Osteogenesis imperfecta type VII: an autosomal recessive form of brittle bone disease.

Osteogenesis imperfecta (OI) is a heritable disease of bone with low bone mass and bone fragility. The disease is generally classified into four types based on clinical features and disease severity, although recently fifth and sixth forms have also been reported. Most forms of OI are autosomal dominant. Rarely, autosomal recessive disease has been described. We report the clinical, radiological, and histological features of four children (age 3.9-8.6 years at last follow-up; all girls) and four adults (age 28-33 years; two women) with a novel form of autosomal recessive OI living in an isolated First Nations community in northern Quebec. In keeping with the established numeric classification for OI forms, we have called this form of the disease OI type VII. The phenotype is moderate to severe, characterized by fractures at birth, bluish sclerae, early deformity of the lower extremities, coxa vara, and osteopenia. Rhizomelia is a prominent clinical feature. Histomorphometric analyses of iliac crest bone samples revealed findings similar to OI type I, with decreased cortical width and trabecular number, increased bone turnover, and preservation of the birefringent pattern of lamellar bone. The disease has subsequently been localized to chromosome 3p22-24.1, which is outside the loci for type I collagen genes. The underlying genetic basis for the disease remains to be determined.

Progressive erosive arthropathy with contractures, multicentric osteolysis-like changes, characteristic craniofacial appearance, and dermatological abnormalities: a new syndrome?

We report a 27-year-old man with an apparently new syndromic form of progressive erosive arthropathy and contractures of small and large joints associated with mild epiphyseal changes, normal vertebrae, and generalized osteopenia. The patient had a characteristic craniofacial appearance, dermatological abnormalities, and normal intelligence. The head was large with frontal bossing. The face was elongated with malar hypoplasia, thin upper lip, prominent lower jaw, high arched palate, dental malocclusion, and prominent ears with absent ear lobules. Dermatological abnormalities included malar erythema and facial telangiectasia together with multiple nevi and lentigenes all over the body. Pseudorheumatoid arthropathy, spondyloarthropathy, and Borrone dermatocardioskeletal syndrome were considered in the differential diagnosis and were excluded. Also, no similar cases have been found in POSSUM or the London Dysmorphology databases.

Imaging of osteomyelitis in children.

Imaging approach to osteomyelitis in children should aim toward a timely and accurate diagnosis in view of the need for prompt therapy to prevent sequelae. One must take advantage of the specific value of each imaging modality and adopt a strategy that works best for a given child in a given institution.

MR imaging evaluation of subacute and chronic bone abscesses in children.

OBJECTIVE: The aim of the present study was to assess the value of magnetic resonance (MR) imaging in subacute and chronic bone abscesses in children. MATERIALS AND METHODS: Seventy-four patients underwent MR imaging because of suspected musculoskeletal infections between January 1996 and January 1999 in Montreal Children's Hospital. The clinical, radiographic, scintigraphic and MR imaging features of patients with a bone abscess were studied. RESULTS: Eleven patients had osteomyelitis with no bone abscess and six had osteomyelitis with a subacute or chronic bone abscess. Although the lucency was eventually seen on plain radiographs in all cases, MR imaging made a significant contribution, as it helped narrow the differential diagnosis and showed better delineated medullary involvement and extension into the epiphysis. CONCLUSION: MR imaging is valuable in the diagnostic evaluation of children with bone infection and abscess. It reveals the extent of subperiosteal and epiphyseal involvement not seen on plain radiographs. The extent of the medullary involvement around the abscess is best visualized with MR imaging, which can also distinguish between isolated soft tissue infection adjacent to bone and true bone infection.

Inflammatory arthritis in children with osteochondrodysplasias.

Osteochondrodysplasias are a heterogeneous group of genetic skeletal dysplasias. Patients with these diseases commonly develop an early degenerative arthritis or osteoarthritis. Occasional observations of inflammatory arthritis have been made in this population but such observations are based on clinical grounds alone without confirmatory imaging studies. Four patients followed up in a paediatric rheumatology clinic with three different skeletal dysplasias, who had both clinical and radiological evidence of an inflammatory arthritis and coexistent degenerative arthritis, are described.

Bone dysplasia series. Melorheostosis: review and update.

