Intrathoracic rib: rare rib anomaly, review of the literature and proposal for classification.

Background: Intrathoracic ribs are very rare congenital anomalies, and often discovered incidentally on chest X-ray. Since its first description by Lutz in 1947, approximately 50 cases have been reported in the literature till date. The aim is to review the all reported intrathoracic ribs, summarize their clinical features, and propose a potential classification. Methods: All relevant literatures were searched and reviewed. The terms include intrathoracic rib, intrathoracic bifid rib, trans-thoracic rib and intrathoracic rib anomaly. We have summarized the first finding events, origination, distribution, related anomalies and imaging features of intrathoracic rib, and propose an updated classification. Results: The patients' age at initial finding was from six weeks to 79 years old. Of all, sixty percent was less than 30 years old. There was no difference in gender. Most of them were reported by authors in western countries (85.3%, 58/68), and incidental findings by radiologist and respiratory physician. The intrathoracic rib occurs more frequently on the right side, and is usually single and unilateral. According to the new classification, type I and II was account for 45.6% and 35.3%, respectively. Conclusion: Intrathoracic rib is rare findings in clinical practice. It is useful that radiologists or clinician are familiarized with the imaging appearances of these malformations. These anomalies reflect some disturbances during the embryo development, leading us to propose a potential classification that could contribute to a better understanding of this rib anomaly.

Medial Metaphyseal Beak Angle as a Predictor for Langenskiöld Stage II of Blount's Disease.

OBJECTIVE: To determine the medial metaphyseal beak (MMB) cut-off angle predicting Langenskiöld stage II of Blount's disease and to study the intra-observer and inter-observer reliabilities of angle measurements and the influence of the experience level of observers. METHODS: A retrospective study was conducted on children aged 2-4 years from January 2000 to December 2017. Children were identified through a computer-based search. Children with Langenskiöld stage II of Blount's disease who had been initially evaluated at our institution were categorized into Blount group and children who were diagnosed with physiologic bowing were categorized into control group. Data on the patients' ages, genders, and affected sides were collected. The MMB angles were measured on standing anteroposterior radiographs of the knees. The angle was formed between one line drawn parallel to the medial cortex of the proximal tibia, and a second line running from the intersection of the first line with the proximal tibial metaphysis through to the most distal point of the MMB. Measurements were independently performed by six observers. All observers repeated the measurements 2 weeks after they were first done. RESULTS: There were 148 legs from 79 children (48 males and 31 females) with an average age of 28.6 months. The average MMB angle of the Blount group was 128.52° ± 5.38° (P-value <0.001) and of the control group was 114.45° ± 4.89°. The average femorotibial angle of the Blount group was 15.48° ± 6.81° (P-value <0.001) and of the control group was 7.71° ± 7.94°. The receiver operating characteristic curve showed that an MMB angle >122° (sensitivity 92.7%; specificity 97.0%) was associated with Langenskiöld stage II. The intraclass correlation coefficient of the intra-observer reliability ranged from 0.93-0.97, and the inter-observer reliability was 0.93. CONCLUSIONS: By using anteroposterior (AP) radiographs of the knee, the MMB angle is a potential radiographic parameter to distinguish between Langenskiöld stage II of Blount's disease and physiologic bowed legs, with an MMB angle >122° predicting Langenskiöld stage II.

Honeycomb sterna: an unusual case of a developmental abnormality in the sternum.

This report details an unusual case of a human sternal developmental abnormality of an anatomical specimen part of the skeletal collection curated by University College London, Anthropology Department skeletal collection. This rarely reported developmental abnormality is caused by the non-fusion of lateral ossification centres in the sternebrae, resulting in the mesosternum having a honeycomb-like appearance. Sternal defects are typically underreported in the clinical literature as many cases being asymptomatic that they are typically diagnosed incidentally, as such there is a dearth in our current understanding of the development and anatomical variants of the sternum. Although in recent years, large-scale CT studies have investigated the prevalence of sternal developmental abnormalities, these studies have not reported sternal defects similar to the individual presented in this report. While most sternal defects are clinically uneventful, the lack of awareness of these variants can result in misinterpretation of radiological and pathological findings as such an understanding of anatomical variants even when asymptomatic is vital.

Assessment of the reliability and reproducibility of the Langenskiöld classification in Blount's disease.

