High prevalence of coxa vara in patients with severe osteogenesis imperfecta

Imaging in osteogenesis imperfecta: Where we are and where we are going

Osteogenesis imperfecta (OI) is a rare phenotypically and genetically heterogeneous group of inherited skeletal dysplasias. The hallmark features of OI include bone fragility and susceptibility to fractures, bone deformity, and diminished growth, along with a plethora of associated secondary features (both skeletal and extraskeletal). The diagnosis of OI is currently made on clinical grounds and may be confirmed by genetic testing. However, imaging remains pivotal in the evaluation of this disease. The aim of this article is to review the current role played by the various radiologic techniques in the diagnosis and monitoring of OI in the postnatal setting as well as to discuss recent advances and future perspectives in OI imaging. Conventional Radiography and Dual-energy X-ray Absorptiometry (DXA) are currently the two most used imaging modalities in OI. The cardinal radiographic features of OI include generalized osteopenia/osteoporosis, bone deformities, and fractures. DXA is currently the most available technique to assess Bone Mineral Density (BMD), specifically areal BMD (aBMD). However, DXA has important limitations and cannot fully characterize bone fragility in OI based on aBMD. Novel DXA-derived parameters, such as Trabecular Bone Score (TBS), may provide further insight into skeletal changes induced by OI, but evidence is still limited. Techniques like Computed Tomography (CT) and Magnetic Resonance Imaging (MRI) can be useful as problem-solvers or in specific settings, including the evaluation of cranio-cervical abnormalities. Recent evidence supports the use of High-Resolution peripheral Quantitative Computed Tomography (HR-pQCT) as a promising tool to improve the characterization of bone fragility in OI. However, HR-pQCT remains a primarily research technique at present. Quantitative Computed Tomography (QCT) is an alternative to DXA for the determination of BMD at central sites, with distinct advantages but considerably higher radiation exposure. Quantitative Ultrasound (QUS) is a portable, inexpensive, and radiation-free modality that may complement DXA evaluation, providing information on bone quality. However, evidence of usefulness of QUS in OI is poor. Radiofrequency Echographic Multi Spectrometry (REMS) is an emerging non-ionizing imaging method that holds promise for the diagnosis of low BMD and for the prediction of fracture risk, but so far only one published study has investigated its role in OI. To conclude, several different radiologic techniques have proven to be effective in the diagnosis and monitoring of OI, each with their own specificities and peculiarities. Clinicians should be aware of the strategic role of the various modalities in the different phases of the patient care process. In this scenario, the development of international guidelines including recommendations on the role of imaging in the diagnosis and monitoring of OI, accompanied by continuous active research in the field, could significantly improve the standardization of patient care.

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.

Patterns of femoral neck fracture and its treatment methods in patients with osteogenesis imperfecta

Femoral neck fracture (FNF) is not common in osteogenesis imperfecta patients but may result in serious complications if not properly treated in due time. We present three types of FNF in osteogenesis imperfecta and their characteristics, treatment methods and outcomes. Cases of FNF followed for more than 2 years were selected from the osteogenesis imperfecta database. Medical records and radiographs were reviewed to obtain demographic information and to determine ambulatory status, mode of injury, location of the fracture line, presence of preexisting implants, treatment methods and complications. Outcomes were evaluated according to the radiographic results and ambulatory function. The study investigated 15 FNFs in 10 patients including 1 Sillence type I, 1 type III and 8 type IV. They were either community or household ambulators. The mean age at fracture was 11.7 years. The fractures were followed for an average of 6.3 years. Six fractures were attributed to accidental injuries and nine without noticeable trauma. The fracture pattern was categorized into undisplaced (n = 3), angulated-stable (n = 7) or displaced-unstable (n = 5) types. Five fractures were fixed in-situ using screws or Kirschner wires. Other five fractures were treated by closed reduction and screw fixation and the remaining five fractures were managed by femoral valgus osteotomy. Bony union was achieved, and prefracture ambulatory status was restored in all cases. A high index of suspicion is required in the diagnosis of undisplaced or angulated-stable fractures. Treatment is usually challenging, but a judicious approach considering the fracture pattern and patient characteristics result in successful outcomes. The angulated-stable pattern of fracture is unique in osteogenesis imperfecta patients and requires special attention.