Melorheostosis is a rare nongenetic developmental anomaly first described in 1922 by Léri and Joanny. Its etiology is unknown. Patients present at any age, and both sexes are affected equally. Onset is usually insidious, with deformity of the extremity, pain, limb stiffness and limitation of motion in the joints first manifesting in late childhood or early adolescence and progressing into adult life. The characteristic radiographic appearance consists of irregular hyperostotic changes of the cortex, generally on one side of the bone, resembling melted wax dripping down one side of a candle. This appearance gave the anomaly its name, which is taken from the Greek words for member (melos) and flow (rhein). There is usually a distinct demarcation between the affected and normal bone. Dense, sclerotic linear areas are seen mainly in the cortex but also extending into the cancellous bone. Melorheostosis affects mainly the long bones of the upper and lower limbs, but also the short bones of the hand and foot and, rarely, the axial skeleton. It may co-exist with osteopoikilosis and osteopathia striata as well as with tumours or malformations of blood vessels or lymphatics. Soft-tissue ossifications at the site of the joint are common. Bone scintigraphy is positive and shows moderately increased uptake of tracer. Computed tomography and magnetic resonance imaging can further characterize the lesion, but rarely contribute to the diagnosis. The forme fruste of melorheostosis may mimic other conditions such as myositis ossificans, osteoma and parosteal osteosarcoma. Treatment of this chronic and sometimes debilitating condition consists of surgical soft-tissue procedures and even, in very severe cases, amputation.

Bone dysplasia series. Achondroplasia, hypochondroplasia and thanatophoric dysplasia: review and update.

The authors summarize the clinical, genetic and histopathologic features, as well as the complications, and radiological diagnosis of 3 related generalized short-limb skeletal dysplasias: achondroplasia, hypochondroplasia and thanatophoric dysplasia. In all of these dysplasias, there is abnormal endochondral ossification, but periosteal ossification is not affected. These 3 relatively common entities are known to be allelic to the same gene: the fibroblast growth factor receptor 3 gene on chromosome 4p. Heterozygous achondroplasia is the most common nonlethal skeletal dysplasia. The distinctive clinical and radiological features allow a precise diagnosis, as there is little variability in the appearance of affected patients. There is also a very evident molecular homogeneity. On histopathology of the growth plate, there is a quantitative decrease in endochondral ossification. Precise prenatal ultrasonographic diagnosis is possible in the third trimester, and sometimes even in the second. Hypochondroplasia is a relatively common, milder form of achondroplasia, which varies within and between families and lacks the neurological complications often seen in achondroplasia of this group. An accurate prenatal ultrasonographic diagnosis is rare. There are milder changes on histology of the growth plate. Thanatophoric dysplasia is the lethal and most severe dysplasia. It has distinct features--mainly short tubular bones and short ribs with platyspondyly--allowing a precise radiologic and prenatal ultrasonographic diagnosis. On histopathology of the growth plate, there is disruption of endochondral ossification.

Sternocostoclavicular hyperostosis in children: a report of eight cases.

OBJECTIVE: The aim of this paper is to clarify the clinical and radiologic features of sternocostoclavicular hyperostosis by reviewing eight previously unpublished cases in children, identifying its similarities to chronic recurrent multifocal osteomyelitis and the differences between the pediatric and adult population affected with sternocostoclavicular hyperostosis. Appropriate imaging workup will obviate unnecessary diagnostic and therapeutic procedures. MATERIALS AND METHODS: We investigated the clinical and imaging features of sternocostoclavicular hyperostosis in eight children (seven girls and one boy) and compared those features with the characteristic features of chronic recurrent multifocal osteomyelitis and sclerosing Garré's osteomyelitis to determine if sternocostoclavicular hyperostosis can justifiably be classified as a separate entity. All patients underwent one or more bone biopsies to determine the cause of the bone lesion(s). RESULTS: Seven of the eight patients had involvement of the clavicle. Five of the eight patients had associated distant involvement in the pelvis, femur, tibia, fibula, talus, or sacroiliac joints. Except for predominant localization in the anterior chest wall, the symptoms, the clinical and imaging features, and the results of biopsy and histopathologic examination resemble those of chronic recurrent nonspecific sclerosing osteomyelitis. No skin lesion and no causative organism was found in any of the cases. CONCLUSION: Sternocostoclavicular hyperostosis is a descriptive term used to designate a form of chronic sclerosing osteomyelitis. Its only distinctive feature is localization on one or more sites of the anterior chest wall.

Disorders of the upper extremity in children.

