isolated osteoclast precursors from both spleen and bone marrow formed osteoclasts more rapidly than wild-type controls. We found that serum TNFα levels were increased in OIM, as was IL1α in OIM females. We targeted inflammation therapeutically by treating growing animals with murine TNFR2:Fc, a compound that blocks TNFα activity. Anti-TNFα treatment marginally decreased spleen mass in OIM females, but failed to reduce bone resorption, or improve bone parameters or fracture rate in OIM animals. We have demonstrated that OIM mice have changes in their hematopoietic system, and form osteoclasts more rapidly even in the absence of OI osteoblast signals, however therapy targeting TNFα did not improve disease parameters.

Bisphosphonate therapy and osteogenesis imperfecta: The lived experience of children and their mothers

PURPOSE

Osteogenesis imperfecta (OI) is a chronic, genetic condition frequently described as "brittle bones." This condition is expressed by low bone density and characterized by frequent fractures with and without trauma. Additional symptoms include pain, altered growth, and challenges with mobility. This experience has a great impact on the daily life of the child diagnosed with OI and their family. With the introduction of bisphosphonate therapy children diagnosed with OI experienced an increase in bone density that included a change in symptoms and improvement in daily functioning. The purpose of this study was to describe the lived experience of children receiving bisphosphonate therapy for osteogenesis imperfecta (OI) and their mothers.

DESIGN AND METHODS

A phenomenological study was conducted using interviews with a purposive sample of six children diagnosed with OI and their six mothers (N = 12). Children ranged in age from 6 to 18 years. The Giorgi (2009) methodology was used to discover the meaning of living day to day since initiating the bisphosphonate infusion therapy.

RESULTS

Four themes emerged from the synthesis of the meaning units that reflected the experience that bisphosphonate therapy had on daily life with OI. These four themes explicitly described the phenomena being studied and included living daily life in stride; normalcy is living with uncertainty; renewal with infusions; and making choices and living with the consequences.

PRACTICE IMPLICATIONS

Nurses must take an active role in developing and promoting family-centered interventions for transition and support.

Osteogenesis imperfecta

Skeletal deformity and bone fragility are the hallmarks of the brittle bone dysplasia osteogenesis imperfecta. The diagnosis of osteogenesis imperfecta usually depends on family history and clinical presentation characterized by a fracture (or fractures) during the prenatal period, at birth or in early childhood; genetic tests can confirm diagnosis. Osteogenesis imperfecta is caused by dominant autosomal mutations in the type I collagen coding genes (COL1A1 and COL1A2) in about 85% of individuals, affecting collagen quantity or structure. In the past decade, (mostly) recessive, dominant and X-linked defects in a wide variety of genes encoding proteins involved in type I collagen synthesis, processing, secretion and post-translational modification, as well as in proteins that regulate the differentiation and activity of bone-forming cells have been shown to cause osteogenesis imperfecta. The large number of causative genes has complicated the classic classification of the disease, and although a new genetic classification system is widely used, it is still debated. Phenotypic manifestations in many organs, in addition to bone, are reported, such as abnormalities in the cardiovascular and pulmonary systems, skin fragility, muscle weakness, hearing loss and dentinogenesis imperfecta. Management involves surgical and medical treatment of skeletal abnormalities, and treatment of other complications. More innovative approaches based on gene and cell therapy, and signalling pathway alterations, are under investigation.

Application of anti-Sclerostin therapy in non-osteoporosis disease models

Sclerostin, a known inhibitor of the low density lipoprotein related protein 5 and 6 (LRP5 and LRP6) cell surface signaling receptors, is integral in the maintenance of normal bone mass and strength. Patients with loss of function mutations in SOST or missense mutations in LRP5 that prevent Sclerostin from binding and inhibiting the receptor, have significantly increased bone mass. This observation leads to the development of Sclerostin neutralizing therapies to increase bone mass and strength. Anti-Sclerostin therapy has been shown to be effective at increasing bone density and strength in animal models and patients with osteoporosis. Loss of function of Sost or treatment with a Sclerostin neutralizing antibody improves bone properties in animal models of Osteoporosis Pseudoglioma syndrome (OPPG), likely due to action through the LRP6 receptor, which suggests patients may benefit from these therapies. Sclerostin antibody is effective at improving bone properties in mouse models of Osteogenesis Imperfecta, a genetic disorder of low bone mass and fragility due to type I collagen mutations, in as little as two weeks after initiation of therapy. However, these improvements are due to increases in bone quantity as the quality (brittleness) of bone remains unaffected. Similarly, Sclerostin antibody treatment improves bone density in animal models of other diseases. Sclerostin neutralizing therapies are likely to benefit many patients with genetic disorders of bone, as well as other forms of metabolic bone disease.

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.

The clinical features of osteogenesis imperfecta in Vietnam

PURPOSE

Osteogenesis imperfecta (OI) has not been studied in a Vietnamese population before. The aim of this study was to systematically collect epidemiological information, investigate clinical features and create a clinical database of OI patients in Vietnam for future research and treatment strategy development.

METHOD

Participants underwent clinical and physical examinations; also medical records were reviewed. Genealogical information was collected and family members' phenotypical manifestations recorded. Cases were classified according to the Sillence classification.

