Long-term vascular access for infants with moderate to severe osteogenesis imperfecta.

PURPOSE: Osteogenesis imperfecta (OI) is a genetic disorder that causes skeletal fragility. For the most fragile infants and young children with OI, intravenous (IV) bisphosphonate administration is essential, but IV access attempts often cause fractures. Port-a-caths help prevent these events, but some surgeons are hesitant to insert these devices in these infants due to lack of data on their safety. METHODS: Retrospective study of pediatric patients with OI who underwent port-a-cath placement from 1999 to 2018; incidence of complications such as infection and thrombosis and need for reoperation or replacement are described. RESULTS: Port-a-caths were placed in 17 patients with OI (median age, 8 mos [5-23 mos]; median weight, 5.8 kg [3.96-9.08 kg]) and remained in place for a median of 53.5 mos (10-127 mos). One port-a-cath was replaced because of thrombosis. Two port-a-caths were removed because of malfunction, one for skin erosion, and one for infection. In these five cases, replacement was not needed because patients could safely tolerate IV access. Two patients have their port-a-cath in place and the remaining ten patients had theirs removed electively as it was no longer needed. CONCLUSION: Port-a-cath placement in pediatric patients with OI is safe and efficacious for durable central access, enabling reliable IV bisphosphonate delivery and reducing iatrogenic trauma.

Cervical kyphosis: A predominant feature of patients with osteogenesis imperfecta type 5.

OBJECTIVES: Osteogenesis imperfecta (OI) is a heterogeneous group of genetic disorders of connective tissue that cause skeletal fragility and extra-skeletal manifestations. Classically, four different types of OI were distinguished. Type 5 OI was added due to its distinct clinical and radiographic features. In 2012, two independent groups identified a recurrent heterozygous c.-14C>T mutation in IFITM5 as the responsible genetic change for this type of OI. To our knowledge, cervical kyphosis has not been identified in the literature as a finding in type 5 OI patients. This is a retrospective review of a cohort of patients with type 5 OI and a description of associated cervical spine deformity. METHODS: After institutional review board approval, a retrospective review identified 13 patients with type 5 OI. Clinical, radiologic, and genetic data from 2002 to 2020 were reviewed. RESULTS: We identified 13 patients with clinical diagnosis of type 5 OI. Twelve had molecular confirmation and the classic IFITM5, c.14C>T gene mutation was identified. The remaining individual did not undergo genetic testing. Dentinogenesis imperfecta was observed in one patient, while blue sclerae or hearing loss were not present. All patients had at least one fracture and four underwent intramedullary rodding. Radiologic features included subphyseal metaphyseal radiodense line in 12/13 patients (92%), interosseous membrane calcification in seven of 13 patients (54%) (more commonly noted in the upper extremities), and hypertrophic callus in six of 13 patients (46%). Thoracolumbar spinal deformities were seen in six of 13 patients (46%) with two of these individuals requiring surgery. Cervical kyphosis was noted in nine of 13 individuals (69%) ranging in age from 3 months to 22 years. Anterior wedging of the cervical vertebral bodies was noted in the absence of any fractures. Six of nine individuals demonstrated listhesis of C2-C3 or C3-C4 segment. Magnetic resonance imaging studies were performed and reviewed in patients with cervical kyphosis and subluxation; three patients showed narrowing of spinal canal without cervical cord compression and one asymptomatic patient showed impingement of the spinal cord. CONCLUSIONS: Cervical kyphosis appears to be a common feature of type 5 OI. It can be a presenting and apparently life-long association and does not appear to be caused by vertebral body fractures. Evaluation for cervical kyphosis should be performed in patients with a suspected or confirmed diagnosis of type 5 OI. Furthermore, if cervical kyphosis is noted in an individual with OI, type 5 OI should be considered.Level of evidence: IV.

A moderate form of osteogenesis imperfecta caused by compound heterozygous LEPRE1 mutations.

Osteogenesis imperfecta (OI) is a genetic disorder causing skeletal fragility, multiple fractures, and other extraskeletal manifestations. Most cases are caused by mutations in COL1A1 or COL1A2. Recent investigations have discovered several other autosomal recessive genes responsible for OI. Among these genes is LEPRE1, which is involved in post-translational modifications of collagen. To date, more than 40 LEPRE1 mutations have been described. One of these mutations is carried by 1.5% of West Africans and 0.4% of African Americans, and is associated with OI Type VIII. We describe the case of a five year old male with a moderate form of OI and compound heterozygous LEPRE1 mutations (c.1080 + 1G > T; c.1646 T > G, p.Met549Arg). He was diagnosed shortly after birth following a skeletal survey demonstrating multiple healing fractures as well as lower extremity deformity suggestive of remote fractures. He was then without a fracture until a calvarial fracture at 18 months of age, a femur fracture at 4 years and seven months and a second femur fracture at 5 years and 4 months. He walked at age 14 months and has been an active boy. Pamidronate infusions began at seven weeks of age and were discontinued at three years of age due to increased bone mineral density and absence of fractures. Type VIII OI typically causes a severe to lethal phenotype presenting at birth with severe osteopenia, congenital fractures and other clinical manifestations. Only a few individuals have survived to childhood. This case description serves to expand the clinical phenotyping of this recessive form of OI into the more moderate spectrum.