This article presents a brief overview of the indications of MR imaging in a variety of disorders of the upper extremity of the pediatric patient. This covers congenital anomalies: Sprengel shoulder, Poland sequence, arthrogryposis; posttraumatic lesions of cartilage, bone, tendon, muscle and nerve including the brachial plexus injury; inflammatory arthritis and synovitis; bone and joint infection; osteochondritis dissecans, bone necrosis and infarcts in sickle cell anemia and juvenile Gaucher disease, as well as tumors. In this last category, the authors briefly describe the appearances of cysts and tumors of bones and soft tissues of the upper extremity. Indications for the intravenous administration of Gadolinium are given throughout the article with emphasis on the synovial enhancement seen in active arthritis and synovitis.

Keutel syndrome: further characterization and review.

Keutel syndrome is a rare autosomal recessive disorder characterized by diffuse cartilage calcification, characteristic physiognomy, brachytelephalangism, peripheral pulmonary stenosis, hearing loss, and borderline to mild mental retardation. We report on an Arab boy with Keutel syndrome and cerebral calcifications identified at 15 years while investigating a seizure disorder. The parents are phenotypically normal first cousins. Thirteen cases in 9 families (including this case) have been published. Six families were consanguineous, two had multiple affected sibs (males and females) and 4 families originated from the Middle East.

Bone dysplasias: an introduction.

Although individual bone dysplasias are rare, as a group they are relatively common and have a significant effect on morbidity and mortality at all ages. In this brief introduction, radiologic classification, diagnosis and differential diagnosis are given. The radiologic diagnosis is emphasized, since distinction among the various bone dysplasias is based largely on radiographic findings. Prenatal diagnosis relies heavily on high-resolution real-time ultrasonography of the fetus. Precise antenatal ultrasonographic diagnosis of a bone dysplasia may be very difficult; however, accurate differentiation of a lethal versus a nonlethal anomaly is relatively easy. There has been a recent explosion of knowledge about the genetic basis of skeletal dysplasias. Collagen gene mutations have been found to be responsible for osteogenesis imperfecta and many other bone dysplasias. The locations of the genes implicated in achondroplasia and some other chondrodysplasias are now known. Histologic analysis of the growth plate may also provide specific diagnostic features in achondroplasia and other bone dysplasias. A team approach is mandatory for the diagnosis and management of this fascinating and challenging group of diseases.

MRI of the abnormal pediatric hand and wrist with plain film correlation.

Based on a pool of 24 selected cases of nontraumatic pathology of the hand and wrist in patients under the age of 18 years, collected from three pediatric hospitals, the authors have illustrated a number of congenital, inflammatory, and infectious conditions as well as tumors of bones and soft tissues, utilizing MRI with plain film correlation. Due to different MR signal characteristics, the etiology of macrodactyly may be recognized, e.g., vascular and/or fatty versus neurofibromatosis, etc. In septic arthritis, MR has shown abnormal marrow signal in adjacent bones denoting osteomyelitis, often unexpected from the plain film appearance. Tenosynovitis has a specific MR appearance: Fluid in the tendon sheath gives high signal on T2-weighted imaging. In arthritis--because of the associated hyperemia--there is definite synovial enhancement easily visible immediately after Gd-chelate injection. Gd also helps identify viable tissues postinfection as well as viable tumor tissue (versus scar or necrotic tissue) in tumors. Plain radiography is the imaging method of choice for diagnosis and differential diagnosis of most cases of bone cysts, tumors, and tumor-like conditions, e.g., simple and aneurysmal bone cysts, enchondroma, and osteoid osteoma. In the study of masses, MRI gives excellent detail regarding tumor staging and the extent of soft tissue tumors as well as the soft tissue component of bone tumors. In the hand and wrist, aneurysmal bone cysts are usually confined within a metacarpal or carpal bone, showing high signal intensity on T2-weighted imaging, often with fluid/fluid levels. If ganglion cysts are excluded, the most commonly encountered soft tissue masses are the vascular malformations. MR angiography can demonstrate the vascularity of the lesion. Some benign soft tissue lesions have a characteristic MR appearance, e.g., ganglion cysts, lipomata, and accessory muscles.

Skeletal dysplasias with gracile bones: three new cases, including two offspring of a mother with a dwarfing condition.