Combined two-centre experience of single-entry telescopic rods identifies characteristic modes of failure

AIMS

The Fassier Duval (FD) rod is a third-generation telescopic implant for children with osteogenesis imperfecta (OI). Threaded fixation enables proximal insertion without opening the knee or ankle joint. We have reviewed our combined two-centre experience with this implant.

METHODS

In total, 34 children with a mean age of five years (1 to 14) with severe OI have undergone rodding of 72 lower limb long bones (27 tibial, 45 femoral) for recurrent fractures with progressive deformity despite optimized bone health and bisphosphonate therapy. Data were collected prospectively, with 1.5 to 11 years follow-up.

RESULTS

A total of 24 patients (33%) required exchange of implants (14 femora and ten tibiae) including 11 rods bending with refracture. Four (5%) required reoperation with implant retention. Loss of proximal fixation in the femur and distal fixation in the tibia were common. Four patients developed coxa vara requiring surgical correction. In total, 13 patients experienced further fractures without rod bending; eight required implant revision. There was one deep infection. The five-year survival rate, with rod revision as the endpoint, was 63% (95% confidence interval (CI) 44% to 77%) for femoral rods, with a mean age at implantation of 4.8 years (1.3 to 14.8), and 64% (95% CI 36% to 82%) for tibial rods, with a mean age at implantation of 5.2 years (2.0 to 13.8).

CONCLUSION

FD rods are easier to implant but do not improve on the revision rates reported for second generation T-piece rods. Proximal femoral fixation is problematic in younger children with a partially ossified greater trochanter. Distal tibial fixation typically fails after two years. Future generation implants should address proximal femoral and distal tibial fixation to avoid the majority of complications in this series. Cite this article: Bone Joint J 2020;102-B(8):1048-1055.

Using a corkscrew-tipped telescopic nail in the treatment of osteogenesis imperfecta: a biomechanical study and preliminary results of 17 consecutive cases

High complication rates were reported with the telescopic nail technique systems. To overcome such technical difficulties, we designed a corkscrew-tipped telescopic nail (CTTN). We biomechanically compared its pullout strength with that of two other tip designs. We used CTTN in 17 patients with osteogenesis imperfecta and reported their preliminary results. Average patient age was 82.6 months, and mean follow-up was 32.0±6 months. Telescoping and osteotomy site healing were assessed using radiological studies. Successful telescoping with event-free osteotomy site healing was achieved in 94.1% of patients; limited telescoping and delayed union were detected in one case each. Our results show that CTTN provides sufficient pullout strength and reduced complication rates compared with other designs.

Surgical correction of coxa vara: Evaluation of neck shaft angle, Hilgenreiner-epiphyseal angle for indication of recurrence

BACKGROUND

Coxa vara is a hip deformity in which the femoral neck-shaft angle decreases below its normal value. Standard surgical treatment for this condition is corrective valgus osteotomy. Appropriate correction of the Hilgenreiner-epiphyseal angle is important to prevent recurrence. The purpose of this study is to: 1) evaluate the recurrence of the deformity at the latest follow up; and 2) find the appropriate angle of correction associated with the lowest recurrence.

METHODS

34 hips in 31 patients who underwent surgery for treatment of coxa vara from 2005 to 2014 were included. Patient-reported outcomes, Hilgenreiner-epiphyseal angle, and neck-shaft angle were assessed preoperatively, postoperatively, and at latest follow-up.

RESULTS

The mean age at surgery was 10.99, with a range of 5-30, years. Preoperative neck-shaft angle ranged from 60 to 100 degrees, and Hilgenreiner-epiphyseal angle ranged from 60 to 90 degrees. At the latest follow up, the neck-shaft angle ranged from 120 to 135 degrees and the Hilgenreiner-epiphyseal angle ranged from 22 to 35 degrees (p < 0.001). The Harris hip score improved from 47.20 (34-66) to 79.68 (60-100) (p < 0.001). There was no recurrence of deformities at the mean follow up of 37.87 months.

CONCLUSION

Surgical correction of coxa vara in various pathologies can be done successfully with the Hilgenreiner-epiphyseal angle corrected to ≤ 35 degrees or the neck shaft angle corrected to > 120 degrees in order to prevent recurrence of the deformity. Majority of the patients were reported improvement of hip function. However, a longer-term follow up is required to determine further outcomes regarding to recurrence of the deformity.