The Langenskiöld classification is the most commonly utilized classification system for the radiological features of Blount's disease. Although there is only a single study found on the interobserver variability and none found on the intraobserver variability, it is commonly used for prognostication and guiding management decisions. The aim of this study was to determine the reliability and reproducibility of the Langenskiöld classification. A retrospective review of radiographs was done of patients treated for infantile and juvenile Blount's disease at Chris Hani Baragwanath Academic Hospital from 2006 to 2016. There were 70 radiographs of acceptable quality, which were reviewed and staged on two occasions according to the Langenskiöld classification by three orthopaedic consultants and three orthopaedic surgery senior residents. Pearson correlation coefficients, percentage agreements, and κ statistics were used to evaluate both the reliability and reproducibility. Of the 70 images staged, only two (2.9%) were staged the same by all six observers, and 20 (28.6%) images differed by a single stage. The consultants had 17 (24.3%) images staged the same whereas the residents had 12 (17.1%) images staged the same. The overall κ for all six observers showed a fair agreement of 0.24. Again, the consultants had a higher κ-value compared to residents of 0.25 and 0.24, respectively. The reproducibility amongst all observers was fair with a κ-value of 0.38. The consultants had a higher mean score of 0.48 compared to 0.26 for the residents. There was only a fair overall reliability and reproducibility amongst the six observers. We recommend the Langenskiöld classification be used with caution when being used for prognostication and management planning as well as when interpreting any research relying on this classification. Level of evidence: Level III, diagnostic study.

Recurrence After Surgical Intervention for Infantile Tibia Vara: Assessment of a New Modified Classification.

BACKGROUND: To propose a modified classification of infantile tibia vara based on the morphology of the metaphyseal/epiphyseal tibial slope that better correlates with treatment outcomes than the traditional Langenskiold classification. METHODS: We performed a retrospective review of 82 patients and 115 limbs that underwent surgery for infantile tibia vara over a 22-year period (1990 to 2012) at a single institution. A modified Langenskiold classification was applied to all patients preoperatively and the outcomes were assessed. The modified system created a 3-stage classification (types A, B, and C): type A has a partially lucent medial metaphyseal defect, with or without "beaking"; type B deformity has downward-sloping curvature of the lateral and inferior rim of a completely lucent metaphyseal defect, which then has an upslope at the medial rim, resembling a ski-jump, with no epiphyseal downward slope; type C has vertical, downsloping deformity of both the epiphysis and metaphysis, with no upward curvature projecting medially at the inferior extent, while the epiphysis slopes downward into the metaphyseal defect. RESULTS: Sixty-seven limbs did not develop recurrence following corrective osteotomy, whereas 48 limbs required at least 1 repeat surgery for recurrent deformity. Preoperative mechanical axis deviation, medial proximal tibial angle, lateral distal tibial angle, and body mass index did not differ significantly between those with recurrence and those with without. Mean age at surgery was significantly different for those who developed recurrence compared with those who did not. Patients without recurrence were 4.3 years of age (range, 2.4 to 10.3 y) compared with 6.2 years of age (range, 2.9 to 10.1 y) for those who recurred (P<0.01). Of patients who developed recurrent deformity, there were significantly more patients with type C changes (71.7%, P<0.01) then either type A (22.5%) or type B (20.7%). High rates of recurrence were seen for both Langenskiold stage III (50%) and stage IV (69.6%). CONCLUSIONS: Consistent with prior studies, age 5 seems to be a critical transition in the risk for recurrent deformity after tibial osteotomy. Extreme vertical sloping of the medial metaphyseal defect, as in some classic Langenskiold III lesions and more precisely described by type C in a newer, modified classification, carries a poor prognosis for successful correction by high tibial osteotomy alone or in combination with epiphysiolysis. LEVEL OF EVIDENCE: Level II.

Blount disease.

Blount disease is an asymmetrical disorder of proximal tibial growth that produces a three-dimensional deformity. Tibia vara is the main component of the deformity. Blount disease exists as two clinical variants, infantile or early-onset, and adolescent or late-onset, defined based on whether the first manifestations develop before or after 10 years of age. The pathophysiological mechanisms are unclear. In the Americas and Caribbean, Blount disease chiefly affects black obese children. Without treatment, the prognosis is often severe, particularly in the infantile form due to the development of medial tibial epiphysiodesis at about 6 to 8 years of age. In other parts of the world, the associations with black ethnicity and obesity are less obvious and the prognosis is often less severe. A consensus exists about the optimal treatment in two situations: before 4 years of age, progressive Blount disease should be corrected, preferably by a simple osteotomy; and once medial tibial epiphysiodesis has developed, both a complementary epiphysiodesis and gradual external fixator correction of the other alignment abnormalities, rotational deformity, and limb length are required. After 4 years of age, the outcome in the individual patient is difficult to predict. Magnetic resonance imaging supplies information on the morphology and vascularisation of the growth regions, thereby helping to guide treatment decisions. In the adolescent form, morbid obesity limits the treatment options. Untreated Blount disease in adults is rarely encountered. A more common occurrence is the presence of residual abnormalities at skeletal maturity in patients treated for Blount disease in childhood. Premature osteoarthritis may develop. In this situation, osteotomy may delay the need for total knee arthroplasty.