RESULTS

In total, 146 OI patients from 120 families were studied: 46 with OI Type I, 46 with Type III and 54 with Type IV. Almost patients had skeletal deformations. One hundred and forty-two had a history of fractures, 117 blue sclera, 89 dentinogenesis imperfecta and 26 hearing loss. The total number of fractures was 1,932. Thirty-four patients had intra-uterine fractures and nine had perinatal fractures. Surgery was performed 163 times in 58 patients; 100 osteosyntheses and 63 osteotomies. Bisphosphonate treatment was used in 37 patients. The number of affected individuals and predominance of severe forms of OI indicate that the disease is under diagnosed in Vietnam, especially in cases without a family history or with mild form of OI. Deformities appeared in all patients with different severity and localisation, affecting mostly the lower limbs. OI medical and surgical treatment rates are low and in most cases surgery was performed due to fractures.

CONCLUSIONS

Compared to previous studies, our results indicate a lower OI prevalence and greater severity of symptoms in the Vietnamese population when compared with other areas. Further investigation, improved diagnosis and treatment are needed to increase the patients' quality of life.

New Genetic Forms of Childhood-Onset Primary Osteoporosis

Recent developments in genetic technology have given us the opportunity to look at diseases in a new and more detailed way. This Mini Review discusses monogenetic forms of childhood-onset primary osteoporosis, with the main focus on osteoporosis caused by mutations in WNT1 and PLS3, two of the most recently discovered genes underlying early-onset osteoporosis. The importance of WNT1 in the accrual and maintenance of bone mass through activation of canonical WNT signaling was recognized in 2013. WNT1 was shown to be a key ligand for the WNT-signaling pathway, which is of major importance in the regulation of bone formation. More recently, mutations in PLS3, located on the X chromosome, were shown to be the cause of X-linked childhood-onset primary osteoporosis affecting mainly males. The function of PLS3 in bone metabolism is still not completely understood, but it has been speculated to have an important role in mechanosensing by osteocytes and in matrix mineralization. In this new era of genetics, our knowledge on genetic causes of childhood-onset osteoporosis expands constantly. These discoveries bring new possibilities, but also new challenges. Guidelines are needed to implement this new genetic knowledge to clinical patient care and to guide genetic investigations in affected families.

Enhanced Wnt signaling improves bone mass and strength, but not brittleness, in the Col1a1(+/mov13) mouse model of type I Osteogenesis Imperfecta

Osteogenesis Imperfecta (OI) comprises a group of genetic skeletal fragility disorders. The mildest form of OI, Osteogenesis Imperfecta type I, is frequently caused by haploinsufficiency mutations in COL1A1, the gene encoding the α1(I) chain of type 1 collagen. Children with OI type I have a 95-fold higher fracture rate compared to unaffected children. Therapies for OI type I in the pediatric population are limited to anti-catabolic agents. In adults with osteoporosis, anabolic therapies that enhance Wnt signaling in bone improve bone mass, and ongoing clinical trials are determining if these therapies also reduce fracture risk. We performed a proof-of-principle experiment in mice to determine whether enhancing Wnt signaling in bone could benefit children with OI type I. We crossed a mouse model of OI type I (Col1a1(+/Mov13)) with a high bone mass (HBM) mouse (Lrp5(+/p.A214V)) that has increased bone strength from enhanced Wnt signaling. Offspring that inherited the OI and HBM alleles had higher bone mass and strength than mice that inherited the OI allele alone. However, OI+HBM and OI mice still had bones with lower ductility compared to wild-type mice. We conclude that enhancing Wnt signaling does not make OI bone normal, but does improve bone properties that could reduce fracture risk. Therefore, agents that enhance Wnt signaling are likely to benefit children and adults with OI type 1.

Bisphosphonate Use and Risk of Implant Revision after Total Hip/Knee Arthroplasty: A Meta-Analysis of Observational Studies

Objective

Several studies investigated the association between bisphosphonate use and the risk of implant revision after total hip or knee arthroplasty (THA or TKA); However, the findings were inconsistent. We performed this meta-analysis to evaluate the overall relative risk of such an event.

Methods

We searched the PubMed, EMBASE and Cochrane library databases to identify relevant publications on April 22, 2015. To calculate the pooled risk ratios (RRs) with 95% confidential intervals (CIs), a fixed- or random-effects model was applied based on the heterogeneity across studies.

Results

Three cohort studies and one case-control study were included in this meta-analysis. Compared with the bisphosphonate nonusers, the patients who used bisphosphonates for a long period of time had a significantly decreased risk of implant revision after THA/TKA (summary adjusted RR = 0.48, 95% CI: 0.38–0.61), and the summary adjusted RRs for the users who underwent THA and those who underwent TKA were 0.47 (95% CI: 0.36–0.61) and 0.45 (95% CI: 0.21–0.95), respectively.

Conclusions

Long-term use of bisphosphonates is correlated with a significantly decreased risk of implant revision after THA/TKA. However, due to limited number of the included studies, the findings of the present study should be treated with caution. More well-designed studies are required to further confirm our findings.