Radiology and histopathology of the bent limbs in campomelic dysplasia: implications in the aetiology of the disease and review of theories

Skeletal dysplasia with bowing long bones: Proposed flowchart for prenatal diagnosis with case demonstration

OBJECTIVE

Skeletal dysplasia with bowing long bones is a rare group of multiple characterized congenital anomalies.

MATERIALS AND METHODS

We introduce a simple, practical diagnostic flowchart that may be helpful in identifying the appropriate pathway of obstetrical management.

RESULTS

Herein, we describe four fetal cases of bent bony dysplasia that focus on ultrasound findings, phenotype, molecular tests, distinctive X-ray features, and chondral growth plate histology. The first case was a typical campomelic dysplasia resulting from a de novo mutation in the SOX9 gene. The second fetus was affected by osteogenesis imperfecta Type II carrying a mutation in the COLA1 gene. The third case was a rare presentation of campomelic dysplasia, Cumming type, in which SOX9 examination was normal. Subsequently, a femoral hypoplasia unusual facies syndrome is also discussed.

CONCLUSION

Targeted molecular tests and genetic counseling are required for supplementing ultrasound imaging in order to diagnose the correct skeletal disorders.

Isolated femoral hypoplasia: an intrauterine differential diagnosis to campomelia

The isolated form of femoral bowing is an important differential diagnosis of campomelia. Therefore, knowledge of isolated anomalies is fundamental for prenatal diagnosis, especially for the differential diagnosis from severe syndromes. Four cases are presented to discuss the differential diagnosis of femoral bowing including a review of the literature. We report four newborn babies with unilateral bowing and shortening of the femur. Three had no further anomaly; one child had additional abnormalities due to coumarin embryopathy. The radiological findings were shortened femora with bowing and varus deformity and cortical thickening on the concave side. All other parts showed normal bone structure. The aetiology of femoral bowing is unknown. Early damage of the cartilaginous model followed by remodelling with thickening on the concave side of the bone similar to the healing of malaligned fractures is suspected. The isolated form of femoral bowing without any other anomalies has to be differentiated from complex and more often severe congenital syndromes such as campomelia. Postpartum radiological examination should be reduced to a single exposure of the affected limb and follow-up should be done by clinical examination.

Orthopaedic manifestations of campomelic dysplasia

Campomelic dysplasia is a rare form of congenital dwarfism associated with potentially fatal respiratory insufficiency. There are several types of campomelic dysplasia; however, it is characterized by the presence of anteriorly bowed tibias with cutaneous dimpling, anterolaterally bowed femurs, thoracic kyphoscoliosis, hypoplastic scapulas, and absence or delayed ossification of thoracic pedicles. With improving treatment of respiratory insufficiency, the survival rate of affected infants has increased, thereby necessitating treatment of the musculoskeletal malformations to prevent additional morbidity. In an attempt to increase awareness of the presentation of infants with campomelic dysplasia and to emphasize the difficulties of treating associated developmental dislocation of the hip early, the current authors report the case of a 2-year-old girl with campomelic dysplasia who was treated for dislocation of the right hip. The postoperative course of this child was complicated seriously by several apneic episodes secondary to tracheobronchial malacia for which she required admission to the pediatric intensive care unit.

New form of bone dysplasia with multiple fractures associated with monosomy X

We report on the clinical, radiologic, and pathologic findings in a 20-week-old fetus with monosomy X and severe hydrops associated with fetal dwarfism. The fetus presented with osteoporosis, bent bones, multiple fractures, and distinctive symmetric submetaphyseal transverse bone interruptions or pseudofractures. We excluded by radiologic and histopathologic examination the diagnoses of osteogenesis imperfecta, hypophosphatasia, campomelic dysplasia, achondrogenesis, hypochondrogenesis, and other types of bone dysplasia. To our knowledge, this is a previously undescribed bone dysplasia associated with monosomy X. This bone dysplasia may be inherited as an X-linked recessive disorder.

Vascular anomalies in campomelic syndrome

We report on 4 patients with the campomelic syndrome (CS) in whom postmortem angiography of the lower limbs was performed. Of the 4 patients, 3 were phenotypic females (2 of them with a 46,XY karyotype) and one was a male with a normal 46,XY karyotype. Three fulfilled the criteria of CS, and one (phenotypically female with a 46,XY karyotype) lacked the lower limb bowing and the talipes equinovarus typical of CS. This infant may constitute a further example of the recently reported CS without campomelia. The results of the angiographic study are compared with 46 postmortem angiographies of normal fetuses and newborn infants at different gestational ages. In the first 3 CS patients the main arterial axis of the lower limb, formed by the superficial femoral and anterior tibial arteries, had smaller diameters than expected while the profunda femoris and posterior tibial arteries had greater diameters than age-matched controls. However, the most striking abnormality was the absence or marked deficiency of the anterior tibial artery. Its terminal branch, the dorsalis pedis artery, was also absent and the plantar arch was abnormally formed by the posterior tibial artery either alone or in conjunction with the peroneal artery. The normal arterial pattern was found in the patient who lacked bowed bones. This finding supports a developmental association between vascular defects and lower limb anomalies in CS. This aberrant arterial pattern in CS may affect or be affected by muscle development. The shortness of the posterior femoral and calf muscles fix the knee and the ankle joints.(ABSTRACT TRUNCATED AT 250 WORDS)

In utero ultrasonographic features of campomelic dysplasia

A prenatal diagnosis of campomelic dysplasia in a primigravida is described. First level fetal ultrasonography demonstrated bowing and shortening of lower limbs. Second level examination allowed the correct diagnosis by demonstrating several skeletal anomalies pathognomonic of campomelic dysplasia.