Trevor's Disease: Management Difficulties and Proposed Classification.

Dysplasia epiphysealis hemimelica, also known as Trevor's disease, is a rare developmental disorder with osteocartilagenous overgrowth of the epiphysis or epiphyseal equivalent. The condition bears similarities to osteochondroma in terms of its radiographic appearance, but differs in its pathobiology and geographic occurrence. Unlike the metaphyseal occurrence of osteochondromata, it arises from the epiphysis. The clinical presentation is wide and varied, but mechanical symptoms and deformities predominate. Early reports of the condition suggested involvement of the lower limbs only. However, since then, numerous reports have indicated a more generalized distribution. Difficulties in management and recurrence rates seem to hinge on whether its origin is intra-articular or extra-articular. A new classification system to include these parameters is discussed. [Orthopedics.2016; 39(5):e967-e969.].

Condrodisplasia metafisaria tipo Schmid: presentación de un caso / Schimd methaphyseal chondrodysplasia: a case presentation

Fundamento: condrodisplasia metafisaria tipo Schmid, forma parte de las displasias óseas poco frecuentes. Se caracteriza por talla baja, genu varum, pélvis pequeña, cifoescoliosis progresiva, deformidad de la muñeca, miopía, huesos largos cortos y displasia metafisaria grave, con cambios moderados en la columna y cambios mínimos en las manos y los pies.Objetivo: presentar un caso con diagnóstico de displasia ósea tratado por un equipo multidisciplinario para su posterior corrección quirúrgica.Caso clínico: paciente femenina de tres años de edad, con deformidad en miembros inferiores que le provocan baja talla por genu varum. Los antecedentes familiares no refieren datos de interés. En los antecedentes personales prenatales, perinatales y posnatales se encontró que el desarrollo fue normal hasta los 16 meses que comienza a caminar y se observa ligera deformidad que fue aumentando.Conclusiones: la condrodisplasia metafisaria tipo Schmid es una enfermedad hereditaria poco frecuente que se presenta con un patrón de herencia autonómico dominante. Al no existir otro miembro de la familia afectado, se planteó que en este caso ocurrió una nueva mutación o mutación de novo. Es necesario indagar acerca de su presencia en un paciente con deformidad severa de miembros inferiores, con estudio renal y bioquímicos normales. Es importante realizar un diagnóstico precoz, tratamiento y seguimiento multidisciplinario para corregir la deformidad con tratamiento quirúrgico.(AU)

Background: methaphyseal chondrodysplasia is a type of non-frequent bone dysplasia. It is characterized by short stature, genu varum, small pelvis, progressive kyphoscoliosis, wrist deformities, myopia, short long bones and serious methaphyseal dysplasia with moderate changes in the back and minimal changes in hands and feet.Objective: to present the case of a patient with the diagnosis of bone dysplasia treated by a multidisciplinary medical team for a subsequent surgical correction.Clinical case: a three-year-old female patient with a deformity in the lower limbs that causes short stature by genu varum. There was no information of interest in the family medical history. The medical history of the patient showed a normal prenatal, perinatal and postnatal development until she turned 16 months old and started to walk presenting a slight deformity that increased.Conclusions: Schmid methaphyseal chondrodysplasia is an uncommon hereditary disease with a dominant autosomal heredity pattern. Since no other member in the family was affected, there was a De novo mutation in this case. It is necessary to search for its presence in a patient with a serious deformity in the lower limbs with normal biochemical and renal studies. It is important to make an early diagnosis as well as to carry out a treatment and a multidisciplinary follow-up to correct the deformity by means of surgical treatment.(AU)