Pauwels Osteotomy for Femoral Neck Nonunion in Two Adult Siblings with Osteogenesis Imperfecta

This is a retrospective review of two adult siblings with osteogenesis imperfecta (OI) type III (according to Sillence classification), who sustained a spontaneous femoral neck fracture and subsequent nonunion. The diagnosis of OI in these two patients was made based on clinical, radiological and genetic findings. The fracture was most likely caused by femoroacetabular impingement secondary to OI induced acetabular protrusio. A valgus osteotomy according to Pauwels'principles and fixation of the osteotomy and nonunion with a locking plate resulted in healing despite compromised bone quality and limited bone stock. Long-term follow up (4.5 years and 6.5 years, respectively) is provided.

When treating this difficult problem, improving the mechanobiological environment and decreasing the femoroacetabular impingement by a Pauwels type osteotomy should be considered.

Femoral neck fractures in osteogenesis imperfecta treated with bisphosphonates

PURPOSE

Osteogenesis imperfecta (OI) is a condition characterised by bone fragility and multiple fractures, which cause considerable morbidity in the affected patients. Most cases are associated with mutations in one of the type I collagen genes. Recently, bisphosponates have been used widely to reduce pain and the incidence of fragility fractures in OI in children, even though there have been concerns raised regarding the long-term complications of it due to their effect on the bone. The fragility fractures involving the neck of the femur in children with intramedullary rods in the femoral shaft are very difficult to treat. Although these fractures are frequently un-displaced, they require optimal internal fixation to achieve fracture union. The aim of this study was to assess the clinical and radiological outcomes of OI patients with intracapsular femoral neck fracture treated with headless compression screws.

METHOD AND RESULTS

At our institute, we identified seven patients (11 hips) with OI who underwent internal fixation with headless compression screws for a neck of femur fracture between June 2010 and Dec 2012. The time to fractures healing was on average 14 weeks (12 to 16). All patients gained their pre-injury ambulatory status.

CONCLUSION

It is very challenging and technically demanding for orthopaedic surgeons when treating the fragility fracture of the neck of femur in patients with intramedullary rod in the femoral shaft. The published data regarding the management of these complex conditions are very limited. We describe our experience with the technique of percutaneous headless compression screw fixation for treating the femoral neck fractures in OI patients.

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.

Muscle strength, joint range of motion, and gait in children and adolescents with osteogenesis imperfecta

PURPOSE

To analyze clinical and functional features of children and adolescents with osteogenesis imperfecta (OI).

METHODS

A cross-sectional study of 62 participants examined clinical, body structure and function and activity features.

RESULTS

A total of 31 participants had OI type I, 9 had type III, and 22 had type IV. Mild (type I) and moderate/severe (types III and IV) OI differed significantly in occurrence of fractures, presence of bone deformities, the use of intramedullary rods, bone mineral density, and bisphosphonate therapy. Age of gait acquisition showed an association with overall joint range of motion and an inverse relationship with overall muscle strength. Level of ambulation was associated with overall muscle strength and inversely associated with overall joint range of motion.

CONCLUSIONS

Features vary according to OI type. Moderate and severe forms of OI are associated with greater functional limitation, influenced by fracture history, which negatively affects the acquisition and level of ambulation.

Results and complications of a surgical technique for correction of coxa vara in children with osteopenic bones

BACKGROUND

Surgical correction of coxa vara in children with osteopenic bone diseases could be very challenging. In this study, we describe a modified surgical technique for the correction of coxa vara in children with bone fragility. We also report the results and complications of this technique in 16 children (21 coxa vara) with osteopenic bone diseases.

METHODS

Charts, clinic notes, and radiology images of 16 patients (21 hips) who had a proximal femoral osteotomy for the treatment of coxa vara in osteogenesis imperfecta (18 hips) and fibrous dysplasia (3 hips) in our institution between 1996 and 2005 were reviewed. The modified surgery involved an intertrochanteric osteotomy and the use of Kirshner wires and intramedullary rods. Neck-shaft angle, Hilgenreiner-epiphyseal angle, and head-shaft angle were assessed at preoperative, postoperative, and final follow-up.