We describe 3 new cases of a rare form of dwarfism (so-called "lethal skeletal dysplasia with gracile bones" or "osteocraniostenosis"), a condition characterized by thin, brittle bones and death in late gestation or early neonatal life. The first was a 37-week gestation female who died at delivery. She had facial anomalies and positional abnormalities of the hands and feet. The others were male stillborn sibs, who died in utero in the third trimester. Their mother had an undiagnosed dwarfing condition associated with body asymmetry, microcephaly, and unusual facial appearance. Both fetuses were documented by ultrasound to have short limbs and probable long bone fractures late in the second trimester. At autopsy, one fetus had no spleen and the other a hypoplastic spleen. Radiographically, all three cases had very thin diaphyses, diaphyseal fractures, and thin ribs and clavicles. In contrast to the first case who had a normally mineralized calvaria, the sibs had grossly deficient calvarial mineralization. Microscopically, endochondral ossification was qualitatively normal but quantitatively deficient in all three cases. The long bones, especially those of the sibs, lacked the well-defined outer cortex in the mid-shaft normally seen by the third trimester. This failure of organization into the cortex and medulla suggests a failure of bone remodelling. Given the variable presentation in these cases, "lethal skeletal dysplasia with gracile bones" is probably a heterogeneous disorder. The recurrence in one family suggests that the mother has somatic/germline mosaicism of a lethal gene, expressed clinically as growth failure and asymmetry.

Arthrogryposis multiplex congenita, craniofacial, and ophthalmological abnormalities and normal intelligence: a new syndrome?

We report on an 8-year-old boy with clinical manifestations suggestive of a new arthrogryposis syndrome. These included characteristic craniofacial abnormalities, cleft palate, arthrogryposis multiplex congenita, pulmonary hypoplasia, cryptorchidism, and unusual ophthalmological findings. There was no intrauterine growth retardation or decreased fetal movements. Despite the poor prognosis expected in early life, the patient presented with normal mental capability on follow-up. Family data showed that a maternal first cousin of the mother (mother's brother's son) had similar findings and died in infancy. Differential diagnosis included Pena-Shokeir syndrome or phenotype, Gordon syndrome, Marden-Walker syndrome, and the syndrome of arthrogryposis with ophthalmoplegia and retinopathy. The possibility of autosomal dominant inheritance with reduced penetrance is suggested for this apparently new syndrome.

Small patella syndrome: a bone dysplasia to recognize and differentiate from the nail-patella syndrome.

We report a 5-year, 9-month-old boy with bilateral patellar hypoplasia. The radiographic skeletal survey revealed absent ossification of the ischium and inferior pubic ramus on both sides, characteristic of the newly recognized benign bone dysplasia known as small patella syndrome, or ischiopatellar dysplasia. No nail change, iliac horn, elbow anomaly, or renal disease is associated with this condition.

MRI appearances of dysplasia epiphysealis hemimelica of the knee.

OBJECTIVE: The study was undertaken to describe the magnetic resonance imaging (MRI) appearances of dysplasia epiphysealis hemimelica (DEH) of the knee and to determine whether MRI provides additional information concerning the anomaly compared with more traditional methods of diagnosis. DESIGN AND PATIENTS: The subjects of the study were three children (one girl and two boys, aged 13 months, 3 years and 11 years) with DEH of the knee. All the patients had plain films of the knee and MRI scans. RESULTS AND CONCLUSION: Plain radiographs showed bone overgrowth and asymmetrical ossification centres with adjacent scattered calcifications which coalesced to form a lobulated irregular mass. MRI showed a definite cartilaginous or osteocartilaginous lesion. Its origin from the epiphysis was much more clearly defined. MRI showed the extent of the lesion non-invasively, as well as any potential cleavage plane between the epiphysis and the mass lesion. Abnormal surface nodularity and joint involvement could be determined. It is concluded that plain films supplemented with MRI provide the greatest amount of diagnostic information in cases of DEH. MRI is useful to show the exact location and extent of the lesion, any joint involvement and any potential cleavage between the epiphysis and the mass lesion.

Osteoglophonic dysplasia: appearance and progression of multiple nonossifying fibromata.

The appearance and gradual enlargement of fibrous cortical defects and multiple nonossifying fibromata are documented in this report of a 2-year-old boy with a very rare skeletal dysplasia known as osteoglophonic dysplasia, characterized by multiple and recurrent craniosynostoses, platyspondyly, short tubular bones, and epiphyseal dysplasia.