Manejo de displasias esqueléticas / Skeletal dysplasias management

Las displasias esqueléticas son un grupo heterogéneo de enfermedades caracterizadas por la alteración primaria del tejido óseo y/o cartilaginoso. La incidencia de muchas de estas entidades es desconocida, estimándose una incidencia general de 1 de 4.000 recién nacidos vivos. Frente a pacientes con restricción prenatal de crecimiento o que presentan talla baja durante la niñez, especialmente si existe desproporción corporal, debemos sospechar la presencia de una displasia esquelética. El estudio radiológico es fundamental para confirmar la afección ósea e intentar aproximarse a un diagnóstico preciso, pero requiere de especialistas expertos. En la actualidad contamos con estudio molecular confirmatorio y son las alteraciones de los genes FGFR3, COL2α1 y SHOX los que dan cuenta de las displasias que más frecuentemente observaremos en nuestra práctica clínica. En los últimos años la mayor precisión diagnóstica se ha acompañado de mayores oportunidades terapéuticas. El desarrollo de nuevas técnicas quirúrgicas de apoyo en casos de deformidades óseas y de técnicas menos invasivas de alargamiento han determinado mejoría en talla final, pero por sobre todo, en la calidad de vida de nuestros pacientes.

The skeletal dysplasias are a heterogeneous group of diseases characterized primarily by impaired primary bone and/or cartilage development. The incidence of many of these entities is unknown; an overall incidence of 1 in 4,000 live births is estimated. Clinically, we must suspect the presence of a skeletal dysplasia in patients with prenatal growth restriction or childhood with short stature, especially in the presence of body disproportion. The radiological study is essential to confirm the bone condition so to try approach an accurate diagnosis, and skilled experts are required. Today we have the possibility to confirm the diagnosis by molecular studies, and we know that molecular alterations in FGFR3, COL2α1 and SHOX genes account for the most frequent cases that we will observe in our clinical practice. In recent years the increased diagnostic accuracy has been accompanied by major therapeutic opportunities. The development of new surgical techniques in bone deformity management and less invasive enlargement techniques have certainly improved the final height, but above all, in the quality of life of our patients.

Taxonomy of rare genetic metabolic bone disorders.

UNLABELLED: This article reports a taxonomic classification of rare skeletal diseases based on metabolic phenotypes. It was prepared by The Skeletal Rare Diseases Working Group of the International Osteoporosis Foundation (IOF) and includes 116 OMIM phenotypes with 86 affected genes. INTRODUCTION: Rare skeletal metabolic diseases comprise a group of diseases commonly associated with severe clinical consequences. In recent years, the description of the clinical phenotypes and radiographic features of several genetic bone disorders was paralleled by the discovery of key molecular pathways involved in the regulation of bone and mineral metabolism. Including this information in the description and classification of rare skeletal diseases may improve the recognition and management of affected patients. METHODS: IOF recognized this need and formed a Skeletal Rare Diseases Working Group (SRD-WG) of basic and clinical scientists who developed a taxonomy of rare skeletal diseases based on their metabolic pathogenesis. RESULTS: This taxonomy of rare genetic metabolic bone disorders (RGMBDs) comprises 116 OMIM phenotypes, with 86 affected genes related to bone and mineral homeostasis. The diseases were divided into four major groups, namely, disorders due to altered osteoclast, osteoblast, or osteocyte activity; disorders due to altered bone matrix proteins; disorders due to altered bone microenvironmental regulators; and disorders due to deranged calciotropic hormonal activity. CONCLUSIONS: This article provides the first comprehensive taxonomy of rare metabolic skeletal diseases based on deranged metabolic activity. This classification will help in the development of common and shared diagnostic and therapeutic pathways for these patients and also in the creation of international registries of rare skeletal diseases, the first step for the development of genetic tests based on next generation sequencing and for performing large intervention trials to assess efficacy of orphan drugs.

Fetal skeletal dysplasias in a tertiary care center: radiology, pathology, and molecular analysis of 112 cases.

Fetal skeletal dysplasias are a heterogeneous group of rare genetic disorders, affecting approximately 2.4-4.5 of 10,000 births. We performed a retrospective review of the perinatal autopsies conducted between the years 2002-2011 at our center. The study population consisted of fetuses diagnosed with skeletal dysplasia with subsequent termination, stillbirth and live-born who died shortly after birth. Of the 2002 autopsies performed, 112 (5.6%) were diagnosed with skeletal dysplasia. These 112 cases encompassed 17 of 40 groups of Nosology 2010. The two most common Nosology groups were osteogenesis imperfecta [OI, 27/112 (24%)] and the fibroblast growth factor receptor type 3 (FGFR3) chondrodysplasias [27/112 (24%)]. The most common specific diagnoses were thanatophoric dysplasia (TD) type 1 [20 (17.9%)], and OI type 2 [20 (17.9%)]. The combined radiology, pathology, and genetic investigations and grouping the cases using Nosology 2010 resulted in a specific diagnosis in 96 of 112 cases.

