Bone Abstracts

Overall objective: To describe the incidence and relationship between the period of application of zoledronic acid and the presence of atypical diaphyseal fractures and subtrochanteric pattern in pediatric patients with osteogenesis imperfecta in the Mexican population.

Method: Type of study: Ambispective cohort in pediatric patients with a diagnosis of osteogenesis imperfecta. Prognostic variable: duration of treatment with AZ Outcome variable: presence of atypical fractures.

Eligibility Criteria: 1. Patients with a clinical diagnosis of osteogenesis imperfecta

• That they are being treated with zoledronic acid.

• With complete radiographic file.

• With control densitometry

• That they have a complete clinical history, including a description of bone health.

• With initial laboratories of vitamin D and serum calcium.

Monitoring methods: • X-rays in anteroposterior and lateral views of the thigh, hip every 6 months, these radiographs will be studied by two pediatric orthopaedists

• Densitometry every 6 months

• Laboratory studies serum calcium, albumin, PTH and vitamin D, PIN, CTX every 6 months

• Bone health questionnaire every 6 months

Results: Retrospective phase: We studied 26 patients with a mean age of 10 years, 17 men, 9 women, 10 patients with type I OI, 13 patients with type III OI and 3 patients with type IV OI found in the radiographic record, 5 patients with atypical fractures in the region. subtrochanteric with an average of 6 times AZ application

Prospective phase: Twelve patients were followed, with a mean age of 10.2 years, 7 men, 5 women, 7 patients with type I OI, 3 patients with type III OI and 2 patients with type IV OI, with vitamin D levels of insufficiency (less than 30 ng/ml). To date, 5 atypical fractures have been found, 1 patient with OI type IV after 3 applications, and a patient with OI type III with 18 applications, 2 patients with OI type I with 10 applications, and 1 patient with OI type I with 6 Applications.

Conclusions: After finding the atypical fracture, we suspend the treatment for 6 months, finding regeneration of the fracture zone.

Disclosure: The authors declared no competing interests.