RESULTS

The average age at surgery was 8.3 years (range, 3.3-15.8 years). The average correction of the neck-shaft angle was from 84.6 to 114.4 degrees, and for the Hilgenreiner-epiphyseal angle, it was from 67.7 to 42 degrees at final follow-up. All osteotomies were healed at 3 months postoperatively. The mean follow-up was 4.29 years (range, 1.70-8.12 years). The average improvement in abduction and external rotation of the hips was 14 and 15 degrees, respectively. There were no cases of infection and 2 cases (12%) of implant-related complications. One patient with fibrous dysplasia needed replacement of the intramedullary rod and additional distal femoral osteotomy 1 week postsurgery. In another patient, the intramedullary rod had migrated proximally, which was corrected 5 months postsurgery by advancing the rod distally.

CONCLUSION

Results suggest that this surgical technique provides satisfactory correction of coxa vara in children with osteopenic bone diseases.

CLINICAL RELEVANCE

The described surgical technique used to correct coxa vara is reproducible and safe and has few complications. Furthermore, the size of the implants used allows surgery to be performed in very young children.

Osteogenesis imperfecta: diagnosis and treatment

Osteogenesis imperfecta is a heritable disorder characterized by extremely fragile bones, blue sclerae, dentinogenesis imperfecta, hearing loss, and scoliosis. In 1979, Sillence classified the condition into four types based on genetic and clinical criteria. Three more classifications have subsequently been added. Diagnosis of osteogenesis imperfecta may be done prenatally (in severe cases), clinically, radiographically, or via biochemical or genetic examination. Medical treatment consists of bisphosphonate use, even in patients younger than age 2 years. Surgical treatment consists of internal splinting of long bones. Research is currently being done on the use of smart intramedullary rods (ie, composed of nitinol shape-memory alloy) for correction of bone deformity and on the use of bone marrow transplantation to increase osteoblast density, thereby reducing fracture frequency.

Osteogenesis Imperfecta: update on presentation and management

Osteogenesis Imperfecta (OI) is a rare heritable condition characterized by bone fragility and reduced bone mass. Traditionally OI was classified into OI types I to IV and thought to be only due to a defect in the collagen gene, however through the discovery of the new types of OI-V to VII, breakthroughs have been made in understanding the pathophysiology of autosomal recessive OI and new genetic mutations, such as in CRTAP and P3H1 genes. OI can present at any age and be difficult to diagnose because of the wide phenotypic variation. Awareness of the new forms of OI, the differential diagnosis and the limitations of diagnostic tools, all help to correctly diagnose and manage a patient with OI. Cyclical intravenous pamidronate is now the standard of care for moderately to severely affected children with OI, given in combination with good orthopedic, physiotherapy and rehabilitation programs. The benefits and short term safety of cyclic bisphosphonates have been amply reported in the literature; however their long term effects are still under investigation. Newer more potent forms of bisphosphonates such as zoledronic acid have undergone and are still being subject to international multicentric drug trials and are beginning to replace pamidronate in some centers.

Surgical treatment of osteogenesis imperfecta: current concepts

PURPOSE OF REVIEW

The treatment of osteogenesis imperfecta requires a multidisciplinary team to maximize function and comfort, and decrease fracture incidence. Medical treatment with bisphosphonates has allowed for safer, more effective surgical management of children with osteogenesis imperfecta. The purpose of this review is to outline treatment indications and choices of surgical techniques based on recent clinical studies, and in addition to identify persistent clinical problems addressed in recent literature.

RECENT FINDINGS

Several new intramedullary rodding surgical techniques and modifications of older techniques have been developed to correct deformities of the long bones. These techniques decrease the trauma associated with surgical treatment. The newer techniques limit postoperative immobilization, enabling earlier rehabilitation, and allowing for treatment of multiple bones simultaneously.

SUMMARY

Recent medical and surgical advances have allowed improved safety, function and comfort in treating children with osteogenesis imperfecta. The selection of surgical techniques is dependent on surgeon experience, severity of disease and patient function, and availability of specific instrumentation. Intramedullary fixation rather than plating is preferred, and allowing early protected weight bearing and rehabilitation of children with ambulatory potential is the ideal goal.