Classifications of glenoid dysplasia, glenoid bone loss and glenoid loosening: a review of the literature.

So far, glenoid implantation still remains a challenge and is technically demanding even for an experienced shoulder surgeon. Each shoulder pathology has its own evolution. In primary glenohumeral osteoarthritis, glenoid involvement and proper morphology vary considerably. Erosion is more posterior and inferior. In rheumatoid arthritis, glenoid erosion is more medial with a very weak and soft bone. In eccentric arthritis, glenoid erosion is most of the time superior. Glenoid component loosening has been recognized as one of the common indications for revision surgery after total shoulder arthroplasty. Scapular notching is specific to the reverse shoulder arthroplasty. Moreover, there is concern about the high frequency of glenoid components that demonstrate radiographic periprosthetic lucencies. There is little information available to guide clinical decision making regarding glenoid surgery. Placement or replacement with a standard glenoid component is usually possible. In some instances, bone graft reconstruction or the use of augmented or custom components can be an option. The purpose of this study is to evaluate the main glenoid erosion classifications.

Tópicos sobre displasias óseas / Topics about bone dysplasia

Es importante saber reconocer a las displasias esqueléticas como un grupo heterogéneo de patologías, cuya clasificación es bastante extensa y presenta limitaciones. Por lo anterior, es muy importante obtener mediciones antropométricas y un estudio esquelético completo para poder delinear adecuadamente el fenotipo, y así identificar el grupo diagnóstico al cual pertenece cada paciente y, en lo posible, establecer el diagnóstico. El diagnóstico de los casos que no pertenecen a las patologías más conocidas y comunes, como el grupo de la acondroplasia, presenta desafíos mayores y requiere de un enfrentamiento diagnóstico multidisciplinario.

It is important to recognize skeletal dysplasia as a heterogeneous group of conditions with many classifications all of which have shortcomings. In consequence, it is very important to obtain anthropometric measurements and a complete skeletal work-up so as to properly establish phenotype. Once this is done patients can be assigned to diagnostic groups and diagnosis may be established. Diagnosing conditions that do not belong to the more common and well known diseases – such as achondroplasia – is more challenging and requires a multi-disciplinary approach.

Molecular defects causing skeletal dysplasias.

Almost 400 different forms of skeletal dysplasias have been described, each with characteristic clinical and radiographic features. The underlying genetic and molecular pathology is known in several forms. Correct diagnosis is important for genetic counseling, treatment decisions, follow-up and for predicting long-term outcome. With advances in molecular genetics it has become evident that variable phenotypes can be caused by mutations in one gene, depending on the mutation type and location within the gene. On the other hand, mutations in different genes can result in similar phenotypes. Careful clinical assessment with thorough radiographic evaluation are of key importance.

TRPV4 related skeletal dysplasias: a phenotypic spectrum highlighted byclinical, radiographic, and molecular studies in 21 new families.

BACKGROUND: The TRPV4 gene encodes a calcium-permeable ion-channel that is widely expressed, responds to many different stimuli and participates in an extraordinarily wide range of physiologic processes. Autosomal dominant brachyolmia, spondylometaphyseal dysplasia Kozlowski type (SMDK) and metatropic dysplasia (MD) are currently considered three distinct skeletal dysplasias with some shared clinical features, including short stature, platyspondyly, and progressive scoliosis. Recently, TRPV4 mutations have been found in patients diagnosed with these skeletal phenotypes. METHODS AND RESULTS: We critically analysed the clinical and radiographic data on 26 subjects from 21 families, all of whom had a clinical diagnosis of one of the conditions described above: 15 with MD; 9 with SMDK; and 2 with brachyolmia. We sequenced TRPV4 and identified 9 different mutations in 22 patients, 4 previously described, and 5 novel. There were 4 mutation-negative cases: one with MD and one with SMDK, both displaying atypical clinical and radiographic features for these diagnoses; and two with brachyolmia, who had isolated spine changes and no metaphyseal involvement. CONCLUSIONS: Our data suggest the TRPV4 skeletal dysplasias represent a continuum of severity with areas of phenotypic overlap, even within the same family. We propose that AD brachyolmia lies at the mildest end of this spectrum and, since all cases described with this diagnosis and TRPV4 mutations display metaphyseal changes, we suggest that it is not a distinct entity but represents the mildest phenotypic expression of SMDK.